[Federal Register Volume 61, Number 89 (Tuesday, May 7, 1996)]
[Rules and Regulations]
[Pages 20696-20699]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11374]



      

[[Page 20695]]


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Part V





Department of Transportation





_______________________________________________________________________



Federal Aviation Administration



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14 CFR Part 21



Type Certification Procedures: Changes in Helicopter Type Design for 
External Equipment; Final Rule

  Federal Register / Vol. 61, No. 89 / Tuesday, May 7, 1996 / Rules and 
Regulations  

[[Page 20696]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 21

[Docket No. 28334; Amendment No. 21-73]
RIN 2120-AF10


Amendment of the Type Certification Procedures for Changes in 
Helicopter Type Design to Attach or Remove External Equipment

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule amends the existing helicopter noise 
certification procedures with respect to certain changes in type 
designs. The applicability of the noise certification procedures is 
amended to exclude those changes in type design that involve the 
attachment or removal of external equipment, floats and skis, and 
certain airframe and operational changes made to accommodate such 
changes in type design (acoustical change requirements). Also excluded 
from the applicability of the acoustical change requirements are 
helicopter flight operations with doors and/or windows removed or in an 
open position. This amendment also makes U.S. helicopter noise 
certification regulations more consistent with the International Civil 
Aviation Organization (ICAO) standards.

EFFECTIVE DATE: May 7, 1996.

FOR FURTHER INFORMATION CONTACT:
Mr. Kenneth E. Jones, Research and Engineering Branch (AEE-110), 
Technology Division, Office of Environment and Energy, FAA, 800 
Independence Avenue, SW., Washington, D.C. 20591; telephone (202) 267-
8933, facsimile (202) 267-5594.

SUPPLEMENTARY INFORMATION: The purpose of this rulemaking is to amend 
the applicability of the helicopter noise certification procedures to 
exclude those changes in helicopter type design that involve the 
attachment or removal of external equipment, floats and skis, and 
certain airframe and operational changes made to accommodate such 
changes in type design (acoustical change requirements). Also excluded 
from the acoustical change requirements are helicopter flight 
operations with doors and/or windows removed or in an open position. 
This amendment is based on Notice of Proposed Rulemaking (NPRM) Notice 
No. 95-15 (60 FR 48790, September 20, 1995; Docket No. 28334) in which 
comments were invited. No comments were received in the docket in 
response to the NPRM. Accordingly, the final rule is adopted as 
proposed in the NPRM.

Background

Statement of the Problem

    The certification procedures for aeronautical products and parts 
are contained in 14 CFR part 21. Under part 21, an applicant for 
approval of a change to a helicopter type certificate must show 
compliance with the noise regulations in 14 CFR part 36 (part 36) if 
the change in type design may increase the noise level of the 
helicopter (an acoustical change). Section 21.93 defines an 
``acoustical change'' and classifies the aircraft which must 
demonstrate compliance with part 36 following an acoustical change. 
Section 21.93(b)(4) describes helicopters required to demonstrate 
compliance with part 36 for an acoustical change, and specifically 
excludes helicopters designated exclusively for ``agricultural aircraft 
operations,'' ``dispensing firefighting materials,'' or ``carrying 
external loads.'' The intent of the existing Sec. 21.93(b)(4) is to 
exclude helicopters designated exclusively to carry external loads from 
the requirement to demonstrate compliance with part 36.
    This amendment addresses type certification (including noise 
requirements) procedures for changes to helicopter type designs to 
configure helicopters for carriage of external equipment. External 
equipment is defined herein as any instrument, mechanism, part, 
apparatus, or accessory that is attached to or extends from the 
helicopter exterior but is not used nor is intended to be used in 
operating or controlling a helicopter in flight and its not part of an 
airframe or engine. Examples of external equipment are spotlights, 
cameras, airborne signs, and cargo tanks and baskets.
    External equipment may be attached to a helicopter as a Class A 
Rotorcraft External Load Combination under 14 CFR part 133 (part 133) 
``Rotorcraft External Load Operations'', or alternatively, the external 
equipment may be attached to the helicopter as a change in type design 
under Subpart D of part 21. The noise certification requirements do not 
apply to any helicopter, regardless of airworthiness certification 
category, that is designated exclusively for carrying external loads 
pursuant to part 133. Section 133.51 states that ``[a] Rotocraft 
External-Load Operator Certificate is a current and valid airworthiness 
certificate for each rotocraft . . . listed by registration number on a 
list attached to the certificate, when the rotocraft is being used in 
operations conducted under [part 133].'' However, when the original 
helicopter noise certification rules were adopted in part 21, external 
equipment was not excluded from the acoustical change provisions of 
Sec. 21.93. Thus, except for helicopters operated under part 133, the 
addition of external equipment was, prior to this amendment, subject to 
the acoustical change provisions of Sec. 21.93. This amendment of 
Sec. 21.93 reconciles the procedural treatment of external equipment 
added to helicopters with the intent of Sec. 21.93(b)(4) by expanding 
the acoustical change exception to include carriage of external 
equipment.

History of Aircraft Noise Certification Regulations Relevant to This 
Amendment

    On November 3, 1969, the Administrator of the FAA adopted part 36 
entitled ``Noise Standards: Aircraft Type Certification.'' That action 
implemented the FAA's regulatory noise abatement program by prescribing 
type certification noise standards for subsonic turbojet powered 
airplanes. Procedural changes were concurrently made to part 21, 
``Certification Procedures for Products and Parts,'' to provide 
criteria and requirements for demonstrating compliance with the 
specifications in part 36 (34 FR 18355, November 18, 1969). The noise 
certification requirements of parts 21 and 36 are designed to promote 
the incorporation of noise abatement technology into aircraft design. 
Parts 21 and 36 have been amended as appropriate to add new aircraft 
types to the certification requirements or change the technical 
specifications as necessary. Subsequently, helicopter noise 
certification requirements were adopted with amendment 36-14 to part 36 
and amendment 21-61 to part 21 (53 FR 3534, February 5, 1988).
    The first amendment to part 21 relevant to the original aircraft 
noise certification regulation was amendment 21-27 (34 FR 18355, 
November 10, 1969). That amendment established the general requirement 
that an applicant must demonstrate compliance with the applicable 
provisions of the part 36 procedures prior to issuance of an original, 
amended, or supplemental type certificate. The same amendment to part 
21 included the addition under Sec. 21.93(b) that specified an 
``acoustical change'' as any voluntary change in type design of a 
transport category or turbojet-powered airplane that may increase the 
noise levels of that airplane. Section 21.93 was subsequently amended 
in response to

[[Page 20697]]

the promulgation of part 36 noise standards for propeller-driven 
airplanes (Amdt. 21-42; 40 FR 1029, January 6, 1975), supersonic 
airplanes (Amdt. 21-47; 43 FR 28406, June 29, 1978), commuter category 
airplanes (Amdt. 21-59; 52 FR 1806, January 15, 1987), and helicopters 
(Admt. 21-61; 53 FR 3534, February 5, 1988).
    Section 21.93 has also been amended to exclude certain changes in 
aircraft type design from the acoustical change requirements. The 
necessity for excluding these changes in type design became apparent 
only after experience was gained from implementation of the original 
noise certification regulations for the aircraft type in question. For 
turbojet-powered airplanes, amendment 21-56 (47 FR 756, January 7, 
1982) excludes time-limited engine and/or nacelle changes, where the 
change in type design specifies that the airplane may not be operated 
for a period of more than 90 days, and amendment 21-62 (53 FR 16360, 
May 6, 1988) excludes both gear down flight with one or more 
retractable landing gear down during the entire flight and spare engine 
and nacelle carriage external to the skin of the aircraft. For 
propeller-driven commuter category and propeller-driven small 
airplanes, amendment 21-63 (53 FR 47394, November 22, 1988) excludes 
``antique'' airplanes (i.e., those airplanes that have flight time 
before January 1, 1955) and land configurated aircraft reconfigured 
with floats and skis.

Synopsis of the Amendment

    This amendment changes the acoustical change provisions of 
Sec. 21.93 to exclude helicopters that have been modified by the 
addition or removal of external equipment mounted on the helicopter 
airframe or floats (rigid or bag) and skis. This amendment also 
excludes certain changes in helicopter type design from the acoustical 
change requirements otherwise applicable to certain airframe changes 
made to accommodate the external equipment and to helicopter flight 
operations with doors and/or windows removed or in an open position. 
This amendment also applies to any operating limitations placed on, or 
removed from the helicopter as a consequence of the addition or removal 
of external equipment, floats, and skis.
    The FAA recognizes the utility aspect of the helicopter as an 
aerial platform of external equipment. It is a common practice in the 
helicopter industry to add or remove external equipment as mission 
requirements vary. Although external equipment may be offered by the 
original manufacturer of the helicopter, it is usually added as an 
after-market addition by individual operators to meet specific mission 
needs. Given the potential variety of external equipment, the nature of 
the external equipment is not considered part of the basic design of a 
given helicopter and does not influence the basic aerodynamic design or 
the incorporation of noise abatement technology into the helicopter 
design. As stated in the preamble of the final rule (cited previously) 
for the original helicopter noise certification rulemaking, ``. . . the 
[helicopter] noise standards apply [only] to internal load 
configurations.''
    This amendment is consistent with a similar provision in the 
applicability section of the helicopter noise certification standard 
approve by the ICAO under its International Standards and Recommended 
Practices: Environmental Protection; Annex 16, Volume 1, Chapters 8 and 
11 (Third Edition-July 1993). This amendment brings the acoustical 
change provision in the U.S. noise certification regulations into 
closer harmony with that used by foreign noise certification 
authorities.
    The FAA has determined that this amendment will provide benefits in 
the form of regulatory relief to the helicopter industry and to 
individual helicopter operators. This amendment will result in little 
or no increase of public exposure to helicopter noise emissions. Prior 
to this amendment, type certification procedures and the helicopter 
regulations changed by this amendment imposed an undue financial burden 
on the helicopter industry and operators without providing any 
measurable benefit to the public.
    Details of the amendment and limitations of the amendment are 
provided in the following analysis.


Sec. 21.93  Classification of changes in type design.

    Part 21 prescribes that certain types of aircraft, including 
helicopters, must demonstrate compliance with the applicable 
requirements of part 36 if a change in type design results in an 
acoustical change. Section 21.93 specifies an ``acoustical change'' as 
any voluntary change in type design (including operational limitations) 
that may increase the noise levels of an aircraft. This amendment, 
applicable only to helicopters, excludes the installation or removal of 
external equipment from being considered an acoustical change. The 
amendment specifically excludes from the acoustical change provision 
the addition or removal of all external equipment where ``external 
equipment'' means any instrument, mechanism, part, apparatus, 
appurtenance, or accessory (e.g., spotlights, cameras and other optical 
devices, public address systems, hoists, airborne signs, tow banners, 
cargo tanks and baskets, emergency flotation gear, personnel platforms, 
wire strike kits, crop spraying equipment, scientific apparatus and 
their accessories) that is not used or intended to be used in operating 
or controlling an aircraft in flight, that is attached to the 
helicopter, and is not part of an airframe or engine. This amendment 
applies to changes in the airframe made to:

    (1) Accommodate the addition or removal of external equipment:

    (2) Facilitate the use of external equipment; or

    (3) Facilitate the safe operation of the helicopter with external 
equipment mounted on the helicopter.

    Examples of airframe changes that are excepted include fairings, 
attachment hardware, cavities constructed in the airframe to 
accommodate conformally attached equipment, and bubble windows. This 
amendment also excludes from the acoustical change provision external 
load attaching means, the airworthiness certification of which is 
specified in Secs. 27.865 and 29.865.

    This amendment excludes the addition or removal of floats and skis 
on helicopters from the acoustical change provision. This amendment 
makes it clear that any changes in the operating limitations placed on 
the helicopter as a consequence of the addition or removal of external 
equipment, floats, and skis is not an acoustical change. Similarly, it 
also excludes flight operations conducted with one or more doors and/or 
windows removed or in an open position.

    The FAA has included addition or removal of floats and skis on 
helicopters under this amendment in order to provide the same provision 
for helicopters as is currently provided small propeller driven 
airplanes and propeller driven commuter category airplanes under 
Sec. 21.93(b)(3). The acoustical change requirements of Sec. 21.93 do 
not require a noise certification compliance demonstration for such 
airplanes because the FAA did not have a rational basis to consider 
such design configurations in the original rulemaking that established 
noise certification requirements for theses aircraft. While the 
addition of floats and skis adversely affects the aerodynamic 
performance, and consequently the noise levels, of both small airplanes 
and helicopters, the FAA lacks the acoustical and performance data 
necessary to develop

[[Page 20698]]

noise certification regulations relevant to small airplanes and 
helicopters that are reconfigured by the addition of floats or skis.
    If a noise compliance demonstration is otherwise required for 
compliance with part 36, the noise flight test must be conducted 
without any external equipment, floats, or skis mounted to the 
helicopter and with doors and windows mounted and closed (i.e., 
aerodynamically clean configuration) unless otherwise approved or 
required by the FAA. In granting such approvals or establishing such 
requirements, the rationale for the FAA's decision will be based on 
whether or not the measured helicopter noise levels from a proposed 
noise compliance demonstration would be representative of a ``clean 
configured'' helicopter. For example, assume a cavity was created in 
the fuselage (as a related airframe change) to accommodate a 
conformally (flush) fitted camera. Under this amendment, both the 
camera and the cavity are excluded from the acoustical change 
requirements of part 21. However, in the event of any future noise 
testing of that helicopter for a change in type design unrelated to the 
camera and cavity, such a noise test without the camera mounted and the 
cavity exposed would likely lead to unrepresentative noise levels due 
to alternation of the aerodynamic performance of the helicopter. In 
this example, during the actual noise test for the unrelated change in 
type design, the FAA would probably require that the flush-mounted 
camera be inserted in its associated fuselage cavity or that the 
fuselage cavity be covered in a manner that would return the fuselage 
to its original aerodynamic shape. Similarly, any analysis for the 
purpose of demonstrating a ``non-acoustical change'' under Sec. 21.93 
must assume performance levels consistent with an aerodynamically clean 
helicopter (relative to the changes in type design excluded under this 
amendment). That is, a decrease in a noise certification level effected 
by the addition of equipment excluded under this amendment may not be 
used to ``mathematically'' offset an increase in noise from a change in 
type design not affected by this amendment. For example, assuming the 
certification basis for a given helicopter is part 36 Appendix J, an 
increase in the flyover noise certification level caused by the upgrade 
of a transmission may not be offset by the decrease in noise from the 
assumed addition of external equipment, floats or skis as part of the 
change in type design for the transmission.
    The FAA also deletes by this amendment the previous text in 
Sec. 21.93(b)(4)(i) and (ii). Those paragraphs indicated examples of 
design changes which would be considered acoustical changes. Since 
Sec. 21.93(b) already makes it clear that ``any voluntary change in the 
type design of an aircraft that may increase the noise levels of the 
aircraft is an `acoustical change' . . . .'' paragraphs 
Sec. 21.93(b)(4)(i) and (ii) could have been erroneously interepreted 
to indicate that (any) change to a muffler (including a change to a 
quieter muffler) is by regulation an acoustical change. Paragraphs (i) 
and (ii) did not represent a regulatory requirement and added nothing 
toward the interpretation of the acoustical change requirements for 
helicopters. The amended text addresses the definition of external 
equipment and the exclusions discussed earlier in this synopsis.
    The FAA has examined such factors as the utility aspect of the 
helicopter mission, the necessity for the addition or removal of 
external equipment to meet mission needs, the relevance of such 
equipment with regard to the incorporation of noise abatement 
technology in the design of the helicopter, and the desire for 
commonality of U.S. noise certification regulations with relevant 
international standards and foreign national regulations. After 
consideration of these factors, the Administrator determined that the 
amendment is consistent with the criteria set forth for proposing and 
amending aircraft noise abatement regulations under the authority of 
Sec. 611(d) of the Federal Aviation Act of 1958.

International Compatibility

    The FAA has reviewed corresponding ICAO standards and JAA 
regulations, were they exist. This amendment makes U.S. helicopter 
noise certification regulations more consistent with the ICAO 
standards.

Paper Reduction Act

    In accordance with the Paperwork Reduction Act of 1980 (Pub. L. 96-
511), there are no requirements for information collection associated 
with this amendment.

Regulatory Evaluation Summary

    Three principal requirements pertain to the economic impacts of 
changes to the Federal Regulations. First, Executive Order 12866 
directs Federal agencies to promulgate new regulations or modify 
existing regulations only if the expected benefits to society outweigh 
the expected costs. Second, the regulatory Flexibility Act of 1980 
requires agencies to analyze the economic impact of regulatory changes 
on small entities. Finally, the Office of Management and Budget 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 costs; (2) is not 
``significant'' as defined in the Executive Order and DOT's policies 
and procedures; (3) will not have a significant impact on a substantial 
number of small entities; (4) will lessen restraints on international 
trade. These analyses, available in the docket, are summarized below.

Benefits

    The final rule will provide regulatory relief and a cost savings of 
$31,690,468 (non-discounted) or $23,409,159 discounted, over a ten year 
period, to helicopter manufacturers, modifers, and operators. Of this 
amount, the projected cost savings for part 36 noise certification 
testing are as follows: Appendix H testing for helicopter manufacturers 
is $4,800,000 (non-discounted) or $4,264,244 discounted; Appendix J 
testing for helicopter manufacturers is $3,000,000 (non-discounted) or 
$2,330,305 discounted; and Appendix J Testing for modifers, $22,500,000 
(non-discounted) or $15,803,025 discounted. The FAA will also realize 
administrative cost savings under these appendices as follows: Appendix 
H, $222,460 (non-discounted) or $178,312 discounted; Appendix J, 
$231,740 (non-discounted) or $173,525 discounted; and Appendix J (for 
modifiers), $936,268 (non-discounted) or $659,748 discounted.

Costs

    From a number of noise certification studies, the FAA has learned 
that allowing applicants to attach external equipment to their 
helicopters will result in no net increase in helicopter noise or, at 
worst, insignificant increases in noise levels.

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 government regulations. The RFA requires 
a Regulatory Flexibility Analysis if a rule will have a significant 
economic impact, either detrimental or beneficial, on a substantial 
number of small entities. FAA Order 2100.14A, Regulatory Flexibility 
Criteria and Guidance prescribes standards for complying with RFA 
review requirements in FAA

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rulemaking actions. The order defines ``small entities'' in terms of 
size thresholds, ``significant economic impact'' in terms of annualized 
cost threshold, and ``substantial number'' as a number that is not less 
than eleven and that is more than one-third of the small entities 
subject to the final rule.
    The FAA has determined that, in accordance with the above order, 
the final rule to part 21 will not have a significant economic impact 
on a substantial number of small entities. The final rule will directly 
affect two types of entities: (1) Light helicopter manufacturers, and 
(2) small helicopter modifiers.
    For small aircraft and aircraft parts manufacturers, Order 2100.14A 
specifies a size threshold for classification as a small entity as 75 
or fewer employees. Based upon this size threshold, all of the affected 
U.S. manufacturers are large. For the purpose of the regulatory 
flexibility determination, an aircraft modifier is considered a small 
entity if it has 200 on fewer employees.
    The FAA concludes that a substantial number of small entities (less 
than one third) will not be significantly affected by the final rule. 
Therefore, the final rule will not impose a significant economic impact 
on a substantial number of small entities, and a regulatory flexibility 
analysis is not required.

Trade Impact Assessment

    The FAA has determined that the final rule will neither affect the 
sale of foreign aviation products and services in the United States nor 
the sale of U.S. products and services in foreign countries. This 
determination is based on the FAA's contention that the final rule will 
align the U.S. standards more closely with foreign standards for noise 
certification of external equipment.

Federalism Implications

    The regulations herein will not have a substantial direct effects 
on the states, on the relationship 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 proposed rule would 
not have sufficient federalism implications to warrant the preparation 
of a Federalism Assessment.

Environmental Analysis

    Pursuant to the Department of Transportation ``Policies and 
Procedures for Considering Environmental Impacts'' (FAA Order 1050.1D), 
the FAA has determined that this rule does not significantly affect the 
human environment. A Finding of No Significant Impact has been prepared 
and placed in the docket.

Justification for Immediate Adoption

    The FAA has determined that further delay in the adoption of this 
rule would cause undue burden to U.S. manufacturers, modifiers, and 
operators of helicopters. This final rule does not impose new 
regulatory requirements; rather, it corrects an oversight in the 
original helicopter noise certification rulemaking, which unnecessarily 
applied acoustical change noise certification requirements to some 
external load configurations. Although the preamble of that original 
rulemaking stated that the noise certification regulations applied only 
to internal load configurations, the necessary amendatory language that 
would effect that applicability was not made in all of the relevant 
portions of the noise certification regulations. At present, there are 
several applications pending for changes in helicopter type design 
which call for the addition of external equipment. Without this rule, 
those applicants are unintentionally subject to costly noise 
certification testing. Accordingly, the FAA has determined that good 
cause exist to make this rule effective in less than 30 days.

Conclusion

    The FAA has determined that this final rule: (1) is not a 
significant regulatory action under Executive Order 12866; (2) is not a 
significant regulatory action under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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. In addition, this final rule will have little or no 
affect on trade opportunities for U.S. firms doing business overseas, 
or on foreign firms doing business in the United States.

List of Subjects in 14 CFR Part 21

    Aircraft, Helicopters, Noise control.

The Amendment

    Accordingly, the Federal Aviation Administration amends 14 CFR part 
21 as follows:

PART 21--CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS

    1. The authority citation for part 21 continues to read as follows:

    Authority: 42 U.S.C. 7572; 49 U.S.C. 106(g), 40105, 40113, 
44701-44702, 44707, 44709, 44711, 44713, 44715, 45303.

    2. Section 21.93 is amended by revising paragraph (b)(4) to read as 
follows:


Sec. 21.93  Classification of changes in type design.

* * * * *
    (b) * * *
    (4) Helicopters except:
    (i) Those helicopters that are designated exclusively:
    (A) for ``agricultural aircraft operations'', as defined in 
Sec. 137.3 of this chapter, as effective on January 1, 1966;
    (B) for dispensing fire fighting materials; or
    (C) for carrying external loads, as defined in Sec. 133.1(b) of 
this chapter, as effective on December 20, 1976.
    (ii) Those helicopters modified by installation or removal of 
external equipment. For purposes of this paragraph, ``external 
equipment'' means any instrument, mechanism, part, apparatus, 
appurtenance, or accessory that it attached to, or extends from, the 
helicopter exterior but is not used nor is intended to be used in 
operating or controlling a helicopter in flight and is not part of an 
airframe or engine An ``acoustical change'' does not include:
    (A) addition or removal of external equipment;
    (B) changes in the airframe made to accommodate the addition or 
removal of external equipment, to provide for an external load 
attaching means, to facilitate the use of external equipment or 
external loads, or to facilitate the safe operation of the helicopter 
with external equipment mounted to, or external loads carried by, the 
helicopter;
    (C) reconfiguration of the helicopter by the addition or removal of 
floats and skis;
    (D) flight with one or more doors and/or windows removed or in an 
open position; or
    (E) any changes in the operational limitations placed on the 
helicopter as a consequence of the addition or removal of external 
equipment, floats, and skis, or flight operations with doors and/or 
windows removed or in an open position.
* * * * *
    Issued in Washington DC on May 1, 1996.
David R. Hinson,
Administrator.
[FR Doc. 96-11374 Filed 5-6-96; 8:45 am]
BILLING CODE 4910-13-M