97-5463. Airworthiness Directives; Gulfstream Aerospace Corporation Model G-159 (G-I) Airplanes  

  • [Federal Register Volume 62, Number 44 (Thursday, March 6, 1997)]
    [Proposed Rules]
    [Pages 10224-10226]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 97-5463]
    
    
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    Proposed Rules
                                                    Federal Register
    ________________________________________________________________________
    
    This section of the FEDERAL REGISTER contains notices to the public of 
    the proposed issuance of rules and regulations. The purpose of these 
    notices is to give interested persons an opportunity to participate in 
    the rule making prior to the adoption of the final rules.
    
    ========================================================================
    
    
    Federal Register / Vol. 62, No. 44 / Thursday, March 6, 1997 / 
    Proposed Rules
    
    [[Page 10224]]
    
    
    
    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 97-NM-18-AD]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Gulfstream Aerospace Corporation Model 
    G-159 (G-I) Airplanes
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Notice of proposed rulemaking (NPRM).
    
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    SUMMARY: This document proposes the supersedure of an existing 
    airworthiness directive (AD), applicable to all Gulfstream Model G-159 
    (G-I) airplanes, that currently requires repetitive inspections to 
    detect corrosion in the wing planks under the bottom wing center 
    fairings, and repair, if necessary. This action would require the 
    installation of a protective paint system which, when accomplished, 
    will allow the inspections to be conducted at longer intervals. This 
    action was prompted by the development of a modification that will 
    improve the corrosion resistance of the subject area. The actions 
    specified by the proposed AD are intended to detect and prevent 
    corrosion in the lower skins of the wing center section. If corrosion 
    in this area remains unchecked, it could reduce the integrity of the 
    wing-to-fuselage fitting, and consequently could lead to separation of 
    the wing from the airplane.
    
    DATES: Comments must be received by April 14, 1997.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), Transport Airplane Directorate, ANM-103, 
    Attention: Rules Docket No. 97-NM-18-AD, 1601 Lind Avenue, SW., Renton, 
    Washington 98055-4056. Comments may be inspected at this location 
    between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
    holidays.
        The service information referenced in the proposed rule may be 
    obtained from Gulfstream Aerospace Corporation, Technical Operations 
    Department, P.O. Box 2206, M/S D-10, Savannah, Georgia 31402-2206. This 
    information may be examined at the FAA, Transport Airplane Directorate, 
    1601 Lind Avenue, SW., Renton, Washington.
    
    FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer, 
    Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane 
    Directorate, Atlanta Aircraft Certification Office, Campus Building, 
    1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; 
    telephone (404) 305-7362; fax (404) 305-7348.
    
    SUPPLEMENTARY INFORMATION:
    
    Comments Invited
    
        Interested persons are invited to participate in the making of the 
    proposed rule by submitting such written data, views, or arguments as 
    they may desire. Communications shall identify the Rules Docket number 
    and be submitted in triplicate to the address specified above. All 
    communications received on or before the closing date for comments, 
    specified above, will be considered before taking action on the 
    proposed rule. The proposals contained in this notice may be changed in 
    light of the comments received.
        Comments are specifically invited on the overall regulatory, 
    economic, environmental, and energy aspects of the proposed rule. All 
    comments submitted will be available, both before and after the closing 
    date for comments, in the Rules Docket for examination by interested 
    persons. A report summarizing each FAA-public contact concerned with 
    the substance of this proposal will be filed in the Rules Docket.
        Commenters wishing the FAA to acknowledge receipt of their comments 
    submitted in response to this notice must submit a self-addressed, 
    stamped postcard on which the following statement is made: ``Comments 
    to Docket Number 97-NM-18-AD.'' The postcard will be date stamped and 
    returned to the commenter.
    
    Availability of NPRMs
    
        Any person may obtain a copy of this NPRM by submitting a request 
    to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
    Docket No. 97-NM-18-AD, 1601 Lind Avenue, SW., Renton, Washington 
    98055-4056.
    
    Discussion
    
        In 1967, the FAA issued AD 67-04-01, amendment 39-1234 (36 FR 
    12688, July 3, 1971), applicable to all Gulfstream Model G-159 (G-I) 
    airplanes. That AD requires a visual inspection to detect corrosion of 
    the wing planks under the bottom wing center fairing assemblies (having 
    part numbers 159W10400-121 and 159W10401-121), and repair if necessary. 
    After the initial inspection is accomplished, and after any repair is 
    made, the inspection is required to be repeated at intervals of 26 
    weeks.
        That action was prompted by reports indicating that corrosion was 
    found in the lower skins of the wing center section of several of these 
    airplanes. The requirements of that AD are intended to detect and 
    correct corrosion in this area. If such corrosion remains unchecked, it 
    could reduce the integrity of the wing-to-fuselage fitting, and 
    consequently could lead to separation of the wing from the airplane.
    
    Actions Since Issuance of Previous Rule
    
        As part of its on-going program to address issues relevant to the 
    continued operational safety of the aging transport fleet, the FAA, 
    along with Gulfstream Aerospace Corporation and several U.S. and non-
    U.S. operators of the affected airplanes, agreed to undertake the task 
    of identifying and implementing procedures to ensure the continuing 
    structural airworthiness of aging commuter-class airplanes. This group 
    recently reviewed selected service bulletins, applicable to Gulfstream 
    Model G-159 airplanes, to be recommended for mandatory rulemaking 
    action to ensure the continued operational safety of these airplanes.
    
    Explanation of Relevant Service Information
    
        The group reviewed and recommended Grumman Gulfstream I Aircraft 
    Service Change No. 190, dated June 28, 1971, for mandatory regulatory 
    action. That service change describes procedures for repetitive 
    inspections to detect corrosion of the center section lower wing 
    planks, and repair, if necessary. It also describes the
    
    [[Page 10225]]
    
    installation of a protective paint system to the fairing assemblies and 
    bottom wing cover. This protective system is intended to improve the 
    corrosion resistance of this area. Once it is installed, the repetitive 
    inspections may be conducted at longer intervals.
    
    Explanation of Requirements of Proposed Rule
    
        Since an unsafe condition has been identified that is likely to 
    exist or develop on other products of this same type design, the 
    proposed AD would supersede AD 67-04-01. It would continue to require 
    the repetitive visual inspections, specified in AD 67-04-01, to detect 
    corrosion of the wing planks under the bottom wing center fairing 
    assemblies, and repair, if necessary.
        For airplanes on which a protective paint system had not been 
    installed previously, this new action would require that the inspection 
    continue to be repeated at intervals of 6 months (26 weeks), until a 
    protective paint system is installed within 12 months. Once the paint 
    system is installed, the repetitive inspections would be required to 
    continue, but the repetitive interval would be extended to 18 months.
        For airplanes on which a protective paint system was installed 
    previously, this new action would extend the currently-required 
    repetitive inspection interval of 12 months to 18 months.
        These actions would be required to be accomplished in accordance 
    with the aircraft service change described previously.
    
    Cost Impact
    
        There are approximately 146 Gulfstream Model G-159 airplanes of the 
    affected design in the worldwide fleet. The FAA estimates that 72 
    airplanes of U.S. registry would be affected by this proposed AD.
        The inspections that are currently required by AD 67-04-01, and 
    those that would be required by this proposed action, take 
    approximately 40 work hours per airplane to accomplish, at an average 
    labor rate of $60 per work hour. Based on these figures, the cost 
    impact of the proposed inspection actions on U.S. operators is 
    estimated to be $172,800, or $2,400 per airplane, per inspection.
        The installation of the protective paint system that is proposed in 
    this AD action would take approximately 30 work hours per airplane to 
    accomplish, at an average labor rate of $60 per work hour. Required 
    materials would cost approximately $100 per airplane. Based on these 
    figures, the cost impact of the proposed requirements of this AD on 
    U.S. operators is estimated to be $136,800, or $1,900 per airplane.
        The cost impact figures discussed above are based on assumptions 
    that no operator has yet accomplished any of the current or proposed 
    requirements of this AD action, and that no operator would accomplish 
    those actions in the future if this AD were not adopted.
    
    Regulatory Impact
    
        The regulations proposed herein would 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 
    proposal would not have sufficient federalism implications to warrant 
    the preparation of a Federalism Assessment.
        For the reasons discussed above, I certify that this proposed 
    regulation (1) is not a ``significant regulatory action'' under 
    Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
    Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
    and (3) if promulgated, 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. A copy of the draft 
    regulatory evaluation prepared for this action is contained in the 
    Rules Docket. A copy of it may be obtained by contacting the Rules 
    Docket at the location provided under the caption ADDRESSES.
    
    List of Subjects in 14 CFR Part 39
    
        Air transportation, Aircraft, Aviation safety, Safety.
    
    The Proposed Amendment
    
        Accordingly, pursuant to the authority delegated to me by the 
    Administrator, the Federal Aviation Administration proposes to amend 
    part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
    follows:
    
    PART 39--AIRWORTHINESS DIRECTIVES
    
        1. The authority citation for part 39 continues to read as follows:
    
        Authority: 49 U.S.C. 106(g), 40113, 44701.
    
    Sec. 39.13   [Amended]
    
        2. Section 39.13 is amended by removing amendment 39-1234 (36 FR 
    12688, July 3, 1971), and by adding a new airworthiness directive (AD), 
    to read as follows:
    
    Gulfstream Aerospace Corporation: Docket 97-NM-18-AD. Supersedes AD 
    67-04-01, Amendment 39-1234.
    
        Applicability: All Model G-159 (G-I) airplanes, certificated in 
    any category.
    
        Note 1: This AD applies to each airplane identified in the 
    preceding applicability provision, regardless of whether it has been 
    otherwise modified, altered, or repaired in the area subject to the 
    requirements of this AD. For airplanes that have been modified, 
    altered, or repaired so that the performance of the requirements of 
    this AD is affected, the owner/operator must request approval for an 
    alternative method of compliance in accordance with paragraph (d)(1) 
    of this AD. The request should include an assessment of the effect 
    of the modification, alteration, or repair on the unsafe condition 
    addressed by this AD; and, if the unsafe condition has not been 
    eliminated, the request should include specific proposed actions to 
    address it.
        Compliance: Required as indicated, unless accomplished 
    previously.
        To detect and prevent corrosion in the lower skins of the wing 
    center section, which could reduce the integrity of the wing-to-
    fuselage fitting and consequently could lead to separation of the 
    wing from the airplane, accomplish the following:
        (a) For all airplanes: Within 4 weeks after July 3, 1971 (the 
    effective date of AD 67-04-01, amendment 39-1234), remove the bottom 
    wing center fairings having part numbers (P/N) 159W10400-121 and 
    159W10401-121, or use an FAA-approved equivalent method, to perform 
    a visual inspection to detect corrosion of the wing planks under 
    these fairings.
    
        Note 2: Paragraph (a) of this AD merely restates the actions 
    previously required by AD 67-04-01, amendment 39-1234. As allowed by 
    the phrase, ``unless accomplished previously,'' if those 
    requirements of AD 67-04-01 have already been accomplished, this AD 
    does not require that those actions be repeated.
        Note 3: Care must be exercised when removing the fairings, since 
    the attaching rivets go into the pressure vessel. Use caution not to 
    enlarge rivet holes when removing rivets. When reinstalling the 
    fairings, an adequate type fastener and sealant must be used.
        Note 4: Grumman Service Newsletter, Volume 166, dated August-
    September 1966, pertains to this subject.
    
        (b) For airplanes on which a protective paint system has not 
    been installed in accordance with Grumman Gulfstream I Aircraft 
    Service Change No. 190, dated June 28, 1971: Accomplish paragraphs 
    (b)(1) and (b)(2) of this AD. As of the effective date of this AD, 
    the inspections required by this paragraph shall be accomplished in 
    accordance with Grumman Gulfstream I Aircraft Service Change No. 
    190, dated June 28, 1971.
    
        Note 5: The repeated inspection referred to in this paragraph is 
    the same inspection previously required by AD 67-04-01. Paragraph 
    (b)(1) of this AD merely restates
    
    [[Page 10226]]
    
    the requirement of AD 67-04-01 to repeat the inspection at intervals 
    of 6 months. Paragraph (b)(2) permits the reinspection interval to 
    be extended to 18 months once the specified protective paint system 
    is installed.
    
        (1) As a result of the inspection required by paragraph (a) of 
    this AD:
        (i) If no corrosion is detected, repeat the inspection 
    thereafter at intervals not to exceed 6 months (26 weeks) until the 
    actions specified in paragraph (b)(2) of this AD are accomplished.
        (ii) If any corrosion is detected, prior to further flight, 
    either repair the corroded part with an FAA-approved repair; or 
    replace the corroded part with a new or serviceable part of the same 
    part number; or replace the corroded part with a part approved by 
    the FAA. Thereafter, continue to perform the inspection at intervals 
    not to exceed 6 months (26 weeks) until paragraph (b)(2) of this AD 
    is accomplished.
        (2) Within 12 months after the effective date of this AD, 
    install the protective paint system in accordance with Grumman 
    Gulfstream I Aircraft Service Change No. 190, dated June 28, 1971. 
    After installation, continue to perform the inspection required by 
    this paragraph at intervals not to exceed 18 months.
        (c) For airplanes on which a protective paint system has been 
    installed previously in accordance with Grumman Gulfstream I 
    Aircraft Service Change No. 190, dated June 28, 1971: Accomplish 
    paragraphs (c)(1) and (c)(2) of this AD. As of the effective date of 
    this AD, the inspections required by this paragraph shall be 
    accomplished in accordance with Grumman Gulfstream I Aircraft 
    Service Change No. 190, dated June 28, 1971.
    
        Note 6: The repeated inspection referred to in this paragraph is 
    the same inspection previously required by AD 67-04-01. Paragraph 
    (c)(1) of this AD merely restates the requirement of AD 67-04-01 to 
    repeat the inspection at intervals of 12 months. Paragraph (c)(2) 
    permits the reinspection interval to be extended to 18 months.
        (1) As a result of the inspection required by paragraph (a) of 
    this AD:
        (i) If no corrosion is detected, repeat the inspection 
    thereafter at intervals not to exceed 12 months until paragraph 
    (c)(2) of this AD is accomplished.
        (ii) If any corrosion is detected, prior to further flight, 
    either repair the corroded part with an FAA-approved repair; or 
    replace the corroded part with a new or serviceable part of the same 
    part number; or replace the corroded part with a part approved by 
    the FAA. Thereafter, continue to perform the inspection at intervals 
    not to exceed 12 months until paragraph (c)(2) of this AD is 
    accomplished.
        (2) Within 18 months since the last inspection accomplished in 
    accordance with paragraph (c)(1) of this AD (i.e., the last 
    inspection accomplished in accordance with AD 67-04-01), repeat the 
    inspection specified in paragraph (c)(1) of this AD.
        (i) If no corrosion is detected, repeat the inspection 
    thereafter at intervals not to exceed 18 months.
        (ii) If any corrosion is detected, prior to further flight, 
    repair in accordance with the service change. After repair, continue 
    to perform the inspection at intervals not to exceed 18 months.
        (d)(1) An alternative method of compliance or adjustment of the 
    compliance time that provides an acceptable level of safety may be 
    used if approved by the Manager, Atlanta Aircraft Certification 
    Office (ACO), FAA, Small Airplane Directorate. Operators shall 
    submit their requests through an appropriate FAA Principal 
    Maintenance Inspector, who may add comments and then send it to the 
    Manager, Atlanta ACO.
        (2) Alternative methods of compliance, approved previously in 
    accordance with AD 67-04-01, amendment 39-1234, are approved as 
    alternative methods of compliance with this AD.
    
        Note 7: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Atlanta ACO.
    
        (e) Special flight permits may be issued in accordance with 
    sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
    CFR 21.197 and 21.199) to operate the airplane to a location where 
    the requirements of this AD can be accomplished. Issued in Renton, 
    Washington, on February 27, 1997.
    Darrell M. Pederson,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 97-5463 Filed 3-5-97; 8:45 am]
    BILLING CODE 4910-13-U
    
    
    

Document Information

Published:
03/06/1997
Department:
Federal Aviation Administration
Entry Type:
Proposed Rule
Action:
Notice of proposed rulemaking (NPRM).
Document Number:
97-5463
Dates:
Comments must be received by April 14, 1997.
Pages:
10224-10226 (3 pages)
Docket Numbers:
Docket No. 97-NM-18-AD
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
97-5463.pdf
CFR: (1)
14 CFR 39.13