Airworthiness Standards; Flight Proposals Based on European Joint Aviation Requirements Proposals; Proposed Rule DEPARTMENT OF TRANSPORTATION

SUMMARY: This document proposed changes to the flight airworthiness

standards for normal, utility, acrobatic, and commuter category

airplanes. These proposals arise from the joint effort of the Federal

Aviation Administration (FAA) and the European Joint Aviation

Authorities (JAA) to harmonize the Federal Aviation Regulations (FAR)

and the Joint Aviation Requirements (JAR) for airplanes that will be

certificated in these categories. The proposed changes would provide

nearly uniform flight airworthiness standards for airplanes

certificated in the United States under 14 CFR part 23 (part 23) and in

the JAA countries under Joint Aviation Requirements 23 (JAR 23)

simplifying airworthiness approvals for import and export purposes.

DATES: Comments must be submitted on or before November 22, 1994.

ADDRESSES: Comments on this notice should be mailed in triplicate to:

Federal Aviation Administration, Office of the Chief Counsel,

Attention: Rules Docket (AGC-200), Docket No. 27807, 800 Independence

Avenue, SW., Washington, DC 20591. Comments delivered must be marked

Docket No. 27807. Comments may be inspected in Room 915G weekdays

between 8:30 a.m. and 5:00 p.m., except on Federal holidays.

In addition, the FAA is maintaining a duplicate information docket

of comments in the Office of the Assistant Chief Counsel, ACE-7,

Federal Aviation Administration, Central Region, 601 East 12th Street,

Kansas City, Missouri 64106. Comments in the duplicate information

docket may be inspected in the Office of the Assistant Chief Counsel

weekdays, except Federal holidays, between the hours of 7:30 a.m. and

4:00 p.m.

FOR FURTHER INFORMATION CONTACT: Lowell Foster, ACE-111, Small Airplane

Directorate, Aircraft Certification Service, Federal Aviation

Administration, 601 East 12th Street, Kansas City, Missouri 64106;

telephone (816) 426-5688.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Comments relating to the environmental, energy, or

economic impact that might result from adopting the proposals in this

notice are also invited. Substantive comments should be accompanied by

cost estimates. Comments should identify the regulatory docket or

notice number and should be submitted in triplicate to the Rules Docket

address specified above. All comments received on or before the

specified closing date for comments will be considered by the

Administrator before taking action on this proposed rulemaking. The

proposals contained in this notice may be changed in light of comments

received. All comments received will be available, both before and

after the closing date for comments, in the Rules Docket for

examination by interested persons. A report summarizing each FAA-public

contact concerned with the substance of this proposal will be filed in

the docket. Commenters wishing the FAA to acknowledge receipt of their

comments submitted in response to this notice must include a

preaddressed, stamped postcard on which the following statement is

made: ``Comments to Docket No. 27807.'' The postcard will be date

stamped and returned to the commenter.

Availability of NPRM

Any person may obtain a copy of this Notice of Proposed Rulemaking

(NPRM) by submitting a request to the Federal Aviation Administration,

Office of Public Affairs, Attention: Public Inquiry Center, APA-200,

800 Independence Avenue, SW., Washington, DC 20591, or by calling (202)

267-3484. Communications must identify the notice number of this NPRM.

Persons interested in being placed on the mailing list for future

NPRM's should request, from the above office, a copy of Advisory

Circular No. 11-2A, Notice of Proposed Rulemaking Distribution System,

which describes the application procedure.

Background

At the June 1990 meeting of the JAA Council (consisting of JAA

members from European countries) and the FAA, the FAA Administrator

committed the FAA to support the harmonization of the FAR with the JAR

being developed for use by the European authorities who are members of

the JAA. In response to this commitment, the FAA Small Airplane

Directorate established an FAA Harmonization Task Force to work with

the JAR 23 Study Group to harmonize part 23 and the proposed JAR 23.

The General Aviation Manufacturers Association (GAMA) also established

a JAR 23/part 23 Committee to provide technical assistance in this

effort.

Following a review of the first draft of proposed JAR 23, members

of the FAA Harmonization Task Force and the GAMA Committee met in

Brussels, Belgium for the October 1990 meeting of the JAR 23 Study

Group. Representatives from the Association Europeenne des

Constructeures de Material Aerospatial (AECMA), an organization of

European airframe manufacturers, also attended. The main agenda item

for this meeting was the establishment of procedures to accomplish

harmonization of the airworthiness standards for normal, utility, and

acrobatic category airplanes. The JAA had decided that its initial

rulemaking effort should be limited to these three categories and that

commuter category airworthiness standards should be addressed

separately.

After that meeting, technical representatives from each of the four

organizations (GAMA, AECMA, FAA and JAA) met to resolve differences

between the proposed JAR and part 23. This portion of the harmonization

effort involved a number of separate meetings of specialists in the

flight, airframe, powerplant, and systems disciplines. These meetings

showed that harmonization would require revisions to both part 23 and

the proposed JAR 23.

Near the end of the effort to harmonize the normal, utility, and

acrobatic category airplane airworthiness standards, the JAA requested

and received recommendations from its member countries on proposed

airworthiness standards for commuter category airplanes. The JAA and

the FAA held specialist and study group meetings to discuss these

recommendations, which resulted in proposals to revise portions of the

part 23 commuter category airworthiness standards.

Unlike the European rules, where commuter category airworthiness

standards are separate, for U.S. rulemaking, it is advantageous to

adopt normal, utility, acrobatic, and commuter category airworthiness

standards simultaneously, since commuter category airworthiness

standards are already contained in part 23. Accordingly, this NPRM

proposes to revise the flight airworthiness standards for all part 23

airplanes.

During the part 23 harmonization effort, the FAA established an

Aviation Rulemaking Advisory Committee (ARAC) (56 FR 2190, January 22,

1991), which held its first meeting on May 23, 1991. The ARAC on

General Aviation and Business Airplane (GABA) Issues was established at

that meeting to provide advice and recommendations to the Director,

Aircraft Certification Service, FAA, regarding the airworthiness

standards in part 23 as well as related provisions of parts 91 and 135

of the regulations.

The FAA announced, on June 2-5, 1992, at the JAA/FAA Harmonization

Conference in Toronto, Ontario, Canada, that it would consolidate

within the ARAC structure an ongoing objective to ``harmonize'' the JAR

and the FAR. Coinciding with that announcement, the FAA assigned the

ARAC on GABA Issues those rulemaking projects related to JAR 23/part 23

harmonization that were in final coordination between the JAA and the

FAA. The harmonization process included the intention to present the

results of JAA/FAA coordination to the public as NPRM's. Subsequently,

the ARAC on GABA Issues established an ARAC-JAR 23 Study Group.

The JAR 23 Study Group made recommendations to the ARAC on GABA

Issues concerning the FAA's disposition of the rulemaking issues

coordinated between the JAA and the FAA. The draft NPRM's previously

prepared by the FAA harmonization team were made available to the

harmonization working group to assist them in their effort.

A notice of the formation of the JAR/FAR 23 Harmonization Working

Group was published on November 30, 1992 (57 FR 56626). The group held

its first meeting on February 2, 1993. These efforts resulted in the

proposals for flight airworthiness standards contained in this notice.

The ARAC on GABA Issues agreed with these proposals.

The FAA received unsolicited comments from the JAA dated January

20, 1994, concerning issues that were left unresolved with the JAR 23

Study Group. The JAR/FAR 23 Harmonization Working Group did not address

some of the unresolved issues because the JAA had not yet reached

positions on those issues. Unresolved issues will be dealt with at

future FAR/JAR Harmonization meetings. With respect to other issues

unresolved by the JAR 23 Study Group, the JAR/FAR 23 Harmonization

Working Group recommendations did not reflect harmonization, but

reflected the technical discussion of the merits of each issue that had

been throroughly debated at the JAR/FAR 23 Harmonization meetings. (The

Working Group Chairperson had been present at the Harmonization

meetings.) The JAA comments have been placed in the docket for this

proposal, and will be considered along with those received during the

comment period.

Following completion of these harmonization efforts, the FAA

determined that the proposed revisions to part 23 were too numerous for

a single NPRM. The FAA decided to simplify the issues by issuing four

NPRM's. These NPRM's address the airworthiness standards in the

specific areas of systems and equipment, powerplant, flight, and

airframe. These NPRM's propose changes in all seven subparts of part

23. Since there is some overlap, interested persons are advised to

review all four NPRM's to identify all proposed changes to a particular

section.

Discussion of Proposals

Section 1.1 General Definitions

This proposal would amend Sec. 1.1 to add a definition of ``maximum

speed for stability characteristics, VFC/MFC.'' This proposed

change would harmonize part 1 and JAR 1. The definition is currently

contained in Sec. 23.175(b)(2) and also in Sec. 25.253(b). Moving the

definition to part 1 would simplify the text of part 23 and ease the

referencing of the term VFC/MFC. The definition would be

deleted from Sec. 23.175(b)(2).

Section 23.3 Airplane Categories

This proposal would make a change to the limited aerobatic

operations authorized for utility category certification, change the

authorized commuter category certification maneuvers and prohibit dual

type certification of commuter category airplanes.

The limitation for utility category airplanes in Sec. 23.3(b)(2)

would be revised to add an outside limit of 90 degrees in angle of bank

for lazy eights, chandelles, and steep turns.

Section 23.3(d) would be revised to delete chandelles and lazy

eights as approved operations in commuter category airplanes because

the FAA does not anticipate any operational need for such maneuvers.

Further, Sec. 23.3(e) would be revised to prohibit type

certification of commuter category airplanes in any other category. In

the preamble discussion of Proposal 3 for Amendment No. 23-34 (52 FR

1806, January 15, 1987), the FAA discussed the issue of dual

certification, with emphasis on the issuance of airworthiness

certificates. Since then, the FAA has gained experience with airplanes

certificated in both normal and commuter categories. The FAA has found

confusion among pilots and operators about the appropriate performance

limitations.

Although the proposed performance requirements, based on weight,

altitude, and temperature (WAT) criteria (see proposal for Sec. 23.45),

would alleviate some of the problems with current airplanes, the FAA

proposes that commuter category airplanes not have dual type

certificates. One problem with dual type certification is pilot

confusion. WAT limits would differ between normal and commuter

categories, requiring pilots who get type rated in these airplanes to

know two sets of limitations and to remember when each set of

limitations is applicable. This proposed rule would not preclude the

type certification of similar airplanes with different model numbers,

such as the present Cessna models 500 and 501.

Section 23.25 Weight Limits

This proposal would make changes to Sec. 23.25(a) and remove

references to commuter category zero fuel weight in paragraph (a) and

standby power rocket engines in paragraph (a)(1)(iii).

Revised Sec. 23.25(a) would clarify that the maximum weight that

must be selected is the least of the three choices given in

Sec. 23.25(a)(1). The airframe NPRM proposes moving the commuter

category zero fuel weight requirement in Sec. 23.25(a) to Sec. 23.343.

The FAA proposes removing the reference to both standby power rocket

engines and to appendix E in Sec. 23.25(a)(1)(iii) because this is a

rare and obsolete design feature. If standby power rocket engines were

proposed as a design feature, the FAA would issue special conditions to

ensure adequate airworthiness.

Section 23.33 Propeller Speed and Pitch Limits

Proposed revisions to Sec. 23.33(b)(1) would delete the reference

to Vy and replace it with ``the all engine(s) operating climb

speed specified in Sec. 23.65.'' This would be done for consistency

with other changes in performance requirements. Section 23.33(b)(2)

would be revised to use ``VNE'' in place of ``never exceed

speed,'' since VNE is defined in part 1, and to delete the world

``placarded'' which is unnecessary.

Section 23.45 General

In Notice of Proposed Rulemaking, Small Airplane Airworthiness

Review Program Notice No. 4, Notice No. 90-18 (55 FR 26534, June 28,

1990), the FAA requested comments on the need for weight, altitude, and

temperature (WAT) criteria, as information or as a limitation on

piston-powered, twin-engine part 23 airplanes. The FAA also requested

comments about WAT criteria on turbine-powered twin-engine part 23

airplanes, specifically during takeoff and landing.

WAT criteria is used to determine the maximum weight an airplane

can have in relation to altitude and temperature for safe takeoff. This

criteria provides a pilot with the information needed to determine if a

takeoff and climb can be successfully completed, including for

multiengine airplanes, if one engine becomes inoperative. WAT criteria

has been required under part 23 for commuter category airplanes, at all

approved altitudes. A limited WAT criteria has been required for

turbine engine powered airplanes at 5,000 feet and at standard

temperatures plus 40 deg.F, but not for higher altitudes or

temperatures. For some multiengine powered airplanes WAT data has been

provided by the manufacturer as information to pilots but is not

required to be followed.

The FAA received three comments on mandating WAT criteria in part

23. One commenter (GAMA) ``believes that WAT information is useful but

certainly not the only way to present operating data for any airplane''

and that making WAT criteria an airplane or operating limitation for

part 23 airplanes is ``an unnecessary and unjustified expansion or

redirection of operating criteria.''

Another commenter (the Airline Pilots Associaton--ALPA) wants WAT

information furnished during the certification process. The commenter

cites the variety of operational uses of these airplanes including in

scheduled air carrier and regional airline service. The commenter also

cities the need for ``one level'' of safety as justification for

expanding the WAT requirements.

The other commenter (JAA) also supports WAT criteria. This

commenter believes that the chance of a single-engine failure on any

airplane is high. Also, this commenter warns that safety considerations

include airplane occupants and personnel on the ground. According to

the commenter, transport category airplanes follow WAT criteria by

limiting the operation of the airplane. Beyond the point where takeoff

can be rejected, one-engine-inoperative climbs must guarantee obstacle

clearance. The commenter recognizes a need for generally similar

requirements for commuter category airplanes.

The JAA believes that requiring a continued flight capability would

preclude the operation of single-engine airplanes. Also, the commenter

believes that airplane size and stall speed provide characteristics

that permit safe landings in the event of an inoperative engine for

single-engine airplanes and smaller multiengine airplanes.

The commenter points out that between the two extremes of the

transport category airplane and the single-engine airplane lies the

light twin-engine reciprocating airplanes and turbine engine airplanes,

ranging from four seats to nine and from 4,000 to 12,500 pounds. The

commenter notes that, for these types of airplanes, it would be

burdensome to require compliance with full net flight path obstacle

clearance. In the commenter's opinion, a safe forced landing becomes

less satisfactory with increased takeoff weight, involving longer

stopping distances even for the same landing speed. The commenter notes

that the twin-engine airplanes have other significant adverse

characteristics compared to single-engine airplanes. First, an engine

failure is twice as probable; second, asymmetric power demands

immediate pilot action.

The commenter also points out that the inability to continue flight

with one engine inoperative creates the following situation: the chance

of a second engine failure is increased; a suitable site for an

emergency landing is reduced; and the pilot resists the inevitable

forced landing and tries to maintain flight. Training under more

favorable conditions may have taught the pilot to expect success in

those situations. In unfavorable conditions, attempts to maintain

flight may lead to loss of airspeed at high asymmetric power and,

commonly, loss of directional control that results in a stall/spin

accident.

The commenter advocates certification and operating criteria for

multiengine airplanes that blend the performance requirements for a

single-engine airplane and a transport category airplane. The commenter

believes that the existing requirements accept a limited period of risk

just before and just after liftoff, where engine failure may not be

fully accounted for. The commenter believes that the application of WAT

limits clearly accounts for actual conditions, although the climb

gradient requirements are lower than the requirements of part 25/JAR

25.

The commenter proposes no distinction between reciprocating and

turbine engines. In the commenter's opinion, the WAT criteria should be

imposed, where applicable, as limitations through the Airplane Flight

Manual (AFM).

The commenter does not believe that such proposals would involve

costs disproportionate to the benefit. The commenter suggests that the

comment from the Small Airplane Airworthiness Review Conference, held

October 22-26, 1984, that such criteria would ``eliminate the

certification of an entire class of airplanes,'' is an exaggeration.

The proposals are achievable, in the commenter's view, by typical

modern light twin-engine airplanes with realistic payloads,

particularly the more significant executive/air taxi airplanes. The

adoption of the WAT concept, in the commenter's opinion, would instill

a greater awareness of performance consideration in pilots from an

early stage of their training.

The commenter also believes that the requirements on climb and

handling qualities of the present Secs. 23.65 and 23.67 are illogical

and unreasonable. The commenter recommends using WAT criteria so that

it applies equally to all airplane operations because it offers

improved airplane capability.

The commenter points out that manufacturers of ``WAT type''

airplanes routinely determine performance under a wide range of

conditions. The commenter also notes that flight manuals produced to

the widely accepted General Aviation Manufacturers Association (GAMA)

specification already contain performance data beyond the minimum

requirements of part 23. In the commenter's opinion, additional testing

or data scheduling create no additional costs.

To determine the necessity of applying WAT criteria to other than

transport and commuter airplanes, the commenter notes that present

draft JAR 23 applies WAT limits only to piston-engine airplanes above

6,000 pounds and turbine-engine airplanes. The JAR Operations Study

Group proposes applying WAT limits to all JAR 23 airplanes in

commercial operations.

In 1991, the FAA studied the accident record of reciprocating

engine-powered, multiengine part 23 airplanes of over 6,000 pounds

maximum takeoff weight with a substantial fleet size. The FAA completed

the study using the National Transportation Safety Board (NTSB)

accident briefs and evaluated those statistics over the study period of

the individual airplanes. The statistics show the following:

(a) Over 100 accidents and 200 fatalities occurred due to engine

failure during the study period.

(b) Forty-seven of the engine failure accidents occurred because

the pilot failed to maintain flying speed and/or directional control.

(c) Engine reliability is a significant factor in the accident

study. (For example, airplanes of similar or the same aerodynamic

configuration, but with different engines, have significantly different

accident records.)

After reviewing the accident statistics, and recognizing the

performance capabilities of the accident airplanes, the FAA concludes

the following:

(a) Engine reliability would not be of major concern if the

airplane had adequate performance on the remaining operative engine.

(b) The loss of flying speed and subsequent loss of airplane

control would not be a significant problem if the airplane exhibited

adequate climb performance capabilities to fly out of an engine loss

situation at low speeds.

Based on these statistics and conclusions from the FAA 1991 study

and on comments, the FAA has determined that WAT limits are necessary

for safe operation of multiengine airplanes of the type that will be

involved in transporting passengers for hire. Operating rules (part

135) are already in place that specify some performance limitations.

The cutoff weight for reciprocating engine-powered airplanes of 6,000

pounds would encompass most airplanes of concern. All turbine engine-

powered airplanes are included because of the adverse effect of

increasing temperatures on turbine engine performance.

This proposal would change Sec. 23.45 to require weight, altitude,

and temperature (WAT) performance accountability for normal, utility,

and acrobatic airplanes with a maximum takeoff weight over 6,000 pounds

and all turbine-powered airplanes. Including WAT accountability

necessitates reorganization and revisions to all paragraphs of this

section. The inclusion of WAT accountability in part 23 also requires

changes to several other sections in part 23.

Paragraph (a)(1) would be revised to require that performance

requirements be met for still air and ``standard atmosphere.'' Current

(a)(1) uses the term ``standard atmospheric conditions.''

The applicability of paragraph (a) (1) and (2) would be revised to

require that all airplanes meet the performance requirements in still

air and standard atmosphere, and that ambient atmospheric conditions,

which currently must be met by commuter category airplanes, would have

to be met by (1) commuter category airplanes, (2) reciprocating engine-

powered airplanes of more than 6,000 pounds maximum weight, and (3)

turbine engine-powered airplanes.

Proposed paragraph (b) would replace current requirements of

paragraph (b), pertaining to power or thrust available, with the

altitude and temperature requirements for performance data.

Proposed Sec. 23.45(c) is modified Sec. 23.51. It would require

that performance data be determined with the cowl flaps in the position

used in cooling tests required by Sec. 23.1041 to Sec. 23.1047 and

permits the cowl flap position to be addressed uniformly.

Proposed paragraph (d) is the same as current paragraph (c)

pertaining to the determination of available propulsion thrust.

Proposed changes to Sec. 23.45 (b), (c), (d), and (e) would delete

references to ``thrust'' and retain just ``power,'' for standardization

with the JAR. This is considered appropriate since power covers engine

output, despite how the absorbed power is transmitted to the

atmosphere. The FAA proposes this change in subsequent sections where

the term ``power or thrust'' is used.

Proposed paragraph (e) is the same as requirements of current

paragraph (d) with a minor editorial revision.

Proposed new paragraph (f) is based on current paragraphs (e)(3)

and (e)(5)(i), which apply only to commuter category airplanes.

Proposed changes to Sec. 23.45(f) would extend to all airplane

categories the requirement for all takeoff and landing procedures to be

consistently executable by pilots of average skill. This is considered

appropriate since takeoffs and landings must be made routinely by

operational pilots. It is also appropriate that takeoff and landing

performance data published in the Airplane Flight Manual (AFM) can be

consistently achieved by operational pilots.

Proposed new paragraph (g) would require determining takeoff

distance, accelerate-stop distance, takeoff distance and takeoff run,

and landing distance on a smooth, dry, hard-surfaced runway. The FAA

considers these limitations necessary for WAT limited airplanes since

the WAT takeoff performance is only valid on a particular defined

surface. The FAA does not consider the testing necessary to extend the

same limitations to non-WAT airplanes burdensome to applicants since

that information is already available in GAMA Spec. No. 1 AFM's.

Additionally, the proposal allows for the derivation of landing and

takeoff data on non-hard surfaces, such as grass and gravel and, thus,

may not require additional flight testing.

Proposed paragraph (h) is the same as current paragraph (e), which

covers additional performance requirements for commuter category

airplanes, except for some minor revisions. In the list of items to be

determined in paragraph (h)(3), ``landing distance'' would not be

included since it would already be covered in proposed Sec. 23.45(g). A

reference to Sec. 23.67 in paragraph (h)(4) would be updated to be

consistent with proposed revisions to that section in this notice; and

the phrase ``missed approaches'' would be changed to ``discontinued

approaches'' to be consistent with the proposed change to Sec. 23.143.

Proposed paragraph (h)(5)(i) requiring that the procedures must be able

to be consistently executed by a crew of average skill would have added

to it ``in atmospheric conditions reasonably expected to be encountered

in service.'' These clarifying words would also appear in paragraph

(h).

Section 23.49 Stalling Speed

Section 23.49 would be reorganized and edited for clarification.

Currently the requirements for VS0 and VS1 are separated with

parallel configuration items under paragraphs (a) and (d). The proposed

clarification would merge the VS0 and VS1 requirements under

paragraph (a). Existing paragraph (b) would be moved to paragraph (c)

and existing paragraph (c) would be moved to paragraph (d). Existing

paragraph (e) would become paragraph (b) and the thrust conditions in

paragraph (f) would be incorporated under paragraph (a) items (1) and

(2).

Proposed changes to paragraph (a) are as follows:

(1) Proposed paragraph (a)(4) would be a requirement that the

airplane be in the condition existing in the test, in which VS0

and VS1 are being used.

(2) Proposed paragraph (a)(5) would be a revised version of current

paragraph (a)(6). The current requirement states that the center of

gravity must be in the most unfavorable position within the allowable

landing range. The proposed requirement would state that the center of

gravity must be in the position that results in the highest value of

VS0 and VS1.

(3) As mentioned under Sec. 23.45, the current paragraph (a)(5)

would be moved to Sec. 23.45(c).

All of the changes are clarifying and not an increase in

requirements.

Section 23.51 Takeoff Speeds

This proposal would revise the paragraph heading from ``Takeoff''

to ``Takeoff speeds'' and incorporate the takeoff speed requirements

currently contained in Sec. 23.53. This revision to the heading and

reorganization of takeoff requirements is proposed for harmony with JAR

23.

Current Sec. 23.51(a) would be moved to Sec. 23.53(a). Current

paragraph (a) requires that the distance required to take off and climb

over a 50-foot obstacle must be determined with the engines operating

within approved operating limitations and with cowl flaps in the normal

takeoff position. These requirements as modified would be covered under

proposed Secs. 23.45 (c) and (d) and 23.1587.

Current Sec. 23.51(b) in measuring seaplane and amphibian takeoff

distances would be deleted because it is a statement of an acceptable

method of compliance. Also, there is not a need for addressing a

separate seaplane starting point.

Current Sec. 23.51(c) concerning pilot skills and conditions would

be deleted since it would be covered under the general requirements in

proposed Sec. 23.45(f).

Current Sec. 23.51(d) would be deleted because the requirements are

partly covered under Sec. 23.45 in commuter category performance and

other performance requirements. In addition, the information

requirements would be covered under Sec. 23.1587. Subpart G, under

which Sec. 23.1587 appears, is generally used to specify what

information must be in the AFM.

For multiengine normal, utility, and acrobatic category airplanes,

the determination of VR is transferred from Sec. 23.53(a) to

proposed Sec. 23.51(a) with minor changes in the specified rotation

speed. For multiengine airplanes, in proposed paragraph (a)(1), the

margin between rotation speed and VMC increases to 1.05 VMC,

or a margin of 1.10 VS1 is established between VR and stall.

Proposed paragraph (a) would define VR as the speed at which

the pilot makes a control input, with the intention of lifting the

airplane out of contact with the runway or water surface. This

definition would apply to tail wheel and tricycle gear airplanes,

seaplanes, and single-engine airplanes.

In addition to the multiengine rotation speed discussed above,

proposed paragraph (a) would include rotation speeds for single-engine

airplanes and seaplanes and amphibians. This proposed rule would extend

VR applicability to all part 23 airplanes to establish a safe and

standardized procedure that can be used by operational pilots to

achieve AFM takeoff performance. This proposed use of rotation speed is

consistent with part 25.

In proposed paragraph (b) the speed at 50 feet is based on current

Sec. 23.53(b) with no change in requirements.

For commuter category airplanes, the takeoff speed requirements

move from Sec. 23.53(c) to proposed Sec. 23.51(c) with editorial

changes. The option in proposed (c)(1)(i) for an applicant to determine

a VMCG and establish a V1 based on VMCG rather than a

margin above VMCA is added.

Section 23.53 Takeoff Performance

The heading of Sec. 23.53 would be new and the content would come

primarily from existing Sec. 23.51. This section would now provide

general takeoff performance requirements.

The proposal would move the takeoff speed requirements of the

current Sec. 23.53 to Sec. 23.51. (See proposal for Sec. 23.51.)

Proposed Sec. 23.53 provides general takeoff performance requirements

for normal, utility, acrobatic, and commuter category airplanes.

Proposed paragraph (a) is based on current Sec. 23.51(a). Proposed

paragraph (b) is a modification of current Sec. 23.1587(a)(5). Proposed

paragraph (c) is based on Sec. 23.51(d).

Section 23.55 Accelerate-stop Distance

This proposal would revise Sec. 23.55 to clarify the accelerate-

stop segments and to make editorial changes.

This proposal would divide the accelerate-stop maneuver into three

segments, rest to VEF (proposed (a)(1)), VEF to V1

(proposed (a)(2)), and V1 to rest (proposed (a)(3)). This is not a

new requirement, but it divides the total distance into three segments

to be considered. The phrase, ``in the case of engine failure,'' in

current Sec. 23.55(a)(2) would be deleted because it would be included

in proposed (a)(2). Also, the phrase, ``assuming that * * * the pilot

has decided to stop as indicated by application of the first retarding

means at the speed V1,'' is deleted because it is stated in

proposed Sec. 23.51(c)(1)(ii). The ``exceptional skill'' phrase of

Sec. 23.55(b)(3) would be deleted because it will remain in proposed

Sec. 23.45(h)(5)(i). The Sec. 23.55(b) phrase ``if that means is

available with the critical engine inoperative'' would be deleted

because it is covered by the safe and reliable requirements.

Section 23.57 Takeoff Path

Section 23.57 would be revised to clarify and specify which takeoff

path segments must be determined in flight. Proposed paragraph (a)

would clarify that the transition to the enroute configuration should

be completed on or before reaching 1500 feet above the takeoff surface.

In current Sec. 23.57(c)(1), the slope of the airborne part of the

takeoff path must be ``positive at each point''; this is changed in

proposed (c)(1) to ``not negative at any point,'' to allow acceleration

in level flight, which is implied by current Sec. 23.61(c). A proposed

editorial change to Sec. 23.57(c)(3) would specify that the climb

gradient ``must not be less than * * *,'' as opposed to ``may not be

less than. * * *'' The option in current Sec. 23.57(d) of determining

the takeoff path, either by continuous demonstration or by synthesis

from segments, no longer reflects current practice, nor is it entirely

desirable. The only viable option in determining the takeoff path from

rest to 35 feet above the takeoff surface is by a continuous

demonstration. The most practical method of determining the takeoff

path from 35 feet to 1500 feet above the takeoff surface is by

synthesis from segments. Accordingly, proposed Sec. 23.57(d) and (e)

would incorporate these changes.

Section 23.59 Takeoff Distance and Takeoff Run

This proposal would clarify Sec. 23.59 with no substantial change

in requirements. The proposal would change the opening text to clarify

that the determination of takeoff run is the applicant's option since

the applicant may choose not to present clearway data. The reference in

current Sec. 23.59(a)(2) and (b)(2) to ``along the takeoff path,'' in a

takeoff with all engines operating, would be deleted since takeoff path

is a one-engine-inoperative condition. Additionally, the reference to

VLOF is replaced with the words ``liftoff point'' to clarify that

the requirements specify a point and related distance, not a speed.

Section 23.63 Climbs: General

Proposed new Sec. 23.63 would assemble general climb requirements

from Secs. 23.65 and 23.67 into a single section and differentiate

between WAT limited airplanes (reciprocating engine powered airplanes

of above 6,000 pounds maximum takeoff weight and all turbine engine

powered airplanes) and those airplanes that are not WAT limited

(reciprocating engine powered airplanes of 6,000 pounds or less). (See

the proposed change to Sec. 23.45 for discussion of WAT limits.)

Proposed new Sec. 23.63(a)(1) would require that compliance be shown

out of ground effect. This requirement is in current Sec. 23.67(e),

which applies to commuter category airplanes. Proposed new

Sec. 23.63(a)(3) requires that compliance must be shown, unless

otherwise specified, with one engine inoperative, at a bank angle not

exceeding 5 degrees. This requirement is in current Sec. 23.149 and has

been applied generally for part 23 airplanes except commuter category

airplanes in certain circumstances.

Section 23.65 Climb: All Engines Operating

This proposal would clarify Sec. 23.65 and would change minimum

climb speeds for multiengine airplanes.

Proposed revisions to Sec. 23.65(a) would change the applicability

from ``each airplane'' as adopted in Amendment No. 23-45 (58 FR 42136,

August 6, 1993) to ``each normal, utility, and acrobatic category

reciprocating engine-powered airplane of 6,000 pounds or less maximum

weight.'' It would change the phrase ``angle of climb'' to ``climb

gradient'' and establish the climb gradient at 8.3 percent for

landplanes and 6.7 percent for seaplanes and amphibians with certain

specified performance conditions.

Proposed (a)(4) would establish a minimum climb speed for

multiengine airplanes of not less than the greater of 1.1 VMC and

1.2 VS1, which would provide a margin above VMC.

The cowl flap requirements currently in paragraph (a)(5) would be

moved to Sec. 23.45(c).

Current Sec. 23.65(b) would be deleted. These requirements should

have been deleted in Amendment No. 23-45 (58 FR 42136, August 6, 1993),

but they were overlooked. Since the adoption of Amendment No. 23-45

there is no longer a rate of climb requirement in Sec. 23.65(a). The

alternative means of compliance allowed by paragraph (b), therefore, is

obsolete and not consistent with the more stringent performance

requirements proposed by this NPRM. Also, the alternative means of

compliance in paragraph (b) was rarely used by applicants.

The proposed Sec. 23.65(b) would add WAT limits for reciprocating

engine-powered airplanes of more than 6,000 pounds maximum weight and

turbine engine-powered airplanes. (See proposal for Sec. 23.45 for

discussion of WAT limits.)

Current Sec. 23.65(c) would be moved to Sec. 23.65(b) and the

temperature and altitude requirements would be deleted since WAT limits

are proposed for turbine engine-powered airplanes and the four percent

gradient would apply at any approved takeoff ambient condition.

Proposed Sec. 23.65(b)(2) provides for landing gear down unless the

gear can be retracted in not more than seven seconds. This is more

stringent than the present requirement, but the same as the proposed

one-engine-inoperative takeoff climb requirements, and is considered

appropriate to this weight and class of airplane with WAT limits.

Current Sec. 23.65(d) would be deleted since the requirements would

be covered in the proposed Sec. 23.45(h)(2) and current Sec. 23.21.

Section 23.66 Takeoff Climb; One-engine Inoperative

Proposed new Sec. 23.66 would require the determination of the one-

engine-inoperative climb capacity of all WAT limited reciprocating

engine-powered and turbine engine-powered airplanes immediately after

takeoff. Since most reciprocating engine-powered airplanes do not have

autofeather, the condition immediately after takeoff can be critical.

There is not a minimum climb requirement in this configuration, only

the determination of the climb or descent gradient. This information

does not become a limitation; it is provided to the pilot in the AFM

(see Sec. 23.1587) to allow the pilot to make informed judgments before

takeoff.

Section 23.67 Climb: One Engine Inoperative

This proposal would reorganize Sec. 23.67 for harmonization with

the JAR; and would require WAT limits for some airplanes; require wings

level climb up to 400 feet for commuter category airplanes, and make

minor changes in airplane configuration requirements.

Revised Sec. 23.67(a) would specify the climb requirements for non-

WAT airplanes with no change in requirements for those airplanes.

Proposed Sec. 23.67(b) would specify climb requirements for WAT

airplanes. WAT criteria would be applied for both reciprocating engine-

powered airplanes of more than 6,000 pounds maximum weight and turbine

engine-powered airplanes. (See the discussion of WAT limits in the

proposed change to Sec. 23.45.) Turbine engine-powered airplanes are

currently subject to limited WAT limitations under Sec. 23.67(c), which

would be incorporated into proposed Sec. 23.67(b).

The takeoff flap position for normal, utility, and acrobatic

category reciprocating engine-powered airplanes of 6,000 pounds or less

is changed to ``wing flaps retracted'' from ``most favorable position''

(current Sec. 23.67(4)). Wing flaps retracted is the position most used

in certification and in service for this size of airplane. The proposed

change is contained in Sec. 23.67(a)(1)(iv), (a)(2)(iv), and

(b)(2)(iv).

Current Sec. 23.67(d) is deleted since all climb speeds (both all-

engine and one engine inoperative) are scheduled and the determination

of VY is no longer required. VY is also proposed to be

deleted in all other sections of part 23 for the same reason.

Current Sec. 23.67(e) for commuter category airplanes would be

redesignated as Sec. 23.67(c) with no change in requirements except

that the takeoff climb with landing gear extended must be conducted

with the landing gear doors open. This is a conservative approach

offered by the JAA to specify a definite gear door configuration and to

delete the requirement to determine performance during the transient

condition of gear doors opening and closing. Proposed Sec. 23.67(c)(1)

specifies that the first segment climb must be conducted with the wings

level and further specifies that the climb speed for the segment must

be V2 instead of the current requirement for a range of speeds

from VLOF and whatever the applicant selects at gear retraction.

Proposed Sec. 23.67(c)(2) requires conducting the second segment climb

with wings level, which would be appropriate for operational scenarios.

The current Sec. 23.67(e)(1) requirements are partially moved to

Sec. 23.67(c) and the remainder are contained in Sec. 23.63(a)(1) and

(d).

Proposed Sec. 23.67(c)(3), enroute climb, adds a minimum climb

speed to ensure an adequate margin above stall speed.

The proposed Sec. 23.67(c)(4) makes no substantive changes in the

current requirements of Sec. 23.67(e)(3) but does change the paragraph

heading from ``Approach'' to ``Discontinued approach.'' In addition,

proposed Sec. 23.67(c)(4) clarifies that the climb gradients must be

met at an altitude of 400 feet above the landing surface.

Section 23.69 Enroute Climb/Descent

Proposed new Sec. 23.69 would require the determination of all

engine and one-engine-inoperative climb/descent rates and gradients in

the enroute configuration under all operational WAT conditions. This

information is necessary for enroute flight planning and dispatch.

Climb speeds are specified to provide a margin above VSI.

Section 23.71 Glide: Single-engine Airplanes

Proposed new Sec. 23.71 would require the determination of glide

distance and speed for single-engine airplanes. The information is

necessary for flight planning and for providing the pilot with

information from which to make informed decisions.

Section 23.73 Reference Landing Approach Speed

Proposed new Sec. 23.73 would define the reference landing approach

speeds, VREF. Establishing a definition for these speeds

simplifies the use of VREF in other portions of the rule. The

VREF speeds for the various category airplanes are established as

not less than 1.3 V S0. Also, the established speeds consider the

appropriate relationship to VMC determined under Sec. 23.149.

Section 23.75 Landing Distance

This proposal would revise the heading, reorganize Sec. 23.75 for

harmonization with the JAR, add the landing reference speed, VREF,

and move the portion on brake pressures to Sec. 23.735, Brakes.

The introductory paragraph of this section would be revised to

delete the reference to the AFM because part 23, subpart B, is

generally used to specify what must be determined during flight test

and part 23, subpart G, is generally used to specify what must be

placed in the AFM. The introductory paragraph would also be revised to

require landing distances to be determined at standard temperature for

each weight and altitude. Service experience has shown that landing

distances are not sensitive to temperatures. The use of standard

temperature is consistent with WAT requirements and the increased level

of safety introduced in this NPRM. The revised introductory paragraph

deletes the reference to ``approximately 3 knots'' for seaplanes and

amphibians because this information will be moved to advisory material

on acceptable methods of compliance.

Revised Sec. 23.75(a) adds VREF and requires its use. (See

proposal for Sec. 23.73.)

The text of the current Sec. 23.75(b) is deleted because proposed

Sec. 23.45 would specify these general requirements. Proposed new

Sec. 23.75(b) clarifies that a constant configuration must be

maintained throughout the maneuver.

Revised Sec. 23.75(d) would continue the current requirement for

showing that a safe transition to the balked landing conditions can be

made and specify the weight that must be considered for the transition

to the balked landing conditions. This proposed new requirement

reflects current industry practice.

Proposed new Sec. 23.75(e) is a general requirement to ensure the

reliability of the brakes and tires.

Proposed Sec. 23.75(f) is revised by changing the first use of the

word ``means'' to ``retardation means,'' and by deleting paragraph

(f)(3). Paragraph (f)(3) requires that no more than average skill shall

be required to control the airplane. This topic is covered in proposed

Sec. 23.45(f).

Section Sec. 23.75(h) is deleted because the introductory paragraph

of proposed Sec. 23.75 would contain commuter category requirements and

proposed Sec. 23.1587 would require landing distance correction

factors.

Section 23.77 Balked Landing

This section would be revised to include additional WAT

requirements and to make editorial changes.

Proposed revisions to Sec. 23.77 (a) and (b) would differentiate

between WAT and non-WAT; and, in paragraph (b), would include the more

stringent WAT limited airplane requirements. (See proposal for

Sec. 23.45.) Section 23.77(a)(4) adds a new climb speed requirement to

ensure that acceleration is not required during the transition from

landing to balked landing. The climb gradient of Sec. 23.77(b) was

selected to be slightly less than the non-WAT airplane sea level

requirement as a tradeoff for a balked landing climb capability at all

altitudes and temperatures.

The commuter category climb gradient of 3.3 percent specified in

Sec. 23.77(c) changes to 3.2 percent for consistency with part 25.

Additional editorial changes and deletions are proposed for

Sec. 23.77(c) because the general requirements would be covered in the

proposed Sec. 23.45.

Section 23.143 General

Proposed Sec. 23.143(a) would be revised to add the phrase ``during

all flight phases'' to the lead-in of the paragraph. ``Go-around''

would be added to the list of flight phases.

The JAA/FAA decided, during FAR/JAR Harmonization meetings, that

the term ``go-around'' included the all engine balked landings of

Sec. 23.77, various all engine and one-engine-inoperative aborted

landings specified in the AFM, and the commuter category discontinued

approach of Sec. 23.67(c)(4). In this NPRM, balked landing refers only

to the all engine balked landing of Sec. 23.77.

The table in paragraph (c) would be changed to show a change in

two-hand roll force from 60 to 50 pounds, which is consistent with JAR

25. The table also would be changed to show a one-hand on the rim roll

force of 25 pounds. This is a JAA/FAA harmonized value.

Section 23.145 Longitudinal Control

Proposed Sec. 23.145 would be revised by changing the speed ranges

applicable to the takeoff, enroute, and landing configurations. In

proposing paragraph (b)(2) the requirement for ``altering and

maintaining, as a minimum, the speed used to show compliance with

Sec. 23.77'' would be changed ``to allow the airspeed to transition

from 1.3 VS0 to 1.3 VS1.'' In proposed paragraph (b)(5) for

landing configuration, the speed reference would be changed from 1.4

VS0 to VREF.

Editorial changes are also proposed for the lead-in to paragraphs

(b) with no substantive change.

Current paragraphs (b)(2)(i) and (ii) would be redesignated as

(b)(2) and (b)(3), respectively.

Proposed paragraph (b)(3) would add more specific requirements if

gated flap positions are used.

Proposed paragraph (b)(4) is the same as current paragraph (b)(4).

Proposed paragraph (b)(5) is the same as current paragraph (b)(5)

except for changes in trim speed to VREF and the allowance of a

two-handed control. Use of two hands is considered appropriate because

the pilot does not need to change power settings.

Proposed paragraph (b)(6) is current paragraph (b)(3).

Proposed paragraph (c) could change the speed range for maneuvering

capability from ``above VMO/MMO and up to VD/MD''

to ``above VMO/MMO and up to the maximum speed shown under

Sec. 23.251.'' This change is considered necessary because a range of

speeds can be chosen as VD/MD. Reference to Sec. 23.251 would

ensure a flight demonstrated speed instead of a design speed.

Proposed paragraph (d) would change the speed that must be

maintained for power-off glide from 1.3 VSO to VREF.

Section 23.147 Directional and Lateral Control

This proposal would make minor revisions to Sec. 23.147(a) and add

two new requirements in proposed paragraphs (b) and (c). The flaps

retracted configuration for Sec. 23.127(a)(4) would be consistent with

the proposed Sec. 23.67.

Proposed Sec. 23.147(b) would add a test for the condition when,

during enroute climb, an engine fails and a time delay of two seconds

occurs before the pilot takes corrective action. The intent of this

proposed change is to test for a likely operational scenario and to

ensure a satisfactory result.

Proposed Sec. 23.147(c) would test for the failure or disconnection

of the primary lateral control. This paragraph requires that the

airplane exhibit adequate dihedral effect throughout the airplane's

operational envelope to ensure continued safe flight and landings if a

lateral control disconnects. In addition, this requirement provides

compatibility with the relaxed requirements of proposed Sec. 23.177(b)

(see proposal for Sec. 23.177).

Section 23.149 Minimum Control Speed

This proposal would clarify Sec. 23.149, add a VMC in the

landing configuration, and provide the procedure for determining a

ground VMC.

Current Sec. 23.149(a) would be revised in the proposal by making

clarifying and editorial changes with no change in requirements.

Section 23.149(b) would be revised by making clarifying changes and

deleting the reference to lesser weights in paragraph (b)(4) because

the range of weights is covered in Sec. 23.21.

Proposed Sec. 23.149(c) specifies the requirement for a VMC in

the landing configuration for WAT and commuter airplanes. This proposed

new requirement is necessary for airplanes in this category to provide

a VREF margin above the VMC determined in the landing

configuration. (See proposal for Sec. 23.73.)

The new Sec. 23.149(f) proposes the requirements for determining a

VMCG for commuter category airplanes, at the option of the

applicant, to comply with Sec. 23.51. (See proposal for Sec. 23.51.)

Section 23.153 Control During Landings

This proposal would revise Sec. 23.153 to reference landing speeds

to VREF and to reorganize the section.

Section 23.155 Elevator Control Forces in Maneuvers

Proposed Sec. 23.155 would make changes to the power and gradient

of the stick force curve.

Proposed Sec. 23.155(b) specifies the maximum continuous power for

the test instead of allowing a power selected by the applicant as an

operating limitation. This revision would eliminate a power

specification that is unnecessary and would simplify normal operations

for the pilot.

Proposed Sec. 23.155(c) addresses stick force gradient to ensure

that stick force lightening is not excessive. The FAA will issue

advisory material on acceptable methods of compliance.

Section 23.157 Rate of Roll

This proposal would revise Sec. 23.157(d) power and trim

requirements and would clarify the flap position. Proposed

Sec. 23.157(d)(1) would clarify that the flaps should be in the landing

position. Proposed Sec. 23.157(d)(3) would make the power consistent

with the approach configuration, which is the configuration being

tested. Proposed Sec. 23.157(d)(4) would relate the trim speed to the

proposed VREF. (See proposal for Sec. 23.73.)

Section 23.161 Trim

This proposal would revise Sec. 23.161 power, configurations, and

speeds.

Proposed Sec. 23.161(a) would state the safety principles

underlying the trim requirements and would provide a regulatory

requirement for considering conditions that might be encountered

outside the requirements addressed in paragraphs (b) through (d).

Proposed Sec. 23.161(b)(1) would add a requirement to trim at

MMO in addition to VMO. This proposed change only clarifies

that the airplane must trim in the Mach limited speed range.

Proposed Sec. 23.161(b)(2) would require lateral and directional

trim over a range of 1.4 VS1 to VH or VMO/MMO for

commuter category airplanes instead of only the high speed requirement

in the present rules. It is appropriate for commuter category airplanes

to trim in the proposed range. It would not be burdensome because all

present commuter category airplanes were designed to the proposed

standard.

The proposed introductory paragraph of Sec. 23.161(c) would delete

the reference to VMO/MMO, since it is addressed in other

appropriate places. Proposed Sec. 23.161(c)(1) would require trim at

takeoff power, as this is a likely operational scenario for most

airplanes and the condition should be tested. In addition, the proposed

change would relate the maximum continuous power climb speeds and

configuration to Sec. 23.69, the enroute climb requirement. Current

Sec. 23.161(c)(2) moves to Sec. 23.161(c)(4), changes the reference

VREF for a landing speed, and adds a requirement for the airplane

to trim at the steepest landing approach gradient the applicant chooses

under Sec. 23.75. It is appropriate for the airplane to trim at all

landing conditions. Current Sec. 23.161(c)(3) moves to

Sec. 23.161(c)(2) with editorial changes. Current Sec. 23.161(c)(4)

moves to Sec. 23.161(c)(3) with an increase in the trim speed from 0.9

VNO or VMO to VNO or VMO/MMO. The increase in

trim speed is appropriate because descent is permitted and is common at

VMO.

Proposed Sec. 23.161(d) would make editorial changes in the

introductory paragraph. It would reference the appropriate Sec. 23.67

requirements and delete commuter category speed ranges, which are moved

to the new Sec. 23.161(e). Section Sec. 23.161(d)(4) is revised to

specify flaps retracted instead of referencing the Sec. 23.67

configurations. Flaps retracted is the likely sustained configuration

where a pilot would need to trim. Also, the flaps retracted

configuration for Sec. 23.161(d)(4) would be consistent with the

proposed Sec. 23.67.

Proposed new Sec. 23.161(e) would ensure that excessive forces are

not encountered in commuter category airplanes during extended climbs

at V2 in the takeoff configuration, when climb above 400 feet is

required.

Section 23.175 Demonstration of Static Longitudinal Stability

This proposal would make changes to Sec. 23.175 power,

configurations, and speeds.

Proposed Sec. 23.175(a)(1) would change the flap position from the

climb position to the flaps retracted position. This is a clarifying

change since virtually all part 23 airplanes use flaps retracted for

climb. Also, this proposed change would align the part 23 and part 25

climb static longitudinal stability requirements.

Proposed Sec. 23.175(a)(3) would delete the option for the

applicant to select some power other than maximum continuous power as

an operating limitation. As noted in the proposed change to

Sec. 23.155, this would eliminate a power specification that is

unnecessary and simplify normal operations for the pilot. Proposed

Sec. 23.175(a)(4) would make the trim speed consistent with the enroute

all-engine climb speed.

The proposed change to Sec. 23.175(b) would rearrange the section

with no change in requirements. The definition of VFC/MMC

contained in Sec. 23.175(b)(2) is proposed to be moved to part 1, to

harmonize with JAR 1. (See the proposed change to Sec. 1.1.)

Current Sec. 23.175(c), which requires the test for gear down

cruise static longitudinal stability, would be deleted. This test is

considered superfluous to the land configuration static longitudinal

stability test and does not represent a likely operating scenario.

Proposed Sec. 23.175(c) would be current Sec. 23.175(d) with only a

change to use VREF as the trim speed.

Section 23.177 Static Directional and Lateral Stability

Proposed revisions to Sec. 23.177 would delete the requirements for

two-control airplanes, make minor clarifying changes, and specify an

exclusion for acrobatic category airplanes.

Proposed Sec. 23.177 would delete the introductory phrase

concerning three-control airplanes, which is consistent with the

deletion of the requirements for two-control airplanes in current

paragraph (b). The two-control airplane regulations were introduced in

1945 but no two-control airplanes have been certificated for several

decades and no need is foreseen for these regulations. If an applicant

proposes a two-control airplane, the FAA would issue special

conditions. After deleting the introductory portion of Sec. 23.177(a),

paragraph (a)(1) would be redesignated as (a). In the first sentence,

the proposed change replaces ``skid'' with ``wings level sideslip'' to

clarify the intended maneuver. Also, the proposed change increases the

power requirement for demonstration of directional stability in the

landing configuration. The current requirement specifies power

necessary to maintain a three degree angle of decent. Maximum

continuous power is considered appropriate since directional stability

should be maintained during a balked landing, particularly since

directional instability is an undesirable characteristic at any point

in the flight envelope. Also, VA is replaced by VO to be

consistent with Sec. 23.1507.

Proposed Sec. 23.177(b), currently (a)(2), replaces ``any'' with

``all'' in the first sentence to clarify that all landing gear and flap

positions must be addressed. Also, the proposed paragraph would specify

a minimum speed at which static lateral stability may not be negative,

as 1.3 VS, for all configurations except takeoff. This is

consistent with the other speeds specified in Sec. 23.177(b) and

relieves the requirement for other than takeoff speeds.

Proposed new Sec. 23.177(c) would provide an exclusion for the

dihedral effect for acrobatic category airplanes approved for inverted

flight. The proposed change recognizes that, in fully acrobatic

airplanes, the dihedral effect is not a desired characteristic.

The addition of proposed Sec. 23.147(c), which ensures lateral

control capability without the use of the primary lateral control

system, compensates for the relieving nature of proposed Sec. 23.177(b)

and the exception from the requirements of Sec. 23.177(b) for acrobatic

category airplanes.

Present Sec. 23.177(a)(3) is redesignated as Sec. 23.177(d). The

proposed Sec. 23.177(d) deletes the next to the last sentence,

concerning bank angle and heading, because the current requirement is

not a necessary test condition and a constant heading during the

sideslip may be impossible in some airplanes.

Present Sec. 23.177(b) is deleted, as previously discussed, because

it applies to two-control airplanes.

Section 23.201 Wings Level Stall

This proposal would delete both two-control airplanes and altitude

loss requirements and would make clarifying changes in Sec. 23.201.

The proposed change to Sec. 23.201(a) deletes the applicability

reference for an airplane with independently controlled roll and

directional controls. The last word, ``pitches'' is replaced by

``stalls'' since stalls may be defined by other than nose-down

pitching.

Present Sec. 23.201(b) is deleted since it applies to two-control

airplanes. (See proposed change for Sec. 23.177 for discussion of two-

control airplane requirements.)

Current Sec. 23.201(c) is divided into proposed Sec. 23.201 (b) and

(c). Proposed Sec. 23.201(b) covers stall recognition and proposed

Sec. 23.201(c) addresses stall recovery. Proposed Sec. 23.201(b)

clarifies that the test should start from a speed at least 10 knots

above the stall speed. Proposed Sec. 23.201(b) has no change in

requirements. Section 23.201(c) is changed to specify how long the

control must be held against the stop. This change would ensure that

the procedure for determining stall speed is the same procedure used to

test stall characteristics. The last sentence of current paragraph (c)

on the increase of power is deleted because it would only apply to

altitude loss.

Present Sec. 23.201(d) would be deleted, as suggested by the JAA,

since the determination of altitude loss, and its subsequent furnishing

in the AFM, is not considered information useful to the pilot for safe

operation of the airplane.

Proposed Sec. 23.201(d) would be based on present Sec. 23.210(e)

and would be revised to clarify that the roll and yaw limits apply

during both entry and recovery.

Proposed Sec. 23.201(e) is present paragraph (f) with some

revisions. During FAR/JAR harmonization meetings, the JAA pointed out

to the FAA that in high power-to-weight ratio airplanes, extreme nose-

up attitudes were the principal criteria for use of reduced power, not

the presence of undesirable stall characteristics. The FAA concurs and

proposes to delete the phrase concerning stall characteristics.

Section 23.203 Turning Flight and Accelerated Turning Stalls

Proposed Sec. 23.203 would be revised by adding the word

``turning'' before ``stalls'' and after ``accelerated'' in the heading,

the introductory text, and in proposed paragraphs (a)(2) and (b)(5).

This proposed change clarifies that accelerated stalls are performed in

turning flight. Also, it clarifies the definition to show that

accelerated stalls are not intended to be performed in straight flight.

This clarification reflects current practice.

Proposed Sec. 23.203 (a) and (b) would reference the stall

definition in Sec. 23.201(b), which is more specific than the present

general words ``when the stall has fully developed or the elevator has

reached its stop.''

For clarification, current paragraph (b)(4) would be separated into

proposed paragraphs (b)(4) and (b)(5) without substantive change, and

current paragraph (b)(5) would be redesignated as paragraph (b)(6).

Proposed Sec. 23.203(c)(1) would clarify the wing flap positions by

changing ``each intermediate position'' to ``each intermediate normal

operating position.''

The proposed change to Sec. 23.203(c)(4) would clarify the use of

reduced power. (See the proposed change to Sec. 23.201(f).)

Proposed new paragraph (c)(6) has been added to be consistent with

new Sec. 23.207(c)(6) configurations (Amendment No. 23-45).

Section 23.205 Critical Engine-Inoperative Stalls

This proposal would delete Sec. 23.205. The present requirement to

demonstrate stalls with the critical engine inoperative is restricted

to the enroute configuration and to a level of power asymmetry with

which the airplane is controllable with wings level at the stalling

speed. As a result, the power on the operating engines at the stall is

normally fairly low, and neither the configuration nor the power

setting represent the conditions most likely to accompany an

inadvertent stall in service. Reduction of power of the operating

engine(s) during the recovery is permitted, and it is questionable

whether such action would be taken promptly in an inadvertent stall in

service. Experience shows that stalls with significant power asymmetry

can result in a spin, even on airplanes that are certificated to the

present requirement. Apparently the requirement for demonstrating one-

engine-inoperative stalls is not effective in ensuring that inadvertent

stalls in service with one engine inoperative will have satisfactory

characteristics and be recoverable. Sufficient protection against the

hazard of stalling with one engine inoperative is provided by the one-

engine-inoperative performance requirements and operating speed

margins, coupled with the requirements for determination of VMC,

the addition of a directional and lateral control test under

Sec. 23.147(b), and demonstration of stalling characteristics with

symmetric power.

Section 23.207 Stall Warning

This proposal would delete the upper limit on stall speed margin

and provide for mutable stall warning on acrobatic category airplanes

in Sec. 23.207.

Proposed Sec. 23.207(c) would reference the stall tests required by

Sec. 23.201(b) and Sec. 23.203(a)(1) and specify that during such tests

for one knot per second deceleration stalls, both wings level and

turning, the stall must begin at a speed exceeding the stalling speed

by a margin of not less than 5 knots. The quantified upper limit in the

current rule of 10 knots or 15 percent of the stalling speed would be

deleted. The upper limit has created problems for manufacturers because

of the complex design features required to show compliance. The upper

limit requirement was in effect replaced by the nuisance stall warning

requirement in Sec. 23.207.(d).

Present Sec. 23.207(d) would be divided and moved to proposed

Sec. 23.207 (d) and (e). Proposed Sec. 23.207(d) on nuisance stall

warnings would have no change in requirements. Proposed Sec. 23.207(e)

would delete the bottom limit of five knots for decelerations greater

than one knot per second. Also, it would specify that the stall warning

must begin sufficiently before the stall so that the pilot can take

corrective action. This is considered appropriate because, at the

higher deceleration rates of three to five knots per second, a

specified five knots may not be enough stall warning.

Proposed new Sec. 23.207(f) allows for a mutable stall warning

system for acrobatic category airplanes, with automatic arming for

takeoff and rearming for landing. This feature is useful for acrobatic

pilots and provides safeguards for takeoff and landing.

Secion 23.221 Spinning

This proposal would revise the point to start the one-turn-spin

recovery count, delete the ``characteristically incapable of spinning''

option, and make minor changes in acrobatic category spins in

Sec. 23.221.

Proposed Sec. 23.221(a) would replace the exception for airplanes

characteristically incapable of spinning with an exception for

airplanes that demonstrate compliance with the optional spin resistant

requirements of paragraph (a)(2) of this section. Criteria for an

airplane incapable of spinning are unnecessary since criteria for spin

resistant airplanes are provided. Proposed Sec. 23.221(a) would change

the point at which the count for the one-turn-spin recovery begins. The

change would specify a more specific point to begin the count by

replacing the current phrase ``after the controls have been applied''

with ``after initiation of the first control action for recovery.''

Under the present rules, if an applicant proposes a multiple step

recovery procedure that starts with the rudder, then the airplane may

be effectively recovered before the start of the recovery count.

Proposed Sec. 23.221(a)(1)(ii) would specify that no control force

or characteristic can adversely affect prompt recovery. This would be

an improvement over the present prohibition of excessive back pressure

in current Sec. 23.221(a)(1)(ii).

Present Sec. 23.221(a)(1) is proposed to be recodified into

Sec. 23.221(a)(1)(i) through (a)(1)(iv) with no changes in the

requirements. Present Sec. 23.221(a)(2) on spin resistant airplanes

would be restated with minor editorial changes but with no change in

requirements.

Proposed Sec. 23.221(b) would specify the emergency egress

requirements of Sec. 23.807(b)(5) for those utility category airplanes

approved for spinning. This is considered an appropriate way to cross-

reference the requirements of Sec. 23.807 to the flight requirements.

The proposed Sec. 23.221(c) introductory paragraph would require

acrobatic category airplanes to meet the one-turn-spin requirements of

Sec. 23.221(a). This change is proposed because acrobatic category

airplanes should have sufficient controllability to recover from the

developing one-turn-spin under the same conditions as normal category

airplanes. The proposed introductory paragraph would also cross-

reference Sec. 23.807 for emergency egress requirements.

Proposed Sec. 23.221(c) pertaining to acrobatic category airplanes

would add a requirement in proposed paragraph (c)(1) for spin recovery

after six turns or any greater number of turns for which certification

is requested. The proposed rule would require recovery within 1.5 turns

after initiation of the first control action for recovery. This

proposed requirement would ensure recovery within 1.5 turns if the spin

mode changes beyond six turns. As an alternative, the applicant may

stop at six turns and provide a limitation of six turns.

Proposed Sec. 23.221(c)(2) would delete the option to retract flaps

during recovery and would provide the applicant with a choice of flaps

up or flaps deployed for spin approval. The paragraph would continue to

prohibit exceeding applicable airspeed limits and limit maneuvering

load factors.

A new Sec. 23.221(c)(4) is proposed to ensure that the acrobatic

spins do not cause pilot incapacitation.

The present Sec. 23.221(d) is proposed to be deleted. The

recognition of airplanes that are ``characteristically incapable of

spinning'' has been in the regulation since at least 1937. In 1942, the

present weight, center of gravity, and control mis-rig criteria were

introduced into Civil Air Regulation (CAR) 03. Since then, the National

Aeronautics and Space Administration (NASA) spin resistant

requirements, which are based on research, have been developed and

incorporated in the regulations by Amendment No. 23-42 (56 FR 344,

January 3, 1991). If an applicant proposes a non-spinable airplane, it

would be appropriate to apply the more technologically advanced

requirements of proposed Sec. 23.221(a)(2); therefore, Sec. 23.221(d)

would be deleted.

Section 23.233 Directional Stability and Control

This proposal would make minor word changes to Sec. 23.233(a) to

harmonize this section with the corresponding JAR section.

Section 23.235 Operation on Unpaved Surfaces

This proposal would revise the heading of Sec. 23.235 and delete

water operating requirements, which are moved to proposed new

Sec. 23.237.

Section 23.237 Operation on Water

Proposed new Sec. 23.237, for operation on water, is essentially

the same as the current Sec. 23.235(b).

Section 23.253 High Speed Characteristics

This proposal would delete the current paragraph (b)(1), since the

requirement for piloting strength and skill is covered in Sec. 23.141.

Section 23.562 Emergency Landing Dynamic Conditions

This proposal would change the one engine inoperative climb

reference in Sec. 23.562(d) to Sec. 23.67(a)(1).

Section 23.1325 Static Pressure System

This proposal would revise Sec. 23.1325(e) to clarify that the

calibration must be conducted in flight, which is standard practice.

The text of Sec. 23.1325(f) would be removed and the paragraph would be

reserved. The text of paragraph (g) would be moved to paragraph (f) in

a future rulemaking action. The results of the calibration would be

required in the proposed Sec. 23.1587.

Section 23.1511 Flap Extended Speed

This proposal would delete from Sec. 23.1511(a) references to

Sec. 23.457 because Sec. 23.457 is proposed to be deleted from the FAR

in a related NPRM on airframes, Notice No. 94-20 (59 FR 35196, July 8,

1994).

Section 23.1521 Powerplant Limitations

This proposal would require, under Sec. 23.1521, maximum

temperature to be established for takeoff operation and would require

an ambient temperature limit for reciprocating engines in airplanes of

more than 6,000 pounds.

Proposed Sec. 23.1521(b)(5) would require the establishment of

maximum cylinder head, liquid coolant, and oil temperature limits for

takeoff operation without regard to the allowable time. Presently,

temperature limits are required only if the takeoff power operation is

permitted for more than two minutes. It is appropriate to require

operating temperature limitations because most takeoff operations will

exceed two minutes.

Proposed Sec. 23.1521(e) would require an ambient temperature limit

for turbine engine-powered airplanes and reciprocating engine-powered

airplanes over 6,000 pounds. This change is proposed because these

airplanes are subject to WAT limits and it will ensure that airplane

engines will cool at the ambient temperature limit.

Section 23.1543 Instrument Markings: General

Proposed new Sec. 23.1543(c) would require that all related

instruments be calibrated in compatible units. This is considered

essential for safe operation.

Section 23.1545 Airspeed Indicator

Proposed revisions to Sec. 23.1545 would differentiate between WAT

limited and non-WAT limited airplanes in Sec. 23.1545.

Proposed Sec. 23.1545(b)(5) would delete any one-engine-inoperative

best rate of climb speed marking requirements for WAT limited

airplanes. These airplanes would already have scheduled speeds in case

of an engine failure. Proposed paragraph (b)(5) would apply only to

non-WAT airplanes for which the one-engine-inoperative best rate of

climb speed marking has been simplified to sea level at maximum weight.

Since the blue arc rule was promulgated in Amendment No. 23-23 (43 FR

50593, October 30, 1978), certification experience has shown that the

marking of an arc is unnecessarily complicated. For many airplanes, the

arc was so narrow that the arc was a line. Therefore, proposed

paragraph (b)(5) would require a blue radial line instead of an arc.

Proposed Sec. 23.1545(b)(6) would retain the same VMC

requirement for non-WAT airplanes and delete any VMC markings for

WAT airplanes since WAT airplanes already have scheduled speeds in case

of engine failure.

Section 23.1553 Fuel Quantity Indicator

This proposal would delete, from Sec. 23.1553, the use of an arc to

show a quantity of unusable fuel. The proposed rule references the

unusable fuel determination and requires only a red radial line, which

would provide a clearer indication of fuel quantity for pilots.

Section 23.1555 Control Markings

This proposal would add to Sec. 23.1555(e)(2) the requirement that

no other control be red. This would help prevent use of a wrong control

in an emergency.

Section 23.1559 Operating Limitations Placard

This proposal would simplify the present Sec. 23.1559 and delete

duplicate material.

Proposed Sec. 23.1559(a), (b), and a new paragraph (c), would

provide essentially the same information as the current rule. All

airplanes currently operate with an AFM and the new rule places

emphasis on using the AFM to define required operating limitations.

Section 23.1563 Airspeed Placards

This proposal would add a new paragraph (c) to Sec. 23.1563. The

new paragraph would be applicable to WAT limited airplanes and would

require providing the maximum VMC in the takeoff configuration

determined under Sec. 23.149(b). This is desirable since the VMC

is not marked on the airspeed indicator for these airplanes.

Section 23.1567 Flight Maneuver Placard

Proposed new Sec. 23.1567(d), which would be applicable to

acrobatic and utility airplanes approved for intentional spinning,

would require a placard listing control actions for recovery. Also, it

would require a statement on the placard that the airplane be recovered

when spiral characteristics occur, or after six turns, or at any

greater number of turns for which certification tests have been

conducted. This paragraph would replace the similar placard requirement

in current Sec. 23.1583(e)(3) for acrobatic category airplanes, and the

placard requirement would be deleted from Sec. 23.1583(e).

Section 23.1581 General

This proposal would make editorial changes in Sec. 23.1581 and

would recognize WAT limited and non-WAT limited airplanes.

Proposed new Sec. 23.1581(a)(3) would require information necessary

to comply with relevant operating rules. This is a FAR/JAR

harmonization item and is considered necessary because some operational

rules, such as Sec. 135.391, require flight planning with one-engine-

inoperative cruise speed and/or driftdown data. For airplanes operated

under part 135 in the United States, it represents no change in

requirements.

Proposed Sec. 23.1581(b)(2) would require that only WAT limited

airplane AFM's provide data necessary for determining WAT limits.

Proposed new Sec. 23.1581(c) would require the AFM units to be the

same as on the instruments. This requirement would enhance operational

safety.

Proposed Sec. 23.1581(d) would delete the current requirement for a

table of contents. This is considered to be a format requirement and

not appropriate for this section, which specifies AFM content. Current

Sec. 23.1581(d) is being replaced by a requirement to present all

operational airspeeds as indicated airspeeds. Although not currently

required, this is current practice.

Section 23.1583 Operating Limitations

Proposed revisions to Sec. 23.1583 would make minor changes in the

operating limitations information furnished in the AFM. These proposed

changes include revising airspeed limitations for commuter category

airplanes, requiring AFM limitations for WAT limited airplanes,

furnishing ambient temperature limitations, furnishing smoking

restriction information, and furnishing information specifying types of

runway surfaces.

Proposed Sec. 23.1583(a)(3) would make the VMO/VMO

airspeed operating limitations applicable only to turbine powered

commuter category airplanes. This is consistent with current practice

since no reciprocating engine-powered commuter category airplanes have

been proposed.

Proposed Sec. 23.1583(c)(3) would add takeoff and landing weight

limitations for WAT limited airplanes. (See the Sec. 23.45 proposal for

discussion of WAT limited airplanes.)

Proposed Sec. 23.1583(c)(4) and (5) renumber the present

Sec. 23.1583(c)(3) and (4). These proposed paragraphs are revised

editorially and cross-references are updated. Proposed paragraph

(c)(4)(ii) would impose a new requirement that the AFM include the

maximum takeoff weight for each airport altitude and ambient

temperature within the range selected by the applicant at which the

accelerate-stop distance determined under Sec. 23.55 is equal to the

available runway length plus the length of any stopway, if available.

This is currently required for transport category airplanes and is

necessary for harmonization with the JAR.

Proposed new Sec. 23.1583(c)(6) would establish the zero wing fuel

weight of Sec. 23.343 as a limitation. This would provide the pilot

with information necessary to prevent exceeding airplane structural

limits.

Proposed new Sec. 23.1583(d) has editorial changes only.

Proposed new Sec. 23.1583(e)(1) and (2) would delete references to

``characteristically incapable of spinning.'' As discussed under

Sec. 23.221, requirements for ``characteristically incapable of

spinning'' would be deleted.

Proposed new Sec. 23.1583(e)(3) and (4) would replace present

paragraph (e)(3). Proposed Sec. 23.1583(e)(4) would add the requirement

for specifying limitations associated with spirals, six turn spins, or

more than six turn spins. The requirement for a placard has been

deleted since the requirement would be covered in Sec. 23.1567.

Proposed new Sec. 23.1583(e)(5) would be based on current paragraph

(e)(4) for commuter category airplanes. It would be revised to define

the maneuvers as those proposed for commuter category airplanes in

Sec. 23.3.

Proposed new Sec. 23.1583(f) would revise the heading of the

paragraph and add the limit negative load factor for acrobatic category

airplanes. The limit negative load factor is essential for safe

operational use.

Proposed new Sec. 23.1583(g) would make editorial changes with no

change in requirements. The paragraph would reference the requirements

of flight crews in Sec. 23.1523.

Proposed Sec. 23.1583 (i), (j) and (k) are the current

Sec. 23.1583(k), (l) and (m), as redesignated.

Proposed new Sec. 23.1583(l) would require furnishing baggage and

cargo loading limits.

Proposed new Sec. 23.1583(m) would require furnishing any special

limitations on systems and equipment. This would provide the pilot with

information necessary for safe operation of the airplane systems and

equipment.

Proposed new Sec. 23.1583(n) would require a statement on ambient

temperature limitations. Maximum cooling temperature limits have been

required for turbine powered airplanes by Sec. 23.1521(e); however, the

requirement for the limitation has never been specified in

Sec. 23.1583. Proposed Sec. 23.1583(n) would require furnishing both

maximum and minimum temperature limits if appropriate. A minimum

temperature limit would provide the pilot with information necessary to

avoid airplane damage during low temperature operations.

Proposed new Sec. 23.1583(o) would require furnishing any occupant

smoking limitations on the airplane. This would enhance safe operation

of the airplane.

Proposed new Sec. 23.1583(p) would require the applicant to state

what runway surfaces have been approved. This provides the pilot with a

positive indication of which runway types may be used.

Section 23.1585 Operating Procedures

This proposal would rearrange the current material in Sec. 23.1585

and add additional requirements as discussed below.

Proposed Sec. 23.1585(a) would contain the requirements applicable

to all airplanes. The requirements would be arranged in a different

order from the current requirements in paragraph (a). The requirements

for information that must be included cover--unusual flight or ground

handling characteristics; maximum demonstrated values of crosswinds;

recommended speed for flight in rough air; restarting an engine in

flight; and making a normal approach and landing in accordance with

Sec. 23.73 and Sec. 23.75. All of these requirements are in current

Sec. 23.1585(a) except for restarting a turbine engine in flight, which

is in current paragraph (c)(5) pertaining only to multiengine

airplanes. The FAA decided that a restart capability is not required

for single reciprocating engine airplanes for the reasons given in the

preamble discussion of proposal 3 in Amendment No. 23-43 (58 FR 18958,

April 9, 1993). The requirement for providing restart information

should apply to single turbine engines, since turbine engine designs

incorporate a restart capability and inadvertent shutdowns may occur.

Normal approach and landing information in accordance with the landing

requirement in proposed Sec. 23.73 and Sec. 23.75 is new. This is

necessary to enable pilots to achieve the published landing distances

and, if necessary, to safely transition to a balked landing.

Proposed Sec. 23.1585(b) would be a revision of Sec. 23.1585(b) on

gliding after an engine failure for single-engine airplanes. The

proposed version would reference requirements in proposed Sec. 23.71.

Proposed Sec. 23.1585(c) for multiengine airplanes would require

compliance with (a) plus the following information requirements from

current paragraph (c): approach and landing with an engine inoperative;

balked landing with an engine inoperative; and VSSE as determined

in Sec. 23.149. Current paragraph (c) requirements for information on

procedures for continuing a takeoff following an engine failure and

continuing a climb following an engine failure would be moved to

proposed (e) for normal, utility, and acrobatic multiengines.

Proposed Sec. 23.1585(d) would apply to normal, utility and

acrobatic airplanes. These airplanes would have to comply with

paragraph (a) and either (b) or (c). These airplanes would also have to

comply with the normal takeoff, climb, and the abandoning a takeoff

procedures, which are currently contained in paragraph (a).

As discussed above, Sec. 23.1585(c), for normal, utility and

acrobatic multiengine airplanes, would require compliance with proposed

(a), (c), and (d) plus requirements for continuing a takeoff or climb

with one engine inoperative, which are now in current paragraph (c) (1)

and (2).

Proposed Sec. 23.1585(f) would require commuter category airplanes

to comply with paragraphs (a) and (c) plus the normal takeoff

requirements from current paragraph (a)(2) revised; accelerate-stop

requirements, which are new, and continuing takeoff after engine

failure, which are in current paragraph (c)(1).

Proposed Sec. 23.1585(g) would be the same as current paragraph (d)

on identifying operating conditions, which necessitate fuel system

independence.

Proposed Sec. 23.1585(h) would be the same as current paragraph (e)

for disconnecting the battery from its charging source.

Proposed Sec. 23.1585(i) is based on current paragraph (g) on the

total quantity of usable fuel and adds information on the effect of

pump failure on unusable fuel.

Proposed new Sec. 23.1585(j) would require procedures for safe

operation of the airplanes' systems and equipment. Although not

currently required, this is current industry practice.

Present Sec. 23.1585(h), commuter category airplane procedures for

restarting turbine engines in flight, would no longer be necessary

because the requirement would be covered under paragraph (a)(4).

Section 23.1587 Performance Information

Proposed Sec. 23.1587 would rearrange existing material, delete ski

plane performance exceptions, delete the option of calculating

approximate performance, delete stall altitude loss data, and require

overweight landing performance in Sec. 23.1587. Stalling speed

requirements of current paragraph (c) (2) and (3) would be combined and

moved to paragraph (a)(1) and would reference the stalling speed

requirement of Sec. 23.49. Information on the steady rate and gradient

of climb with all engines operating would be required by proposed

paragraph (a)(2). This is revised from current paragraph (a)(2). The

reference would be changed to proposed Sec. 23.69(a).

Proposed (a)(3) would require, as is now required, that landing

distance be determined under Sec. 23.75, and would add that this must

be provided for each airport altitude, standard temperature, and type

of surface for which it is valid. Proposed paragraph (a)(4) would

require information on the effect on landing distance when landing on

other than hard surface, as determined under Sec. 23.45(g). Proposed

paragraph (a)(5) would cover information on the effects on landing

distance of runway slope and wind. This would provide the pilot with

data with which to account for these factors in his or her takeoff

calculations.

Current requirements in Sec. 23.1587(b) on ski planes would be

deleted. Proposed paragraph (b) would add a steady angle of climb/

descent requirement as determined under Sec. 23.77(a). This requirement

would apply to all non-WAT airplanes.

Proposed paragraph (c) would apply to normal, utility, and

acrobatic category airplanes, rather than all airplanes as in current

paragraph (c). The proposed (c) would delete stall altitude loss

requirements that are in current paragraph (c)(1). As mentioned,

current stalling speed requirements would be moved to proposed

paragraph (a)(1). Current paragraph (c)(4) on cooling climb speed data

would also be deleted since all airplanes would cool at scheduled

speeds.

Proposed paragraph (c)(1) would pertain to the takeoff distance

determined under Sec. 23.53 and the type of surface. Proposed paragraph

(c)(2) and (c)(3) pertain to the effect on takeoff distance of the

runway surface, slope, and headwind and tailwind component.

Proposed paragraph (c)(4) would impose a new requirement pertaining

to the one-engine inoperative takeoff climb/descent performance for

WAT-limited airplanes. This pertains only to reciprocating engine-

powered airplanes. It would provide the pilot with the information

determined under proposed Sec. 23.66.

Proposed paragraph (c)(5) pertains to enroute rate and gradient of

climb/descent determined under Sec. 23.69(b), for multiengine

airplanes.

Proposed Sec. 23.1587(d) for commuter category airplanes would

incorporate the present data plus the addition of accelerate-stop data,

overweight landing performance, and the effect of operation on other

than smooth hard surfaces. In addition, in order to consolidate all of

the requirements for what must appear in the AFM in subpart G, proposed

Sec. 23.1587(d)(10) would contain the requirement, found in existing

Sec. 23.1323(d), to show the relationship between IAS and CAS in the

AFM.

Section 23.1589 Loading Information

Proposed Sec. 23.1589(b) would make editorial changes to simplify

the text, with no change in requirements.

Appendix E

Appendix E would be deleted for the reasons given in the proposed

change to Sec. 23.25.

Preliminary Regulatory Evaluation, Initial Regulatory Flexibility

Determination, and Trade Impact Assessment

Proposed changes to Federal regulations must undergo several

economic analyses. First, Executive Order 12866 directs that each

Federal agency shall propose or adopt a regulation only upon a reasoned

determination that the benefits of the intended regulation justify its

costs. Second, the Regulatory Flexibility Act of 1980 requires agencies

to analyze the economic impact of regulatory changes on small entities.

Third, the Office of Management and Budget directs agencies to assess

the effects of regulatory changes on international trade. In conducting

these analyses, the FAA has determined that this rule: (1) Would

generate benefits that justify its costs and is not a ``significant

regulatory action'' as defined in the Executive Order; (2) is not

significant as defined in DOT's Policies and Procedures; (3) would not

have a significant impact on a substantial number of small entities;

and (4) would not constitute a barrier to international trade. These

analyses, available in the docket, are summarized below.

Regulatory Evaluation Summary

Of the 57 sections that would be amended or added in this proposed

rule, the FAA has identified 15 that could result in additional

compliance costs in one or more airplane categories. Amendments to five

sections could result in cost savings. The greatest costs would be

incurred by manufacturers of WAT limited airplanes (e.g., multiengine

airplanes with maximum weights of more than 6,000 pounds). When

amortized over a production run, the quantified incremental costs would

be relatively modest--less than $100 per airplane. The FAA solicits

comments concerning the incremental certification/development costs

attributable to the proposed rule.

The primary benefit of the proposed rule would be the cost

efficiencies of harmonization with the JAR for those manufacturers that

choose to market airplanes in JAA countries as well as to manufacturers

in JAA countries that choose to market airplanes in the U.S. Other

benefits of the proposed rule would be decreased reliance on special

conditions, simplification of the certification process through

clarification of existing requirements, and increased flexibility

through optional designs.

Regulatory Flexibility Determination

The Regulatory Flexibility Act of 1980 (RFA) was enacted by

Congress to ensure that small entities are not unnecessarily and

disproportionately burdened by Federal regulations. The RFA requires a

Regulatory Flexibility Analysis if a proposed rule would have a

significant economic impact, either detrimental or beneficial, on a

substantial number of small entities. Based on FAA Order 2100.14A,

Regulatory Flexibility Criteria and Guidance, the FAA has determined

that the proposed amendments would not have a significant economic

impact on a substantial number of small entities.

International Trade Impact Assessment

The proposed rule would not constitute a barrier to international

trade, including the export of American airplanes to foreign countries

and the import of foreign airplanes into the United States. Instead,

the proposed flight certification procedures would be harmonized with

those of the JAA and would lessen restraints on trade.

Federalism Implications

The regulation proposed herein would not have substantial direct

effects on the States, on the relationship between the national

government and the States, or on the distribution of power and

responsibilities among the various levels of government. Therefore, in

accordance with Executive Order 12612, it is determined that this

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

Conclusion

The FAA proposes to revise the flight airworthiness standards for

normal, utility, acrobatic, and commuter category airplanes to be

compatible with the same standards that will be proposed for the same

category airplanes by the Joint Airworthiness Authority in Europe. If

adopted, the proposed revision would reduce the regulatory burden on

the United States and European airplane manufacturers by relieving them

of the need to show compliance with different standards each time they

seek certification approval of an airplane in a different country.

For the reasons discussed in the preamble, and based on the

findings in the Regulatory Evaluation, the FAA has determined that this

proposed regulation is not a significant regulatory action. In

addition, the FAA certifies that this proposal, if adopted, will not

have a significant economic impact on a substantial number of small

entities under the criteria of the Regulatory Flexibility Act. This

proposal is not considered significant under DOT Regulatory Policies

and Procedures (44 FR 11034, February 26, 1979). An initial regulatory

evaluation of the proposal has been placed in the docket. A copy may be

obtained by contacting the person identified under FOR FURTHER

INFORMATION CONTACT.

List of Subjects

14 CFR Part 1

Air transportation.

14 CFR Part 23

Aircraft, Aviation safety, Signs and symbols.

The Proposed Amendment

In consideration of the foregoing, the Federal Aviation

Administration proposes to amend parts 1 and 23 of the Federal Aviation

Regulations (14 CFR parts 1 and 23) as follows:

PART 1--DEFINITIONS AND ABBREVIATIONS

1. The authority citation for part 1 continues to read as follows:

Authority: 49 U.S.C. app. 1347, 1348, 1354(a), 1357(d)(2), 1372,

1421 through 1430, 1432, 1442, 1443, 1472, 1510, 1522, 1652(e),

1655(c), 1657(f); 49 U.S.C. 106(g).

2. A new definition is added in alphabetical order to Sec. 1.1 to

read as follows:

Sec. 1.1 General definitions.

* * * * *

Maximum speed for stability characteristics, VFC/MFC

means a speed that may not be less than a speed midway between maximum

operating limit speed (VMO/MMO) and demonstrated flight

diving speed (VDF/MDF), except that, for altitudes where the

Mach number is the limiting factor, MFC need not exceed the Mach

number at which effective speed warning occurs.

* * * * *

PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND

COMMUTER CATEGORY AIRPLANES

3. The authority citation for part 23 is revised to read as

follows:

Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1425,

1428, 1429, 1430; 49 U.S.C. 106(g).

4. Section 23.3 is amended by revising paragraphs (b)(2), (d), and

(e) to read as follows:

Sec. 23.3 Airplane categories.

* * * * *

(b) * * *

(2) Lazy eights, chandelles, and steep turns, or similar maneuvers,

in which the angle of bank is more than 60 degrees but not more than 90

degrees.

* * * * *

(d) The commuter category is limited to propeller-driven,

multiengine airplanes that have a seating configuration, excluding

pilot seats, of 19 or less, and a maximum certificated takeoff weight

of 19,000 pounds or less. The commuter category operation is limited to

any maneuver incident to normal flying, stalls (except whip stalls),

and steep turns, in which the angle of bank is not more than 60

degrees.

(e) Except for commuter category, airplanes may be type certified

in more than one category if the requirements of each requested

category are met.

5. Section 23.25 is amended by revising paragraphs (a) introductory

text and (a)(1) introductory text, and paragraphs (a)(1)(i) and

(a)(1)(iii) to read as follows:

Sec. 23.25 Weight limits.

(a) Maximum weight. The maximum weight is the highest weight at

which compliance with each applicable requirement of this part (other

than those complied with at the design landing weight) is shown. The

maximum weight must be established so that it is--

(1) Not more than the least of--

(i) The highest weight selected by the applicant; or

* * * * *

(iii) The highest weight at which compliance with each applicable

flight requirement is shown, and

* * * * *

6. Section 23.33 is amended by revising paragraphs (b) (1) and (2)

to read as follows:

Sec. 23.33 Propeller speed and pitch limits.

(b) * * *

(1) During takeoff and initial climb at the all engine(s) operating

climb speed specified in Sec. 23.65, the propeller must limit the

engine r.p.m., at full throttle or at maximum allowable takeoff

manifold pressure, to a speed not greater than the maximum allowable

takeoff r.p.m.; and

(2) During a closed throttle glide, at VNE, the propeller may

not cause an engine speed above 110 percent of maximum continuous

speed.

* * * * *

7. Section 23.45 is revised to read as follows:

Sec. 23.45 General.

(a) Unless otherwise prescribed, the performance requirements of

this part must be met for--

(1) Still air and standard atmosphere; and

(2) Ambient atmospheric conditions, for commuter category

airplanes, for reciprocating engine-powered airplanes or more than

6,000 pounds maximum weight, and for turbine engine-powered airplanes.

(b) Performance data must be determined over not less than the

following ranges of conditions--

(1) Airport altitudes from sea level to 10,000 feet; and

(2) For reciprocating engine-powered airplanes of 6,000 pounds, or

less, maximum weight, temperature from standard to 30 deg.C above

standard; or

(3) For reciprocating engine-powered airplanes of more than 6,000

pounds maximum weight and turbine engine-powered airplanes, temperature

from standard to 30 deg.C above standard, or the maximum ambient

atmospheric temperature at which compliance with the cooling provisions

of Sec. 23.1041 to Sec. 23.1047 is shown, if lower.

(c) Performance data must be determined with the cowl flaps or

other means for controlling the engine cooling air supply in the

position used in the cooling tests required by Sec. 23.1041 to

Sec. 23.1047.

(d) The available propulsive thrust must correspond to engine

power, not exceeding the approved power, less--

(1) Installation losses; and

(2) The power absorbed by the accessories and services appropriate

to the particular ambient atmospheric conditions and the particular

flight condition.

(e) The performance, as affected by engine power or thrust, must be

based on a relative humidity:

(1) Of 80 percent, at and below standard temperature; and

(2) From 80 percent at the standard temperature, varying linearly

down to 34 percent at the standard temperature plus 50 deg.F.

(f) Unless otherwise prescribed, in determining the takeoff and

landing distances, changes in the airplane's configuration, speed, and

power must be made in accordance with procedures established by the

applicant for operation in service. These procedures must be able to be

executed consistently by pilots of average skill in atmospheric

conditions reasonably expected to be encountered in service.

(g) The following, as applicable, must be determined on a smooth,

dry, hard-surfaced runway--

(1) Takeoff distance of Sec. 23.53(b);

(2) Accelerate-stop distance of Sec. 23.55;

(3) Takeoff distance and takeoff run of Sec. 23.59; and

(4) Landing distance of Sec. 23.75.

The effect on these distances of operation on other types of surfaces

(for example, grass, gravel) when dry, may be determined or derived and

these surfaces listed in the Airplane Flight Manual in accordance with

Sec. 23.1583(p).

(h) For commuter category airplanes, the following also apply:

(1) Unless otherwise prescribed, the applicant must select the

takeoff, enroute, approach, and landing configurations for the

airplane.

(2) The airplane configuration may vary with weight, altitude, and

temperature, to the extent that they are compatible with the operating

procedures required by paragraph (h)(3) of this section.

(3) Unless otherwise prescribed, in determining the critical-

engine-inoperative takeoff performance, takeoff flight path, and

accelerate-stop distance, changes in the airplane's configuration,

speed, and power must be made in accordance with procedures established

by the applicant for operation in service.

(4) Procedures for the execution of discontinued approaches and

balked landings associated with the conditions prescribed in

Sec. 23.67(c)(4) and Sec. 23.77(c) must be established.

(5) The procedures established under paragraphs (h)(3) and (h)(4)

of this section must--

(i) Be able to be consistently executed by a crew of average skill

in atmospheric conditions reasonably expected to be encountered in

service;

(ii) Use methods or devices that are safe and reliable; and

(iii) Include allowances for any reasonably expected time delays in

the execution of the procedures.

8. Section 23.49 is revised to read as follows:

Sec. 23.49 Stalling speed.

(a) VS0 and VS1 are the stalling speeds or the minimum

steady flight speeds, in knots (CAS), at which the airplane is

controllable with--

(1) For reciprocating engine-powered airplanes, the engine(s)

idling, the throttle(s) closed or at not more than the power necessary

for zero thrust at a speed not more than 110 percent of the stalling

speed;

(2) For turbine engine-powered airplanes, the propulsive thrust not

greater than zero at the stalling speed, or, if the resultant thrust

has no appreciable effect on the stalling speed, with engine(s) idling

and throttle(s) closed;

(3) The propeller(s) in the takeoff position;

(4) The airplane in the condition existing in the test, in which

VS0 and VS1 are being used;

(5) The center of gravity in the position that results in the

highest value of VS0 and VS1; and

(6) The weight used when VS0 or VS1 are being used as a

factor to determine compliance with a required performance standard.

(b) VS0 and VS1 must be determined by flight tests, using

the procedure and meeting the flight characteristics specified in

Sec. 23.201.

(c) Except as provided in paragraph (d) of this section, VS0

at maximum weight must not exceed 61 knots for--

(1) Single-engine airplanes; and

(2) Multiengine airplanes of 6,000 pounds or less maximum weight

that cannot meet the minimum rate of climb specified in

Sec. 23.67(a)(1) with the critical engine inoperative.

(d) All single-engine airplanes, and those multiengine airplanes of

6,000 pounds or less maximum weight with a VS0 of more than 61

knots that do not meet the requirements of Sec. 23.67(a)(1), must

comply with Sec. 23.562(d).

9. Section 23.51 is revised to read as follows:

Sec. 23.51 Takeoff speeds.

(a) For normal, utility, and acrobatic category airplanes, rotation

speed, VR, is the speed at which the pilot makes a control input,

with the intention of lifting the airplane out of contact with the

runway or water surface.

(1) For multiengine landplanes, VR must not be less than the

greater of 1.05 VMC or 1.10 VS1;

(2) For single-engine landplanes, VR, must not be less than

VS1; and

(3) For seaplanes and amphibians taking off from water, VR,

may be any speed that is shown to be safe under all reasonably expected

conditions, including turbulence and complete failure of the critical

engine.

(b) For normal, utility, and acrobatic category airplanes, the

speed at 50 feet above the takeoff surface level must not be less than:

(1) For multiengine airplanes, the highest of--

(i) A speed that is shown to be safe for continued flight (or

emergency landing, if applicable) under all reasonably expected

conditions, including turbulence and complete failure of the critical

engine;

(ii) 1.10 VMC; or

(iii) 1.20 VS1.

(2) For single-engine airplanes, the higher of--

(i) A speed that is shown to be safe under all reasonably expected

conditions, including turbulence and complete engine failure; or

(ii) 1.20 VS1.

(c) For commuter category airplanes, the following apply:

(1) V1 must be established in relation to VEF as follows:

(i) VEF is the calibrated airspeed at which the critical

engine is assumed to fail. VEF must be selected by the applicant

but must not be less than 1.05 VMC determined under Sec. 23.149(b)

or, at the option of the applicant, not less than VMCG determined

under Sec. 23.149(f).

(ii) The takeoff decision speed, V1, is the calibrated

airspeed on the ground at which, as a result of engine failure or other

reasons, the pilot is assumed to have made a decision to continue or

discontinue the takeoff. The takeoff decision speed, V1, must be

selected by the applicant but must not be less than VEF plus the

speed gained with the critical engine inoperative during the time

interval between the instant at which the critical engine is failed and

the instant at which the pilot recognizes and reacts to the engine

failure, as indicated by the pilot's application of the first retarding

means during the accelerate-stop determination of Sec. 23.55.

(2) The rotation speed, VR, in terms of calibrated airspeed,

must be selected by the applicant and must not be less than the

greatest of the following:

(i) V1;

(ii) 1.05 VMC determined under Sec. 23.149(b);

(iii) 1.10 VS1; or

(iv) The speed that allows attaining the initial climb-out speed,

V2, before reaching a height of 35 feet above the takeoff surface

in accordance with Sec. 23.57(c)(2).

(3) For any given set of conditions, such as weight, altitude,

temperature, and configuration, a single value of VR must be used

to show compliance with both the one-engine-inoperative takeoff and

all-engines-operating takeoff requirements.

(4) The takeoff safety speed, V2, in terms of calibrated

airspeed, must be selected by the applicant so as to allow the gradient

of climb required in Sec. 23.67(c)(1) and (c)(2) but must not be less

than 1.10 VMC or less than 1.20 Vs1.

(5) The one-engine-inoperative takeoff distance, using a normal

rotation rate at a speed 5 knots less than VR, established in

accordance with paragraph (c)(2) of this section, must be shown not to

exceed the corresponding one-engine-inoperative takeoff distance,

determined in accordance with Sec. 23.57 and Sec. 23.59(a)(1), using

the established VR. The takeoff, otherwise performed in accordance

with Sec. 23.57, must be continued safely from the point at which the

airplane is 35 feet above the takeoff surface and at a speed not less

than the established V2 minus 5 knots.

(6) The applicant must show, with all engines operating, that

marked increases in the scheduled takeoff distances, determined in

accordance with Sec. 23.59(a)(2), do not result from over-rotation of

the airplane or out-of-trim conditions.

10. Section 23.53 is revised to read as follows:

Sec. 23.53 Takeoff performance.

(a) For normal, utility, and acrobatic category airplanes, the

takeoff distance must be determined in accordance with paragraph (b) of

this section, using speeds determined in accordance with Sec. 23.51(a)

and (b).

(b) For normal, utility, and acrobatic category airplanes, the

distance required to takeoff and climb to a height of 50 feet above the

takeoff surface must be determined for each weight, altitude, and

temperature within the operational limits established for takeoff

with--

(1) Takeoff power on each engine;

(2) Wing flaps in the takeoff position(s); and

(3) Landing gear extended.

(c) For commuter category airplanes, takeoff performance, as

required by Secs. 23.55 through 23.59, must be determined with the

operating engine(s) within approved operating limitations.

11. Section 23.55 is amended by revising paragraph (a) and the

introductory text of paragraph (b) to read as follows:

Sec. 23.55 Accelerate-stop distance.

* * * * *

(a) The accelerate-step distance is the sum of the distances

necessary to--

(1) Accelerate the airplane from a standing start to VEF with

all engines operating;

(2) Accelerate the airplane from VEF, to V1, assuming the

critical engine fails at VEF; and

(3) Come to a full stop from the point of which V1 is reached.

(b) Means other than wheel brakes may be used to determine the

accelerate-stop distances if that means--

* * * * *

12. Section 23.57 is amended by revising paragraphs (a)

introductory text, (b), (c)(1), (c)(3) introductory text, (c)(4), and

(d); and by adding a new paragraph (e) to read as follows:

Sec. 23.57 Takeoff path.

* * * * *

(a) The takeoff path extends from a standing start to a point in

the takeoff at which the airplane is 1500 feet above the takeoff

surface at or below which height the transition from the takeoff to the

enroute configuration must be completed; and

* * * * *

(b) During the acceleration to speed V2, the nose gear may be

raised off the ground at a speed not less than VR. However,

landing gear retraction must not be initiated until the airplane is

airborne.

(c) * * *

(1) The slope of the airborne part of the takeoff path must not be

negative at any point;

* * * * *

(3) At each point along the takeoff path, starting at the point at

which the airplane reaches 400 feet above the takeoff surface, the

available gradient of climb must not be less than--

* * * * *

(4) Except for gear retraction and automatic propeller feathering,

the airplane configuration must not be changed, and no change in power

that requires action by the pilot may be made, until the airplane is

400 feet above the takeoff surface.

(d) The takeoff path to 35 feet above the takeoff surface must be

determined by a continuous demonstrated takeoff.

(e) The takeoff flight path from 35 feet above the takeoff surface

must be determined by synthesis from segments; and

(1) The segments must be clearly defined and must be related to

distinct changes in configuration, power, and speed;

(2) The weight of the airplane, the configuration, and the power

must be assumed constant throughout each segment and must correspond to

the most critical condition prevailing in the segment; and

(3) The takeoff flight path must be based on the airplane's

performance without utilizing ground effect.

13. Section 23.59 is amended by revising the introductory text for

this section, paragraph (a)(2), and paragraph (b) to read as follows:

Sec. 23.59 Takeoff distance and takeoff run.

For each commuter category airplane, the takeoff distance and, at

the option of the applicant, the takeoff run, must be determined.

(a) * * *

(2) With all engines operating, 115 percent of the horizontal

distance from the start of the takeoff to the point at which the

airplane is 35 feet above the takeoff surface, determined by a

procedure consistent with Sec. 23.57.

(b) If the takeoff distance includes a clearway, the takeoff run is

the greater of--

(1) The horizontal distance along the takeoff path from the start

of the takeoff to a point equidistant between the liftoff point and the

point at which the airplane is 35 feet above the takeoff surface as

determined under Sec. 23.57; or

(2) With all engines operating, 115 percent of the horizontal

distance from the start of the takeoff to a point equidistant between

the liftoff point and the point at which the airplane is 35 feet above

the takeoff surface, determined by a procedure consistent with

Sec. 23.57.

14. A new Sec. 23.63 is added to read as follows:

Sec. 23.63 Climb: general.

(a) Compliance with the requirements of Secs. 23.65, 23.66, 23.67,

23.69, and 23.77 must be shown--

(1) Out of ground effect; and

(2) At speeds that are not less than those at which compliance with

the powerplant cooling requirements of Secs. 23.1041 to 23.1047 has

been demonstrated; and

(3) Unless otherwise specified, with one engine inoperative, at a

bank angle not exceeding 5 degrees.

(b) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of 6,000 pounds or less maximum weight,

compliance must be shown with Sec. 23.65(a), Sec. 23.67(a), where

appropriate, and Sec. 23.77(a) at maximum takeoff or landing weight, as

appropriate, in a standard atmosphere.

(c) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of more than 6,000 pounds maximum weight, and

turbine engine-powered airplanes in the normal, utility, and acrobatic

category, compliance must be shown at weights as a function of airport

altitude and ambient temperature, within the operational limits

established for takeoff and landing, respectively, with--

(1) Sections 23.65(b) and 23.67(b) (1) and (2), where appropriate,

for takeoff, and

(2) Section 23.67(b)(2), where appropriate, and Sec. 23.77(b), for

landing.

(d) For commuter category airplanes, compliance must be shown at

weights as a function of airport altitude and ambient temperature

within the operational limits established for takeoff and landing,

respectively, with--

(1) Sections 23.67(c)(1), 23.67(c)(2), and 23.67(c)(3) for takeoff;

and

(2) Sections 23.67(c)(3), 23.67(c)(4), and 23.77(c) for landing.

15. Section 23.65 is revised to read as follows:

Sec. 23.65 Climb: all engines operating.

(a) Each normal, utility, and acrobatic category reciprocating

engine-powered airplane of 6,000 pounds or less maximum weight must

have a steady climb gradient at sea level of at least 8.3 percent for

landplanes or 6.7 percent for seaplanes and amphibians with--

(1) Not more than maximum continuous power on each engine;

(2) The landing gear retracted;

(3) The wing flaps in the takeoff position(s); and

(4) A climb speed not less than the greater of 1.1 VMC and 1.2

VS1 for multiengine airplanes and not less than 1.2 VS1 for

single-engine airplanes.

(b) Each normal, utility, and acrobatic category reciprocating

engine-powered airplane of more than 6,000 pounds maximum weight and

turbine engine-powered airplanes in the normal, utility, and acrobatic

category must have a steady gradient of climb after takeoff of at least

4 percent with--

(1) Takeoff power on each engine;

(2) The landing gear extended, except that if the landing gear can

be retracted in not more than seven seconds, the test may be conducted

with the gear retracted;

(3) The wing flaps in the takeoff position(s); and

(4) A climb speed as specified in Sec. 23.65(a)(4).

16. A new Sec. 23.66 is added to read as follows:

Sec. 23.66 Takeoff climb: one-engine inoperative.

For normal, utility, and acrobatic category reciprocating engine-

powered airplanes of more than 6,000 pounds maximum weight, and turbine

engine-powered airplanes in the normal, utility, and acrobatic

category, the steady gradient of climb or descent must be determined at

each weight, altitude, and ambient temperature within the operational

limits established by the applicant with--

(a) The critical engine inoperative and its propeller in the

position it rapidly and automatically assumes;

(b) The remaining engine(s) at takeoff power;

(c) The landing gear extended, except that if the landing gear can

be retracted in not more than seven seconds, the test may be conducted

with the gear retracted;

(d) The wing flaps in the takeoff position(s);

(e) The wings level; and

(f) A climb speed equal to that achieved at 50 feet in the

demonstration of Sec. 23.53.

17. Section 23.67 is revised to read as follows:

Sec. 23.67 Climb: one engine inoperative.

(a) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of 6,000 pounds or less maximum weight, the

following apply:

(1) Except for those airplanes that meet the requirements

prescribed in Sec. 23.562(d), each airplane with a VSO of more

than 61 knots must be able to maintain a steady climb gradient of at

least 1.5 percent at a pressure altitude of 5,000 feet with the--

(i) Critical engine inoperative and its propeller in the minimum

drag position;

(ii) Remaining engine(s) at not more than maximum continuous power;

(iii) landing gear retracted;

(iv) Wing flaps retracted; and

(v) Climb speed not less than 1.2 VS1.

(2) For each airplane that meets the requirements prescribed in

Sec. 23.562(d), or that has a VSO of 61 knots or less, the steady

gradient of climb or descent at a pressure altitude of 5,000 feet must

be determined with the--

(i) Critical engine inoperative and its propeller in the minimum

drag position;

(ii) Remaining engine(s) at not more than maximum continuous power;

(iii) Landing gear retracted;

(iv) Wing flaps retracted; and

(v) Climb speed not less than 1.2 VS1.

(b) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of more than 6,000 pounds maximum weight, and

turbine engine-powered airplanes in the normal, utility, and acrobatic

category--

(1) The steady gradient of climb at an altitude of 400 feet above

the takeoff surface must be measurably positive with the--

(i) Critical engine inoperative and its propeller in the minimum

drag position;

(ii) Remaining engine(s) at takeoff power;

(iii) Landing gear retracted;

(iv) Wing flaps in the takeoff position(s); and

(v) Climb speed equal to that achieved at 50 feet in the

demonstration of Sec. 23.53.

(2) The steady gradient of climb must not be less than 0.75 percent

at an altitude of 1,500 feet above the takeoff surface, or landing

surface, as appropriate, with the--

(i) Critical engine inoperative and its propeller in the minimum

drag position;

(ii) Remaining engine(s) at not more than maximum continuous power;

(iii) Landing gear retracted;

(iv) Wing flaps retracted; and

(v) Climb speed not less than 1.2 VS1.

(c) For commuter category airplanes, the following apply:

(1) Takeoff; landing gear extended. The steady gradient of climb at

the altitude of the takeoff surface must be measurably positive for

two-engine airplanes, not less than 0.3 percent for three-engine

airplanes, or 0.5 percent for four-engine airplanes with--

(i) The critical engine inoperative and its propeller in the

position it rapidly and automatically assumes;

(ii) The remaining engine(s) at takeoff power;

(iii) The landing gear extended, and all landing gear doors open;

(iv) The wing flaps in the takeoff position(s);

(v) The wings level; and

(vi) A climb speed equal to V2.

(2) Takeoff; landing gear retracted. The steady gradient of climb

at an altitude of 400 feet above the takeoff surface must be not less

than 2.0 percent for two-engine airplanes, 2.3 percent for three-engine

airplanes, and 2.6 percent for four-engine airplanes with--

(i) The critical engine inoperative and its propeller in the

position it rapidly and automatically assumes;

(ii) The remaining engine(s) at takeoff power;

(iii) The landing gear retracted;

(iv) The wing flaps in the takeoff position(s);

(v) A climb speed equal to V2.

(3) Enroute. The steady gradient of climb at an altitude of 1,500

feet above the takeoff or landing surface, as appropriate, must be not

less than 1.2 percent for two-engine airplanes, 1.5 percent for three-

engine airplanes, and 1.7 percent for four-engine airplanes with--

(i) The critical engine inoperative and its propeller in the

minimum drag position;

(ii) The remaining engine(s) at not more than maximum continuous

power;

(iii) The landing gear retracted;

(iv) The wing flaps retracted; and

(v) A climb speed not less than 1.2 VS1.

(4) Discontinued approach. The steady gradient of climb at an

altitude of 400 feet above the landing surface must be not less than

2.1 percent for two-engine airplanes, 2.4 percent for three-engine

airplanes, and 2.7 percent for four-engine airplanes, with--

(i) The critical engine inoperative and its propeller in the

minimum drag position;

(ii) The remaining engine(s) at takeoff power;

(iii) Landing gear retracted;

(iv) Wing flaps in the approach position(s) in which VS1 for

these position(s) does not exceed 110 percent of the VS1 for the

related all-engines-operating landing position(s); and

(v) A climb speed established in connection with normal landing

procedures but not exceeding 1.5 VS1.

18. A new Sec. 23.69 is added to read as follows:

Sec. 23.69 Enroute climb/descent.

(a) All engines operating. The steady gradient and rate of climb

must be determined at each weight, altitude, and ambient temperature

within the operational limits established by the applicant with--

(1) Not more than maximum continuous power on each engine;

(2) The landing gear retracted;

(3) The wing flaps retracted; and

(4) A climb speed not less than 1.3 VS1.

(b) One engine inoperative. The steady gradient and rate of climb/

descent must be determined at each weight, altitude, and ambient

temperature within the operational limits established by the applicant

with--

(1) The critical engine inoperative and its propeller in the

minimum drag position;

(2) The remaining engine(s) at not more than maximum continuous

power;

(3) The landing gear retracted;

(4) The wing flaps retracted; and

(5) A climb speed not less than 1.2 VS1.

19. A new Sec. 23.71 is added to read as follows:

Sec. 23.71 Glide: Single-engine airplanes.

The maximum horizontal distance traveled in still air, in nautical

miles, per 1,000 feet of altitude lost in a glide, and the speed

necessary to achieve this must be determined with the engine

inoperative, its propeller in the minimum drag position, and landing

gear and wing flaps in the most favorable available position.

20. A new Sec. 23.73 is added to read as follows:

Sec. 23.73 Reference landing approach speed.

(a) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of 6,000 pounds or less maximum weight, the

reference landing approach speed, VREF, must not be less than the

greater of VMC, determined in Sec. 23.149(b) with the wing flaps

in the most extended takeoff position, and 1.3 VSO.

(b) For normal, utility, and acrobatic category reciprocating

engine-powered airplanes of 6,000 pounds maximum weight, and turbine

engine-powered airplanes in the normal, utility, and acrobatic

category, the reference landing approach speed, VREF, must not be

less than the greater of VMC, determined in Sec. 23.149(c), and

1.3 VSO.

(c) For commuter category airplanes, the reference landing approach

speed, VREF, must not be less than the greater of 1.05 VMC,

determined in Sec. 23.149(c), and 1.3 VSO.

21. Section 23.75 is amended by revising the section heading,

introductory text for the section; the introductory text of paragraph

(a); and paragraphs (b), (d), (e), and (f), and by removing paragraph

(h), to read as follows:

Sec. 23.75 Landing distance.

The horizontal distance necessary to land and come to a complete

stop from a point 50 feet above the landing surface must be determined,

for standard temperatures at each weight and altitude within the

operational limits established for landing, as follows:

(a) A steady approach at not less than VREF, determined in

accordance with Sec. 23.73 (a), (b), or (c), as appropriate, must be

maintained down to the 50 foot height and--

* * * * *

(b) A constant configuration must be maintained throughout the

maneuver.

* * * * *

(d) It must be shown that a safe transition to the balked landing

conditions of Sec. 23.77 can be made from the conditions that exist at

the 50 foot height, at maximum landing weight, or at the maximum

landing weight for altitude and temperature of Sec. 23.63(c)(2) or

(d)(2), as appropriate.

(e) The brakes must be used so as to not cause excessive wear of

brakes or tires.

(f) Retardation means other than wheel brakes may be used if that

means--

(1) Is safe and reliable; and

(2) Is used so that consistent results can be expected in service.

* * * * *

22. Section 23.77 is revised to read as follows:

Sec. 23.77 Balked landing.

(a) Each normal, utility, and acrobatic category reciprocating

engine-powered airplane of 6,000 pounds or less maximum weight must be

able to maintain a steady gradient of climb at sea level of at least

3.3 percent with--

(1) Takeoff power on each engine;

(2) The landing gear extended;

(3) The wing flaps in the landing position, except that if the

flaps may safely be retracted in two seconds or less without loss of

altitude and without sudden changes of angle of attack, they may be

retracted; and

(4) A climb speed equal to VREF, as defined in Sec. 23.73(a).

(b) Each normal, utility, and acrobatic category reciprocating

engine-powered airplane of more than 6,000 pounds maximum weight and

each normal, utility, and acrobatic category turbine engine-powered

airplane must be able to maintain a steady gradient of climb of at

least 2.5 percent with--

(1) Not more than the power that is available on each engine eight

seconds after initiation of movement of the power controls from minimum

flight-idle position;

(2) The landing gear extended;

(3) The wing flaps in the landing position; and

(4) A climb speed equal to VREF, as defined in Sec. 23.73(b).

(c) Each commuter category airplane must be able to maintain a

steady gradient of climb of at least 3.2 percent with--

(1) Not more than the power that is available on each engine eight

seconds after initiation of movement of the power controls from the

minimum flight idle position;

(2) Landing gear extended;

(3) Wing flaps in the landing position; and

(4) A climb speed equal to VREF, as defined in Sec. 23.73(c).

23. Section 23.143 is amended by revising paragraphs (a) and (c) to

read as follows:

Sec. 23.143 General.

(a) The airplane must be safely controllable and maneuverable

during all flight phases including--

(1) Takeoff;

(2) Climb;

(3) Level flight;

(4) Descent;

(5) Go-around; and

(6) Landing (power on and power off) with the wing flaps extended

and retracted.

* * * * *

(c) If marginal conditions exist with regard to required pilot

strength, the control forces required must be determined by

quantitative tests. In no case may the control forces under the

conditions specified in paragraphs (a) and (b) of this section exceed

those prescribed in the following table:

------------------------------------------------------------------------

Values in pounds force applied to the

relevant control Pitch Roll Yaw

------------------------------------------------------------------------

(a) For temporary application:

Stick...................................... 60 30

Wheel (Two hands on rim)................... 75 50

Wheel (One hand on rim).................... 50 25

Rudder Pedal............................... ....... ....... 150

(b) For prolonged application................ 10 5 20

------------------------------------------------------------------------

24. Section 23.145 is amended by revising paragraph (b)

introductory text, paragraphs (b)(2) through (b)(5); adding a new

paragraph (b)(6); and revising paragraphs (c) and (d) to read as

follows:

Sec. 23.145 Longitudinal control.

* * * * *

(b) Unless otherwise required, it must be possible to carry out the

following maneuvers without requiring the application of single-handed

control forces exceeding those specified in Sec. 23.143(c). The

trimming controls must not be adjusted during the maneuvers:

* * * * *

(2) With landing gear and flaps extended, power off, and the

airplane as nearly as possible in trim at 1.3 VSO, quickly apply

takeoff power and retract the flaps as rapidly as possible to the

recommended go around setting and allow the airspeed to transition from

1.3 VSO to 1.3 VS1. Retract the gear when a positive rate of

climb is established.

(3) With landing gear and flaps extended, in level flight, power

necessary to attain level flight at 1.1 VSO, and the airplane as

nearly as possible in trim, it must be possible to maintain

approximately level flight while retracting the flaps as rapidly as

possible with simultaneous application of not more than maximum

continuous power. If gated flap positions are provided, the flap

retraction may be demonstrated in stages with power and trim reset for

level flight at 1.1 VS1 in the initial configuration for each

stage--

(i) From the fully extended position to the most extended gated

position;

(ii) Between intermediate gated positions, if applicable; and

(iii) From the least extended gated position to the fully retracted

position.

(4) With power off, flaps and landing gear retracted and the

airplane as nearly as possible in trim at 1.4 VS1, apply takeoff

power rapidly while maintaining the same airspeed.

(5) With power off, landing gear and flaps extended, and the

airplane as nearly as possible in trim at VREF, obtain and

maintain airspeeds between 1.1. VSO and either 1.7 VSO or

VFE, whichever is lower without requiring the application of two-

handed control forces exceeding those specified in Sec. 23.143(c).

(6) With maximum takeoff power, landing gear retracted, flaps in

the takeoff position, and the airplane as nearly as possible in trim at

VFE appropriate to the takeoff flap position, retract the flaps as

rapidly as possible while maintaining constant speed.

(c) At speeds above VMO/MMO, and up to the maximum speed

shown under Sec. 23.251, a maneuvering capability of 1.5 g must be

demonstrated to provide a margin to recover from upset or inadvertent

speed increase.

(d) It must be possible, with a pilot control force of not more

than 10 pounds, to maintain a speed of not more than VREF during a

power-off glide with landing gear and wing flaps extended, for any

weight of the airplane, up to and including the maximum weight.

* * * * *

25. Section 23.147 is revised to read as follows:

Sec. 23.147 Directional and lateral control.

(a) For each multiengine airplane, it must be possible, while

holding the wings level within five degrees, to make sudden changes in

heading safely in both directions. This ability must be shown at 1.4

VS1 with heading changes up to 15 degrees, except that the heading

change at which the rudder force corresponds to the limits specified in

Sec. 23.143 need not be exceeded, with the--

(1) Critical engine inoperative and its propeller in the minimum

drag position;

(2) Remaining engines at maximum continuous power;

(3) Landing gear--

(i) Retracted; and

(ii) Extended; and

(4) Flaps retracted.

(b) For each multiengine airplane, it must be possible to regain

full control of the airplane without exceeding a bank angle of 45

degrees, reaching a dangerous attitude or encountering dangerous

characteristics, in the event of a sudden and complete failure of the

critical engine, making allowance for a delay of two seconds in the

initiation of recovery action appropriate to the situation, with the

airplane initially in trim, in the following conditions:

(1) Maximum continuous power on each engine;

(2) The wing flaps retracted;

(3) The landing gear retracted;

(4) A speed equal to that at which compliance with Sec. 23.69(a)

has been shown; and

(5) All propeller controls in the position at which compliance with

Sec. 23.69(a) has been shown.

(c) For all airplanes, it must be shown that the airplane is safely

controllable without the use of the primary lateral control system in

any all-engine configuration(s) and at any speed or altitude within the

approved operating envelope. It must also be shown that the airplane's

flight characteristics are not impaired below a level needed to permit

continued safe flight and the ability to maintain attitudes suitable

for a controlled landing without exceeding the operational and

structural limitations of the airplane. If a single failure of any one

connecting or transmitting link in the lateral control system would

also cause the loss of additional control system(s), the above

requirement is equally applicable with those additional systems also

assumed to be inoperative.

26. Section 23.149 is revised to read as follows:

Sec. 23.149 Minimum control speed.

(a) VMC is the calibrated airspeed at which, when the critical

engine is suddenly made inoperative, it is possible to maintain control

of the airplane with that engine still inoperative, and thereafter

maintain straight flight at the same speed with an angle of bank of not

more than 5 degrees. The method used to simulate critical engine

failure must represent the most critical mode of powerplant failure

with respect to controllability expected in service.

(b) VMC for takeoff must not exceed 1.2 VS1, where

VS1 is determined at the maximum takeoff weight. VMC must be

determined with the most unfavorable weight and center of gravity

position and with the airplane airborne and the ground effect

negligible, for the takeoff configuration(s) with--

(1) Maximum available takeoff power initially on each engine;

(2) The airplane trimmed for takeoff;

(3) Flaps in the takeoff position(s);

(4) Landing gear retracted; and

(5) All propeller controls in the recommended takeoff position

throughout.

(c) For all airplanes except reciprocating engine-powered airplanes

of 6,000 pounds or less maximum weight, the conditions of paragraph (a)

must also be met for the landing configuration with--

(1) Maximum available takeoff power initially on each engine;

(2) The airplane trimmed for an approach, with all engines

operating, at VREF, at an approach gradient equal to the steepest

used in the landing distance demonstration of Sec. 23.75;

(3) Flaps in the landing position;

(4) Landing gear extended; and

(5) All propeller controls in the position recommended for approach

with all engines operating.

(d) A minimum speed to intentionally render the critical engine

inoperative must be established and designated as the safe,

intentional, one-engine-inoperative speed, VSSE.

(e) At VMC, the rudder pedal force required to maintain

control must not exceed 150 pounds and it must not be necessary to

reduce power of the operative engine(s). During the maneuver, the

airplane must not assume any dangerous attitude and it must be possible

to prevent a heading change of more than 20 degrees.

(f) At the option of the applicant, to comply with the requirements

of Sec. 23.51(c)(1), VMCG may be determined. VMCG is the

minimum control speed on the ground, and is the calibrated airspeed

during the takeoff run at which, when the critical engine is suddenly

made inoperative, it is possible to maintain control of the airplane

using the rudder control alone (without the use of nosewheel steering),

as limited by 150 pounds of force, and using the lateral control to the

extent of keeping the wings level to enable the takeoff to be safely

continued. In the determination of VMCG, assuming that the path of

the airplane accelerating with all engines operating is along the

centerline of the runway, its path from the point at which the critical

engine is made inoperative to the point at which recovery to a

direction parallel to the centerline is completed may not deviate more

than 30 feet laterally from the centerline at any point. VMCG must

be established with--

(1) The airplane in each takeoff configuration or, at the option of

the applicant, in the most critical takeoff configuration;

(2) Maximum available takeoff power on the operating engines;

(3) The most unfavorable center of gravity;

(4) The airplane trimmed for takeoff; and

(5) The most unfavorable weight in the range of takeoff weights.

27. Section 23.153 is revised to read as follows:

Sec. 23.153 Control during landings.

It must be possible, while in the landing configuration, to safely

complete a landing without exceeding the one-hand control force limits

specified in Sec. 23.143(c) following an approach to land--

(a) At a speed of VREF minus 5 knots;

(b) With the airplane in trim, or as nearly as possible in trim and

without the trimming control being moved throughout the maneuver;

(c) At an approach gradient equal to the steepest used in the

landing distance demonstration of Sec. 23.75; and

(d) With only those power changes, if any, that would be made when

landing normally from an approach at VREF.

28. Section 23.155 is amended by revising the introductory text of

paragraph (b) and paragraph (b)(1), and by adding a new paragraph (c)

to read as follows:

Sec. 23.155 Elevator control force in maneuvers.

* * * * *

(b) The requirement of paragraph (a) of this section must be met at

75 percent of maximum continuous power for reciprocating engines, or

the maximum continuous power for turbine engines, and with the wing

flaps and landing gear retracted--

(1) In a turn, with the trim setting used for wings level flight at

VO; and

* * * * *

(c) There must be no excessive decrease in the gradient of the

curve of stick force versus maneuvering load factor with increasing

load factor.

29. Section 23.157 is amended by revising paragraph (d) to read as

follows:

Sec. 23.157 Rate of roll.

* * * * *

(d) The requirement of paragraph (c) of this section must be met

when rolling the airplane in each direction in the following

conditions--

(1) Flaps in the landing position(s);

(2) Land gear extended;

(3) All engines operating at the power for a 3 degree approach; and

(4) The airplane trimmed at VREF.

30. Section 23.161 is amended by revising paragraphs (a), (b)(1),

(b)(2), (c), the introductory text of paragraph (d), and (d)(4), and by

adding a new paragraph (e) to read as follows:

Sec. 23.161 Trim.

(a) General. Each airplane must meet the trim requirements of this

section after being trimmed and without further pressure upon, or

movement of, the primary controls or their corresponding trim controls

by the pilot or the automatic pilot. In addition, it must be possible,

in other conditions of loading, configuration, speed and power to

ensure that the pilot will not be unduly fatigued or distracted by the

need to apply residual control forces exceeding those for prolonged

application of Sec. 23.143(c). This applies in normal operation of the

airplane and, if applicable, to those conditions associated with the

failure of one engine for which performance characteristics are

established.

(b) * * *

(1) For normal, utility, and acrobatic category airplanes, at a

speed of 0.9 VH, VC, or VMO/MMO, whichever is

lowest; and

(2) For the commuter category airplanes, at all speeds from 1.4

VS1 to the lesser of VH or VMO/MMO.

(c) Longitudinal trim. The airplane must maintain longitudinal trim

under each of the following conditions:

(1) A climb with--

(i) Takeoff power, landing gear retracted, wing flaps in the

takeoff position(s), at the speeds used in determining the climb

performance required by Sec. 23.65; and

(ii) Maximum continuous power at the speeds and in the

configuration used in determining the climb performance required by

Sec. 23.69(a).

(2) Level flight at all speeds from the lesser of VH and

either VNO or VMO/MMO (as appropriate), to 1.4 VS1,

with the landing gear and flaps retracted.

(3) A descent at VNO or VMO/MMO, whichever is

applicable, with power off and with the landing gear and flaps

retracted.

(4) Approach with landing gear extended and with--

(i) A 3 degree angle of descent, with flaps retracted and at a

speed of 1.4 VS1;

(ii) A 3 degree angle of descent, flaps in the landing position(s)

at VREF; and

(iii) An approach gradient equal to the steepest used in the

landing distance demonstrations of Sec. 23.75, flaps in the landing

position(s) at VREF.

(d) In addition, each multiengine airplane must maintain

longitudinal and directional trim, and the lateral control force must

not exceed 5 pounds at the speed used in complying with Sec. 23.67(a),

(b)(2), or (c)(3), as appropriate, with--

* * * * *

(4) Wing flaps retracted; and

* * * * *

(e) In addition, each commuter category airplane for which, in the

determine of the takeoff path in accordance with Sec. 23.57, the climb

in the takeoff configuration at V2 extends beyond 400 feet above

the takeoff surface, it must be possible to reduce the longitudinal and

lateral control forces to 10 pounds and 5 pounds, respectively, and the

directional control force must not exceed 50 pounds at V2 with--

(1) The critical engine inoperative and its propeller in the

minimum drag position;

(2) The remaining engine(s) at takeoff power;

(3) Landing gear retracted;

(4) Wing flaps in the takeoff position(s); and

(5) An angle of bank not exceeding 5 degrees.

31. Section 23.175 is revised to read as follows:

Sec. 23.175 Demonstration of static longitudinal stability.

Static longitudinal stability must be shown as follows:

(a) Climb. The stick force curve must have a stable slope at speeds

between 85 and 115 percent of the trim speed, with--

(1) Flaps retracted;

(2) Landing gear retracted;

(3) Maximum continuous power; and

(4) The airplane trimmed at the speed used in determining the climb

performance required by Sec. 23.69(a).

(b) Cruise. With flaps and landing gear retracted and the airplane

in trim with power for level flight at representative cruising speeds

at high and low altitudes, including speeds up to VNO or VMO/

MMO, as appropriate, except that the speed need not exceed

VH--

(1) For normal, utility, and acrobatic category airplanes, the

stick force curve must have a stable slope at all speeds within a range

that is the greater of 15 percent of the trim speed plus the resulting

free return speed range, or 40 knots plus the resulting free return

speed range, above and below the trim speed, except that the slope need

not be stable--

(i) At speeds less than 1.3 VS1; or

(ii) For airplanes with VNE established under Sec. 23.1505(a),

at speeds greater than VNE; or

(iii) For airplanes with VMO/MMO established under

Sec. 23.1505(c), at speeds greater than VFC/MFC.

(2) For commuter category airplanes, the stick force curve must

have a stable slope at all speeds within a range of 50 knots plus the

resulting free return speed range, above and below the trim speed,

except that the slope need not be stable--

(i) At speeds less than 1.4 VS1; or

(ii) At speeds greater than VFC/MFC; or

(iii) At speeds that require a stick force greater than 50 pounds.

(c) Landing. The stick force curve must have a stable slope at

speeds between 1.1 VS1 and 1.8 VS1 with--

(1) Flaps in the landing position;

(2) Landing gear extended; and

(3) The airplane trimmed at--

(i) VREF, or the minimum trim speed if higher, with power off;

and

(ii) VREF with enough power to maintain a 3 degree angle of

descent.

32. Section 23.177 is revised to read as follows:

Sec. 23.177 Static directional and lateral stability.

(a) The static directional stability, as shown by the tendency to

recover from a wings level sideslip with the rudder free, must be

positive for any landing gear and flap position appropriate to the

takeoff, climb, cruise, approach, and landing configurations. This must

be shown with symmetrical power up to maximum continuous power, and at

speeds from 1.2 VS1 up to the maximum allowable speed for the

condition being investigated.

The angle of sideslip for these tests must be appropriate to the

type of airplane. At larger angles of sideslip, up to that at which

full rudder is used or a control force limit in Sec. 23.143 is reached,

whichever occurs first, and at speeds from 1.2 VS1 to VO, the

rudder pedal force must not reverse.

(b) The static lateral stability, as shown by the tendency to raise

the low wing in a sideslip, must be positive for all landing gear and

flap positions. This must be shown with symmetrical power up to 75

percent of maximum continuous power at speeds above 1.2 VS1 in the

takeoff configuration(s) and at speeds above 1.3 VS1 in other

configurations, up to the maximum allowable speed for the configuration

being investigated, in the takeoff, climb, cruise, and approach

configurations. For the landing configuration, the power must be up to

that necessary to maintain 3 degree angle of descent in coordinated

flight. The static lateral stability must not be negative at 1.2

VS1 in the takeoff configuration, or at 1.3 VS1 in other

configurations. The angle of sideslip for these tests must be

appropriate to the type of airplane, but in no case may the constant

heading sideslip angle be less than that obtainable with a 10 degree

bank, or if less, the maximum bank angle obtainable with full rudder

deflection or 150 pound rudder force.

(c) Paragraph (b) of this section does not apply to acrobatic

category airplanes certificated for inverted flight.

(d) In straight, steady slips at 1.2 VS1 for any landing gear

and flap positions, and for any symmetrical power conditions up to 50

percent of maximum continuous power, the aileron and rudder control

movements and forces must increase steadily, but not necessarily in

constant proportion, as the angle of sideslip is increased up to the

maximum appropriate to the type of airplane. At larger slip angles, up

to the angle at which full rudder or aileron control is used or a

control force limit contained in Sec. 23.143 is reached, the aileron

and rudder control movements and forces must not reverse as the angle

of sideslip is increased. Rapid entry into, and recovery from, a

maximum sideslip considered appropriate for the airplane must not

result in uncontrollable flight characteristics.

33. Section 23.201 is revised to read as follows:

Sec. 23.201 Wings level stall.

(a) It must be possible to produce and to correct roll by

unreversed use of the rolling control and to produce and to correct yaw

by unreversed use of the directional control, up to the time the

airplane stalls.

(b) The wings level stall characteristics must be demonstrated in

flight as follows. Starting from a speed at least 10 knots above the

stall speed, the elevator control must be pulled back so that the rate

of speed reduction will not exceed one knot per second until a stall is

produced, as shown by either:

(1) An uncontrollable downward pitching motion of the airplane; or

(2) A downward pitching motion of the airplane that results from

the activation of a stall avoidance device (for example, stick pusher);

or

(3) The control reaching the stop.

(c) Normal use of elevator control for recovery is allowed after

the downward pitching motion of (b)(1) or (b)(2) has unmistakably been

produced, or after the control has been held against the stop for not

less than the longer of two seconds or the time employed in the minimum

steady flight speed determination of Sec. 23.49.

(d) During the entry into and the recovery from the maneuver, it

must be possible to prevent more than 15 degrees of roll or yaw by the

normal use of controls.

(e) Compliance with the requirements of this section must be shown

under the following conditions:

(1) Wing flaps. Retracted, fully extended, and each intermediate

normal operating position.

(2) Landing gear. Retracted and extended.

(3) Cowl flaps. Appropriate to configuration.

(4) Power:

(i) Power off; and

(ii) 75 percent of maximum continuous power. However, if the power-

to-weight ratio at 75 percent of maximum continuous power results in

extreme nose-up attitudes, the test may be carried out with the power

required for level flight in the landing configuration at maximum

landing weight and a speed of 1.4 VSO, except that the power may

not be less than 50 percent of maximum continuous power.

(5) Trim. The airplane trimmed at a speed as near 1.5 VS1 as

practicable.

(6) Propeller. Full increase r.p.m. position for the power off

condition.

34. Section 23.203 is amended by revising the section heading and

introductory text, paragraph (a), the introductory text of paragraph

(b), paragraphs (b)(4) and (b)(5), the introductory text of paragraph

(c), and paragraphs (c)(1) and (c)(4), and by adding new paragraphs

(b)(6) and (c)(6) to read as follows:

Sec. 23.203 Turning flight and accelerated turning stalls.

Turning flight and accelerated turning stalls must be demonstrated

in tests as follows:

(a) Establish and maintain a coordinated turn in a 30 degree bank.

Reduce speed by steadily and progressively tightening the turn with the

elevator until the airplane is stalled, as defined in Sec. 23.201(b).

The rate of speed reduction must be constant, and--

(1) For a turning flight stall, may not exceed one knot per second;

and

(2) For an accelerated turning stall, be 3 to 5 knots per second

with steadily increasing normal acceleration.

(b) After the airplane has stalled, as defined in Sec. 23.201(b),

it must be possible to regain wings level flight by normal use of the

flight controls, but without increasing power and without--

* * * * *

(4) Exceeding a bank angle of 60 degrees in the original direction

of the turn or 30 degrees in the opposite direction in the case of

turning flight stalls;

(5) Exceeding a bank angle of 90 degrees in the original direction

of the turn or 60 degrees in the opposite direction in the case of

accelerated turning stalls; and

(6) Exceeding the maximum permissible speed or allowable limit load

factor.

(c) Compliance with the requirements of this section must be shown

under the following conditions:

(1) Wing flaps: Retracted, fully extended, and each intermediate

normal operating position;

* * * * *

(4) Power:

(i) Power off; and

(ii) 75 percent of maximum continuous power. However, if the power-

to-weight ratio at 75 percent of maximum continuous power results in

extreme nose-up attitudes, the test may be carried out with the power

required for level flight in the landing configuration at maximum

landing weight and a speed of 1.4 VSO, except that the power may

not be less than 50 percent of maximum continuous power.

* * * * *

(6) Propeller. Full increase r.p.m. position for the power off

condition.

Sec. 23.205 [Removed]

35. Section 23.205 is removed.

36. Section 23.207 is amended by revising paragraphs (c) and (d),

and by adding new paragraphs (e) and (f) to read as follows:

Sec. 23.207 Stall warning.

* * * * *

(c) During the stall tests required by Sec. 23,201(b) and

Sec. 23,203(a)(1), the stall warning must begin at a speed exceeding

the stalling speed by a margin of not less than 5 knots and must

continue until the stall occurs.

(d) When following the procedures furnished in accordance with

Sec. 23.1585, the stall warning must not occur during a takeoff with

all engines operating, a takeoff continued with one engine inoperative,

or during an approach to landing.

(e) During the stall tests required by Sec. 23.203(a)(2), the stall

warning must begin sufficiently in advance of the stall for the stall

to be averted by pilot action taken after the stall warning first

occurs.

(f) For acrobatic category airplanes, an artificial stall warning

may be mutable, provided that it is armed automatically during takeoff

and rearmed automatically in the approach configuration.

37. Section 23.221 is revised to read as follows:

Sec. 23.221 Spinning.

(a) Normal category airplanes. A single-engine, normal category

airplane must be able to recover from a one-turn spin or a three-second

spin, whichever takes longer, in not more than one additional turn

after initiation of the first control action for recovery, or

demonstrate compliance with the optional spin resistant requirements of

this section.

(1) The following apply to one turn or three second spins:

(i) For both the flaps-retracted and flaps-extended conditions, the

applicable airspeed limit and positive limit maneuvering load factor

must not be exceeded;

(ii) No control forces or characteristic encountered during the

spin or recovery may adversely affect prompt recovery;

(iii) It must be impossible to obtain unrecoverable spins with any

use of the flight or engine power controls either at the entry into or

during the spin; and

(iv) For the flaps-extended condition, the flaps may be retracted

during the recovery but not before rotation has ceased.

(2) At the applicant's option, the airplane may be demonstrated to

be spin resistant by the following:

(i) During the stall maneuver contained in Sec. 23.201, the pitch

control must be pulled back and held against the stop. Then, using

ailerons and rudders in the proper direction, it must be possible to

maintain wings-level flight within 15 degrees of bank and to roll the

airplane from a 30 degree bank in one direction to a 30 degree bank in

the other direction;

(ii) Reduce the airplane speed using pitch control at a rate of

approximately one knot per second until the pitch control reaches the

stop; then, with the pitch control pulled back and held against the

stop, apply full rudder control in a manner to promote spin entry for a

period of seven seconds or through a 360 degree heading change,

whichever occurs first. If the 360 degree heading change is reached

first, it must have taken no fewer than four seconds. This maneuver

must be performed first with the ailerons in the neutral position, and

then with the ailerons deflected opposite the direction of turn in the

most adverse manner. Power and airplane configuration must be set in

accordance with Sec. 23.201(e) without change during the maneuver. At

the end of seven seconds or a 360 degree heading change, the airplane

must respond immediately and normally to primary flight controls

applied to regain coordinated, unstalled flight without reversal of

control effect and without exceeding the temporary control forces

specified by Sec. 23.143(c); and

(iii) Compliance with Secs. 23.201 and 23.203 must be demonstrated

with the airplane in uncoordinated flight, corresponding to one ball

width displacement on a slip-skid indicator, unless one ball width

displacement cannot be obtained with full rudder, in which case the

demonstration must be with full rudder applied.

(b) Utility category airplanes. A utility category airplane must

meet the requirements of paragraph (a) of this section. In addition,

the requirements of paragraph (c) of this section and Sec. 23.807(b)(7)

must be met if approval for spinning is requested.

(c) Acrobatic category airplanes. An acrobatic category airplane

must meet the spin requirements of paragraph (a) of this section and

Sec. 23.807(b)(6). In addition, the following requirements must be met

in each configuration for which approval for spinning is requested:

(1) The airplane must recover from any point in a spin up to and

including six turns, or any greater number of turns for which

certification is requested, in not more than one and one-half

additional turns after initiation of the first control action for

recovery. However, beyond three turns, the spin may be discontinued if

spiral characteristics appear.

(2) The applicable airspeed limits and limit maneuvering load

factors must not be exceeded. For flaps-extended configurations for

which approval is requested, the flaps must not be retracted during the

recovery.

(3) It must be impossible to obtain unrecoverable spins with any

use of the flight or engine power controls either at the entry into or

during the spin.

(4) There must be no characteristics during the spin (such as

excessive rates of rotation or extreme oscillatory motion) that might

prevent a successful recovery due to disorientation or incapacitation

of the pilot.

38. Section 23.233 is amended by revising paragraph (a) to read as

follows:

Sec. 23.233 Directional stability and control.

(a) A 90 degree cross-component of wind velocity, demonstrated to

be safe for taxiing, takeoff, and landing must be established and must

be not less than 0.2 VSO.

* * * * *

39. Section 23.235 is revised to read as follows:

Sec. 23.235 Operation on unpaved surfaces.

The airplane must be demonstrated to have satisfactory

characteristics and the shock-absorbing mechanism must not damage the

structure of the airplane when the airplane is taxied on the roughest

ground that may reasonably be expected in normal operation and when

takeoffs and landings are performed on unpaved runways having the

roughest surface that may reasonably be expected in normal operation.

40. A new Sec. 23.237 is added to read as follows:

Sec. 23.237 Operation on water.

A wave height, demonstrated to be safe for operation, and any

necessary water handling procedures for seaplanes and amphibians must

be established.

Sec. 23.253 [Amended]

41. Section 23.253 is amended by removing paragraph (b)(1) and by

redesignating paragraphs (b)(2) and (b)(3) as paragraphs (b)(1) and

(b)(2).

42. Section 23.562 is amended by revising paragraph (d) to read as

follows:

Sec. 23.562 Emergency landing dynamic conditions.

* * * * *

(d) For all single-engine airplanes with a VSO of more than 61

knots at maximum weight, and those multiengine airplanes of 6,000

pounds or less maximum weight with a VSO of more than 61 knots at

maximum weight that do not comply with Sec. 23.67(a)(1);

* * * * *

43. Section 23.1325 is amended by revising paragraph (e) and

removing and reserving paragraph (f) to read as follows:

Sec. 23.1325 Static pressure system.

* * * * *

(e) Each static pressure system must be calibrated in flight to

determine the system error. The system error, in indicated pressure

altitude, at sea-level, with a standard atmosphere, excluding

instrument calibration error, may not exceed 30 feet per

100 knot speed for the appropriate configuration in the speed range

between 1.3 VSO with flaps extended, and 1.8 VS1 with flaps

retracted. However, the error need not be less than 30 feet.

* * * * *

44. Section 23.1511 is amended by revising paragraphs (a)(1) and

(a)(2) to read as follows:

Sec. 23.1511 Flap extended speed.

(a) * * *

(1) Not less than the minimum value of VF allowed in

Sec. 23.345(b); and

(2) Not more than VF e

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