95-23208. Proposed Amendment of the Type Certification Procedures for Changes in Helicopter Type Design To Attach or Remove External Equipment  

  • [Federal Register Volume 60, Number 182 (Wednesday, September 20, 1995)]
    [Proposed Rules]
    [Pages 48790-48794]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-23208]
    
    
    
    
    [[Page 48789]]
    
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    Part IV
    
    
    
    
    
    Department of Transportation
    
    
    
    
    
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    Federal Aviation Administration
    
    
    
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    14 CFR Part 21
    
    
    
    Type Certification Procedures for Changes in Helicopter Type Design; 
    Proposed Rule
    
    Federal Register / Vol. 60, No. 182 / Wednesday, September 20, 1995 / 
    Proposed Rules
    
    [[Page 48790]]
    
    
    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 21
    
    [Docket No. 22334; Notice No. 95-15]
    RIN 2120-AF10
    
    
    Proposed Amendment of the Type Certification Procedures for 
    Changes in Helicopter Type Design To Attach or Remove External 
    Equipment
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Notice of proposed rulemaking (NPRM).
    
    -----------------------------------------------------------------------
    
    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: nprmcmts@mail.hq.faa.gov. 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
    
    

Document Information

Published:
09/20/1995
Department:
Federal Aviation Administration
Entry Type:
Proposed Rule
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
95-23208
Dates:
Comments must be submitted on or before November 20, 1995.
Pages:
48790-48794 (5 pages)
Docket Numbers:
Docket No. 22334, Notice No. 95-15
RINs:
2120-AF10: Amendment of the Type Certification Procedures for Changes in Type Design To Attach or Remove External Equipment (Helicopter)
RIN Links:
https://www.federalregister.gov/regulations/2120-AF10/amendment-of-the-type-certification-procedures-for-changes-in-type-design-to-attach-or-remove-extern
PDF File:
95-23208.pdf
CFR: (5)
14 CFR 21.93(b)(3)
14 CFR 21.93(b)(4)
14 CFR 21.93(b)
14 CFR 21.93
14 CFR 137.3