95-11904. Airworthiness Directives; General Electric Company CF6 Series Turbofan Engines  

  • [Federal Register Volume 60, Number 94 (Tuesday, May 16, 1995)]
    [Rules and Regulations]
    [Pages 25985-25987]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-11904]
    
    
    
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    DEPARTMENT OF TRANSPORTATION
    14 CFR Part 39
    
    [Docket No. 95-ANE-17; Amendment 39-9228; AD 95-10-11]
    
    
    Airworthiness Directives; General Electric Company CF6 Series 
    Turbofan Engines
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Final rule; request for comments.
    
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    SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
    is [[Page 25986]] applicable to General Electric Company (GE) CF6-80C2 
    series turbofan engines. This action requires an initial and repetitive 
    brake holding torque check of the fan reverser center drive unit (CDU), 
    visual inspection of the translating cowl inner bondment seal, and 
    functional check of the translating cowl auto re-stow system. This 
    action also requires removal and replacement of certain CDU's as a 
    terminating action to the repetitive check and inspection program. This 
    amendment is prompted by a report of a CDU not able to hold the fan 
    reverser translating cowl at the required position when manually driven 
    to its stow position during routine maintenance. The actions specified 
    in this AD are intended to prevent the loss of the CDU's brake holding 
    feature, which could result in possible movement of the fan reverser 
    translating cowl towards the deploy position in flight.
    
    DATES: Effective May 31, 1995. -
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of May 31, 1995.
        Comments for inclusion in the Rules Docket must be received on or 
    before July 17, 1995.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), New England Region, Office of the Assistant Chief 
    Counsel, Attention: Rules Docket No. 95-ANE-17, 12 New England 
    Executive Park, Burlington, MA 01803-5299.
        The service information referenced in this AD may be obtained from 
    Martin Marietta Services, Inc., Attn: Karen Lyons, 10525 Chester Road, 
    Cincinnati, OH 45215. This information may be examined at the FAA, New 
    England Region, Office of the Assistant Chief Counsel, 12 New England 
    Executive Park, Burlington, MA; or at the Office of the Federal 
    Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    
    FOR FURTHER INFORMATION CONTACT: Robert Ganley, Aerospace Engineer, 
    Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
    New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
    238-7138; fax (617) 238-7199.
    
    SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA) 
    received a report of a center drive unit (CDU) not able to hold the fan 
    reverser translating cowl at the required position when manually driven 
    to its stow position during routine maintenance. Investigation revealed 
    that the CDU brake shaft had worn to the extent that the braking 
    feature was inoperative. This feature, in conjunction with two 
    additional features (auto re-stow and stow retention), prevents the 
    uncommanded movement of the translating cowl towards the deploy 
    position. Further investigation revealed that the wear was due to the 
    low material hardness of the brake shaft. This low material hardness is 
    the result of a heat treat step that was inadvertently omitted from the 
    manufacturing cycle of the brake shaft. This condition, if not 
    corrected, could result in loss of the CDU's brake holding feature, 
    which could result in possible movement of the fan reverser translating 
    cowl towards the deploy position in flight.
        The FAA has reviewed and approved the technical contents of Martin 
    Marietta CF6-80C2 Service Bulletin (SB) No. 78-1002, Revision 1, dated 
    March 23, 1995, that describes procedures for the brake holding torque 
    check of the fan reverser CDU, visual inspection of the translating 
    cowl inner bondment seal, functional check of the translating cowl auto 
    re-stow system, and the removal and replacement of the CDU.
        Since an unsafe condition has been identified that is likely to 
    exist or develop on other General Electric Company (GE) CF6-80C2 series 
    turbofan engines of the same type design, this AD is being issued to 
    prevent the loss of the CDU's brake holding feature, which could result 
    in possible movement of the fan reverser translating cowl towards the 
    deploy position in flight. This AD requires an initial and repetitive 
    brake holding torque check of the fan reverser CDU, visual inspection 
    of the translating cowl inner bondment seal, and functional check of 
    the translating cowl auto re-stow system. This AD also requires removal 
    and replacement of certain CDU's as a terminating action to the 
    repetitive check and inspection program. The actions are required to be 
    accomplished in accordance with the service bulletin described 
    previously.
        Since a situation exists that requires the immediate adoption of 
    this regulation, it is found that notice and opportunity for prior 
    public comment hereon are impracticable, and that good cause exists for 
    making this amendment effective in less than 30 days.
    
    Comments Invited
    
        Although this action is in the form of a final rule that involves 
    requirements affecting flight safety and, thus, was not preceded by 
    notice and an opportunity for public comment, comments are invited on 
    this rule. Interested persons are invited to comment on this rule by 
    submitting such written data, views, or arguments as they may desire. 
    Communications should identify the Rules Docket number and be submitted 
    in triplicate to the address specified under the caption ADDRESSES. All 
    communications received on or before the closing date for comments will 
    be considered, and this rule may be amended in light of the comments 
    received. Factual information that supports the commenter's ideas and 
    suggestions is extremely helpful in evaluating the effectiveness of the 
    AD action and determining whether additional rulemaking action would be 
    needed.
        Comments are specifically invited on the overall regulatory, 
    economic, environmental, and energy aspects of the rule that might 
    suggest a need to modify the 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 that 
    summarizes each FAA-public contact concerned with the substance of this 
    AD 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 95-ANE-17.'' The postcard will be date stamped and 
    returned to the commenter. -
        The regulations adopted 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 final 
    rule does not have sufficient federalism implications to warrant the 
    preparation of a Federalism Assessment. -
        The FAA has determined that this regulation is an emergency 
    regulation that must be issued immediately to correct an unsafe 
    condition in aircraft, and is not a ``significant regulatory action'' 
    under Executive Order 12866. It has been determined further that this 
    action involves an emergency regulation under DOT Regulatory Policies 
    and Procedures (44 FR 11034, February 26, 1979). If it is determined 
    that this emergency regulation otherwise would be significant under DOT 
    Regulatory Policies and Procedures, a final regulatory evaluation will 
    be prepared and placed in the Rules Docket. A copy of it, if filed, may 
    be obtained from the Rules Docket at the location provided under the 
    caption ``ADDRESSES.'' [[Page 25987]] 
    
    List of Subjects in 14 CFR Part 39 -
    
        Air transportation, Aircraft, Aviation safety, Incorporation by 
    reference, Safety.
    
    Adoption of the Amendment -
    
        Accordingly, pursuant to the authority delegated to me by the 
    Administrator, the Federal Aviation Administration amends 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
    106(g); and 14 CFR 11.89.
    
    
    Sec. 39.13  [Amended] -
    
        2. Section 39.13 is amended by adding the following new 
    airworthiness directive:
    
    95-10-11  General Electric Company: Amendment 39-9228. Docket 95-
    ANE-17.
    
        -Applicability: General Electric Company (GE) CF6-80C2 series 
    turbofan engines installed on, but not limited to, Airbus A300 and 
    A310 series, Boeing 747 and 767 series, and McDonnell Douglas MD-11 
    series aircraft.
    
        Note: This airworthiness directive (AD) applies to each engine 
    identified in the preceding applicability provision, regardless of 
    whether it has been modified, altered, or repaired in the area 
    subject to the requirements of this AD. For engines that have been 
    modified, altered, or repaired so that the performance of the 
    requirements of this AD is affected, the owner/operator must use the 
    authority provided in paragraph (e) to request approval from the 
    Federal Aviation Administration (FAA). This approval may address 
    either no action, if the current configuration eliminates the unsafe 
    condition, or different actions necessary to address the unsafe 
    condition described in this AD. Such a request should include an 
    assessment of the effect of the changed configuration on the unsafe 
    condition addressed by this AD. In no case does the presence of any 
    modification, alteration, or repair remove any engine from the 
    applicability of this AD.-
    
        -Compliance: Required as indicated, unless accomplished 
    previously. -
        To prevent a loss of the center drive units (CDU) brake holding 
    feature, which could result in possible movement of the fan reverser 
    translating cowl towards the deploy position in flight, accomplish 
    the following: -
        (a) For fan reversers that have a CDU identified in paragraph 
    1.A.(1) of Martin Marietta (MM) CF6-80C2 Service Bulletin (SB) No. 
    78-1002, Revision 1, dated March 23, 1995, installed, perform the 
    following: -
        (1) If the requirements of MM CF6-80C2 SB No. 78-1002, dated 
    February 27, 1995, or MM CF6-80C2 SB No. 78-1002, Revision 1, dated 
    March 23, 1995, have not been previously accomplished, perform a 
    brake holding torque check of the fan reverser CDU, a visual 
    inspection of the translating cowl inner bondment seal, and a 
    functional check of the translating cowl auto re-stow system in 
    accordance with paragraphs 2.B, 2.C, and 2.D of MM CF6-80C2 SB No. 
    78-1002, Revision 1, dated March 23, 1995, prior to accumulating 250 
    cycles in service (CIS) or 30 days, after the effective date of this 
    AD, whichever occurs earlier.
        (2) If the requirements of MM CF6-80C2 SB No. 78-1002, dated 
    February 27, 1995, or MM CF6-80C2 SB No. 78-1002, Revision 1, dated 
    March 23, 1995, have been previously accomplished, accomplish the 
    following: -
        (i) Perform a brake holding torque check of the fan reverser CDU 
    in accordance with paragraph 2.B of MM CF6-80C2 SB No. 78-1002, 
    Revision 1, dated March 23, 1995, prior to accumulating 250 CIS 
    since the last brake holding torque check. -
        (ii) Perform a visual inspection of the translating cowl inner 
    bondment seal, and a functional check of the translating cowl auto 
    re-stow system in accordance with paragraphs 2.C and 2.D of MM CF6-
    80C2 SB No. 78-1002, Revision 1, dated March 23, 1995, prior to 
    accumulating 1,000 hours since the last visual inspection of the 
    translating cowl inner bondment seal and functional check of the 
    translating cowl auto re-stow system. -
        (b) Thereafter, for fan reversers that have accomplished the 
    inspection and check requirements in accordance with paragraph (a) 
    of this AD, accomplish the following: -
        (1) Perform a brake holding torque check of the fan reverser CDU 
    in accordance with paragraph 2.B of MM CF6-80C2 SB No. 78-1002, 
    Revision 1, dated March 23, 1995, prior to accumulating 250 CIS 
    since the last brake holding torque check. -
        (2) Perform a visual inspection of the translating cowl inner 
    bondment seal, and a functional check of the translating cowl auto 
    re-stow system in accordance with paragraphs 2.C and 2.D of MM CF6-
    80C2 SB No. 78-1002, Revision 1,dated March 23, 1995, prior to 
    accumulating 1,000 hours since the last visual inspection of the 
    translating cowl inner bondment seal and functional check of the 
    translating cowl auto re-stow system. -
        (c) Remove from service the CDU's identified in paragraph 
    1.A.(1) of MM CF6-80C2 SB No. 78-1002, Revision 1, dated March 23, 
    1995, in accordance with paragraph 2.F of MM CF6-80C2 SB No. 78-
    1002, Revision 1, dated March 23, 1995, prior to December 31, 1995, 
    and replace with a serviceable part. Removal and replacement of the 
    CDU in accordance with this paragraph constitutes terminating action 
    to the initial and repetitive inspection and check requirements of 
    paragraph (a) and (b) of this AD. -
        (d) For the purpose of this AD, a serviceable part is defined as 
    a CDU that has accomplished any revision level of MM CF6-80C2 SB No. 
    78-1014; or a CDU whose shaft has received the hardness inspection 
    in accordance with any revision level of GE CF6-80C2 SB No. 78-131, 
    and that has not had a brake shaft replacement subsequent to the 
    hardness inspection. -
        (e) 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, Engine Certification Office. The 
    request should be forwarded through an appropriate FAA Principal 
    Maintenance Inspector, who may add comments and then send it to the 
    Manager, Engine Certification Office.
    
        Note: Information concerning the existence of approved alternate 
    methods of compliance with this airworthiness directive, if any, may 
    be obtained from the Engine Certification Office.
    
        (f) Special flight permits may be issued in accordance with FAR 
    21.197 and 21.199 to operate the aircraft to a location where the 
    requirements of this AD can be accomplished.
        (g) The actions required by this AD shall be done in accordance 
    with the following service bulletin:
    
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              Document No.--                        Pages--                     Revision-               Date        
    ----------------------------------------------------------------------------------------------------------------
    Martin Marietta CF6-80C2.........  2, 11, 12, 14-18, 20.............  Original............  Feb. 27, 1995.      
    SB No. 78-1002-..................  1, 3-10, 13, 19--................  1...................  Mar. 23, 1995.      
        Total pages: 20.                                                                                            
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        This incorporation by reference was approved by the Director of 
    the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
    part 51. Copies may be obtained from Martin Marietta Services, Inc., 
    Attn: Karen Lyons, 10525 Chester Road, Cincinnati, OH 45215. Copies 
    may be inspected at the FAA, New England Region, Office of the 
    Assistant Chief Counsel, 12 New England Executive Park, Burlington, 
    MA; or at the Office of the Federal Register, 800 North Capitol 
    Street, NW., suite 700, Washington, DC. -
        (h) This amendment becomes effective on May 31, 1995.
    
        Issued in Burlington, Massachusetts, on May 2, 1995.
    Mark C. Fulmer,
    Acting Manager, Engine and Propeller Directorate, Aircraft 
    Certification Service.
    [FR Doc. 95-11904 Filed 5-12-95; 3:16 pm]
    BILLING CODE 4910-13-U
    
    

Document Information

Effective Date:
5/31/1995
Published:
05/16/1995
Department:
Transportation Department
Entry Type:
Rule
Action:
Final rule; request for comments.
Document Number:
95-11904
Dates:
Effective May 31, 1995. -
Pages:
25985-25987 (3 pages)
Docket Numbers:
Docket No. 95-ANE-17, Amendment 39-9228, AD 95-10-11
PDF File:
95-11904.pdf
CFR: (1)
14 CFR 39.13