Revision of Certain Flight Airworthiness Standards To Harmonize With European Airworthiness Standards for Transport Category Airplanes; Proposed Rule and Notice DEPARTMENT OF TRANSPORTATION

SUMMARY: The Federal Aviation Administration (FAA) proposes to amend

part 25 of the Federal Aviation Regulations (FAR) to harmonize certain

flight requirements with standards proposed for the European Joint

Aviation Requirements 25 (JAR-25). This action responds to a petition

from the Aerospace Industries Association of America, Inc. and the

Association Europeenne des Constructeurs de Materiel Aerospatial. These

changes are intended to benefit the public interest by standardizing

certain requirements, concepts, and procedures contained in the

airworthiness standards of the FAR and the JAR.

DATES: Comments must be received on or before July 21, 1994.

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

Federal Aviation Administration, Office of the Chief Counsel,

Attention: Rules Docket (AGC-10), Docket No. 27705, 800 Independence

Avenue SW., Washington, DC 20591; or delivered in triplicate to: Room

915G, 800 Independence Avenue SW., Washington, DC 20591. Comments

delivered must be marked Docket No. 27705. Comments may be examined in

room 915G weekdays, except Federal holidays, between 8:30 a.m. and 5

p.m. In addition, the FAA is maintaining an information docket of

comments in the Transport Airplane Directorate (ANM-100), Federal

Aviation Administration, Northwest Mountain Region, 1601 Lind Avenue

SW., Renton, WA 98055-4056. Comments in the information docket may be

examined weekdays, except Federal holidays, between 7:30 a.m. and 4

p.m.

FOR FURTHER INFORMATION CONTACT:

Donald K. Stimson, Flight Test and Systems Branch, ANM-111, Transport

Airplane Directorate, Aircraft Certification Service, FAA, 1601 Lind

Avenue SW., Renton, WA 98055-4056; telephone (206) 227-1129; facsimile

(206) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in this proposed

rulemaking by submitting such written data, views, or arguments as they

may desire. Comments relating to any environmental, energy, or economic

impact that might result from adopting the proposals contained in this

notice are invited. Substantive comments should be accompanied by cost

estimates. Commenters should identify the regulatory docket or notice

number and submit comments in triplicate to the Rules Docket address

above. All comments received on or before the 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 in the Rules Docket, both before and after the comment period

closing date, for examination by interested persons. A report

summarizing each substantive public contact with FAA personnel

concerning this rulemaking will be filed in the docket. Persons wishing

the FAA to acknowledge receipt of their comments must submit with those

comments a self-addressed, stamped postcard on which is stated:

``Comments to Docket No. 27705.'' The postcard will be date stamped and

returned to the commenter.

Availability of the NPRM

Any person may obtain a copy of this notice by submitting a request

to the Federal Aviation Administration (FAA), Office of Public Affairs,

Attention: Public Inquiry Center, APA-230, 800 Independence Avenue SW.,

Washington, DC 20591; or by calling (202) 267-3484. The notice number

of this NPRM must be identified in all communications. Persons

interested in being placed on a mailing list for future rulemaking

documents should also request a copy of Advisory Circular No. 11-2A,

Notice of Proposed Rulemaking Distribution System, which describes the

application procedure.

Background

Part 25 of the Federal Aviation Regulations (FAR) contains the

airworthiness standards for transport category airplanes. Manufacturers

of transport category airplanes must show that each airplane they

produce of a different type design complies with the relevant standards

of part 25. These standards apply to airplanes manufactured within the

U.S. for use by U.S.-registered operators and to airplanes manufactured

in other countries and imported under a bilateral airworthiness

agreement.

In Europe, the Joint Aviation Requirements (JAR) were developed by

the Joint Aviation Authorities (JAA) to provide a common set of

airworthiness standards for use within the European aviation community.

The airworthiness standards for European type certification of

transport category airplanes, JAR-25, are based on part 25 of the FAR.

Airplanes certificated to the JAR-25 standards, including airplanes

manufactured in the U.S. for export to Europe, receive type

certificates that are accepted by the aircraft certification

authorities of 23 European countries.

Although part 25 and JAR-25 are very similar, they are not

identical. Differences between the FAR and the JAR can result in

substantial additional costs when airplanes are type certificated to

both standards. These additional costs, however, do not always bring

about an increase in safety. For example, part 25 and JAR-25 may use

different means to accomplish the same safety intent. In this case, the

manufacturer is usually burdened with meeting both requirements,

although the level of safety is not increased correspondingly.

Recognizing that a common set of standards would not only economically

benefit the aviation industry, but would also maintain the necessary

high level of safety, the FAA and JAA consider harmonization to be a

high priority.

On May 22, 1990, the Aerospace Industries Association of America,

Inc. (AIA) and the Association Europeenne des Constructeurs de Materiel

Aerospatial (AECMA) jointly petitioned the FAA and JAA to harmonize

certain requirements contained in part 25 of the FAR and in JAR-25. In

their petition, a summary of which was published in the July 17, 1990,

edition of the Federal Register (55 FR 137), AIA and AECMA requested

changes to Secs. 25.143(c), 25.143(f), 25.149, and 25.201 to

standardize the requirements, concepts, and procedures for

certification flight testing and to enhance reciprocity between the FAA

and JAA. In addition, AIA and AECMA recommended changes to FAA Advisory

Circular (AC) 25-7, ``Flight Test Guide for Certification of Transport

Category Airplanes,'' to ensure that the harmonized standards would be

interpreted and applied consistently. A copy of that petition is

included in the docket for this rulemaking.

On September 26, 1991, the Aviation Rulemaking Advisory Committee

(ARAC) established the Flight Test Working Group, assigning it the task

of developing either a draft notice of proposed rulemaking (NPRM) or a

denial of the AIA/AECMA petition. If accepted by the ARAC, the draft

NPRM or petition denial would be delivered to the FAA as an advisory

committee recommendation.

The public notice establishing the Flight Test Working Group

appeared in the Federal Register on January 13, 1992 (57 FR 1297). The

Flight Test Working Group was later renamed the Flight Test

Harmonization Working Group and its scope was clarified to include

developing a similar proposal to amend JAR-25, as necessary, to achieve

harmonization.

The rulemaking proposal contained in this notice was developed by

the Flight Test Harmonization Working Group. It was presented to the

FAA by the ARAC as a recommended response to the AIA/AECMA petition.

Rather than proposing a simple acceptance or denial of the petition,

the working group used the petition as a starting point for developing

a rulemaking proposal that would accomplish the goal of harmonizing not

only the sections of part 25 and JAR-25 addressed in the petition, but

also related sections.

The Aviation Rulemaking Advisory Committee

The ARAC was formally established by the FAA on January 22, 1991

(56 FR 2190), to provide advice and recommendations concerning the full

range of the FAA's safety-related rulemaking activity. This advice was

sought to develop better rules in less overall time using fewer FAA

resources than are currently needed. The committee provides the

opportunity for the FAA to obtain firsthand information and insight

from interested parties regarding proposed new rules or revisions of

existing rules.

There are over 60 member organizations on the committee,

representing a wide range of interests within the aviation community.

Meetings of the committee are open to the public, except as authorized

by section 10(d) of the Federal Advisory Committee Act.

The ARAC establishes working groups to develop proposals to

recommend to the FAA for resolving specific issues. Tasks assigned to

working groups are published in the Federal Register. Although working

group meetings are not generally open to the public, all interested

parties are invited to participate as working group members. Working

groups report directly to the ARAC, and the ARAC must concur with a

working group proposal before that proposal can be presented to the FAA

as an advisory committee recommendation.

The activities of the ARAC will not, however, circumvent the public

rulemaking procedures. After an ARAC recommendation is received and

found acceptable by the FAA, the agency proceeds with the normal public

rulemaking procedures. Any ARAC participation in a rulemaking package

will be fully disclosed in the public docket.

Discussion of the Proposals

The FAA proposes amending certain sections of the FAR, as

recommended by the ARAC, to harmonize these sections with JAR-25. The

JAA intend to publish a Notice of Proposed Amendment (NPA), also

developed by the Flight Test Harmonization Working Group, to revise

JAR-25, as necessary, to ensure harmonization in those areas for which

the proposed amendments differ from the current JAR-25. When it is

published, the NPA will be placed in the docket for this rulemaking.

The FAA proposes to: (1) Introduce the term ``go-around power or

thrust setting'' to clarify certain part 25 flight requirements; (2)

revise the maximum control forces permitted for demonstrating

compliance with the controllability and maneuverability requirements;

(3) provide requirements for stick force and stick force gradient in

maneuvering flight; (4) revise and clarify the requirements defining

minimum control speed during approach and landing; (5) clarify the

procedural and airplane configuration requirements for demonstrating

stalls and revise the list of acceptable flight characteristics used to

define the occurrence of stall; and (6) require that stall

characteristics be demonstrated for turning flight stalls at

deceleration rates up to 3 knots per second.

Revisions are also proposed for AC 25-7 to ensure consistent

application of these proposed revised standards. Public comments

concerning the revisions to AC 25-7 are invited by separate notice

published elsewhere in this issue of the Federal Register.

Proposal 1

Certain part 25 flight requirements involving flight conditions

other than takeoff (i.e., Secs. 25.119, 25.121(d), 25.145(b)(3),

25.145(b)(4), 25.145(b)(5), 25.145(c)(1), 25.149(f)(6), and

25.149(g)(7)(ii)) specify using the maximum available takeoff power or

thrust as being representative of the appropriate maximum in-flight

power or thrust. In practice, however, the power or thrust setting used

to obtain the maximum in-flight power or thrust (commonly referred to

as the go-around power or thrust setting) usually differs from the

setting used for takeoff. In the past, the FAA interpreted the words

``maximum available takeoff power or thrust'' to mean the maximum in-

flight power or thrust, with the takeoff power or thrust setting not

always being ``available'' in flight. The FAA proposes changing the

nomenclature to ``go-around power or thrust setting'' for clarity and

to reflect terminology commonly used in the operational environment.

(In the context of this discussion, the term ``go-around'' refers to a

deliberate maneuver to abort a landing attempt prior to touchdown by

applying the maximum available power or thrust, retracting flaps, and

climbing to a safe level-off altitude).

(The go-around power or thrust setting may differ from the takeoff

power or thrust setting, for example, due to the airspeed difference

between the takeoff and go-around flight conditions. In addition,

complying with the powerplant limitations of Sec. 25.1521 may result in

a lower power setting at the higher airspeeds associated with a go-

around. As another example, the controllability requirements of

Secs. 25.145(b)(3), 25.145(b)(4), 25.145(b)(5), 25.149(f), and

25.149(g) may also limit the go-around power or thrust setting to less

than that used for takeoff. Another reason to separate the takeoff and

go-around power (or thrust) nomenclature is that certification practice

has not required, and applicants have not always proposed, changing the

go-around power or thrust setting when a previously approved takeoff

power or thrust is increased.

The FAA proposes to substitute the term ``go-around power or thrust

setting'' for ``maximum available takeoff power or thrust'' in

Secs. 25.119, 25.121(d), 25.145(b)(3), 25.145(b)(4), 25.145(c)(1),

25.149(f)(6), and 25.49(g)(7)(ii). (Note that the requirement of

Sec. 25.145(b)(5) also uses the power specified in Sec. 25.145(b)(4)).

In addition, the FAA proposes to define ``go-around power or thrust

setting'' in part 1 as ``the maximum allowable in-flight power or

thrust setting identified in the performance data.'' With this

revision, the FAA would clarify that the applicable controllability

requirements should be based on the same power or thrust setting used

to determine the approach and landing climb performance contained in

the approved Airplane Flight Manual (AFM).

The proposed terminology refers to a power or thrust ``setting''

rather than a power or thrust to make it clear that existing engine

ratings would be unaffected. The powerplant limitations of Sec. 25.1521

would continue to apply at the go-around power (or thrust) setting.

Existing certification practices would also remain the same, including

the relationship between the power or thrust values used to comply with

the landing and approach climb requirements of Secs. 25.119 and

25.121(d). For example, the thrust value used to comply with

Sec. 25.121(d) may be greater than that used for Sec. 25.119, if the

operating engine(s) do not reach the maximum allowable in-flight thrust

by the end of the eight second time period specified in Sec. 25.119.

Proposal 2

The FAA proposes to revise the table in Sec. 25.143(c) to match the

control force limits currently provided in JAR 25.143(c). This table

prescribes the maximum control forces for the controllability and

maneuverability flight testing required by Secs. 25.143(a) and

25.143(b). For transient application of the pitch and roll control, the

revised table would contain more restrictive maximum control force

limits for those maneuvers in which the pilot might be using one hand

to operate other controls, relative to those maneuvers in which both

hands are normally available for applying pitch and roll control. The

revised table would retain the current control force limits for

transient application of the yaw control, and for sustained application

of the pitch, roll, and yaw controls.

For maneuvers in which only one hand is assumed to be available,

the FAA proposes to reduce the maximum permissible control forces from

75 pounds to 50 pounds for pitch control, and from 60 pounds to 25

pounds for roll control. These lower control forces would be more

consistent with Sec. 25.145(b), which states that a force of 50 pounds

for longitudinal (pitch) control is ``representative of the maximum

temporary force that readily can be applied by one hand.'' In addition

to adding more restrictive control force limits for maneuvers in which

only one hand may be available to apply pitch and roll control, the FAA

proposes to reduce the maximum permissible force for roll control from

60 pounds to 50 pounds for maneuvers in which the pilot normally has

both hands available to operate the control.

The FAA proposes to further revise Sec. 25.143(c) by specifying

that the table of maximum permissible control forces applies only to

conventional wheel type controls. This restriction, also specified in

the current JAR 25.143(c), recognizes that different control force

limits may be necessary when considering sidestick controllers or other

types of control systems.

For clarification, the FAA proposes to replace the terms

``temporary'' and ``prolonged,'' used in Secs. 25.143(c), 25.143(d),

25.143(e), and 25.145(b), with ``transient'' and ``sustained,''

respectively. ``Transient'' forces refer to those control forces

resulting from maintaining the intended flight path during changes to

the airplane configuration, normal transitions from one flight

condition to another, or regaining control after a failure. The pilot

is assumed to take immediate action to reduce or eliminate these forces

by retrimming or by changing the airplane configuration or flight

condition. ``Sustained forces,'' on the other hand, refer to those

control forces resulting from normal or failure conditions that cannot

readily be trimmed out or eliminated. The FAA is proposing to add these

definitions of ``transient'' and ``sustained'' forces to AC 25-7.

In addition, the FAA proposes several minor editorial changes for

Secs. 25.143(c) through 25.143(e) to improve readability and correct

grammatical errors. For example, the words ``immediately preceding''

are proposed to replace ``next preceding'' in Sec. 25.143(d). These

editorial changes are intended to clarify the existing interpretation

of the affected sections.

Proposal 3

The FAA proposes to add the JAR 25.143(f) requirements regarding

control force characteristics during maneuvering flight to part 25 as a

new Sec. 25.143(f). By adding these requirements, the FAA would ensure

that the force to move the control column, or ``stick,'' must not be so

great as to make excessive demands on the pilot's strength when

maneuvering the airplane, and must not be so low that the airplane can

easily be overstressed inadvertently.

These harmonized requirements would apply up to the speed VFC/

MFC (the maximum speed for stability characteristics) rather than

the speed VMO/MMO (the maximum operating limit speed)

specified by the current JAR 25.143(f). Requiring these maneuvering

requirements to be met up to VFC/MFC is consistent with other

part 25 stability requirements. Section 25.253, which defines VFC/

MFC, would be revised to reference the use of this speed in the

proposed Sec. 25.143(f). An acceptable means of compliance with

Sec. 25.143(f), including detailed interpretations of the stick force

characteristics that meet these requirements, would be added to AC 25-

7.

Proposal 4

Section 25.149(f) requires that the minimum control speed be

determined assuming the critical engine suddenly fails during (or just

prior to) go-around from an all-engines-operating approach. For

airplanes with three or more engines, Sec. 25.149(g) requires the

minimum control speed to be determined for a one-engine-inoperative

landing approach in which a second critical engine suddenly fails. The

FAA proposes to revise Secs. 25.149(f) through 25.149(h) to clarify and

revise the criteria for establishing these minimum control speeds,

VMCL and VMCL-2, respectively, for use during approach and

landing.

The FAA proposes to clarify that VMCL and VMCL-2 apply

not only to the airplane's approach configuration(s), as prescribed in

the current standards, but also to the landing configuration(s). The

FAA recognizes that configuration changes occur during approach and

landing (e.g., flap setting and landing gear position) and considers

that the minimum control speeds provided in the AFM should ensure

airplane controllability, following a sudden engine failure, throughout

the approach and landing.

Applicants would have the option of determining VMCL and

VMCL-2 either for the most critical of the approach and landing

configurations (i.e., the configuration resulting in the highest

minimum control speed), or for each configuration used for approach or

for landing. By determining the minimum control speeds in the most

critical configuration, applicants would not be required to conduct any

additional testing to that already required by the current standards.

Only if these resulting speeds proved too constraining for other

configurations would the FAA expect applicants to exercise the option

of testing multiple configurations.

The FAA also proposes to add provisions to state the position of

the propeller, for propeller airplanes, when establishing these minimum

control speeds. For the critical engine that is suddenly made

inoperative, the propeller position must reflect the most critical mode

of powerplant failure with respect to controllability, as required by

Sec. 25.149(a). Also, since credit cannot be given for pilot action to

feather the propeller during this high flightcrew workload phase of

flight, the FAA proposes that VMCL and VMCL-2 be determined

with the propeller position of the most critical engine in the position

it automatically achieves. For VMCL-2, the engine that is already

inoperative before beginning the approach may be feathered, since the

pilot is expected to ensure the propeller is feathered before

initiating the approach.

To assure that airplanes have adequate lateral control capability

at VMCL and VMCL-2, the FAA proposes to require the airplane

to be capable of rolling, from an initial condition of steady straight

flight, through an angle of 20 degrees in not more than 5 seconds, in

the direction necessary to start a turn away from the inoperative

engine. This proposed addition to Sec. 25.149 is contained in the

current JAR 25.149.

The FAA is proposing guidance material for AC 25-7 to enable

applicants to additionally determine the appropriate minimum control

speeds for an approach and landing in which one engine, and, for

airplanes with three or more engines, two engines, are already

inoperative prior to beginning the approach. These speeds, VMCL(1

out) and VMCL-2(2 out), would be less restrictive than VMCL

and VMCL-2 because the pilot is assumed to have trimmed the

airplane for the approach with an inoperative engine (for VMCL(1

out)) or two inoperative engines (for VMCL-2(2 out)). Also, the

approach and landing procedures under these circumstances may use

different approach and landing flaps than for the situations defining

VMCL or VMCL-2. These additional speeds can be used as

guidance in determining the recommended procedures and speeds for a

one-engine-inoperative, or, in the case of an airplane with three or

more engines, a two-engine-inoperative approach and landing.

The FAA proposes to revise Sec. 25.125 to require the approach

speed used for determining the landing distance to be equal to or

greater than VMCL, the minimum control speed for approach and

landing with all-engines-operating. This provision would ensure that

the speeds used for normal landing approaches with all-engines-

operating would provide satisfactory controllability in the event of a

sudden engine failure during, or just prior to, a go-around.

Proposal 5

The FAA proposes to revise the stall demonstration requirements of

Sec. 25.201 to clarify the airplane configurations and procedures used

in flight tests to demonstrate stall speeds and stall handling

characteristics. The list of acceptable flight characteristics used to

define the occurrence of stall would also be revised. To be consistent

with current practice, Sec. 25.201(b)(1) would require that stall

demonstrations also be conducted with deceleration devices (e.g., speed

brakes) deployed. Additionally, the FAA proposes clarifying the intent

of Sec. 25.201(b) to cover normal, rather than failure, conditions by

requiring that stalls need only be demonstrated for the approved

configurations.

Section 25.201(c) would be revised to more accurately describe the

procedures used for demonstrating stall handling characteristics. The

cross-reference to Sec. 25.103(b), currently contained in

Sec. 25.201(c)(1), would be moved to a new Sec. 25.201(b)(4) for

editorial clarity and harmony with the JAR-25 format. Reference to the

pitch control reaching the aft stop, which would be interpreted as one

of the indications that the airplane has stalled, would be moved from

Sec. 25.201(c)(1) to Sec. 25.201(d)(3).

The list of acceptable flight characteristics that define the

occurrence of a stall, used during the flight tests demonstrating

compliance with the stall requirements, is provided in Sec. 25.201(d).

The FAA proposes to revise this list to conform with current practices.

Section 25.201(d)(1)(ii) would be removed to clarify that a rolling

motion, occurring by itself, is not considered an acceptable flight

characteristic for defining the occurrence of a stall. The proposed

Sec. 25.201(d)(2) would replace the criteria of Secs. 25.201(d)(1)(iii)

and 25.201(d)(2) because only deterrent buffeting (i.e., a distinctive

shaking of the airplane that is a strong and effective deterrent to

further speed reduction) is considered to comply with those criteria.

Finally, the proposed Sec. 25.201(d)(3) would define as a stall a

condition in which the airplane does not continue to pitch up after the

pitch control has been pulled back as far as it will go and held there

for a short period of time. Guidance material would be added to AC 25-7

to define the length of time that the control stick must be held in

this full aft position when using Sec. 25.201(d)(3) to define a stall.

Proposal 6

Section 25.201 currently requires stalls to be demonstrated at

airspeed deceleration rates (i.e., entry rates) not exceeding one knot

per second. JAR 25.201 currently requires, in addition, that turning

flight stalls must also be demonstrated at accelerated rates of entry

into the stall (i.e., dynamic stalls). According to the JAA, the

intended procedure for demonstrating dynamic stalls begins with a 1

knot per second deceleration from the trim speed (similar to normal

stalls). Then, approximately halfway between the trim speed and the

stall warning speed, the flight test pilot applies the elevator control

to achieve an increase in the rate of change of angle-of-attack. The

final angle-of-attack rate and the control input to achieve it should

be appropriate to the type of airplane and its particular control

characteristics.

The AIA/AECMA petition detailed various difficulties with

interpretation of the JAR-25 requirement, noted that the requirement is

not contained in the FAR, and proposed that dynamic stalls be removed

from JAR-25. Some of the concerns with the JAR-25 dynamic stall

requirement include: (1) A significant number of flight test

demonstrations for compliance used inappropriate piloting techniques

considering the capabilities of transport category airplanes; (2) the

stated test procedures depend, to a large extent, on pilot

interpretation, resulting in test demonstrations that could vary

significantly for different test pilots; (3) the safety objective of

the requirement is not well understood within the aviation community;

and (4) the flight test procedures that are provided are inconsistent

with the flight characteristics being evaluated. As a result,

applicants are unable to ensure that their designs will comply with the

JAR-25 dynamic stall requirement prior to the certification flight

test.

In practice, FAA certification testing has typically included stall

demonstrations at entry rates higher than 1 knot per second. For

airplanes with certain special features, such as systems designed to

prevent a stall or that are needed to provide an acceptable stall

indication, higher entry rates are demonstrated to show that the system

will continue to safely perform its intended function under such

conditions. These higher entry rate stalls are different, however, from

the JAR-25 dynamic stalls.

Rather than simply deleting the dynamic stall requirement from JAR-

25, or adding this requirement to part 25 of the FAR, the ARAC

recommended harmonizing the two standards by requiring turning flight

stalls be demonstrated at steady airspeed deceleration rates up to 3

knots per second. The FAA agrees with this recommendation and proposes

to add the requirement for a higher entry rate stall demonstration to

part 25 as Sec. 25.201(c)(2). The current Sec. 25.201(c)(2) would be

redesignated Sec. 25.201(c)(3). The JAA is proposing to replace the

JAR-25 dynamic stall requirement with the ARAC recommendation.

The proposed higher entry rate stall demonstration is a controlled

and repeatable maneuver that meets the objective of evaluating stall

characteristics over a range of entry conditions that might reasonably

be encountered by transport category airplanes in operational service.

Some degradation in characteristics would be accepted at the higher

entry rates, as long as it does not present a major threat to recovery

from the point at which the pilot has recognized the stall. Guidance

material is being proposed for AC 25-7 to point out that the specified

deceleration rate, and associated rate of increase in angle of attack,

should be established from the trim speed specified in

Sec. 25.103(b)(1) and maintained up to the point at which the airplane

stalls.

The FAA proposes to revise Sec. 25.203(c) to specify a bank angle

that must not be exceeded during the recovery from the turning flight

stall demonstrations. Currently, Sec. 25.203(c) provides only a

qualitative statement that a prompt recovery must be easily attainable

using normal piloting skill. By specifying a maximum bank angle limit,

the FAA proposes to augment this qualitative requirement with a

quantitative one.

For deceleration rates up to 1 knot per second, the maximum bank

angle would be approximately 60 degrees in the original direction of

the turn, or 30 degrees in the opposite direction. These bank angle

limits are currently contained in JAR-25 guidance material, and have

been used informally during FAA certification programs as well. For

deceleration rates higher than 1 knot per second, the FAA proposes to

allow a greater maximum bank angle--approximately 90 degrees in the

original direction of the turn, or 60 degrees in the opposite

direction. These are the same acceptance criteria currently used by the

JAA to evaluate dynamic stall demonstrations.

In addition to the amendments to part 25 proposed in this notice,

revisions to AC 25-7 are being proposed to ensure that the harmonized

standards would be interpreted and applied consistently. AC 25-7

provides guidelines that the FAA has found acceptable regarding flight

testing transport category airplanes to demonstrate compliance with the

applicable airworthiness requirements. Public comments concerning the

proposed revisions to AC 25-7 are invited by separate notice published

elsewhere in this issue of the Federal Register.

Regulatory Evaluation Summary

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 effect of the 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.

Cost Benefit Analysis

Three of the proposed 48 revisions to the flight test airworthiness

standards of part 25 would require additional flight testing and

engineering analysis, resulting in compliance costs of $18,500 per type

certification. When amortized over a representative production run of

500 airplanes, this total cost would result in a negligible incremental

cost of $37 per airplane. The FAA solicits comments concerning the

incremental flight test certification costs attributable to the

proposed rule.

The primary benefits of the proposed rule would be harmonization of

flight test airworthiness standards with the European Joint Aviation

Requirements and clarification of existing standards. The resulting

increased uniformity of flight test standards would simplify

airworthiness approval for import and export purposes and would avoid

some of the costs that can result when manufacturers seek type

certification under both sets of standards. While not readily

quantifiable, the potential cost avoidance would exceed the relatively

minor incremental costs of the proposed rule.

The proposed rule would provide additional benefits by updating

certain airworthiness standards. These updated standards would adopt

terminology commonly used in airplane operations as well as better

reflect current flight test practices.

Regulatory Flexibility Determination

The Regulatory Flexibility Act of 1980 (RFA) was enacted by

Congress to ensure that small entities are not unnecessarily or

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.

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 testing standards have been harmonized with those

of foreign aviation authorities, thereby lessening restraints on trade.

Federalism Implications

The amended regulations proposed in this rulemaking 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

preparing a Federalism Assessment.

Conclusion

Because the proposed changes to standardize specific flight

requirements of part 25 of the FAR are not expected to result in

substantial economic cost, the FAA has determined that this proposed

regulation would not be significant under Executive Order 12866.

Because this is an issue which has not prompted a great deal of public

concern, the FAA has determined that this action is not significant

under DOT Regulatory Policies and Procedures (44 FR 11034, February 25,

1979). In addition since there are no small entities affected by this

proposed rulemaking, the FAA certifies, under the criteria of the

Regulatory Flexibility Act, that this rule, if adopted, will not have a

significant economic impact, positive or negative, on a substantial

number of small entities. An initial regulatory evaluation of the

proposal, including a Regulatory Flexibility Determination and Trade

Impact Analysis, 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 25

Aircraft, Aviation safety, Reporting and recordkeeping

requirements.

The Proposed Amendments

Accordingly, the Federal Aviation Administration (FAA) proposed to

amend 14 CFR parts 1 and 25 of the Federal Aviation Regulations (FAR)

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), and 49 U.S.C. 106(g).

2. Section 1.1 is amended by adding a new definition to read as

follows:

Sec. 1.1 General definitions.

* * * * *

``Go-around power or thrust setting'' means the maximum allowable

in-flight power or thrust setting identified in the performance data.

* * * * *

PART 25--AIRWORTHINESS STANDARDS--TRANSPORT CATEGORY AIRPLANES

3. The authority citation for part 25 continues to read as follows:

Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1424,

1425, 1428, 1429, 1430; 49 U.S.C. 106(g); and 49 CFR 1.47(a).

4. Section 25.119 is amended by revising paragraph (a) to read as

follows:

Sec. 25.119 Landing climb: All-engines-operating.

* * * * *

(a) The engines at the power or thrust that is available eight

seconds after initiation of movement of the power or thrust controls

from minimum flight idle to the go-around power or thrust setting; and

* * * * *

5. Section 25.121 is amended by revising paragraph (d)(1) to read

as follows:

Sec. 25.121 Climb: One-engine-inoperative.

* * * * *

(d) * * *

(1) The critical engine inoperative, the remaining engines at the

go-around power or thrust setting;

* * * * *

6. Section 25.125 is amended by revising paragraph (a)(2) to read

as follows:

Sec. 25.125 Landing.

* * * * *

(a) * * *

(2) A stabilized approach, with a calibrated airspeed of not less

than 1.3 VS or VMCL, must be maintained down to the 50 foot

height.

* * * * *

7. Section 25.143 is amended by revising paragraphs (c), (d), and

(e) and adding a new paragraph (f) to read as follows:

Sec. 25.143 General.

* * * * *

(c) The following table prescribes, for conventional wheel type

controls, the maximum control forces permitted during the testing

required by paragraphs (a) and (b) of this section:

------------------------------------------------------------------------

Force, in pounds, applied to the control wheel

or rudder pedals Pitch Roll Yaw

------------------------------------------------------------------------

For transient application for pitch and roll

control--two hands available for control....... 75 50

For transient application for pitch and roll

control--one hand available for control........ 50 25

For transient application for yaw control....... ....... ...... 150

For sustained application....................... 10 5 20

------------------------------------------------------------------------

(d) Approved operating procedures or conventional operating

practices must be followed when demonstrating compliance with the

control force limitations for transient application that are prescribed

in paragraph (c) of this section. The airplane must be in trim, or as

near to being in trim as practical, in the immediately preceding steady

flight condition. For the takeoff condition, the airplane must be

trimmed according to the approved operating procedures.

(e) When demonstrating compliance with the control force

limitations for sustained application that are prescribed in paragraph

(c) of this section, the airplane must be in trim, or as near to being

in trim as practical.

(f) When maneuvering at a constant airspeed or Mach number (up to

VFC/MFC), the stick forces and the gradient of the stick

force versus maneuvering load factor must lie within satisfactory

limits. The stick forces must not be so great as to make excessive

demands on the pilot's strength when maneuvering the airplane, and must

not be so low that the airplane can easily be overstressed

inadvertently. Changes of gradient that occur with changes of load

factor must not cause undue difficulty in maintaining control of the

airplane, and local gradients must not be so low as to result in a

danger of overcontrolling.

8. Section 25.145 is amended by revising the introductory text of

paragraph (b), and paragraphs (b)(3), (b)(4), and (c)(1) to read as

follows:

Sec. 25.145 Longitudinal control.

* * * * *

(b) With the landing gear extended, no change in trim control, or

exertion of more than 50 pounds control force (representative of the

maximum transient force that can be applied readily by one hand) may be

required for the following maneuvers:

* * * * *

(3) Repeat paragraph (b)(2) except at the go-around power or thrust

setting.

(4) With power off, flaps retracted, and the airplane trimmed at

1.4 VS2, rapidly set go-around power or thrust while maintaining

the same airspeed.

(4) WITH POWER OFF, FLAPS RETRACTED, AND THE AIRPLANE TRIMMED AT

1.4 VS1, RAPIDLY SET GO-AROUND POWER OR THRUST WHILE

MAINTAINING THE SAME AIRSPEED.

* * * * *

(c) * * *

(1) Simultaneous movement of the power or thrust controls to the

go-around power or thrust setting;

* * * * *

9. Section 25.149 is amended by revising paragraphs (f), (g) and

(h) to read as follows:

Sec. 25.149 Minimum Control Speed.

* * * * *

(f) VMCL, the minimum control speed during approach and

landing with all engines operating, 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 maintain straight flight with an angle of bank of not

more than 5 degrees. VMCL must be established with--

(1) The airplane in the most critical configuration (or, at the

option of the applicant, each configuration) for approach and landing

with all engines operating;

(2) The most unfavorable center of gravity;

(3) The airplane trimmed for approach with all engines operating;

(4) The most unfavorable weight, or, at the option of the

applicant, as a function of weight;

(5) The propeller of the inoperative engine, if applicable, in the

position it automatically achieves; and

(6) Go-around power or thrust setting on the operating engine(s).

(g) For airplanes with three or more engines, VMCL-2, the

minimum control speed during approach and landing with one critical

engine inoperative, is the calibrated airspeed at which, when a second

critical engine is suddenly made inoperative, it is possible to

maintain control of the airplane with both engines still inoperative,

and maintain straight flight with an angle of bank of not more than 5

degrees. VMCL-2 must be established with--

(1) The airplane in the most critical configuration (or, at the

option of the applicant, each configuration) for approach and landing

with one critical engine inoperative;

(2) The most unfavorable center of gravity;

(3) The airplane trimmed for approach with one critical engine

inoperative;

(4) The most unfavorable weight, or, at the option of the

applicant, as a function of weight;

(5) If applicable, the propeller of the more critical engine in the

position it automatically achieves and the propeller of the other

inoperative engine feathered;

(6) The power or thrust on the operating engine(s) necessary to

maintain an approach path angle of 3 degrees when one critical engine

is inoperative; and

(7) The power or thrust on the operating engine(s) rapidly changed,

immediately after the second critical engine is made inoperative, from

the power or thrust prescribed in paragraph (g)(6) of this section to--

(i) Minimum power or thrust; and

(ii) Go-around power or thrust setting.

(h) In demonstrations of VMCL and VMCL-2--

(1) The rudder force may not exceed 150 pounds;

(2) The airplane may not exhibit hazardous flight characteristics

or require exceptional piloting skill, alertness, or strength;

(3) Lateral control must be sufficient to roll the airplane, from

an initial condition of steady straight flight, through an angle of 20

degrees in the direction necessary to initiate a turn away from the

inoperative engine(s), in not more than 5 seconds; and

(4) For propeller airplanes, hazardous flight characteristics must

not be exhibited due to any propeller position achieved when the engine

fails or during any likely subsequent movements of the engine or

propeller controls.

10. Section 25.201 is amended by revising paragraphs (b), (c), and

(d) to read as follows:

Sec. 25.201 Stall demonstration.

* * * * *

(b) In each condition required by paragraph (a) of this section, it

must be possible to meet the applicable requirements of Sec. 25.203

with--

(1) Flaps, landing gear, and deceleration devices in any likely

combination of positions approved for operation;

(2) Representative weights within the range for which certification

is requested;

(3) The most adverse center of gravity for recovery; and

(4) The airplane trimmed for straight flight at the speed

prescribed in Sec. 25.103(b)(1).

(c) The following procedures must be used to show compliance with

Sec. 25.203:

(1) Starting at a speed sufficiently above the stalling speed to

ensure that a steady rate of speed reduction can be established, apply

the longitudinal control so that the speed reduction does not exceed

one knot per second until the airplane is stalled.

(2) In addition, for turning flight stalls, apply the longitudinal

control to achieve airspeed deceleration rates up to 3 knots per

second.

(3) As soon as the airplane is stalled, recover by normal recovery

techniques.

(d) The airplane is considered stalled when the behavior of the

airplane gives the pilot a clear and distinctive indication of an

acceptable nature that the airplane is stalled. Acceptable indications

of a stall, occurring either individually or in combination, are--

(1) A nose-down pitch that cannot be readily arrested, which may be

accompanied by a rolling motion that is not immediately controllable

(provided that the rolling motion complies with Sec. 25.203 (b) or (c)

as appropriate);

(2) Buffeting, of a magnitude and severity that is a strong and

effective deterrent to further speed reduction; or

(3) The pitch control reaches the aft stop and no further increase

in pitch attitude occurs when the control is held full aft for a short

time before recovery is initiated.

11. Section 25.203 is amended by revising paragraph (c) to read as

follows:

Sec. 25.203 Stall characteristics.

* * * * *

(c) For turning flight stalls, the action of the airplane after the

stall may not be so violent or extreme as to make it difficult, with

normal piloting skill, to effect a prompt recovery and to regain

control of the airplane. The maximum bank angle that occurs during the

recovery may not exceed--

(1) Approximately 60 degrees in the original direction of the turn,

or 30 degrees in the opposite direction, for deceleration rates up to 1

knot per second; and

(2) Approximately 90 degrees in the original direction of the turn,

or 60 degrees in the opposite direction, for deceleration rates in

excess of 1 knot per second.

12. Section 25.253 is amended by revising paragraph (b) to read as

follows:

Sec. 25.253 High-speed characteristics.

* * * * *

(b) Maximum speed for stability characteristics, VFC/MCF.

VFC/MFC is the maximum speed at which the requirements of

Secs. 25.143(f), 25.147(e), 25.175(b)(1), 25.177, and 25.181 must be

met with flaps and landing gear retracted. It may not be less than a

speed midway between VMO/MMO and VDF/MDF, except

that, for altitudes where Mach number is the limiting factor, MFC

need not exceed the Mach number at which effective speed warning

occurs.

Issued in Washington, DC, on April 11, 1994.

Thomas E. McSweeny,

Director, Aircraft Certification Service.

[FR Doc. 94-9758 Filed 4-21-94; 8:45 am]

BILLING CODE 4910-13-M