[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
