Performance and Handling Qualities Requirements for Rotorcraft, 10987-11002 [E8-3817]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 73, Number 41 (Friday, February 29, 2008)]
[Rules and Regulations]
[Pages 10987-11002]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-3817]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

 14 CFR Parts 27 and 29

[Docket No.: FAA-2006-25414; Amendment Nos. 27-44 and 29-51]
RIN 2120-AH87


Performance and Handling Qualities Requirements for Rotorcraft

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule provides new and revised airworthiness 
standards for normal and transport category rotorcraft due to 
technological advances in design and operational trends in normal and 
transport rotorcraft performance and handling qualities. The changes 
enhance the safety standards for performance and handling qualities to 
reflect the evolution of rotorcraft capabilities. This rule harmonizes 
U.S. and European airworthiness standards for rotorcraft performance 
and handling qualities.

DATES: These amendments become effective on March 31, 2008. Affected 
parties, however, do not have to comply with the information collection 
requirements of this rule until the OMB approves the FAA's request for 
this information collection requirement. The FAA will publish a 
separate document notifying you of the OMB Control Number and the 
compliance date(s) for the information collection requirements of this 
rule.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning 
this final

[[Page 10988]]

rule contact Jeff Trang, Rotorcraft Standards Staff, ASW-111, Federal 
Aviation Administration, Fort Worth, Texas 76193-0111; telephone (817) 
222-5135; facsimile (817) 222-5961, e-mail jeff.trang@faa.gov. For 
legal questions concerning this final rule contact Steve Harold, 
Directorate Counsel, ASW-7G, Federal Aviation Administration, Fort 
Worth, Texas 76193-0007, telephone (817) 222-5099; facsimile (817) 222-
5945, e-mail steve.c.harold@faa.gov.

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in 
Title 49 of the United States Code. Subtitle I, Section 106 describes 
the authority of the FAA Administrator. Subtitle VII, Aviation 
Programs, describes in more detail the scope of the agency's authority.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements,'' Section 44702, ``Issuance of Certificates,'' and 
section 44704, ``Type certificates, production certificates, and 
airworthiness certificates.'' Under section 44701, the FAA is charged 
with prescribing regulations and minimum standards for practices, 
methods, and procedures the Administrator finds necessary for safety in 
air commerce. Under section 44702, the FAA may issue various 
certificates including type certificates, production certificates, and 
airworthiness certificates. Under section 44704, the FAA shall issue 
type certificates for aircraft, aircraft engines, propellers, and 
specified appliances when the FAA finds that the product is properly 
designed and manufactured, performs properly, and meets the regulations 
and minimum prescribed standards. This regulation is within the scope 
of that authority because it would promote safety by updating the 
existing minimum prescribed standards used during the type 
certification process to reflect the enhanced performance and handling 
quality capabilities of rotorcraft. It would also harmonize this 
standard with international standards for evaluating the performance 
and handling qualities of normal and transport category rotorcraft.

Background

    Due to technological advances in design and operational trends in 
normal and transport rotorcraft performance and handling qualities, new 
and revised airworthiness standards have been developed. Some current 
part 27 and part 29 regulations do not reflect safety levels attainable 
by modern aircraft and FAA-approved equivalent level of safety 
findings. In fact, it has been more than 20 years since the last major 
promulgation of rules that address rotorcraft performance and handling 
qualities (Amendments 29-24 and 27-21).\1\ Since then, the FAA has 
developed policies and procedures that address certain aspects of these 
requirements to make the rotorcraft airworthiness standards workable 
within the framework of later rotorcraft designs and operational needs. 
Additionally, most rotorcraft manufacturers have routinely exceeded the 
minimum safety requirements in current part 27 and part 29 regulations.
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    \1\ 49 FR 44433 and 49 FR 44436 respectively, November 6, 1984.
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History of the NPRM

    On January 20, 1995, the FAA tasked the Performance and Handling 
Qualities Harmonization Working Group (PHQHWG) to ``review Title 14 
Code of Federal Regulations part 27 and Appendix B, and part 29 and 
Appendix B, and supporting policy and guidance material for the purpose 
of determining the course of action to be taken for rulemaking and/or 
policy relative to the issue of harmonizing performance and handling 
qualities requirements.'' The PHQHWG, which included broad membership 
from government authorities and industry representatives throughout the 
international rotorcraft community, met a total of ten times beginning 
in March 1995 to ensure participation by all interested parties early 
in the rulemaking process. Based on the recommendations of the PHQHWG, 
we published a notice of proposed rulemaking (NPRM 06-11) \2\ in the 
Federal Register on July 25, 2006. The comment period for that NPRM 
closed on October 23, 2006.
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    \2\ 72 FR 142, Docket Number: FAA-2006-25414.
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Summary of Comments

    The FAA received a total of 34 comments to the NPRM from four 
commenters: Erickson Air-Crane, Transport Canada, and three 
individuals, two of whom submitted their comments jointly. One 
commenter agreed with the proposed changes but had a comment relating 
to our economic evaluation. The remaining 33 comments related to 
specific proposed rule changes and included suggested changes, as 
discussed more fully in the discussion of the final rule below.

Discussion of the Final Rule

Weight Limits (Sec. Sec.  27.25, 29.25)

    The FAA proposed Sec.  27.25(a)(1)(iv) to formalize previous 
equivalent level of safety findings by establishing a maximum allowable 
weight if the requirements in Sec.  27.79 or Sec.  27.143(c)(1) cannot 
be met. The equivalent level of safety is attained by prohibiting 
certain operations and including limitations in the Rotorcraft Flight 
Manual (RFM) that reflect the actual capability of the aircraft.
    One commenter suggested that the proposed changes potentially lower 
the level of safety currently required under part 27 standards, are 
redundant and unnecessary, appear to delete the low-speed 
controllability requirements as a component in establishing the maximum 
weight under Sec.  27.25(a)(1)(iii), and therefore should be withdrawn. 
The commenter stated that under the current standard the flight 
requirements that typically establish the maximum weight for a 
helicopter with a single main rotor are in-ground effect (IGE) hover 
performance (Sec.  27.73), height-velocity (Sec.  27.79), and low-speed 
controllability (Sec.  27.143). The commenter further stated that the 
structure of Sec.  27.25 will always establish the maximum weight at a 
value that allows compliance with Sec. Sec.  27.79 and 27.143(c)(1) 
because the applicant will always select the weights allowed by Sec.  
27.25(a)(1)(iii) to show compliance with Sec. Sec.  27.73, 27.79 and 
27.143. Under the scenario the FAA used to justify the proposed change 
(making an equivalent level of safety finding to Sec.  27.143(c) and 
statements in advisory material for Sec.  29.143(c) that relate to 
possible removal, under certain circumstances, of operating limitations 
based on any hover controllability condition), the commenter stated 
that the FAA intends to delete the low-speed controllability 
requirements of the current rule as parameters for establishing maximum 
weight. The commenter maintained that this would reduce the margin of 
safety for helicopter operations, particularly above sea level, and 
would require exceptional piloting skills or exceptionally favorable 
conditions in order to conduct safe operations. Such requirements are 
prohibited by certain regulations, such as Sec.  27.51(a)(1).
    We disagree with a majority of these comments. Proposed Sec.  
27.25(a)(1)(iv) is not redundant or unnecessary because it provides an 
additional standard, rather than a replacement standard, for 
determining the maximum weight. Recent certifications have resulted in 
rotorcraft designs that have been unable

[[Page 10989]]

to meet the current standards for controllability near the ground 
(Sec.  27.143 Controllability and maneuverability) while at the maximum 
weight established at 7,000 feet density altitude when meeting the 
standards for performance at minimum operating speed (Sec.  27.73) and 
for establishing the respective limiting height-speed envelope (Sec.  
27.79). For those certification projects, we have permitted the 
applicant to show compliance through equivalent level of safety 
findings. In those cases, this new standard would allow for weight-
altitude-temperature (WAT) limitations to be established for a part 27 
rotorcraft that cannot meet the requirements of Sec.  27.143(c) at 
7,000 feet. The rotorcraft would then be required to operate within the 
weights, altitudes, and temperatures specified by those WAT 
limitations. This ``part 29 methodology,'' which imposes WAT 
limitations not usually required of normal category rotorcraft, 
therefore raises the minimum level of safety by restricting the 
aircraft from operating in those environmental conditions where the 
low-speed controllability requirements cannot be met.
    As alluded to by the commenter, these equivalent level of safety 
prohibitions and limitations have historically been obtained through 
use of a certification methodology analogous to that for part 29 
rotorcraft certification. They do not circumvent or eliminate the low 
speed controllability requirements for part 27 rotorcraft. As 
previously noted, one factor we have used in establishing WAT 
limitations is the low-speed controllability requirement of Sec.  
29.143(c). After these changes are effective, the low-speed 
controllability requirement of Sec.  27.143(c) will remain a factor in 
establishing the WAT limitations. While we partially agree with the 
commenter's concerns about operating limitations being a greater 
workload on pilots, we do not believe that any new requirements 
proposed in this rule are beyond the scope of normal piloting 
responsibilities. Whether such data are provided in the Rotorcraft 
Flight Manual (RFM) as performance data or in the Limitations Section 
should not materially affect pilot workload. We agree with the 
commenter that certain environmental conditions may require increased 
pilot vigilance in determining wind speed and direction in order to 
adhere to some limitations and prohibitions. However, we believe that 
following such limitations should not require exceptional piloting 
skill. Furthermore, this standard does not reduce the margin of safety 
because, historically, such a margin of safety was maintained by an 
equivalent level of safety finding. Under the new standard, which 
adopts this equivalent level of safety as another alternative, 
prohibiting and limiting certain operations will maintain, not lower, 
that established level of safety. Accordingly, we are adopting the 
changes as proposed.
    We proposed to amend Sec.  29.25 by requiring that the maximum 
weights, altitudes, and temperatures demonstrated for compliance with 
Sec.  29.143(c), which may also include wind azimuths, become operating 
limitations for Category B rotorcraft with a passenger seating capacity 
of nine or less. Such limitations are necessary to ensure safe aircraft 
operations within the demonstrated performance envelope of such 
rotorcraft.
    Four comments were received regarding Sec.  29.25. One commenter 
stated that the intent and applicability in this proposed rule change 
is confusing in the context of discussions associated with previous 
amendments to part 29 of the regulations and associated advisory 
material. The commenter recommended that the paragraph be rewritten to: 
(1) Clarify how this paragraph affects the relief granted to Category B 
rotorcraft at Amendment 29-24; (2) address maximum safe wind 
limitations in Sec.  29.1583; and (3) make the paragraph applicable to 
all Category B rotorcraft, not just those having a passenger capacity 
of nine or less, if the intent of the change is to grant relief under 
certain conditions from any hover controllability conditions determined 
under Sec.  29.143(c).
    The FAA does not agree that the intent and applicability of the 
proposed change is confusing in the context of previous amendments to 
part 29 and the associated advisory material. As explicitly stated in 
the proposed change to Sec.  29.25(a)(4) this paragraph of the 
regulation applies only to Category B rotorcraft with nine or less 
passenger seats. Even though there may be some imprecise wording in our 
advisory material, we chose to exclude Category B rotorcraft with ten 
or more passenger seats from this change to ensure that a higher level 
of safety is maintained for those transport category rotorcraft 
configured for 10 or more passenger seats. In short, we expect a higher 
level of safety to be applied to all Category A rotorcraft and most 
Category B rotorcraft. For those Category B rotorcraft having nine or 
less passenger seats, in prior certifications in which the current 
standards for controllability near the ground (Sec.  29.143(c)) could 
not be met, we have allowed the applicant to show compliance through an 
equivalent level of safety finding. We accepted these findings as 
providing the same level of safety as that for part 27 certifications, 
which also allows for configurations of no more than nine passenger 
seats. In those certification projects, this new standard would allow 
for demonstrated wind velocities and azimuths to be included as an 
operating limitation, which must be stated as such in the RFM. That is, 
for those part 29, Category B rotorcraft with nine or less passenger 
seats, we believe that by requiring the wind operating envelope to be a 
limitation, the proposed standard provides the same level of safety as 
in the standards prescribed by part 27, which also limits the seating 
capacity to nine or less passenger seats. This methodology is 
consistent with the standards adopted by Amendments 29-21 and 29-24, 
which, among other things, established different criteria for Category 
A and Category B rotorcraft certification in Sec.  29.1 as a function 
of both aircraft weight and maximum passenger seating capacity. We 
believe that the proposed change is materially consistent with the 
current guidance material in Advisory Circular (AC) 29-2C, which only 
will need to be revised to reflect the requirement that the appropriate 
limitations be included in the RFM for these aircraft. Even though 
previous amendments did not specifically require that operating 
envelopes be included in the limitations section of the RFM for these 
aircraft, the proposed change makes this a requirement to further 
increase the safety standards. Further, because this standard deals 
with aircraft weight for various conditions--maximum weights, 
altitudes, and temperatures (WAT)--we opted to place the limitations 
requirement in this regulation, rather than in Sec.  29.1583, to 
further emphasize that the maximum WAT conditions at which the 
rotorcraft can safely operate near the ground with maximum wind 
velocity are limitations and may also include other demonstrated wind 
velocities and azimuths.
    Another commenter stated that revising the rule by addition of a 
new paragraph potentially lowers the level of safety established for 
part 29 standards; potentially shifts the burden for maintaining the 
currently established level of safety from the type design to the 
flight crew; and that maintaining the current version of Sec.  29.25(a) 
is satisfactory and need not be changed. The commenter therefore 
recommended that the proposed change to Sec.  29.25(a) be withdrawn. 
The commenter stated that the low-speed-controllability rule

[[Page 10990]]

consists of two elements, wind speed and weight. The commenter further 
stated that, under current regulations, all part 29 Category B 
rotorcraft are at a competitive disadvantage when compared to 
similarly-sized part 27 rotorcraft because, for part 27 rotorcraft, 
there is no requirement to take-off and land above 7,000 feet density 
altitude at a weight which allows all-azimuth low speed controllability 
in winds of at least 17 knots above 7,000 feet density altitude. The 
commenter asserts that part 29 transport category rotorcraft must be 
designed to operate at the maximum weight that allows compliance with 
Sec.  29.143(c) at each takeoff and landing altitude. If the low speed 
requirement is deleted for part 29 Category B rotorcraft with nine or 
less passenger seats as proposed, the commenter believes the part 29 
flight crew of these rotorcraft will be required to compensate by being 
more alert to the wind conditions when operating near maximum weight. 
Because the margin of safety currently provided by the part 29 design 
may no longer be included in the design of the rotorcraft, the 
commenter contends that this requirement would shift the burden for 
maintaining the currently established level of safety from the type 
design holder to the flight crew.
    The FAA does not agree that these requirements will result in a 
lower safety standard for part 29 or that the requirement potentially 
shifts the burden for maintaining safety from the type design holder to 
the flight crew. Not only is this requirement a safety improvement, but 
critical safety information such as maximum weight, altitude, and 
temperature operating limits (which may include limited wind azimuths) 
would be listed in the Limitations Section of the RFM. Currently, we 
require that information to be placed in the Limitations Section of the 
RFM only for Category A rotorcraft. Our position as reflected in the 
preamble of the NPRM (82-12) \3\ leading to Amendment 29-24, states, in 
part, ``The FAA considers the 17-knot controllability requirement an 
appropriate minimum safety requirement for Category A rotorcraft. * * * 
This proposal would add the requirement that the wind value be placed 
in the Flight Manual as a limitation for Category A rotorcraft. * * * 
In roles envisioned for utility rotorcraft and those carrying less than 
10 passengers, takeoffs and landings are frequently conducted from 
sites where wind information is not readily obtainable. To require this 
wind information as an operating limitation for Category B is 
impractical.'' However, we have reevaluated our position relating to 
operating limitations and are now requiring this information for 
Category B rotorcraft with nine or less passenger seats be placed in 
the Limitations Section, for the same reasons described in our 
disposition of the first three comments to this section.
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    \3\ 47 FR 37806-01, August 26, 1982, Docket  23266.
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    The commenter is correct that, under current regulations, all part 
29 Category B rotorcraft must be designed to operate at the maximum 
weight that allows compliance with Sec.  29.143(c) at each takeoff and 
landing altitude, and that for part 27 rotorcraft, there is no 
requirement to demonstrate all-azimuth low speed controllability in 
winds of at least 17 knots, above 7,000 feet density altitude and at 
the maximum weight. The commenter stated that this places part 29, 
Category B rotorcraft at a competitive disadvantage when compared to 
similarly-sized part 27 rotorcraft. We disagree. For Category B 
rotorcraft having nine or less passenger seats, in prior certifications 
in which the current standards for controllability near the ground 
(Sec.  29.143(c)) could not be met, we have allowed the applicant to 
show compliance through equivalent level of safety findings. We 
accepted these findings as providing the same level of safety as that 
for part 27 certifications, which also allows for no more than nine 
passenger seats, by allowing operating limitations in the RFM which may 
include wind velocities and azimuths. In those certification projects, 
this new standard would allow for demonstrated wind velocities and 
azimuths to be included as an operating limitation in the RFM. That is, 
for those part 29, Category B rotorcraft with nine or less passengers, 
we believe that by requiring wind operating envelope to be a 
limitation, the new standard provides the same level of safety as in 
the standards prescribed by part 27, which also limits the seating 
capacity to nine or less passenger seats.
    As discussed earlier, the FAA did not intend to delete the low 
speed requirement for part 29 Category B rotorcraft with nine or less 
passenger seats. One factor we have used in establishing WAT 
limitations is the low-speed controllability requirement of Sec.  
29.143(c), which this final rule now formalizes.

Performance at Minimum Operating Speed (New Sec.  27.49)

    We proposed to re-designate Sec.  27.73 as Sec.  27.49 and add a 
requirement to determine the out-of-ground effect (OGE) hover 
performance, because OGE operations have become commonplace. The 
proposed change mandates that OGE hover data be determined throughout 
the range of weights, altitudes, and temperatures; most manufacturers 
already present this data in the RFM.
    The FAA received a comment, outside of our proposed rule change, 
suggesting that in this final rule, where we are re-designating Sec.  
27.73 as Sec.  27.49, that we revise paragraph (a)(2)(ii) to encompass 
the entire flight envelope requested by the applicant, including the 
temperature-altitude hover ceiling requirements where the temperature 
at sea level is well above the minimum standard 100 [deg]F condition 
envisioned in Sec.  27.1043(b). The commenter further stated that, if 
we adopt their suggested change to re-designate Sec.  27.49(a)(2)(ii), 
for consistency we should revise Sec. Sec.  27.51, 27.79(a)(1) and 
(a)(2), and 27.143(c)(1) to require turbine-powered rotorcraft to 
demonstrate compliance at maximum weight from sea level at temperatures 
established under Sec.  27.1043(b) to 2,500 feet pressure altitude at a 
temperature corresponding to the established sea level temperature 
decreased by the standard lapse rate. The commenter also stated that 
the FAA should consider revising the 7,000 feet density altitude 
standard in proposed Sec. Sec.  27.51(b), 27.79(a)(1), and 27.143(c)(1) 
and (c)(2) to 7,000 feet density altitude with temperature 
corresponding to the sea level temperature established in compliance 
with Sec.  27.1043(b) decreased by the standard lapse rate. The 
commenter further stated that these changes would acknowledge the 
increased capability of turbine-powered rotorcraft by requiring 
compliance at the edge of the envelope requested, not to a single 
density altitude, which may not reflect the intended operational 
envelope of the rotorcraft. Although this comment may have merit, it is 
beyond the scope of our proposals and is not adopted. We may consider 
it in future rulemaking actions. Accordingly, it is adopted as 
proposed.

Takeoff (Sec.  27.51), Landing (Sec.  27.75), and Engines (Sec.  
27.903)

    We received no comments on these proposals; all three are adopted 
as proposed.
    We proposed to revise Sec.  27.51 to recognize in the standard that 
the most critical center-of-gravity (CG) may not be the extreme forward 
CG, and require that tests be performed at the most critical CG 
configuration and at the maximum weight for which takeoff certification 
is requested. Further, we proposed to clarify the requirement to

[[Page 10991]]

demonstrate safe landings after an engine failure at any point along 
the takeoff path up to the maximum takeoff altitude or 7,000 feet, 
whichever is less, to explicitly state that the altitudes cited are 
density altitudes.
    We proposed to revise Sec.  27.75(a) to: (1) State the required 
flight condition in more traditional rotorcraft terminology; (2) 
require multi-engine helicopters to demonstrate landings with one 
engine inoperative and initiated from an established approach; and (3) 
replace the word ``glide'' with the word ``autorotation.''
    We proposed to add paragraph Sec.  27.903(d) to require engine 
restart capability, which is a fundamental necessity for any aircraft 
to minimize the risk of a forced landing. A restart capability will 
enhance safety, even if it may not be useful in every case such as when 
engine damage exists or when there is insufficient altitude to 
implement the engine restart procedure. We intend that the restart 
procedure be included in the RFM.

Glide Performance (Sec.  27.71)

    One commenter noted that the word ``glide'' has been replaced with 
``autorotation'' in the proposed text of Sec.  27.143. However, the 
title of Sec.  27.71 remains ``Glide Performance.'' The commenter 
recommended that the title of Sec.  27.71 be changed to ``Autorotation 
Performance,'' to provide consistency with the proposed changes. The 
FAA agrees with the comment and the title has been changed.

Performance at Minimum Operating Speed (Sec.  27.73)

    One commenter noted that in our proposed re-designation of current 
Sec.  27.73 to Sec.  27.49, we proposed to change the ambient 
temperature in paragraph (a)(2)(ii) from ``[deg] F'' to ``[deg] C.'' 
Consequently, the commenter recommended that all sections of part 27 
containing temperature callouts likewise be revised. We disagree. The 
NPRM does not change the ambient temperature callout from degrees-
Fahrenheit to degrees-Celsius. Rather, it recognizes degrees-Celsius in 
addition to degrees-Fahrenheit when making the temperature callout. 
Incorporating similar changes to other temperature callouts will be 
considered for future changes to part 27. Accordingly, the change is 
adopted as proposed.

Limiting Height--Speed Envelope (Sec.  27.79)

    We proposed to revise Sec.  27.79(a)(1) to include the words 
``density altitude'' after ``7,000 feet.'' We also proposed to revise 
Sec.  27.79(a)(2) by removing ``lesser'' from the first sentence, 
reflecting that current OGE weights for helicopters are not necessarily 
less than the maximum weight at sea level. Finally, we proposed to 
remove the term ``greatest power'' from Sec.  27.79(b)(2) and replace 
it with language that more clearly states the power to be used on the 
remaining engine(s) for multi-engine helicopters. This ``minimum 
installed specification power'' is the minimum uninstalled 
specification power corrected for installation losses.
    One commenter to the proposed language suggested that the FAA seems 
to be aligning the sections of part 27 with part 29, as was proposed 
with the re-designation of Sec.  27.73 as Sec.  27.49. Consequently, 
the commenter recommended that Sec.  27.79 be re-designated as Sec.  
27.87. The FAA agrees that this paragraph re-designation better aligns 
the requirements for performance at minimum operating speed in part 27 
and part 29. Furthermore, the re-designating of the paragraph is 
administrative in nature and imposes no additional requirements on 
applicants. Accordingly, the recommendation is adopted as proposed.
    The second commenter noted that since the height-velocity (H-V) 
envelope for part 27 aircraft is not a limitation, the word 
``limiting'' should be deleted from the title of Sec.  27.79 and from 
any other references to the H-V envelope contained in part 27. The FAA 
agrees with the comment, since Sec.  27.1587 requires that the H-V 
envelope be published in the RFM as performance information. 
Accordingly, the title of the paragraph is changed.

Controllability and Maneuverability (Sec. Sec.  27.143, 29.143)

    We proposed to revise Sec. Sec.  27.143(a)(2)(v) and 
29.143(a)(2)(v) to replace the word ``glide'' with ``autorotation.'' We 
proposed to re-designate portions of Sec.  27.143, and to rewrite 
Sec. Sec.  27.143(c) and 29.143(c) to more clearly state that 
controllability on or near the ground must be demonstrated throughout a 
range of speeds from zero to at least 17 knots. We also proposed to 
clarify the altitude requirement with the addition of the words 
``density altitude.'' We further proposed to revise Sec.  27.143(c)(2) 
to require that controllability be determined at altitudes above 7,000 
feet density altitude if takeoff and landing are scheduled above that 
altitude. Lastly, we proposed to add Sec. Sec.  27.143(d) and 
29.143(d), to require the determination of controllability for wind 
velocities from zero to at least 17 knots OGE at weights selected by 
the applicant. These proposed changes, together with the new OGE hover 
requirement of Sec.  27.49, would increase the level of safety by 
requiring additional performance information.
    Relative to both sections 27.143 and 29.143, one commenter noted 
that the reference to ``paragraph (e)'' in paragraph (b)(4) of the 
current rule (which we did not propose to change in the NPRM) should be 
changed to read ``paragraph (f).'' The FAA agrees. As indicated in the 
NPRM, we proposed to re-designate Sec. Sec.  27.143 and 29.143 
paragraphs (d) and (e) as paragraphs (e) and (f), respectively. 
However, we failed to propose to change the reference in paragraphs in 
Sec. Sec.  27.143 and 29.143(b)(4) from paragraph (e) to paragraph (f). 
That is, we gave no indication that we proposed to delete the exception 
enumerated in (b)(4) to exclude helicopters from the (b)(4) requirement 
if the helicopter demonstrates compliance with current paragraph (e) 
(re-designated paragraph (f)). Because these paragraph re-designations, 
as well as the unchanged provisions of paragraph (b), were intended 
only to continue the current requirements, we believe changing the 
reference in paragraph (b)(4) from (e) to (f) is non-substantive, 
constitutes a correction of an error, is consistent with our intended 
changes without which the proposed change would have unintended 
consequences, and continues the current standard to exclude the same 
helicopters from the provisions of paragraph (b)(4). We have changed 
the reference in the final rule.
    A second comment stated that the NPRM proposes to add requirements 
to determine low-speed controllability: (1) Near the ground for takeoff 
and landing altitudes above 7,000 feet density altitude, and (2) for 
OGE for the altitude range from standard sea level to the maximum 
takeoff and landing altitude capability of the aircraft. The commenter 
stated that under Sec.  27.25(a), the weight selected by the applicant 
to establish the all-azimuth wind velocities would be a factor in 
determining the maximum weight. The commenter stated that this weight 
would undoubtedly be much less than the maximum weight determined under 
the current rule and thus would make the rotorcraft less competitive. 
Further, the commenter assumes that the intent of the proposal is to 
develop additional performance information beyond that currently 
available, to assist the flight crew. The commenter stated that if 
these assumptions are true, the NPRM should be revised to clearly 
indicate that the proposed paragraphs are not applicable as flight 
requirements when establishing the maximum weight under Sec.  27.25(a).

[[Page 10992]]

The FAA does not agree. As noted in the NPRM, the intent of the 
proposed language is to increase the level of safety by providing 
additional performance information in the RFM. This is further 
reflected in the proposed Sec.  27.1587(a)(2), which proposed to 
explicitly require presentation of performance information found in 
meeting the requirements of the proposed Sec.  27.143. Consequently, 
the new Sec.  27.143(d)(4) will not be used in determining the 
rotorcraft's maximum weight under Sec.  27.25(a). Except for the 
reference change in paragraph Sec.  27.143(b)(4), the changes are 
adopted as proposed.
    Another comment suggests that we used the word ``manner'' instead 
of ``maneuver'' in proposed Sec.  29.143(c). The proposed requirement 
reads, in part, ``* * * the rotorcraft can be operated without loss of 
control on or near the ground in any manner appropriate to the type. * 
* *'' The commenter suggests that the word ``manner'' should be changed 
to ``maneuver'' because the latter is used in the current requirement 
and also in the proposed and current requirement in Sec.  27.143(c). We 
agree. The word ``manner,'' as used in the proposed text, is an error. 
We intended to use the word ``maneuver'' in proposed Sec.  29.143(c) 
and we have made that non-substantive change in this final rule.

Static Longitudinal Stability (Sec. Sec.  27.173, 29.173)

    We proposed to clarify Sec. Sec.  27.173(a) and 29.173(a) by 
changing ``a speed'' to ``airspeed.'' We also proposed to combine 
paragraphs (b) and (c) to allow neutral or negative static stability in 
limited areas of the flight envelope, if adequate compensating features 
are present and the pilot can maintain airspeed within five knots of 
the desired trim airspeed under the conditions of Sec. Sec.  27.175 and 
29.175. Such neutral or negative static stability in limited flight 
domains have been allowed for numerous rotorcraft under equivalent 
level of safety findings. Lastly, we proposed to delete the Sec. Sec.  
27.173(c) and 29.173(c) requirements relating to the hover 
demonstration in current Sec. Sec.  27.175(d) and 29.175(d).
    We received no substantive comments relative to the proposed 
changes to Sec.  27.173. One commenter noted that the proposed revision 
to Sec.  29.173(b) has an open parenthesis mark in front of the ``5 
knots'' and suggested that open parenthesis mark should be a ``'' symbol. We agree and have made that change in the final rule. 
The other proposed changes have been adopted as proposed.

Demonstration of Static Longitudinal Stability (Sec. Sec.  27.175, 
29.175)

    We proposed to decrease, in paragraphs (a) and (b) of Sec. Sec.  
27.175 and 29.175, the airspeed range about the specified trim speeds 
to more representative values than are currently contained in the rule. 
We also proposed to add a new paragraph (c) to require an additional 
level flight demonstration point, at a trim airspeed of VNE - 10 knots, 
because the data coverage under the current cruise demonstration speed 
in modern helicopters may no longer represent a normal variation about 
a trim point. Additionally, we proposed to re-designate the current 
paragraph (c) as paragraph (d), and to delete the current paragraph (d) 
containing the hover demonstration, as the safety considerations 
associated with hovering flight are adequately addressed by Sec. Sec.  
27.143(a) and 29.143(a), respectively.
    One commenter suggested that discrepancies may exist between Sec.  
27.175(d)(1) and (2), and Sec. Sec.  27.67 and 27.71. Specifically, 
Sec.  27.175 requires that static longitudinal stability be 
demonstrated in autorotation about the airspeeds for minimum rate-of-
descent and best angle-of-glide. However, Sec.  27.71 requires that the 
minimum rate of descent and the best angle of glide airspeeds be 
determined only for single engine helicopters and multiengine 
helicopters that do not meet Category A engine isolation requirements. 
Therefore, the commenter stated that this requirement would not apply 
to multi-engine helicopters that meet Category A engine isolation 
requirements. The commenter recommended that these sections be 
reconciled for part 27 designs that meet Category A engine isolation 
requirements. The FAA does not agree that any action is necessary. 
While Sec.  27.71 does not have an explicit requirement to determine 
these two autorotation speeds for part 27 rotorcraft that meet Category 
A engine isolation requirements, Sec.  27.141 requires that the 
rotorcraft demonstrate satisfactory flight characteristics for ``any 
condition of speed, power, and rotor r.p.m. for which certification is 
requested; * * *.'' Further, the two trim airspeeds explicitly cited in 
the proposed rule are intended to provide data at the most likely 
operating conditions flown during an autorotation, thereby providing a 
higher level of safety. Consequently, we are adopting the language as 
proposed.
    One commenter stated that the proposed revision to paragraph Sec.  
29.175(b) reads, ``* * * in the climb condition at speeds from Vy-10 
kt, to Vy + 10 kt. * * *'' The commenter recommended that we delete the 
comma after ``Vy-10 kt.'' We agree. That comma in the proposed text is 
a typographical error and has been removed in this final rule. 
Otherwise, the changes are adopted as proposed.

Static Directional Stability (Sec. Sec.  27.177, 29.177)

    We proposed to revise Sec. Sec.  27.177 and 29.177 to provide 
further objective criteria over which the directional stability 
characteristics are evaluated. We also proposed to allow for a minimum 
amount of negative stability around each trim point, which does not 
materially affect the overall safety considerations of static 
directional stability.
    One commenter noted a typographical error in the proposed text of 
Sec.  27.177, in that paragraph (a)(1) has an open parenthesis mark in 
front of ``10 degrees'' and suggests that it should be a ``'' symbol. We agree and have corrected that error in Sec.  
27.177(a)(1) of this final rule. Otherwise, the proposal is adopted as 
proposed.
    Two comments were received regarding Sec.  29.177. In the first 
comment, Transport Canada stated that they do not think that Sec.  
29.177(a)(1) makes sense in relation to Sec.  29.177(a). They recited 
what they assumed we meant by the proposal and stated that ``paragraph 
29.177(a)(1) specifies a range of sideslip angles and the lesser 
sideslip angle in this range will always be the smallest angle in the 
range.'' We do not agree and have not made any changes based on this 
comment. We believe that the commenter has misinterpreted our meaning 
in the ``* * * sideslip angles up to the lesser of--'' language in 
proposed Sec.  29.177(a). This language modifies the four options 
listed in paragraphs Sec.  29.177(a)(1) through Sec.  29.177(a)(4) and 
is intended to mean the lesser value found from each of those four 
subsequent paragraphs. Paragraph 29.177(a)(1) is intended to provide 
options of sideslip angles from trim that are 50[deg] wide (+25[deg] to 
-25[deg]) at the minimum-rate-of-descent airspeed less 15 knots, then 
varying linearly and narrowing to 20[deg] wide (+10[deg] to -10[deg]) 
at the Vne airspeed.
    The second commenter suggested that the phrase in proposed Sec.  
29.177(c) that reads ``paragraph (a) of this paragraph'' be changed to 
read ``paragraph (a) of this section.'' We agree. The correct reference 
is to paragraph (a) of Sec.  29.177. Except for changing the word 
``paragraph'' to ``section'' for proposed Sec.  29.177(c), the other 
changes are adopted as proposed.

[[Page 10993]]

Performance Information (Sec. Sec.  27.1587, 29.1587)

    We proposed to revise Sec.  27.1587(a) to include reference to new 
Sec.  27.49. We also proposed to revise Sec.  27.1587(a)(2)(i) and (ii) 
to specifically include requirements for presenting maximum safe winds 
for OGE operations established in proposed Sec.  27.143. Lastly, we 
proposed to delete Sec.  27.1587(b)(1)(i) and (ii), which were moved 
into Sec.  27.1585(a) by Amendment 27-21 and inadvertently left in 
Sec.  27.1587.
    Three comments were received regarding Sec.  27.1587. The first 
commenter suggested that the term ``maximum wind value'' in Sec.  
27.1587(a)(2)(ii) could be confusing and ambiguous and recommended that 
the term ``maximum wind value'' be replaced with ``in winds of not less 
than 17 knots from all azimuths.'' We disagree. The requirements of 
this proposed rule assume that the requirements of Sec.  27.143(c) can 
be met by the applicant. The proposed change seeks to ensure that 
appropriate performance information will be included in the RFM, 
whether it is 17 knots or some higher demonstrated value.
    The second commenter suggested that Sec.  27.1587(a)(2)(ii) is in 
conflict with the proposed Sec.  27.143(c)(2) and (3). Specifically, 
the former paragraph uses the term ``maximum weight,'' while the latter 
two allow the applicant to select a weight, which may be less than the 
maximum weight. The FAA disagrees. The proposed text of Sec.  
27.1587(a) explicitly requires that the RFM contain information 
determined in accordance with Sec.  27.143(c) and (d). The term 
``maximum weight,'' subsequently used in paragraph (a)(2)(ii) is 
intended to be a further description of the maximum weight used when 
demonstrating compliance with Sec.  27.143(c) and (d).
    The third comment stated that the FAA has no formal definition of 
``maximum safe wind,'' nor is there a flight requirement to demonstrate 
a ``maximum safe wind.'' The commenter recommended that the FAA explain 
the term and include definitions in part 27 and part 29. The FAA agrees 
that the comment may have merit. However, the term is currently used in 
both part 27 and part 29, and has been used throughout the history of 
these regulations, to include Civil Air Regulations 6 and 7, 
predecessors to this regulation. Development of a formal definition may 
be evaluated for incorporation in future rulemaking. Accordingly, the 
changes are adopted as proposed.
    We proposed to revise Sec.  29.1587 to require new performance 
information be included in the RFM, including the requirement for 
presenting maximum safe winds for OGE operations.
    A commenter stated that the proposed paragraphs (a)(7) and (b)(8) 
require, in part, ``* * * the maximum weight for each altitude and 
temperature condition at which the rotorcraft can safely hover in-
ground-effect and out-of-ground effect in winds of not less than 17 
knots. * * *'' The commenter stated that the requirement is redundant, 
is not pertinent to a paragraph referring only to OGE hover 
performance, and that other paragraphs of Sec.  29.1587 already contain 
the in-ground-effect (IGE) hovering requirement. The commenter 
recommended that the IGE requirement be deleted from each proposed 
paragraph. We agree that the ``in-ground-effect'' requirement is 
redundant and unnecessary. In adopting the changes to this section, we 
have deleted the ``in-ground-effect'' hovering requirement from the 
proposed Sec.  29.1587(a)(7) and Sec.  29.1587(b)(8).
    The commenter further stated that the proposed paragraphs (a)(7) 
and (b)(8) conflict with the proposed revision to Sec.  29.143(d). 
Specifically, proposed paragraphs (a)(7) and (b)(8) require the 
applicant to publish performance data for the ``maximum weight,'' 
whereas proposed Sec.  29.143(d) allows a ``weight selected by the 
applicant'' when demonstrating the OGE requirement. The commenter 
stated that the ``weight selected by the applicant'' may not be the 
``maximum weight.'' Therefore, the commenter recommended that Sec.  
29.1587(a)(7) and (b)(8) be changed to reflect the ``weight selected by 
the applicant'' as stated in Sec.  29.143(d). We disagree. Proposed 
Sec.  29.143(d) does allow for a ``weight selected by the applicant'' 
for the controllability and maneuverability standards. However, the 
proposed Sec.  29.1587(a)(7) and (b)(8) also require that OGE 
performance data be provided at minimum operating speeds under Sec.  
29.49 over the ranges of ``weight, altitude, and temperature'' for 
which certification is requested, in addition to performance data at 
the maximum weight for each altitude and temperature at which the 
helicopter can hover safely in winds of not less than 17 knots from all 
azimuths. Consequently, the intent of this final rule is to require new 
OGE hover performance data be provided at the maximum weight used to 
demonstrate compliance with Sec. Sec.  29.49 and 29.143(d).
    The commenter stated that Sec.  29.1587(b)(2) could be revised to 
more clearly indicate that the hover ceiling data is for IGE hovering. 
We agree that making specific reference to the IGE hover ceiling, adds 
clarification, and removes any ambiguity in the requirement. 
Accordingly, the recommendation is adopted.
    The commenter also suggested that since Sec.  29.1587(b)(8) uses 
the term ``winds of at least 17 knots from all azimuths,'' it ``would 
seem reasonable to expect paragraph (b)(4) to be similarly changed.'' 
We do not agree. Section 29.1587(b)(4) assumes that the requirements of 
Sec.  29.143(c) for critical conditions can be met during IGE 
operations. Consequently, the requirements of (b)(4) ensure that, if a 
higher wind value exists that could present an unsafe condition, the 
consideration of those higher wind values are reflected in the 
appropriate performance information in the RFM for the maximum safe 
winds for operations near the ground. Conversely, paragraph (b)(8) 
requires presentation of the maximum weight at which the rotorcraft can 
hover OGE in 17-knot winds from any azimuth.
    The commenter questioned why we proposed to remove the term 
``maximum safe wind'' from current Sec.  29.1587(a)(7) and replace it 
with ``maximum weight for each altitude and temperature condition at 
which the rotorcraft can safely hover in-ground-effect and out-of-
ground effect in winds of not less than 17 knots from all azimuths.'' 
The commenter noted that in Sec.  29.1587(b)(8) the FAA proposed to 
continue to use the current terminology ``maximum safe wind'' but add 
an ``almost separate and distinct parameter,'' that is to say, 
``maximum weight for each altitude and temperature condition at which 
the rotorcraft can safely hover in-ground-effect and out-of-ground 
effect in winds of not less than 17 knots from all azimuths,'' the 
exact language we proposed as replacement language in paragraph (a)(7). 
The commenter stated that there is some apparent confusion over the 
definition and use of the term ``maximum safe wind.'' The commenter 
further postulated that in the proposed paragraph (a)(7), standard 
maximum safe wind seems to be equated with winds established for all-
azimuth low speed controllability as defined in Sec.  29.143(c). 
Conversely, proposed paragraph (b)(8) seems to treat maximum safe wind 
as something other than winds established for all-azimuth low speed 
controllability. The commenter believes that ``maximum safe wind'' 
could be viewed as a range of wind speeds and azimuths for safe 
operation where the wind speed is neither less than the wind speed 
established by Sec.  29.143(c) nor more than

[[Page 10994]]

the demonstrated speed, particularly in non-critical azimuth ranges. 
The commenter stated that the FAA has neither a formal definition of 
``maximum safe wind'' nor a flight requirement to demonstrate a 
``maximum safe wind,'' and therefore recommended that the FAA explain 
the term and include a formal definition in part 27 and part 29. The 
FAA disagrees. In paragraphs (a)(7) and (b)(8), we proposed to more 
explicitly relate these requirements to those of Sec.  29.143. The term 
``maximum safe wind'' is also included in paragraph (b)(8) to provide 
for the presentation of additional wind speeds and azimuths in which 
Category B rotorcraft may be safely operated. While this term is not 
formally defined, it has been used in the certification standards since 
the existence of Civil Air Regulations 6 and 7; development of a formal 
definition will be evaluated in future rule changes. We did not make 
any changes to Sec.  21.1587 based on these comments.

Airworthiness Criteria of Helicopter Instrument Flight (Appendix B to 
Part 27 and Appendix B to Part 29)

    We proposed to amend paragraph V(a) to allow for a minimal amount 
of neutral or negative stability around trim and to replace the phrase 
``in approximately constant proportion'' with ``without 
discontinuity.'' We also proposed to require that the pilot be able to 
maintain the desired heading without exceptional skill or alertness. 
Additionally, we proposed to reorganize paragraphs VII(a)(1) and 
VII(a)(2) and to revise them to specify the standards that must be met 
when considering a stability augmentation system failure. Finally, in 
paragraph V(b) of Appendix B to Part 29, we proposed to replace the 
word ``cycle'' with the correct word, ``cyclic.''
    One commenter noted that, in the proposed change to paragraph 
VII(a) of Appendix B to Part 27 and Part 29, we replaced the term 
``failure condition'' with the term ``failure.'' The commenter stated 
that, ``in the context of a systems safety assessment a `failure' and a 
`failure condition' are two distinctly different things'' and that the 
proposed change represents an alleviation. Consequently, the commenter 
stated support for reinstating the original term ``failure condition'' 
as intended by the ARAC Performance and Handling Qualities Working 
Group. Although not stated specifically in the comment, we believe that 
the commenter is suggesting that the word ``condition'' be inserted 
after the word ``failure'' in the second and third sentences of 
paragraph VII(a). We agree that we should insert the word ``condition'' 
in the two places in paragraph VII(a) but do not agree that, as stated, 
the proposal lessens the safety standard. Rather, we believe that 
omitting the term ``condition,'' as proposed in the NPRM, could result 
in a perceived change to the requirements for the systems safety 
assessment for instrument flight certification or could create 
confusion in future certification activities since its use would not be 
consistent with other current regulations, advisory material, and 
industry practice. No such change was intended by the proposal.
    SAE Aviation Recommended Practice, ARP4761, defines the term 
``failure'' as ``a loss of a function or a malfunction of a system or a 
part thereof.'' It further defines the term ``failure condition'' as 
``a condition with an effect on the aircraft and its occupants, both 
direct and consequential, caused or contributed to by one or more 
failures, considering relevant adverse operation or environmental 
conditions.'' ARP4761 further states that, ``for each failure 
condition, the analyst must assign probability requirements.'' In 
existing certification activities, we accept these definitions for 
assigning probability requirements. In application, the five 
probability classifications (frequent, reasonably probable, remote, 
extremely remote, and extremely improbable) are intended to relate to 
an identified ``failure condition'' resulting from or contributed to by 
the improper operation or loss of a function or functions and not to 
the reliability of specific components or systems. The FAA intends that 
the term ``failure condition'' relate to the assignment of a 
probability requirement (in this case, ``extremely improbable'') to the 
``failure condition,'' and not to the ``failure'' itself. In this 
standard, a Stability Augmentation System (SAS) failure condition, 
under these definitions, requires that the applicant take into 
consideration that the operation is made during instrument flight.
    Because we are concerned that this proposal may be viewed as an 
inadvertent change to the safety standard and the system safety 
analysis requirements associated with SAS for instrument flight 
certification, we have changed the proposed standard and now use the 
term ``failure condition'' in the suggested two locations in paragraph 
VII(a). This change is consistent with the intent of the proposed 
standard, current industry practice, and is the same terminology used 
elsewhere in our regulations and guidance material. The change is 
further consistent with our goal of maintaining harmonized 
certification standards with the European Aviation Safety Agency 
(EASA). The remaining proposals are adopted without change.

Appendix C to Part 27 Criteria for Category A

    One commenter recognized that we did not propose to change Appendix 
C to part 27, but suggested that since we are proposing to revise the 
low speed controllability section of part 27, we should also require 
all-azimuth low speed controllability in winds of not less than 17 
knots at all weights, altitudes and temperatures where Category A 
takeoff and landing operations are requested for certification. The 
commenter stated that current Appendix C to part 27 does not require 
that part 27 rotorcraft certificated for Category A operations meet the 
low speed controllability requirements of Sec.  29.143(c) because that 
requirement is not listed in paragraph C27.2 of Appendix C to part 27. 
The commenter speculated that perhaps ``we reasoned that since the low 
speed controllability requirements of Sec.  27.143(c) and Sec.  
29.143(c) are identical, there was not a need to repeat a requirement 
already in place.'' However, the commenter stated that there is a 
difference; specifically with regards to the altitude range over which 
the two rules apply. The commenter stated that Sec.  27.143(c) applies 
only from sea level to 7,000 feet density altitude, while Sec.  
29.143(c) applies to all altitudes and temperature for takeoff and 
landing requested for certification. The commenter stated that part 27 
rotorcraft certificated for Category A operations should meet the same 
level of safety as that for transport category rotorcraft. We disagree. 
Part 27 rotorcraft certificated for Category A operations were not 
intended to meet the same level of safety as that for transport 
category rotorcraft. If this were the case, Appendix C to part 27 would 
have included all the part 29 requirements for Category A, particularly 
where differences exist between part 27 and part 29. Indeed, different 
Category A certification requirements exist for part 29 rotorcraft, as 
a function of aircraft weight and passenger seating capacity.

Performance at Minimum Operating Speed (New Sec.  27.49)

    We proposed to re-designate Sec.  27.73 as Sec.  27.49 and add a 
requirement to determine the OGE hover performance, because such 
operations have become commonplace. The proposed change mandates that 
OGE hover data be determined throughout the range of weights, 
altitudes, and temperatures;

[[Page 10995]]

most manufacturers already present this data in the RFM.
    Concerning this re-designation of Sec.  27.73 as Sec.  27.49, a 
commenter suggested that we revise paragraph (a)(2)(ii) to encompass 
the entire flight envelope requested by the applicant, including the 
temperature-altitude hover ceiling requirements, where the temperature 
at sea level is well above the minimum standard 100[deg]F condition 
envisioned in Sec.  27.1043(b). The commenter further stated that, if 
we adopt the suggested change to re-designate Sec.  27.49(a)(2)(ii), 
for consistency we should revise Sec. Sec.  27.51, 27.79(a)(1) and 
(a)(2), and 27.143(c)(1) to require turbine-powered rotorcraft to 
demonstrate compliance at maximum weight from sea level at temperatures 
established under Sec.  27.1043(b) to 2,500 feet pressure altitude at a 
temperature corresponding to the established sea level temperature 
decreased by the standard lapse rate. The commenter also stated that 
the FAA should consider revising the 7,000 feet density altitude 
standard in proposed Sec. Sec.  27.51(b), 27.79(a)(1), and 27.143(c)(1) 
and (c)(2) to 7,000 feet density altitude with temperature 
corresponding to the sea level temperature established in compliance 
with Sec.  27.1043(b) decreased by the standard lapse rate.
    The commenter stated that these changes would acknowledge the 
increased capability of turbine-powered rotorcraft by requiring 
compliance at the edge of the requested envelope, not to a single 
density altitude, which may not reflect the intended operational 
envelope of the rotorcraft. Although this comment may have merit, it is 
beyond the scope of our proposals and is not adopted. We may consider 
it in future rulemaking actions.

Takeoff (Sec.  27.51), Landing (Sec.  27.75), and Engines (Sec.  
27.903)

    We received no comments on our proposed changes to these sections. 
All are adopted as proposed, but are included here for informational 
purposes.
    We proposed to revise Sec.  27.51 to recognize in the standard that 
the most critical center-of-gravity (CG) may not be the extreme forward 
CG, and require that tests be performed at the most critical CG 
configuration and at the maximum weight for which takeoff certification 
is requested. Further, we proposed to clarify the requirement to 
demonstrate safe landings after an engine failure at any point along 
the takeoff path up to the maximum takeoff altitude or 7,000 feet, 
whichever is less, to explicitly state that the altitudes cited are 
density altitudes.
    We proposed to revise Sec.  27.75(a) to: (1) State the required 
flight condition in more traditional rotorcraft terminology; (2) 
require multi-engine helicopters to demonstrate landings with one 
engine inoperative and initiated from an established approach; and (3) 
replace the word ``glide'' with the word ``autorotation.''
    We proposed to add paragraph Sec.  27.903(d) to require engine 
restart capability, which is a fundamental necessity for any aircraft 
to minimize the risk of a forced landing. A restart capability will 
enhance safety, even if it may not be useful in every case, such as 
when engine damage exists or when there is insufficient altitude to 
implement the engine restart procedure. We intend to include the 
restart procedure in the RFM.

Economic Evaluation

    Regarding our economic determination, Erickson Air-Crane 
Incorporated asked that we correct the Regulatory Flexibility 
Determination section to show that Erickson is a part 29, rather than a 
part 27, rotorcraft manufacturer; has 600 employees rather than 500; 
and suggested that we recalculate the percentages in the Annual Revenue 
table based on these changes. We concur. We have made these changes and 
do not believe that they materially change the economic determination 
of this rule.

Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the FAA consider the impact of paperwork and other information 
collection burdens imposed on the public. An agency may not collect or 
sponsor the collection of information, nor may it impose an information 
requirement unless it displays a currently valid Office of Management 
and Budget (OMB) control number.
    As required by the Act, we submitted a copy of the new information 
requirements to OMB for their review when we published the NPRM. 
Additionally, in the NPRM, we solicited comments from the public on the 
proposed new information collection requirements. No comments relating 
to the proposed new information collection requirements were received. 
Affected parties, however, do not have to comply with the information 
collection requirements of this rule until the OMB approves the FAA's 
request for this information collection requirement. The FAA will 
publish a separate document notifying you of the OMB Control Number and 
the compliance date(s) for the information collection requirements of 
this rule.

International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to comply with 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
reviewed the corresponding ICAO Standards and Recommended Practices and 
has identified no ``differences'' with these regulations.

Regulatory Evaluation, Regulatory Flexibility Determination, 
International Trade

Impact Assessment, and Unfunded Mandates Assessment

    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 (Pub. L. 96-354) requires 
agencies to analyze the economic impact of regulatory changes on small 
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits 
agencies from setting standards that create unnecessary obstacles to 
the foreign commerce of the United States. In developing U.S. 
standards, this Trade Act requires agencies to consider international 
standards and, where appropriate, that they be the basis of U.S. 
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L. 
104-4) requires agencies to prepare a written assessment of the costs, 
benefits, and other effects of proposed or final rules that include a 
Federal mandate likely to result in the expenditure by State, local, or 
tribal governments, in the aggregate, or by the private sector, of $100 
million or more annually (adjusted for inflation with base year of 
1995). This portion of the preamble summarizes the FAA's analysis of 
the economic impacts of this final rule. We suggest readers seeking 
greater detail read the full regulatory evaluation, a copy of which we 
have placed in the docket for this rulemaking.
    In conducting these analyses, FAA has determined that this final 
rule: (1) Has benefits that justify its costs, (2) is not an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866, (3) is not ``significant'' as defined in 
DOT's Regulatory Policies and Procedures; (4) will not have a 
significant economic

[[Page 10996]]

impact on a substantial number of small entities; (5) will not have a 
significant effect on international trade; and (6) will not impose an 
unfunded mandate on state, local, or tribal governments, or on the 
private sector by exceeding the monetary threshold identified. These 
analyses are summarized below.

Total Benefits and Costs of This Rulemaking

    The estimated cost of this final rule is about $558,250 ($364,955 
in present value). The estimated potential benefits of avoiding at 
least one helicopter accident are about $3.9 million ($2.7 million in 
present value).

Who is Potentially Affected by This Rulemaking?

     Operators of U.S.-registered part 27 or 29 rotorcraft, and
     Manufacturers of part 27 or 29 rotorcraft.

Our Cost Assumptions and Sources of Information

     Discount rate--7%.
     Period of analysis--10 years. During this period 
manufacturers will seek new certifications for one large and one small 
part 27 and two large part 29 rotorcraft.
     Value of fatality avoided--$3.0 million (Source: 
``Economic Values for FAA Investment & Regulatory Decisions'' (March 
2004)).

Benefits of This Rule

    The benefits of this final rule consist of the value of lives and 
property saved due to avoiding accidents involving part 27 or 29 
rotorcraft. Over the 10-year period of analysis, the potential benefit 
of this final rule will be at least $3.9 million ($2.7 million in 
present value) by preventing one accident.

Cost of This Rule

    We estimate the costs of this final rule to be about $558,250 
($364,955 in present value) over the 10-year analysis period. 
Manufacturers of 14 CFR part 27 rotorcraft will incur costs of $383,250 
($234,039 in present value) and manufacturers of 14 CFR part 29 
helicopters will incur costs of $175,000 ($130,916 in present value).

Final Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (RFA) establishes ``as a 
principle of regulatory issuance that agencies shall endeavor, 
consistent with the objective of the rule and of applicable statutes, 
to fit regulatory and informational requirements to the scale of the 
business, organizations, and governmental jurisdictions subject to 
regulation.'' To achieve that principle, the RFA requires agencies to 
solicit and consider flexible regulatory proposals and to explain