Rotorcraft Regulatory Changes Based on European Joint Airworthiness Requirements Proposals

SUMMARY: This notice proposes changes to the type certification

requirements for both normal and transport category rotorcraft. The

changes would revise airworthiness standards for performance, systems,

propulsion, and airframes. The changes would increase the regulatory

safety level, clarify existing regulations, and standardize

terminology. The changes are based on standards that are being

incorporated by the European Joint Aviation Authorities for the Joint

Aviation Requirements (JAR) 27 and 29. These proposed changes are

intended to harmonize the Federal Aviation Regulations rotorcraft type

certification requirements and the European JAR.

DATES: Comments must be received on or before March 28, 1995.

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

Federal Aviation Administration (FAA), Office of the Chief Counsel,

Attention: Rules Docket (AGC-10), Docket No. 28008; 800 Independence

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

Docket No. 28008. Comments may be examined in Room 915G weekdays

between 9 a.m. and 5 p.m., except on Federal holidays.

FOR FURTHER INFORMATION CONTACT: Mr. Carroll Wright, Rotorcraft

Directorate, Aircraft Certification Service, Regulations Group, ASW-

111, FAA, Fort Worth, Texas 76193-0111, telephone number (817) 222-

5120.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to submit written data, views, or

arguments on this proposed rule. Comments relating to the

environmental, energy, federalism, 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 number and be submitted in

triplicate to the address specified under the caption ADDRESSES. All

comments received on or before the closing date for comments will be

considered before taking action on this proposed rule. The proposals

contained in this notice may be changed in light of the 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

substantive public contact with FAA personnel concerned with this

rulemaking 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 on Docket No. 28008.'' The

postcard will be date stamped and mailed to the commenter.

Availability of NPRM's

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

to the FAA, 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 a mailing list for future

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

No. 11-2A, NPRM Distribution System, which describes the application

procedure.

Background

At a meeting between FAA representatives and the European

Airworthiness Authorities Steering Committee (AASC) in Washington, DC,

in April 1983, the aviation manufacturing industry requested that the

certification rules of Europe and the United States be standardized.

The AASC agreed to provide the FAA with a comprehensive list of

recommended changes for the regulations in part 29 of Title 14 of the

Code of Federal Regulations (CFR). These changes would make part 29

acceptable to AASC members for adoption as airworthiness standards. The

AASC subsequently established a Joint Aviation Requirements (JAR) 29

group to develop transport category rotorcraft airworthiness standards

for the issuance of European type certificates. The JAR 29 group was

tasked with providing a list of recommended changes for part 29. The

FAA solicited comments on key issues. The initial responses to that

solicitation were published in the Federal Register (49 FR 19309, May

7, 1984). On September 15, 1984, the AASC submitted a more

comprehensive list of 92 suggested changes to part 29. An FAA review

found that 34 of these proposals had either been incorporated, in whole

or in part, in part 29 or were being considered in active rulemaking

projects. Of the 58 proposals remaining, 25 were rejected for various

reasons involving failure to meet Executive Order or Department of

Transportation rulemaking requirements. The FAA provided the results of

the review to the JAR 29 group including a summary of the status of the

proposals being considered in active rulemaking projects.

During further review of the remaining AASC proposals not included

in existing rulemaking projects, the FAA determined that several of the

proposals warranted public discussion. Accordingly, the FAA held a

public meeting in Fort Worth, Texas, May 1-2, 1986 (51 FR 4504,

February 5, 1986). Over 50 persons attended the meeting, which remained

in session until each proposal not already in rulemaking had been

discussed. The FAA subsequently issued NPRM No. 89-10 (54 FR 17396;

April 25, 1989), which addressed the AASC proposals and resulted in the

issuance of Amendments 27-27 and 29-31 (55 FR 38964; September 21,

1990).

The AASC activities were absorbed by the Joint Aviation Authorities

(JAA), and the JAA established the Helicopter Airworthiness Study Group

(HASG) to formulate JAR 27 and 29 for use by the 19 JAA countries. The

JAA invited the FAA and industry groups to participate in HASG meetings

on March 20-21, 1990. Members of Association Europeene des

Constructeurs de Materiel Aerospatial (AECMA) represented the European

manufacturers at the HASG Meetings, and AECMA invited members of the

Aerospace Industries Association of America (AIA) to represent U.S.

manufacturers. The HASG was chartered to formulate JAR 29, and

subsequently JAR 27, to parallel as closely as possible part 29 as

amended through Amendment 29-31 effective September 21, 1990, and part

27 as amended through Amendment 27-27 effective September 21, 1990. The

JAR 29 includes FAA NPRM's 89-26 (54 FR 39086, September 22, 1989)

which proposes a new 30 second/2 minute One Engine Inoperative power

rating, 89-29 (54 FR 42716, October 17, 1989) which proposes rotorburst

protection, 90-1 (55 FR 698, January 8, 1990) which proposes new

performance requirements, and 90-24 (55 FR 41000, October 5, 1990)

which proposes a Crash Resistant Fuel System; JAR 27 is to also include

NPRM's 89-26 and 90-24.

Aviation Rulemaking Advisory Committee (ARAC) Considerations

By announcement in the Federal Register (57 FR 58846, December 11,

1992), the JAR-FAR 27 and 29 Harmonization Working Group was chartered

by the ARAC. The working group included representatives from four major

rotorcraft manufacturers (normal and transport) and representatives

from AIA, AECMA, Helicopter Association International (HAI), JAA, and

the FAA Rotorcraft Directorate. This broad participation is consistent

with FAA policy to have all known interested parties involved as early

as practicable in the rulemaking process.

The Harmonization Working Group was tasked with making

recommendations to the ARAC concerning the FAA acceptance or rejection

of JAA Notice of Proposed Amendments (NPA's) recently coordinated

between the JAA and the FAA. The ARAC subsequently recommended that the

FAA revise the certification standards for normal and transport

category rotorcraft as now contained in JAR 27 and 29.

FAA Evaluations of ARAC and JAA Proposals

The FAA has evaluated the ARAC recommendations and proposes changes

to the rotorcraft certification rules in both parts 27 and 29. These

proposed changes have evolved from the FAA-JAA industry meetings of

1990-1992 and the ARAC recommendations of 1993. These proposed changes

would (1) incorporate current design and testing practices into the

rules by requiring additional performance data, additional powerplant

and rotor brake controls, and bird-strike protection, and (2) harmonize

the certification requirements between Title 14 and the JAR. The

proposals for part 27 include JAA's harmonized NPA's 27-basic and 27-1;

and the proposals for part 29 include NPA's 29-basic and 29-1 through

29-5. All sections of the harmonized NPA's are included in these

proposals except for Sec. 27.602 of NPA 27-basic and Sec. 29.602 of NPA

29-4. Those JAR sections include a critical parts plan that would

control the design, substantiation, manufacture, maintenance, and

modification of critical parts. While the JAA prescribes manufacturing

and maintenance requirements in JAR 29, the FAA does not do the same in

part 29. Part 21 of Title 14 addresses manufacturing requirements; part

43 of Title 14 prescribes maintenance requirements. Part 29 contains

the airworthiness requirements for rotorcraft certification; part 29

addresses maintenance standards only to the extent that it mandates

that the type certificate holder prepare Instructions for Continued

Airworthiness, which includes the maintenance manual or section and

maintenance instructions, and the Airworthiness Limitations section.

Accordingly, the FAA may propose critical parts requirements in a

separate rulemaking, which may also propose changes to parts 21 and 43.

General Discussion of the Proposals

These proposals would introduce safety improvements, clarify

existing regulations, and standardize terminology with the JAR's by

revising the airworthiness standards for rotorcraft performance,

systems, propulsion, and airframes. These proposed changes are based on

requirements that have been adopted by JAA for JAR 27 and 29. The part

27 proposals would require all-engines-operating (AEO) climb

performance data, powerplant controls to maintain any set position, and

rotor brake control standards. The proposals would also provide an

option for the certification of part 27 rotorcraft to Category A; i.e.,

one engine inoperative (OEI) requirements. The part 29 proposals would

provide standards for electrical bonding of airframe components to

protect against lightning and precipitation static discharge, a design

assessment of rotors and drive train, and bird-strike protection.

Additional powerplant instruments are proposed. The part 29 proposals

would also clarify performance requirements for Category A, flutter and

divergence applicability, and emergency electrical power supply

requirements.

Discussion of Specific Proposals

Section 27.1 Applicability

Proposed new Sec. 27.1(c) would provide an optional basis for

normal category multiengine rotorcraft to be certificated to Category A

requirements by meeting those design and performance requirements of

part 29 as specified in a new appendix C to part 27.

Section 27.65 Climb: all engines operating

This proposed revision of Sec. 27.65(b)(2) would require a

determination of AEO climb performance for all rotorcraft. Currently

rotorcraft AEO climb performance is required only for ambient

conditions where the never-exceed speed (Vne) is less than the

speed for the best rate of climb (Vy). Climb performance

information is necessary for operational planning for rotorcraft, e.g.,

planning for obstacle clearance. Manufacturers have historically

provided this information even though it is not required by the

existing regulations. This change would incorporate that current

practice as a requirement in the FAR.

Section 27.1141 Powerplant controls: general

This proposed new Sec. 27.1141(d) would add to part 27 the

requirement of Sec. 29.1141(d) that powerplant controls must maintain

any set position. The proposed requirement states that each control

``must be able to maintain any set position without constant attention

or tendency to creep due to control loads or vibration.'' ``Must be

able to,'' in this regard, would require that the rotorcraft have

identifiable design features that keep the controls from moving. This

requirement would improve safety by reducing pilot work load for part

27 rotorcraft. Because most rotorcraft manufacturers already comply

voluntarily with this standard, this should require no significant

design or manufacturing effort.

Section 27.1151 Rotor brake controls

This proposed new section would add to part 27 the requirements of

Sec. 29.1151 on rotor brake controls. These proposed requirements are

necessary for the safe operation of any rotorcraft equipped with a

rotor brake. Requirements to prevent inadvertent application of rotor

brakes in flight are necessary to prevent possible damage or fire due

to rotor brake application. Current rotorcraft rotor brake

installations normally incorporate these design features; no

significant design or manufacturing effort should be necessary.

Appendix C to Part 27

This proposed new appendix would provide a list of part 29 Category

A standards that are directly related to the continued safe powered

flight capability of a multiengine rotorcraft in the event of engine or

other system failure. The proposed standards would be required to be

met for an optional Category A approval for a part 27 rotorcraft.

Section 29.547 Main and tail rotor structures

Proposed new Sec. 29.547(b) would require a design assessment that

identifies the critical components of the main and tail rotor

structures. The design assessment must also identify the means (such as

scheduled inspection, removal, and replacement of components) that

minimize the likelihood of failure for each critical component.

Section 29.610 Lightning and static electricity protection

The word ``structure'' would be added to current Sec. 29.610(a) to

clarify that these requirements address the rotorcraft structure and

not equipment, systems, and installations that are adequately covered

under the requirements of Sec. 29.1309. The proposed addition of the

word ``structure'' to paragraph (a) is intended to clarify that the

metallic components and nonmetallic components of paragraphs (b) and

(c) are structural components. Proposed new paragraph (d) would require

electrical bonding of the rotorcraft components for protection against

hazardous effects from lightning and discharge of static electricity.

In this regard, the reference to the bonding and protection ``be[ing]

such as to'' would require that the rotorcraft have identifiable design

features that achieve the standards required in paragraphs (d) (1)

through (4). Part 29 does not currently provide electrical bonding

requirements, and experience has shown that inadequate bonding can

result in hazardous conditions due to discharge of static electricity.

The proposed new paragraph (d)(4) would require electrical bonding and

protection against lightning and static electricity that would reduce

the effects on the functioning of essential electrical and electronic

equipment to an acceptable level (as determined by Secs. 29.1309 and

29.1431).

Section 29.629 Flutter and divergence

This proposed revision of Sec. 29.629 would add the words ``and

divergence'' to the title and text of the section. This proposal would

extend the requirements to cover aeroelastic instability other than

flutter of aerodynamic surfaces. This proposal would require the use of

rational analysis, tests, or a combination of analysis and tests to

demonstrate freedom from aeroelastic instability for the basic design.

Most manufacturers currently do this type of analysis or test; this

change would require formal documentation and approval of that analysis

or test.

Section 29.631 Bird strike

This proposed new section would require bird-strike protection for

transport rotorcraft. Rotorcraft, as well as airplanes, are exposed to

the possibility of collision with a bird. With the potential for higher

speeds by modern transport rotorcraft designs and the changes in

material technology, the possibility of increased damage from bird

strikes exists. In addition, the effects of bird strikes on new

materials used in rotorcraft must be evaluated. The FAA has determined

that a requirement for protection against catastrophic effects from

impact with a 2.2 pound (1 kilogram) bird is reasonable for rotorcraft

certificated in the transport category (part 29). A 2.2 pound bird

represents the typical size for intended structural capability;

therefore, such protection is being proposed. Proposed Sec. 29.631

would require that the rotorcraft be designed to assure capability of

continued safe flight and landing (for Category A) or safe landing (for

Category B) after bird strike. In this regard, ``capability'' means

that the design has features that assure continued safe flight and/or

landing, as would be required. Proposed Sec. 29.631 would also require

that substantiation of the design be based on tests or analysis of

tests carried out on sufficiently representative structures of design

similar to that of the design to be approved. In this regard,

``sufficiently'' means that the structures at least represent the

design to be approved.

Section 29.917 Design

A new Sec. 29.917(b) is proposed for this section, and

redesignation of existing paragraph (b) as (c) is proposed. This

proposed new Sec. 29.917(b) would require a design assessment that

identifies critical components of the rotor drive system. The design

assessment would also identify the means that minimize the likelihood

of failure for each critical component (such as scheduled inspection,

removal, and replacement of components). This proposed section is a

companion to the rotor structure proposal of Sec. 29.547.

Section 29.923 Rotor drive system and control mechanism tests

This proposed revision to Sec. 29.923(b)(3)(i) would increase the

testing for 2 minute OEI power from one to two runs per cycle. The JAA

are concerned that a possible inconsistency exists in the current rule.

Using one run per cycle, a higher and potentially more damaging power

rating could be substantiated by less testing at the 2-minute OEI power

than at the 2\1/2\ minute OEI power. The FAA agrees and increased

testing for 2 minute OEI power is proposed.

Section 29.1305 Powerplant instruments

The current rule requires an oil pressure warning device, which

could be a simple light, for each pressure-lubricated gearbox. Proposed

new Sec. 29.1305(a)(6) would add a requirement for an oil pressure

indicator for each pressure-lubricated gearbox. This change would

provide the crew with an early warning of oil pressure problems and

confirm that the oil pressure warning is valid. The proposed addition

of a new Sec. 29.1305(a)(6) would necessitate renumbering of existing

paragraphs (a)(6) through (a)(25) as (a)(7) through (a)(26).

Section 29.1309 Systems, equipment, and installations

Section 29.610 was referenced in Sec. 29.1309(h) to require

protection against a catastrophic systems failure due to lightning.

Since Sec. 29.1309(h) applies to lightning protection of systems and

equipment, it is unnecessary to reference Sec. 29.610, which applies to

lightning protection of structures, Therefore, this proposed change

would delete the reference to Sec. 29.610 in Sec. 29.1309(h).

Section 29.1351 General

The proposed changes to Secs. 29.1351(d) and 29.1351(d)(1) would

clarify that the regulation applies to the normal electrical power

generating system and would editorially change the Sec. 29.1351(d)

heading. The Sec. 29.1351(d) heading would change from, ``Operation

without normal electrical power'' to ``Operation with the normal

electrical power generating system inoperative,'' and ``generating

system'' would be added after electrical power in Sec. 29.1351(d)(1).

The proposed additions to Sec. 29.1351(d)(2) would provide

requirements for the emergency electrical power system for Category A

rotorcraft. Section 29.1351(d)(2) is entitled ``Category A Aircraft.''

The proposed new Sec. 29.1351(d)(2)(i) would require that emergency

electrical power be provided to those systems necessary for continued

safe flight and landing for rotorcraft certificated to Category A

requirements. Consideration of the possible duration of flight time to

reach a suitable landing site and make a safe landing would be

required. A minimum of 30 minutes flight time is necessary for

continued safe flight and landing for Category A rotorcraft. Proposed

new Sec. 29.1351(d)(2)(ii) would require that loss of both normal and

emergency electrical power systems be shown to be extremely improbable.

This will ensure that no single failure (such as effects of fire or

loss of junction box) will result in the disabling of both the normal

and emergency electrical power systems. Finally, a new

Sec. 29.1351(d)(2)(iii) would require that the emergency electrical

power system include independent, automatic features for electrical

load shedding to conserve the emergency electrical power (batteries)

after loss of the normal electrical power generating system. The intent

is to allow the flight crew time to take corrective actions for engine

fire, cockpit fire, or other in-flight emergencies common to situations

resulting in loss of the normal electrical power generating system

without being distracted by a need to manually switch off or shed

electrical power. In this regard, ``immediate'' refers to those systems

that, if they did not continue to operate, would necessitate the

attention of the flight crew.

Section 29.1587 Performance information

Proposed new Sec. 29.1587(a)(6) would require that the climb

gradient information necessary for the pilot to determine the allowable

maximum takeoff weight to clear any obstacle in the takeoff path be

added to the Rotorcraft Flight Manual for Category A rotorcraft.

Because the data are already available from the other requirements, the

only additional requirement would be to incorporate this data into the

Rotorcraft Flight Manual.

Appendix B to Part 29 Airworthiness Criteria for Helicopter Instrument

Flight

The proposed addition of a section VIII(b)(6) to Appendix B would

provide a reference to new Sec. 29.1351(d)(2) to clarify that

requirements for operation with the normal electrical power generating

system inoperative apply to Instrument Flight Rules (IFR) certificated

rotorcraft. When the emergency electrical power source provided for an

IFR certificated rotorcraft is time limited; e.g., a battery, the

required duration will depend on the type and role of the rotorcraft.

However, an endurance of less than 30 minutes would not be acceptable.

Regulatory Evaluation Summary

Introduction

Proposed changes to federal regulations must undergo several

economic analyses. First, Executive Order 12866 directs Federal

agencies to promulgate new regulations or modify existing regulations

only if the potential benefits to society outweigh the potential costs.

Second, the Regulatory Flexibility Act of 1980 requires agencies to

analyze the economic impact of regulatory changes on small entities.

Finally, the Office of Management and Budget has directed agencies to

assess the effects of regulatory changes on international trade. In

conducting these analyses, the FAA has determined that this proposed

rule (1) would generate benefits exceeding its costs and is neither a

significant regulatory action as defined in the Executive Order nor

significant as defined in DOT's Policies and Procedures, (2) would not

have a significant impact on a substantial number of small entities,

and (3) would lessen restraints on international trade. These analyses,

available in the docket, are summarized below.

Costs and Benefits

All of the proposed changes to part 27 and all but four of the

proposed changes to part 29 would impose no or significant costs on

rotorcraft manufacturers because they reflect current design practices.

In recent years, manufacturers have incorporated engineering and

structural improvements into rotorcraft designs that exceed the minimum

regulatory requirements with the aim of increasing operating

efficiencies, payload capabilities, and marketability in world markets.

Most new rotorcraft designs are based on existing designs. Many of

these improvements have also improved safety. Codification of these

improvements and other proposed changes would ensure that these

features are incorporated in all future rotorcraft designs.

Additionally, adoption of the proposed changes would increase

harmonization and commonality between U.S. and European airworthiness

standards. Harmonization would eliminate differences between

airworthiness requirements, thus reducing manufacturers' cost for dual

certification. Based on experience in a recent certification, one

rotorcraft manufacturer indicated that complying with different FAA/JAA

requirements resulted in several hundred thousand dollars in excessive

certification costs. Aside from the benefits of enhanced safety levels

as described above, the benefits of certification cost savings would,

by themselves, outweigh the relatively modest increase in certification

costs that the amendments would impose.

Following is a brief summary of the four proposed changes to part

29 that would impose additional costs totalling approximately $150,000

per type certification. The safety benefits of these proposed changes

are expected to easily exceed the incremental costs.

Section 29.547--Main and tail rotor structure. While manufactures

currently perform the proposed design assessment as an integral part of

the design requirements of Sec. 29.917, there would be some incremental

costs to formalize the existing information. These costs are included

in the cost estimates of proposed Sec. 29.917 summarized below. Formal

identification and assessment of critical component failures would

increase safety by providing more comprehensive maintenance information

to operators. The benefits of averting a single catastrophic accident

would exceed the relatively low incremental costs of compliance.

Section 29.631--Bird strike. Manufacturers indicate that present

rotorcraft structures can withstand impacts from a 2.2 pound bird;

therefore, no incremental manufacturing costs are anticipated to

implement new designs. Nonrecurring testing and analysis costs of the

proposed requirement are estimated to be $100,000 per type

certification. A review of National Transportation Safety Board (NTSB)

data for the period 1983-1991 reveals two rotorcraft accidents caused

by bird strikes. One accident resulted in one serious injury, one minor

injury, and substantial damage to the rotorcraft (tail rotor

separation); in the other accident the rotorcraft was destroyed but

there were no injuries. There is at least an equal probability of such

accidents and the resultant damage in the future, given the tendencies

toward higher operating speeds and use of composite materials. The

benefits of averting a single catastrophic accident would exceed the

incremental costs.

Section 29.917--Design. The incremental costs to formalize existing

design information for the rotor structure (proposed Sec. 29.547 above)

and drive system are estimated to total $44,000 per type certification.

Formal assessment and identification of critical components of the

rotor drive system would increase safety by providing more

comprehensive maintenance information to operators. The benefits of

averting a single catastrophic accident caused directly or indirectly

by a lack of relevant data would easily exceed the incremental costs of

providing that data.

Section 29.1587--Performance information. Because the required

climb gradient data would already be available from the results of

flight tests required to obtain performance information, the only

additional costs would be those associated with incorporating the data

into the Rotorcraft Flight Manual, estimated to total $5,500 per

certification. Although NTSB accident records do not include any

accidents directly attributable to lack of performance data, there were

a few accidents in which such data were ignored or misinterpreted. The

availability and accuracy of such data would enhance operational

safety. The benefits of averting a single catastrophic accident caused

directly or indirectly by a lack of relevant performance information

would easily exceed the incremental costs of providing that data.

International Trade Impact Analysis

The proposed rule would not constitute a barrier to international

trade, including the export of American rotorcraft to foreign countries

and the import of foreign rotorcraft into the United States. Instead,

the proposed changes on rotorcraft certification procedures, harmonized

with those of the JAA, would lower dual certification costs, thereby

enhancing free trade.

Regulatory Flexibility Determination

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

Congress to ensure that small entities are not unnecessarily and

disproportionately burdened by government regulations. The RFA requires

a Regulatory Flexibility Analysis if a rule would have a significant

economic impact, either detrimental or beneficial, on a substantial

number of small entities. Based on the criteria of FAA Order 2100.14A,

Regulatory Flexibility Criteria and Guidance, the FAA has determined

that the proposed rule would not have a significant economic impact on

a substantial number of small entities.

Conclusion

For the reasons discussed above, including the findings in the

Regulatory Flexibility Determination and the International Trade Impact

Analysis, the Office of Information and Regulatory Affairs (OIRA) in

conjunction with the FAA has determined that this proposed regulation

is not a significant regulatory action under Executive Order 12866 and,

therefore, was not subject to centralized regulatory review by the

OIRA. In addition, the FAA certifies that this regulation will not have

a significant economic impact, positive or negative, on a substantial

number of small entities under the criteria of the Regulatory

Flexibility Act. This proposal is considered to be nonsignificant under

DOT Regulatory Policies and Procedures (44 FR 11034; February 26,

1979). 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 in 14 CFR Parts 27 and 29

Air transportation, Aircraft, Aviation safety, Rotorcraft, Safety.

The Proposed Amendments

Accordingly, the FAA proposes to amend parts 27 and 29 of the

Federal Aviation Regulations (14 CFR parts 27 and 29) as follows:

PART 27--AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT

1. The authority citation for part 27 continues to read as follows:

Authority: 49 U.S.C. 1344, 1354(a), 1355, 1421, 1423, 1425,

1428, 1429, and 1430; 49 U.S.C. 106(g).

2. Section 27.1 is amended by adding a new paragraph (c) to read as

follows:

Sec. 27.1 Applicability.

* * * * *

(c) Multiengine rotorcraft may be type certificated as Category A

provided the requirements of appendix C of this part are met.

3. Section 27.65 is amended by revising paragraphs (b)(2) and

(b)(2)(ii) to read as follows:

Sec. 27.65 Climb: all engines operating.

* * * * *

(b) * * *

(2) The steady rate of climb must be determined--

* * * * *

(ii) Within the range from sea level up to the maximum altitude for

which certification is requested;

* * * * *

4. Section 27.1141 is amended by redesignating existing paragraphs

(c) and (d) as paragraphs (d) and (e) and by adding a new paragraph (c)

to read as follows:

Sec. 27.1141 Powerplant controls: general.

* * * * *

(c) Each control must be able to maintain any set position

without--

(1) Constant attention; or

(2) Tendency to creep due to control loads or vibration.

* * * * *

5. Section 27.1151 is added to read as follows:

Sec. 27.1151 Rotor brake controls.

(a) It must be impossible to apply the rotor brake inadvertently in

flight.

(b) There must be means to warn the crew if the rotor brake has not

been completely released before takeoff.

6. Part 27 is amended by adding a new appendix C to read as

follows:

Appendix C to Part 27--Criteria for Category A

C27.1 General.

A small multiengine rotocraft may not be type certificated for

Category A operation unless it meets the design installation and

performance requirements contained in this appendix in addition to

the requirements of this part.

C27.2 Applicable part 29 sections.

The following sections of part 29 of this chapter must be met in

addition to the requirements of this part:

29.45(a) and (b)(2)--General.

29.49(a)--Performance at minimum operating speed.

29.51--Takeoff data: General.

29.53--Takeoff: Category A.

29.55--Takeoff decision point: Category A.

29.59--Takeoff path: Category A.

29.60--Elevated heliport takeoff path: Category A.

29.61--Takeoff distance: Category A.

29.62--Rejected takeoff: Category A.

29.64--Climb: General.

29.65(a)--Climb: AEO.

29.67(a)--Climb: OEI.

29.75--Landing: General.

29.77--Landing decision point: Category A.

29.79--Landing; Category A.

29.81--Landing distance (Ground level sites): Category A.

29.85--Balked landing: Category A.

29.87(a)--Height-velocity envelope.

29.547(a) and (b)--Main and tail rotor structure.

29.571--Fatigue evaluation of structure. AC Material only: AC29-2A

Item 230 Paragraph 10.

29.861(a)--Fire protection of structure, controls, and other parts.

29.901(c)--Powerplant: Installation.

29.903(b)(c) and (e)--Engines.

29.908(a)--Cooling fans.

29.917(b) and (c)(1)--Rotor drive system: Design.

29.927(c)(1)--Additional tests.

29.953(a)--Fuel system independence.

29.1027(a)--Transmission and gearboxes: General.

29.1045(a)(1), (b), (c), (d), and (f)--Climb cooling test

procedures.

29.1047(a)--Takeoff cooling test procedures.

29.1181(a)--Designated fire zones: Regions included.

29.1187(e)--Drainage and ventilation of fire zones.

29.1189(c)--Shutoff means.

29.1191(a)(1)--Firewalls.

29.1193(e)--Cowling and engine compartment covering.

29.1195(a) and (d)--Fire extinguishing systems (one shot).

29.1197--Fire extinguishing agents.

29.1199--Extinguishing agent containers.

29.1201--Fire extinguishing system materials.

29.1305(a)(6) and (b)--Powerplant instruments.

29.1309(b)(2)(i) and (d)--Equipment, systems, and installations.

29.1323(c)(1)--Airspeed indicating system.

29.1331(b)--Instruments using a power supply.

29.1351(d)(2)--Electrical systems and equipment: General (operation

without normal electrical power).

29.1587(a)--Performance information.

3. In complying with the paragraphs listed in paragraph 2 above,

relevant material in AC 29-2A should be used.

PART 29--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT

7. The authority citation for part 29 continues to read as follows:

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

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

8. Section 29.547 is amended by revising the heading; revising

paragraph (a); adding a new paragraph (b); removing the word ``main''

in the introductory text of paragraphs (c), (d), and (e); and revising

paragraph (e)(1)(ii) to read as follows:

Sec. 29.547 Main and tail rotor structure.

(a) A rotor is an assembly of rotating components, which includes

the rotor hub, blades, blade dampers, the pitch control mechanisms, and

all other parts that rotate with the assembly.

(b) Each rotor assembly must be designed as prescribed in this

section and must function safely for the critical flight load and

operating conditions. A design assessment must be performed, including

a detailed failure analysis to identify all failures that will prevent

continued safe flight or safe landing, and must identify the means to

minimize the likelihood of their occurrence.

* * * * *

(e) * * *

(1) * * *

(ii) For the main rotor, the limit engine torque specified in

Sec. 29.361.

* * * * *

9. In Sec. 29.610 the heading is revised; the word ``structure'' is

added between the words ``rotorcraft'' and ``must'' in paragraph (a);

and a new paragraph (d) is added to read as follows:

Sec. 29.610 Lightning and static electricity protection.

* * * * *

(d) The electrical bonding and protection against lightning and

static electricity must be such as to--

(1) Minimize the accumulation of electrostatic charge;

(2) Minimize the risk of electrical shock to crew, passengers, and

service and maintenance personnel using normal precautions;

(3) Provide an electrical return path, under both normal and fault

conditions, on rotorcraft having grounded electrical systems; and

(4) Reduce to an acceptable level the effects of lightning and

static electricity on the functioning of essential electrical and

electronic equipment.

10. Section 29.629 is revised to read as follows:

Sec. 29.629 Flutter and divergence.

Each aerodynamic surface of the rotorcraft must be free from

flutter and divergence under each appropriate speed and power

condition.

11. A new Sec. 29.631 is added to read as follows:

Sec. 29.631 Bird strike.

The rotorcraft must be designed to assure capability of continued

safe flight and landing (for Category A) or safe landing (for Category

B) after impact with a 2.2 lb (1.0 kg) bird when the velocity of the

rotorcraft (relative to the bird along the flight path of the

rotorcraft) is equal to VNE or VH (whichever is the lesser)

at altitudes up to 8,000 feet. Compliance must be shown by tests or by

analysis based on tests carried out on sufficiently representative

structures of similar design.

12. Section 29.917 is amended by redesignating existing paragraph

(b) as (c) and adding a new paragraph (b) to read as follows:

Sec. 29.917 Design.

* * * * *

(b) Design assessment. A design assessment must be performed to

ensure that the rotor drive system functions safely over the full range

of conditions for which certification is sought. The design assessment

must include a detailed failure analysis to identify all failures that

will prevent continued safe flight or safe landing and must identify

the means to minimize the likelihood of their occurrence.

* * * * *

13. Section 29.923 is amended by revising paragraph (b)(3)(i) to

read as follows:

Sec. 29.923 Rotor drive system and control mechanism tests.

* * * * *

(b) * * *

(3) * * *

(i) Immediately following any one 5-minute power-on run required by

paragraph (b)(1) of this section, simulate a failure for each power

source in turn, and apply the maximum torque and the maximum speed for

use with 30-second OEI power to the remaining affected drive system

power inputs for not less than 30 seconds. Each application of 30-

second OEI power must be followed by two applications of the maximum

torque and the maximum speed for use with the 2 minute OEI power for

not less than 2 minutes each; the second application must follow a

period at stabilized continuous or 30 minute OEI power (whichever is

requested by the applicant). At least one run sequence must be

conducted from a simulated ``flight idle'' condition.

* * * * *

14. Section 29.1305 is amended by redesignating existing paragraphs

(a)(6) through (a)(25) as paragraphs (a)(7) through (a)(26) and adding

a new paragraph (a)(6) to read as follows:

Sec. 29.1305 Powerplant instruments.

* * * * *

(a) * * *

(6) An oil pressure indicator for each pressure-lubricated gearbox;

* * * * *

15. Section 29.1309 is amended by revising paragraph (h) to read as

follows:

Sec. 29.1309 Equipment, systems, and installations.

* * * * *

(h) In showing compliance with paragraphs (a) and (b) of this

section, the effects of lightning strikes on the rotorcraft must be

considered.

16. Section 29.1351 is amended by revising the heading of paragraph

(d), redesignating the introductory text of paragraph (d) as (d)(1) and

adding the words ``generating system'' after the words ``normal

electrical power'' in new (d)(1), redesignating paragraphs (d)(1),

(d)(2), and (d)(3) as (d)(1)(i), (d)(1)(ii), and (d)(1)(iii), and

adding a new paragraph (d)(2) to read as follows:

Sec. 29.1351 General.

* * * * *

(d) Operation with the normal electrical power generating system

inoperative. * * *

* * * * *

(2) Additional requirements for Category A Rotorcraft.

(i) Unless it can be shown that the loss of the normal electrical

power generating system is extremely improbable, an emergency

electrical power system, independent of the normal electrical power

generating system, must be provided, with sufficient capacity to power

all systems necessary for continued safe flight and landing.

(ii) Failures, including junction box, control panel, or wire

bundle fires, which would result in the loss of the normal and

emergency systems, must be shown to be extremely improbable.

(iii) Systems necessary for immediate safety must continue to

operate following the loss of the normal electrical power generating

system, without the need for flight crew action.

17. Section 29.1587 is amended by adding a new paragraph (a)(6),

removing ``and'' from end of paragraph (a)(4), and adding ``and'' to

end of paragraph (a)(5).

Sec. 29.1587 Performance information.

* * * * *

(a) * * *

(6) The steady gradient of climb for each weight, altitude, and

temperature for which takeoff data are to be scheduled, along the

takeoff path determined in the flight conditions required in Sec. 29.67

(a)(1) and (a)(2):

(i) In the flight conditions required in Sec. 29.67(a)(1) between

the end of the takeoff distance and the point at which the rotorcraft

is 200 feet above the takeoff surface (or 200 feet above the lowest

point of the takeoff profile for elevated heliports).

(ii) In the flight conditions required in Sec. 29.67(a)(2) between

the points at which the rotorcraft is 200 and 1000 feet above the

takeoff surface (or 200 and 1000 feet above the lowest point of the

takeoff profile for elevated heliports).

* * * * *

18. Part 29 Appendix B is amended by adding a new paragraph

VIII(b)(6).

Appendix B to Part 29--Airworthiness Criteria for Helicopter

Instrument Flight

* * * * *

VIII. * * *

(b) * * *

(6) In determining compliance with the requirements of

Sec. 29.1351(d)(2), the supply of electrical power to all systems

necessary for flight under IFR must be included in the evaluation.

Issued in Washington, DC, on December 12, 1994.

Thomas E. McSweeny,

Director, Aircraft Certification Service.

[FR Doc. 94-31311 Filed 12-27-94; 8:45 am]

BILLING CODE 4910-13-M