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

SUMMARY: This document proposes to amend the existing helicopter noise

certification procedures with respect to certain changes in type

designs. This proposal would amend the applicability of the noise

certification procedures 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). This

proposal would also exclude helicopter flight operations with doors

and/or windows removed or in an open position from the applicability of

the acoustical change requirements. This change would reconcile 14 CFR

part 21 with the procedural treatment of external equipment in the

original helicopter noise certification rulemaking effort and would

make U.S. helicopter noise certification regulations more consistent

with the International Civil Aviation Organization (ICAO) standards.

DATES: Comments must be submitted on or before November 20, 1995.

ADDRESSES: Send comments on this proposal to: Federal Aviation

Administration, Office of the Chief Counsel, Attn.: Rules Docket (AGC-

10), Docket No. 28334, 800 Independence Avenue, S.W., Room 915G,

Washington, DC 20591 or deliver comments in triplicate to: FAA Rules

Docket, Room 915G, 800 Independence Avenue, S.W., Washington, DC 20591.

Comments may also be submitted electronically to the following Internet

address: [email protected]. Comments may be inspected in Room

915G between 8:30 a.m. and 5 p.m., weekdays, except Federal holidays.

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:

Comments Invited

Interested persons are invited to participate in this rulemaking by

submitting written data, views, or arguments and by commenting on the

possible environmental, energy, or economic impacts of this proposal.

Comments should identify the regulatory docket or notice number and be

submitted in triplicate to the address above. All comments received, as

well as a report summarizing any substantive public contact with

Federal Aviation Administration (FAA) personnel on this rulemaking will

be filed in the docket, and will be considered by the Administrator

before taking action on this proposed rulemaking. The docket is

available for public inspection both before and after the closing date

for comments. The FAA will acknowledge the receipt of a comment if the

commenter includes a self-addressed, stamped postcard on which the

following statement is made: ``Comments to Docket No. 28334''. When the

comment is received by the FAA, the postcard will be dated, time

stamped, and returned to the commenter.

Availability of the NPRM

Any person may obtain a copy of this notice of proposed rulemaking

(NPRM) by submitting a request to the Federal Aviation Administration,

Office of Public Affairs, Attention: Public Information Center, APA-

230, 800 Independence Avenue, SW, Washington, DC 20591, or by calling

(202) 267-3474. Requests should be identified by the docket number of

this proposed rule.

Persons interested in being placed on a mailing list for future

notices of proposed rulemaking should also request a copy of Advisory

Circular No. 11-2A, Notice of Proposed Rulemaking Distribution System,

which describes the application procedure.

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) described 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 proposal 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 is 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] Rotorcraft

External-Load Operator Certificate is a current and valid airworthiness

certificate for each rotorcraft . . . listed by registration number on

a list attached to the certificate, when the rotorcraft 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 is currently subject to the acoustical

change provisions of Sec. 21.93. This proposed change to Sec. 21.93

would reconcile the procedural treatment of external equipment added to

helicopters with the intent of Sec. 21.93(b)(4) by expanding the

acoustical change

[[Page 48791]]

exception to include carriage of external equipment.

While many helicopter operators would like to use their aircraft to

perform specialized operations that require the use of external

equipment, many of these operations do not take place because the cost

of complying with the noise regulations is financially impractical;

i.e., the cost of demonstrating compliance with the noise regulations

would substantially deplete any profit the operation might generate.

Some helicopter operators suggest that the current acoustical change

type certification procedures are hampering the growth of their

industry because compliance costs deter them from performing certain

operations that require the addition of external equipment.

History of Aircraft Noise Certification Regulations Relevant to This

Proposed 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 13855, 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 the promulgation of part 36 noise standards for

propeller-driven small 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 (Amdt. 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 exempting 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 configured aircraft reconfigured with

floats and skis.

Synopsis of the Proposal

The FAA has determined that this proposed rulemaking would provide

benefits in the form of regulatory relief to the helicopter industry

and to individual helicopter operators. From a number of noise

certification studies, the FAA has concluded that this rulemaking will

result in little or no increase of public exposure to helicopter noise

emissions. The portion of the existing helicopter regulations relevant

to this rulemaking imposes an undue financial burden on the helicopter

industry and operators without providing any measurable benefit to the

public.

This proposal would amend 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. The proposal would also

exclude certain changes in helicopter type design from the acoustical

change requirements 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. The proposal 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 for 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 proposed rule is consistent with a similar provision in the

applicability section of the helicopter noise certification standard

approved by the ICAO under its International Standards and Recommended

Practices: Environmental Protection; Annex 16, Volume 1, Chapters 8 and

11 (Third Edition-July 1993). The proposed rule change would bring the

acoustical change provision in the U.S. noise certification regulations

into closer harmony with that used by foreign noise certification

authorities.

Details of the proposed amendment and limitations of the amendment

are provided in the following analysis.

Section 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 specified an ``acoustical change'' as

any voluntary change in type design (including operational limitations)

that may increase the noise levels of an aircraft. The proposed rule,

applicable only to helicopters, would exclude the installation or

removal of external equipment from being considered an acoustical

change. The proposed rule

[[Page 48792]]

would specifically exclude 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. The proposed rule

would apply 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 would be excepted include

fairings, attachment hardware, cavities constructed in the airframe to

accommodate conformally attached equipment, and bubble windows. The

proposed rule would also exclude from the acoustical change provision

external load attaching means, the airworthiness certification of which

is specified in Secs. 27.865 and 29.865.

The proposed rule change would also exclude the addition or removal

of floats and skis on helicopters from the acoustical change provision.

The proposal would also make 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 would also exclude 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 proposed rule change 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, and would not for helicopters under this proposal, because

the FAA did not have a rational basis to consider such design

configurations in the original rulemaking that established noise

certification requirements for these aircraft. While the additions 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

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 exemptions and establishing conditions

of exemptions, 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 the proposed rule change, both

the camera and the cavity would be exempt 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 alteration 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 ``nonacoustical change'' under Sec. 21.93 must assume

performance levels consistent with an aerodynamically clean helicopter

(relative to the changes in type design excepted under this proposed

rulemaking). That is, a decrease in a noise certification level

effected by the addition of equipment exempted under this proposed

rulemaking may not be used to ``mathematically' offset an increase in

noise from a change in type design not affected by this proposed

rulemaking. For example, assuming the certification basis for a given

helicopter is part 36 Appendix J, an increase in 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 proposed to delete the current text in

Sec. 21.93(b)(4) (i) and (ii). These paragraphs indicate 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' * * *'' existing paragraphs

Sec. 21.93(b)(4) (i) and (ii) may be erroneously interpreted to

indicate that (any) change to a muffler (including a change to a

quieter muffler) is by regulation an acoustical change. The existing

paragraphs (i) and (ii) do not represent a regulatory requirement and

add nothing toward the interpretation of the acoustical change

requirements for helicopters. The proposed new text addresses the

definition of external equipment and the exclusions discussed earlier

in this synopsis.

During development of this proposed rule change, 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

has determined that the proposed rule change 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, where they exist. These proposed amendments would make

U.S. helicopter noise certification regulations more consistent with

the ICAO standards.

Paperwork 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 proposed rule.

[[Page 48793]]

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; and (4) will lessen restraints on

international trade. These analyses, available in the docket, are

summarized below.

Benefits

The proposed rule would 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, modifiers, and

operators. Of this amount, the projected cost savings for part 36 noise

certification testing under Appendix H for major helicopter

manufacturers is $4,800,000 (non-discounted) or $4,264,244 discounted;

Appendix J Testing for light helicopter manufacturers, $3,000,000 (non-

discounted) or $2,330,305 discounted; and Appendix J Testing for

modifiers, $22,500,000 (non-discounted) or $15,803,025 discounted. The

FAA would also realize a cost savings under these appendices: 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 the 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 would 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 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 proposed rule.

The FAA has determined that, in accordance to the above order, the

proposed rule to part 21 would not have a significant economic impact

on a substantial number of small entities. The proposed rule would

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 or fewer employees.

The FAA concludes that a substantial number of small entities (less

than one third) would not be significantly affected by the proposed

rule. Therefore, the proposed rule would 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 proposed rule would 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 proposed rule

would parallel more closely the U.S. standards with foreign standards

for noise certification of external equipment.

Federalism Implications

The regulations herein will not have 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),

a draft environmental analysis will be prepared and placed in the

docket.

Conclusion

The FAA has determined that this proposed 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 proposed rule would have little or

no effect 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 Proposed Amendment

Accordingly, the Federal Aviation Administration proposes to amend

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: 49 U.S.C. App. 1344, 1348(c), 1352, 1354(a), 1355,

1421 through 1431, 1502, 1651(b)(2); 42 U.S.C. 7572; E.O. 11514; 49

U.S.C. 106(g).

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.

[[Page 48794]]

(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 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 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 September 11, 1995.

James D. Erickson,

Director, Office of Environment and Energy.

[FR Doc. 95-23208 Filed 9-19-95; 8:45 am]

BILLING CODE 4910-13-M