[Federal Register Volume 61, Number 92 (Friday, May 10, 1996)]
[Rules and Regulations]
[Pages 21904-21908]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11493]




[[Page 21903]]


_______________________________________________________________________

Part VI





Department of Transportation





_______________________________________________________________________



Federal Aviation Administration



_______________________________________________________________________



14 CFR Parts 27 and 29



Rotorcraft Regulatory Changes Based on European Joint Aviation 
Requirements; Final Rule

  Federal Register / Vol. 61, No. 92 / Friday, May 10, 1996 / Rules and 
Regulations  

[[Page 21904]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 27 and 29

[Docket No. 28008; Amendment No. 27-33, 29-39]
RIN 2120-AF65


Rotorcraft Regulatory Changes Based on European Joint Aviation 
Requirements

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: The Federal Aviation Administration (FAA) is amending the 
airworthiness standards for normal and transport category rotorcraft. 
The changes revise airworthiness standards for performance, systems, 
propulsion, and airframes. The changes increase the regulatory safety 
level, clarify existing regulations, and standardize terminology. The 
changes are based on standards incorporated by the European Joint 
Aviation Authorities (JAA) for Joint Aviation Requirements (JAR) 27 and 
29. These changes are intended to harmonize the U.S. rotorcraft 
airworthiness standards with the European JAR.

EFFECTIVE DATE: August 8, 1996.

FOR FURTHER INFORMATION CONTACT:
Carroll Wright, Regulations Group Rotorcraft Directorate, Aircraft 
Certification Service, Federal Aviation Administration, Fort Worth, 
Texas 76193-0111, telephone (817) 222-5120.

SUPPLEMENTARY INFORMATION:

Background

    These amendments are based on Notice of Proposed Rulemaking (NPRM) 
No. 94-36 published in the Federal Register on December 28, 1994 (59 FR 
67068). That notice proposed to amend the airworthiness standards for 
both normal and transport category rotorcraft based on recommendations 
from the Aviation Rulemaking Advisory Committee (ARAC). 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 Aerospace 
Industries Association of America, Inc. (AIA), Association Europeene 
des Constructeurs de Material Aerospatial (AECMA), Helicopter 
Association International (HAI), JAA, and the FAA Rotorcraft 
Directorate. This broad participation is consistent with FAA policy to 
involve all known interested parties as early as practicable in the 
rulemaking process.
    The Harmonization Working Group was tasked with making 
recommendations to the ARAC regarding JAA Notices of Proposed Amendment 
(NPA's). The ARAC subsequently recommended that the FAA revise the 
airworthiness standards for normal and transport category rotorcraft to 
those currently in the JAR 27 and 29.
    The FAA evaluated the ARAC recommendations and proposed changes to 
the rotorcraft airworthiness standards in 14 CFR parts 27 and 29 (parts 
27 and 29). These proposed changes evolved from the FAA, JAA, and 
industry meetings of 1990-1992 and the ARAC recommendations of 1993. 
The changes proposed to (1) incorporate current design and testing 
practices into the rules by requiring additional performance data, (2) 
incorporate additional powerplant and rotor brake controls 
requirements, (3) incorporate bird-strike protection requirements, and 
(4) harmonize the certification requirements between parts 27 and 29 
and the JAR. The proposals for part 27 included JAA's harmonized NPA's 
27-Basic and 27-1, and the proposals for part 29 included NPA's 29-
Basic and 29-1 through 29-5. This rule contains the harmonized rule 
language of those sections of the NPA's except for Sec. 27.602 of NPA 
27-Basic and Sec. 29.602 of NPA 29-4.
    In proposed rule, NPRM 94-36, there were several instances in which 
a few descriptive words were proposed to either be removed from or 
added to regulatory text. These word changes were adequately described 
in the amendatory language to NPRM 94-36 when that proposal was 
published in the Federal Register. However, at least one commenter 
misunderstood the amendatory language. Therefore, to avoid possible 
misunderstanding about the final rule language, the paragraphs with the 
minor rule language changes are reproduced in their entirety in this 
final rule. Also, the numbering of other regulations referenced in 
Secs. 29.1587(a)(4) and (a)(5) has been changed, and a new 
Sec. 29.1587(a)(6) has been added. The current Sec. 29.1587(a)(6), 
which is being redesignated in this rule as Sec. 29.1587(a)(7), was 
added by the Transport Category Rotorcraft Performance Rule published 
elsewhere in this issue of the Federal Register.
    In this final rule, under the heading ``Appendix C to Part 27--
Criteria for Category A,'' the NPRM 94-36 cites to Advisory Circular 
(AC) material have been removed since AC material is advisory only. A 
note has been added that informs the reader that there is appropriate 
guidance material available. Further, the requirement to meet 
Sec. 29.571 standards for certification as a part 27 Category A 
rotorcraft has been removed from the Appendix C listing. The FAA has 
determined that the current Sec. 27.571 contains sufficient 
certification standards to maintain an adequate level of safety for 
part 27 Category A rotorcraft, and an additional requirement of testing 
to Sec. 29.571 standards is unnecessary.

Discussion of Comments

    Interested persons have been afforded an opportunity to participate 
in the making of these amendments. Due consideration has been given to 
the comments received. Comments were received from the JAA, HAI, 
Transport Canada, and the United Kingdom Civil Aviation Authority 
(UKCAA).
    The JAA agrees with the proposed rule and the effort to harmonize 
certification regulations of the U.S. and the European communities. To 
fulfill harmonization objectives, the JAA prepared an NPA identical to 
the NPRM and will publish the JAR final rule at the same time as this 
time as this final rule for parts 27 and 29.
    HAI comments that the proposals faithfully reflect the 
recommendation made to the FAA by the ARAC on rotorcraft regulatory 
changes. HAI further comments that the NPRM reflects prudent rulemaking 
to increase safety, economic viability, and harmonization within 
realistic requirements and urges the adoption of the proposal.
    Transport Canada comments that the NPRM was not the same as the 
ARAC recommendations in that there were changes in the nonregulatory 
sections (preamble) and in the proposed text of the rule. The commenter 
states that these changes cause concern because the discrepancies may 
lead to different interpretations. The commenter notes that the meaning 
of Sec. 29.547 was changed because the word ``main'' had been removed 
in the ARAC recommendations but was not removed in the NPRM. This 
commenter also states that the requirements of Secs. 29.547 and 29.917 
are redundant because Sec. 29.571 also requires the identification of 
the principal structural elements (PSE) that includes rotors and rotor 
drive systems with the establishment of the inspections and replacement 
times for those PSE's. Additionally, the commenter says that 
Sec. 29.610 should state that it addresses only ``direct effects'' of 
lightning and electricity and

[[Page 21905]]

that indirect effects are covered elsewhere in Secs. 29.954, 29.863, 
29.1309, etc. This commenter also states that Sec. 29.1309 should 
retain the reference to Sec. 29.610. This commenter also suggests 
adding a new requirement and paragraph to Appendix B to part 29 that 
would require an additional, self-powered third attitude indicator.
    The FAA agrees with Transport Canada that editorial changes between 
the ARAC recommendations and the NPRM are a concern because the 
differences may lead to different interpretations. To obviate this 
concern, editorial changes have been made in the final rule language to 
make it consistent with the ARAC recommended language. Also, the FAA 
agrees with Transport Canada that the word ``main'' had been removed 
from the introductory paragraph of Sec. 29.547(c), (d), and (e) in the 
ARAC recommended language but, as previously discussed, had not been 
shown as removed in the NPRM rule language. However, the word ``main'' 
is being removed from this final rule.
    The FAA does not agree with this commenter that Secs. 29.547, 
29.571, and 29.917 are redundant in requiring identification of 
principal structural elements (PSE's), which include rotors and rotor 
drive systems, and the establishment of the inspections, replacement 
times of those PSE's. Section 29.547(b) requires a design assessment 
for main and tail rotor structure components (rotor hub, blades, pitch 
control mechanisms, etc); Sec. 29.571 requires fatigue evaluation of 
structural components; and Sec. 29.917 requires a design assessment of 
the rotor drive system (drive shafts, transmission, gearboxes, etc). 
Therefore, these are non redundant requirements. The language is 
adopted as proposed.
    The FAA agrees with the intent of this commenter's suggestion that 
Sec. 29.610 should clearly indicate that it addresses only ``direct 
effects'' of lightning and electricity. However, this was achieved in 
the NPRM by adding the word ``structure'' between the words 
``rotorcraft'' and ``must'' in Sec. 29.610(a) to clarify that this 
paragraph applied to rotorcraft structure and not to systems and 
equipment. Accordingly, the language is adopted as proposed.
    The FAA does not agree with this commenter that Sec. 29.1309 should 
retain the reference to Sec. 29.610. The NPRM added the word 
``structure'' to Sec. 29.610 to clarify that the paragraph applied to 
rotorcraft structure and not to systems and equipment. Since 
Sec. 29.1309(h) applies to lightning protection of systems and 
equipment, it is inappropriate to reference Sec. 29.610, which applies 
to lightning protection of structures. The commenter's proposal to 
retain the reference to Sec. 29.610 is not adopted.
    The FAA disagrees with this commenter's suggestion that a new 
requirement and paragraph be added to part 29, Appendix B, to require 
an additional, self-powered third attitude indicator. Part 29, Appendix 
B, paragraph VIII(a)(2) currently requires a standby attitude indicator 
that is independent of the aircraft electrical generating system. 
Additionally, part 29, Appendix B, paragraph VIII(b)(5)(iii) states, 
``The equipment, systems, and installations must be designed so that 
one display of the information essential to the safety of flight that 
is provided by the instruments will remain available to a pilot, 
without additional crew-member action, after any single failure or 
combination of failures that is not shown to be extremely improbable * 
* *.'' Currently, the only practical design to meet the extremely 
improbable (10-9) requirement of part 29, Appendix B, for the 
display of information essential to flight safety after a single 
failure or combination of failures is the design that uses a third 
attitude indicator powered by a source other than the aircraft 
electrical generating system. However, the FAA does not wish to limit 
future alternative designs that may meet the extremely improbable 
standard without a third attitude indicator. The suggestion of the 
commenter to add a requirement for a self-powered third attitude 
indicator is not adopted.
    The UKCAA comments that Proposal No. 13 in NPRM 94-36 proposed to 
amend Sec. 29.923(b)(3)(i), to require two applications of 2-minute 
power following each application of 30-second power, instead of the one 
application of 2-minute power previously proposed. The UKCAA fully 
supports the proposed changes in NPRM 94-36. However, the UKCAA further 
comments that since publication of NPRM 94-36, the FAA published 
Amendment 29-34 (59 FR 47764, September 16, 1994) that states in part, 
``When conducted on a bench test, the test sequence must be conducted 
following stabilization at take-off power.'' The commenter states that 
the reason for adding this sentence, as stated in the preamble to 
Amendment 29-34, remains valid, and this sentence should therefore be 
included in the final rule developed from NPRM 94-36.
    The FAA concurs with the UKCAA that the reason for adding the 
sentence, ``When conducted on a bench test, the test sequence must be 
conducted following stabilization at take-off power'' remains valid and 
the sentence should be retained in Sec. 29.923(b)(3)(i). The sentence 
was adopted in Amendment 29-34 due to a commenter's statement that if 
the 5-minute takeoff power run to qualify the drive system is conducted 
as part of the endurance run, and the 30-second/2-minute OEI 
requirements are conducted on a bench test, then the takeoff power 5-
minute run will be conducted twice on the same set of gears. The FAA 
did not intend to duplicate the takeoff power 5-minute run if the OEI 
requirements are conducted on a bench test, and the sentence was 
adopted for clarification. Since the omission of the sentence in NPRM 
94-36 was inadvertent, since the reasons for including the sentence 
remain valid, and since the sentence is relieving in nature and does 
not place any additional burden on manufacturers, it is unnecessary to 
solicit prior public comment. Therefore, the sentence is restored as 
requested by the commenter.
    After considering all of the comments, the FAA has determined that 
air safety and the pubic interest support adoption of the amendments 
with the changes noted.

Regulatory Evaluation Summary

    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 regulatory changes on small entities. 
Third, the Office of Management and Budget directs agencies to assess 
the effect 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 
nonsignificant as defined in DOT's Regulatory Policies and Procedures; 
(3) would not have a significant impact on substantial number of small 
entities; and (4) will lessen restraints on international trade. These 
analyses, available in the docket, are summarized below.

Cost-Benefit Analysis

    All of the changes to part 27 and all but four of the changes to 
part 29 will impose no or insignificant costs on rotorcraft 
manufacturers since they largely reflect current design practices. In 
recent years, manufacturers have incorporated engineering and 
structural improvements into rotorcraft designs

[[Page 21906]]

that exceed minimum regulatory requirements with the aim of increasing 
operating efficiencies, payload capabilities, and marketability in 
world markets. Many of these improvements have also inherently improved 
safety codification of these improvement and other changes will ensure 
continuation of enhanced safety levels in future rotorcraft designs.
    The changes will also increase harmonization and commonality 
between U.S. and European airworthiness standards. Harmonization will 
eliminate the need to comply with different FAA and JAA airworthiness 
requirements, thus reducing manufacturers' certification costs. Based 
on experience in a recent certification, one rotorcraft manufacturer 
indicated that complying with different FAA and JAA requirements 
resulted in several hundred thousand dollars of excessive certification 
costs (as related to all part 27 and 29 requirements). The duplicate 
certification costs avoided by the harmonized rule alone could outweigh 
the relatively modest increase in certification costs imposed by the 
few new requirements. Following is a summary of the four changes to 
part 29 that will impose additional costs totaling approximately 
$160,000 per type certification. The safety benefits of these changes 
are expected to easily exceed the incremental costs.
    Section 29.547--Main and tail rotor structure. While manufacturers 
currently perform the design assessment as an integral part of the 
design requirements of Sec. 29.917, there will be some incremental 
costs to formalize the existing information. These costs are included 
in the cost estimates of Sec. 29.917 summarized below. Formal 
identification and assessment of critical component failures will 
increase safety by providing more comprehensive maintenance information 
to operators. The benefits of averting a single accident will exceed 
the relatively low incremental costs of compliance.
    Section 29.631--Bird strike. Manufacturers indicate that present 
rotorcraft structures can withstand impacts with 2.2 pound birds; 
therefore, no incremental manufacturing costs are anticipated. 
Nonrecurring testing and analysis costs of the requirement are 
estimated to be $107,000 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 in the future, 
given the tendencies toward higher operating speeds. The benefits of 
averting a single accident will exceed the incremental costs of the 
amendment.
    Section 29.917--Design. The incremental costs to formalize existing 
design information for the rotor structure (Sec. 29.547 above) and 
drive system are estimated to total $47,000 per type certification. 
Formal identification and assessment of critical component failures of 
the rotor drive system will increase safety by providing more 
comprehensive maintenance information to operators. The benefits of 
averting a single accident caused directly or indirectly by a lack of 
relevant data would easily exceed the incremental costs.
    Section 29.1587--Performance information. Since the required climb 
gradient data are already available from the results of flight tests 
required to obtain performance information, the only additional costs 
will be those associated with incorporating the data into the Flight 
Manual, estimated to total $6,000 per type certification. The 
availability and accuracy of performance data are paramount to 
operational safety. The benefits of averting a single accident caused 
directly or indirectly by a lack of relevant performance information 
will easily exceed the incremental costs.

Regulatory Flexibility determination

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily and 
disproportionately burdened by Federal Regulations. The RFA requires a 
Regulatory Flexibility Analysis if a proposed rule would have ``a 
significant economic impact on a substantial number of small 
entities.'' Based on the criteria of FAA Order 2100.14A, the FAA has 
determined that the rule will not have a significant impact on a 
substantial number of small entities.
    The rule will affect manufacturers of future type-certificated 
normal (part 27) and transport category (part 29) rotorcraft. For 
manufacturers, Order 2100.14A defines a small entity as one with 75 or 
fewer employees and a significant economic impact as annualized costs 
of $19,000 or more. The FAA has determined that the rule will not have 
a significant economic impact on a substantial number of small 
manufacturers since (1) no part 29 and only two part 27 rotorcraft 
manufacturers have 75 or fewer employees, and (2) the annualized 
certification costs of the rule are less than $19,000.

International Trade Impact Assessment

    The rule will not constitute a barrier to international trade, 
including the export of American rotorcraft to other countries and the 
import of rotorcraft into the United States. Instead, the changes will 
harmonize with certification procedures of the JAA and thereby enhance 
free trade.

Conclusion

    For the reasons discussed above, including the findings in the 
Regulatory Flexibility Determination and the International Trade Impact 
Analysis, the FAA has determined that this regulation is not a 
significant regulatory action under Executive Order 12866. 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 
regulation is considered nonsignificant under DOT Order 2100.5. A final 
regulatory evaluation of the regulation, including a final Regulatory 
Flexibility Determination and International 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 Amendments

    In consideration of the foregoing, the Federal Aviation 
Administration amends parts 27 and 29 of Title 14, Code of Federal 
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. 106(g), 40113, 44701, 44702, 44704.

    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 referenced in appendix C of this part are 
met.
    3. Section 27.65 is amended by revising paragraphs (b)(2) 
introductory text and (b)(2)(ii) to read as follows:

[[Page 21907]]

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. New Sec. 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 rotorcraft 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.
29.861(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.

    Note: In complying with the paragraphs listed in paragraph C27.2 
above, relevant material in the AC ``Certification of Transport 
Category Rotorcraft'' 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. 106(g), 40113, 44701, 44702, 44704.

    8. Section 29.547 is amended by revising the heading; by revising 
paragraph (a); by revising the introductory text in paragraphs (c), 
(d), and (e); by revising paragraph (e)(1)(ii); and by adding paragraph 
(b) 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.
    (c) The rotor structure must be designed to withstand the following 
loads prescribed in Secs. 29.337 through 29.341 and 29.351:
 * * * * *
    (d) The rotor structure must be designed to withstand loads 
simulating--
 * * * * *
    (e) The rotor structure must be designed to withstand the limit 
torque at any rotational speed, including zero.
    In addition:
    (1) * * *
 * * * * *
    (ii) For the main rotor, the limit engine torque specified in 
Sec. 29.361.
 * * * * *
    9. Section 29.610 is amended by revising the heading; by revising 
paragraph (a); and by adding a new paragraph (d) to read as follows:


Sec. 29.610  Lightning and static electricity protection.

    (a) The rotorcraft structure must be protected against catastrophic 
effects from lightning.
 * * * * *
    (d) The electric bonding and protection against lightning and 
static electricity must--
    (1) Minimize the accumulation of electrostatic charge;
    (2) Minimize the risk of electric shock to crew, passengers, and 
service and maintenance personnel using normal precautions;
    (3) Provide an electrical return path, under both normal and static 
electricity on the functioning of essential electrical and electronic 
equipment.
    (4) Reduce to an acceptable level the effects of lightning and 
static electricity on the functioning of essential 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. Section 29.631 is added before the undesignated center heading, 
``Rotors'' to read as follows:


Sec. 29.631  Bird strike.

    The rotorcraft must be designated to ensure 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

[[Page 21908]]

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 by 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. When conducted on 
a bench test, the test sequence must be conducted following 
stabilization at take-off power.
* * * * *
    14. Section 29.1305 is amended by redesignating existing paragraphs 
(a)(6) through (a)(25) as paragraphs (a)(7) through (a)(26) and by 
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(d) is revised to read as follows:


Sec. 29.1351  General

* * * * *
    (d) Operation with the normal electrical power generating system 
inoperative.
    (1) It must be shown by analysis, tests, or both, that the 
rotorcraft can be operated safely in VFR conditions for a period of not 
less than 5 minutes, with the normal electrical power generating system 
(electrical power sources excluding the battery) inoperative, with 
critical type fuel (from the standpoint of flameout and restart 
capability), and with the rotorcraft initially at the maximum 
certificated altitude. Parts of the electrical system may remain on 
if--
    (i) A single malfunction, including a wire bundle or junction box 
fire, cannot result in loss of the part turned off and the part turned 
on;
    (ii) The parts turned on are electrically and mechanically isolated 
from the parts turned off; and
    (iii) The electrical wire and cable insulation, and other 
materials, of the parts turned on are self-extinguishing when tested in 
accordance with Sec. 25.1359(d) in effect on September 1, 1977.
    (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 redesignating (a)(6) as (a)(7), 
by removing ``and'' from the end of paragraph (a)(5), and by adding a 
new paragraph (a)(6) to read as follows:


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); and
* * * * *
    18. Part 29 Appendix B is amended by adding a new paragraph 
VIII(b)(6) to read as follows:

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 May 2, 1996.
David R. Hinson,
Administrator.
[FR Doc. 96-11493 Filed 5-9-96; 8:45 am]
BILLING CODE 4910-13-M