[Federal Register Volume 61, Number 50 (Wednesday, March 13, 1996)]
[Rules and Regulations]
[Pages 10436-10438]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-6019]




[[Page 10435]]

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Part III





Department of Transportation





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Federal Aviation Administration



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14 CFR Parts 27 and 29



Airworthiness Standards; Occupant Protection in Normal and Transport 
Category Rotorcraft; Final Rule

  Federal Register / Vol. 61, No. 50 /  Wednesday, March 13, 1996 / 
Rules and Regulations  
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[[Page 10436]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 27 and 29

[Docket No. 27681; Amendment No. 27-32, 29-38]
RIN 2120-AE88


Airworthiness Standards; Occupant Protection in Normal and 
Transport Category Rotorcraft

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: The Federal Aviation Administration (FAA) is amending the 
airworthiness standards to improve occupant protection in normal and 
transport category rotorcraft. These amended standards significantly 
increase the static design ultimate inertial load factors for 
restraining heavy items located above or behind the occupied areas 
during emergency landings. These increased load factors also apply to 
certain cargo and baggage compartments. These amendments further 
complement and enhance the standards previously adopted for occupant 
restraint and protection in normal and transport category rotorcraft in 
the event of a survivable emergency landing.

EFFECTIVE DATE: June 11, 1996.

FOR FURTHER INFORMATION CONTACT:
Mr. Mike Mathias, Regulations Group, Rotorcraft Directorate, Aircraft 
Certification Service, FAA, Forth Worth, Texas 76193-0111, telephone 
number (817) 222-5110.

SUPPLEMENTARY INFORMATION:

Background

    These amendments are based on Notice of Proposed Rulemaking (NPRM) 
No. 94-8, which was published in the Federal Register on April 11, 1994 
(59 FR 17156). That notice proposed to amend the occupant protection 
airworthiness standards of 14 CFR parts 27 and 29 (parts 27 and 29) to 
increase the ultimate inertial load factors in Secs. 27.561(c) and 
29.561(c) and to add a new 1.5g rearward design load factor to 
Secs. 27.561(b) and 29.561(b). The amended standards of Secs. 27.561(c) 
and 29.561(c) would apply to restraining heavy items located above and 
behind the cabin and other occupied areas against the loads created 
during emergency landings; and the amended standards of Secs. 27.561(b) 
and 29.561(b) would apply to restraining and protecting occupants and 
restraining heavy items in the cabin and other occupied areas against 
the loads created during emergency landings. In addition, the amended 
standards of Secs. 27.561 (b) and (c) and 29.561 (b) and (c) would 
apply to current cargo and baggage compartment standards by their 
reference within the text of Secs. 27.787 and 29.787.
    The Crash Resistant Fuel Systems (CRFS) in Normal and Transport 
Category Rotorcraft Final Rule, Amendments 27-30 and 29-35 (59 FR 
50380, October 3, 1994), amended the fuel tank and compartment 
standards of Secs. 27.963 and 29.963 (which utilized the inertial 
factors contained in Secs. 27.561 and 29.561, respectively) to 
specifically state the CRFS inertial factor standards in 
Secs. 27.952(b)(2) and 29.952(b)(2). However, the specific inertial 
factors adopted in Secs. 27.952(b)(2) and 29.952(b)(2) for fuel tanks 
located above or behind the occupied areas are lower than those factors 
adopted in these amendments. The FAA will consider whether further 
rulemaking is necessary to increase the inertial load factors for CRFS 
design in Secs. 27.952(b)(2) and 29.952(b)(2) to the levels of those 
adopted in Secs. 27.561(c) and 29.561(c) of these amendments.
    In summary, occupant protection will be enhanced through the 
increased strength requirements for retention of items of mass, such as 
engines, transmissions, and baggage and cargo compartment contents 
located above or behind occupied areas. These amended standards stem 
from recommendations from the Aviation Rulemaking Advisory Committee 
(ARAC) to increase certain design inertial load factors. These amended 
standards will complement and enhance the occupant protection standards 
adopted by Amendments 27-25 and 29-29 (54 FR 47310, November 13, 1989) 
for survivable emergency landings.

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 from the four commenters. The commenters are the 
Civil Aviation Authority (CAA) Australia, the Airline Pilots 
Association (ALPA), the Association Europeene des Constructeurs de 
Material Aerospatial (AECMA), and the National Transportation Safety 
Board (NTSB).
    The CAA agrees that increased design inertial load factors are 
appropriate but questions the logic in the difference between design 
factors for occupant restraint and protection previously adopted for 
interior items and the proposed factors for restraint of external 
items. This commenter recommends adoption of the larger design inertial 
factors found in Secs. 27.561(b) and 29.561(b) applicable to restraint 
of occupants and cabin items rather than the factors proposed. The 
commenter highlights the differences between the two sets of design 
inertial factors.
    ALPA supports the proposal but requests that the FAA determine if 
the proposed 1.5g rearward inertial factor for seats is sufficient in 
light of a possible emergency landing scenario in which the rotorcraft 
would itself rotate 180 degrees and cause the seats and occupants to 
exceed the 1.5g design inertial load factor.
    AECMA notes that publication and prompt adoption of the final rule 
as proposed are essential to harmonize these sections of the Federal 
Aviation Regulations with the comparable European Joint Aviation 
Regulations (JAR) 27 and 29 Rotorcraft Standards.
    The NTSB comments that the proposed standards represent a 
significant advancement in occupant protection and in crashworthiness 
of normal and transport category rotorcraft and supports the proposal.
    The FAA acknowledges the CAA's concern with proposed differing 
design inertial factors and attempted to address these concerns in the 
preamble of Notice No. 94-8 under the heading ``FAA Evaluation of ARAC 
Recommendation.'' In addition, the information in Report No. DOT/FAA/
CT-85/11, ``Analysis of Rotorcraft Crash Dynamics for Development of 
Improved Crashworthiness Design Criteria,'' June 1985, was the genesis 
for the inertial factors contained in a previous amendment to 
Secs. 27.561 and 29.561. According to that report, inertial factors for 
restraint of external items can safely differ from the factors for 
interior items since severe injury due to penetration into the cabin is 
not identified as a significant hazard in that earlier report. However, 
the increased design inertial factors proposed in Notice 94-8 will 
improve both occupant protection from external items and rotorcraft 
structural crashworthiness.
    The FAA understands ALPA's concern about the adequacy of the 1.5g 
rearward load factor in the event of an emergency landing impact in 
which the rotorcraft fuselage is either fully or partially reversed for 
some time interval during the overall impact sequence. Some cases of 
reverse impact could exceed the proposed rearward load factor. However, 
FAA research has considered the overall spectrum of reverse impacts and 
that research shows that occurrences of severe, sustained reverse 
impacts are remote. This

[[Page 10437]]
research also shows that reverse impacts constitute an extremely small 
portion of all rotorcraft impacts. In addition, the research shows that 
the gravity forces felt by occupants are significantly less in most 
reverse impacts because of the larger crushing distances inherent in 
most rotorcraft aft fuselage structures and because the reverse 
direction of the impact is typically not sustained. Additional fuselage 
motion such as tumbling and further rotation usually occur, thus the 
full impact is not in a reverse direction. Therefore, the total impact 
energy dissipated in a reverse impact is considered minimal. In 
addition, the complementary inertial design factors in Secs. 27.561(b) 
and 29.561(b), as well as the companion dynamic test standards in 
Secs. 27.562 and 29.562, inherently provide strength for occupant 
protection in the event of a reverse impact. Therefore, the FAA has 
determined that the 1.5g rearward inertial factor is an adequate, 
practical safety standard.
    In response to AECMA's concern that the publication date of this 
final rule correspond to the publication date of the JAR amendment, the 
FAA is committed to processing this final harmonized rule so that it 
can be published as near as possible to the publication date of the 
JAR.
    The CAA also recommends application of a 1.33 inertial attachment 
factor for litter and berth installations as a logical application of 
the seat design standard found in Secs. 27.785(f)(2) and 29.785(f)(2) 
but recognizes that this request exceeds the scope of the proposal. The 
CAA further recommends a research program to address litter 
installations and litter occupant protection. To improve protection of 
litter occupants, the FAA anticipates conducting an internal FAA 
research program to address litter installations for airplanes and 
rotorcraft.
    After considering all of the comments, the FAA has determined that 
air safety and the public interest require adoption of the amendments 
as proposed.

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) Will 
generate benefits exceeding its costs and is not significant as defined 
in Executive Order 12866; (2) is not significant as defined in DOT's 
Policies and Procedures; (3) will not have a significant impact on a 
substantial number of small entities; and (4) will not affect 
international trade. These analyses, available in the docket, are 
summarized below.

Cost-Benefit Analysis

    The increased forward, sideward, and downward load factors can be 
accommodated without changing current design practices. In many cases, 
sizable increases in load factors have been achieved by the use of 
larger bolts and/or fasteners and minor reinforcements to attach items 
of mass to the rotorcraft structure. The addition of 1.5g rearward load 
factors will require no design or production modifications because the 
12g and 16g forward load factors of the new and current standards will 
inherently result in sufficient structural strength to meet this 
rearward requirement.
    Consequently, the amendments that add and revise requirements will 
impose little or no incremental costs on rotorcraft manufacturers. 
Additionally, they will impose no or minimal weight penalties and 
operating costs on rotorcraft operators.
    Occupant safety will be enhanced by the amendments, but this 
enhancement is difficult to quantify. The FAA study, ``Analysis of 
Rotorcraft Crash Dynamics for Development of Improved Crashworthiness 
Design Criteria'' (Report No. DOT/FAA/CT-85/11, June 1985), identified 
separation of items of mass from the rotorcraft structure and 
penetration into occupied areas as one of 14 hazards associated with 
otherwise survivable rotorcraft accidents. Such occurrences have 
resulted in approximately one injury (of at least moderate severity) 
per year. The benefits of averting just one such occurrence will more 
than offset the negligible costs of the rule. The FAA therefore finds 
the rule to be cost-beneficial.

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 rule has significant economic 
impact on a substantial number of small entities. FAA Order 2100.14A 
outlines FAA's procedures and criteria for implementing the RFA. The 
FAA has determined that this rule will not have a significant economic 
impact on a substantial number of small manufacturers or operators of 
rotorcraft because there are no small rotorcraft manufacturers, as that 
term is defined in the Order.

International Trade Impact Assessment

    This rule will not constitute a barrier to international trade, 
including the export of American goods and services to foreign 
countries and the import of foreign goods and services into the United 
States. Each applicant for a new type certificate for a transport or 
normal category rotorcraft, whether the applicant be U.S. or foreign, 
will be required to show compliance with this rule. This rule will have 
no effect on the sale of U.S. rotorcraft in foreign markets and the 
sale of foreign rotorcraft in the United States.

Federalism Implications

    The regulations adopted herein will not have substantial direct 
effects on the states, on the relationships between the national 
government and the states, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
regulation will not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.

Conclusion

    For the reasons stated above, including the findings of 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 on a substantial number of small entities under the 
criteria of the Regulatory Flexibility Act. This rule is not considered 
significant under DOT Regulatory Policies and Procedures (44 FR 11034; 
February 26, 1979). A regulatory evaluation of this regulation, 
including a Regulatory Determination and Trade Impact Analysis, has 
been placed in the docket. A copy may be obtained by contacting the 
person identified under the section entitled FOR FURTHER INFORMATION 
CONTACT.

List of Subjects in 14 CFR Parts 27 and 29

    Air transportation, Aircraft, Aviation safety, Rotorcraft, Safety.
    
[[Page 10438]]


The Amendments

    Accordingly, the Federal Aviation Administration amends 14 CFR 
parts 27 and 29 of the Federal Aviation Regulations 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 27.561 is amended by adding new paragraphs (b)(3)(v) and 
(c)(5) and by revising paragraphs (c)(2), (c)(3), and (c)(4) to read as 
follows:


Sec. 27.561  General.

 * * * * *
    (b) * * *
    (3) * * *
    (v) Rearward--1.5g.
    (c) * * *
    (2) Forward--12g.
    (3) Sideward--6g.
    (4) Downward--12g.
    (5) Rearward--1.5g.
 * * * * *

PART 29--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT

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

    Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44704.

    4. Section 29.561 is amended by adding new paragraphs (b)(3)(v) and 
(c)(5) and by revising paragraphs (c)(2), (c)(3), and (c)(4) to read as 
follows:


Sec. 29.561  General.

 * * * * *
    (b) * * *
    (3) * * *
    (v) Rearward--1.5g.
    (c) * * *
    (2) Forward--12g.
    (3) Sideward--6g.
    (4) Downward--12g.
    (5) Rearward--1.5g.
 * * * * *
    Issued in Washington, DC, on March 8, 1996.
David R. Hinson,
Administrator.
[FR Doc. 96-6019 Filed 3-12-96; 8:45 am]
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