# Rotorcraft Regulatory Changes Based on European Joint Airworthiness Requirements Proposals

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URL: https://www.frixlaw.com/law-library/documents/fr%3A94-31311

## Record

- **Collection:** Federal Register
- **Document type:** Uncategorized Document
- **Published:** December 28, 1994

## Text

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

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A94-31311. Public record. Not legal advice.