95-16377. Airworthiness Directives; Learjet Model 60 Airplanes  

  • [Federal Register Volume 60, Number 138 (Wednesday, July 19, 1995)]
    [Rules and Regulations]
    [Pages 36984-36986]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 95-16377]
    
    
    
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    DEPARTMENT OF TRANSPORTATION
    14 CFR Part 39
    
    [Docket No. 95-NM-119-AD; Amendment 39-9303; AD 95-14-09]
    
    
    Airworthiness Directives; Learjet Model 60 Airplanes
    
    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 applicable to certain Learjet Model 60 airplanes. This action 
    requires inspection to detect bends in or damage to the fuel crossflow 
    tube; inspection to determine clearance between the fuel crossflow tube 
    and the flight control cables; and replacement or repair of the tube, 
    if necessary. This amendment is prompted by reports of damage to the 
    fuel crossflow tube and inadequate clearance between the fuel crossflow 
    tube and the flight control cables due to bends in the fuel crossflow 
    tube. The actions specified in this AD are intended to prevent chafing 
    and eventual failure of the fuel crossflow tube due to inadequate 
    clearance between the tube and the flight control cables; this 
    condition could result in loss of fuel from one fuel tank during normal 
    operating conditions or loss of fuel from both main fuel tanks during 
    fuel cross feeding operations.
    
    DATES: Effective August 3, 1995. -
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of August 3, 1995. -
    
    [[Page 36985]]
    
        Comments for inclusion in the Rules Docket must be received on or 
    before September 18, 1995.
    
    ADDRESSES: Submit comments in triplicate to the Federal Aviation 
    Administration (FAA), Transport Airplane Directorate, ANM-103, 
    Attention: Rules Docket No. 95-NM-119-AD, 1601 Lind Avenue, SW., 
    Renton, Washington 98055-4056. -
        The service information referenced in this AD may be obtained from 
    Learjet, P.O. Box 7707, Wichita, Kansas 67277-7707. This information 
    may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
    Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft 
    Certification Office, Small Airplane Directorate, 1801 Airport Road, 
    Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of 
    the Federal Register, 800 North Capitol Street, NW., suite 700, 
    Washington, DC.
    
    FOR FURTHER INFORMATION CONTACT: Charles D. Riddle, Aerospace Engineer, 
    Propulsion Branch, ACE-117W, FAA, Wichita Aircraft Certification 
    Office, Small Airplane Directorate, 1801 Airport Road, Room 100, Mid-
    Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4144; fax 
    (316) 946-4407.
    
    SUPPLEMENTARY INFORMATION: Recently, the FAA has received reports from 
    operators of Learjet Model 60 airplanes that the fuel crossflow tube in 
    the underwing keelbeam area was bent slightly upward. In two instances, 
    the fuel crossflow tube was found to be chafed by the flight control 
    cables due to inadequate clearance between the flight control cables 
    and the fuel crossflow tube. Investigation revealed that the tube was 
    installed improperly. Chafing and eventual failure of the fuel 
    crossflow tube due to inadequate clearance between the tube and the 
    flight control cables, if not corrected, could result in loss of fuel 
    from one fuel tank during normal operating conditions or loss of fuel 
    from both main fuel tanks during fuel cross feeding operations. -
        The FAA has reviewed and approved Learjet Alert Service Bulletin SB 
    A60-28-3, dated May 12, 1995, which describes procedures for inspection 
    to detect bends in or damage to the fuel crossflow tube, and 
    replacement of bent or damaged tubes with new tubes; and inspection to 
    determine the clearance between the fuel crossflow tube and the flight 
    control cables, and replacement of tubes with new tubes if inadequate 
    clearance exists. This alert service bulletin describes procedures for 
    replacement of the fuel crossflow tube with a new tube for a certain 
    group of airplanes. Replacement procedures for the remaining group of 
    airplanes is described in Learjet Service Bulletin SB 60-28-4, dated 
    May 12, 1995, which the FAA has reviewed and approved. -
        Since an unsafe condition has been identified that is likely to 
    exist or develop on other Learjet Model 60 airplanes of the same type 
    design, this AD is being issued to prevent chafing and eventual failure 
    of the fuel crossflow tube due to inadequate clearance between the tube 
    and the flight control cables; this condition could result in loss of 
    fuel from one fuel tank during normal operating conditions or loss of 
    fuel from both main fuel tanks during fuel cross feeding operations. 
    This AD requires inspection to detect bends in or damage to the fuel 
    crossflow tube, inspection to determine clearance between the fuel 
    crossflow tube and the flight control cables, and replacement of tubes, 
    if necessary. The actions are required to be accomplished in accordance 
    with the service bulletins described previously. -
        This AD differs from the service bulletin in that the AD requires 
    replacement of the tube if the tube is not bent or damaged and minimum 
    clearance does not exist. This AD also requires the repair of certain 
    fuel crossflow tubes in accordance with a method approved by the FAA. -
        As a result of recent communications with the Air Transport 
    Association (ATA) of America, the FAA has learned that, in general, 
    some operators may misunderstand the legal effect of AD's on airplanes 
    that are identified in the applicability provision of the AD, but that 
    have been altered or repaired in the area addressed by the AD. The FAA 
    points out that all airplanes identified in the applicability provision 
    of an AD are legally subject to the AD. If an airplane has been altered 
    or repaired in the affected area in such a way as to affect compliance 
    with the AD, the owner or operator is required to obtain FAA approval 
    for an alternative method of compliance with the AD, in accordance with 
    the paragraph of each AD that provides for such approvals. A note has 
    been included in this rule to clarify this long-standing requirement. -
        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 shall 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 rule must submit a self-addressed, 
    stamped postcard on which the following statement is made: ``Comments 
    to Docket Number 95-NM-119-AD.'' 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 that it 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 
    
    [[Page 36986]]
    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.
    
    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:
    95-14-09 Learjet: Amendment 39-9303. Docket 95-NM-119-AD. -
        Applicability: Model 60 airplanes having serial numbers 60-001 
    through 60-058 inclusive, certificated in any category.
    
         -Note 1: This AD applies to each airplane 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 airplanes 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 (c) of this AD to request approval from the 
    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 airplane from the applicability of this AD.
    
         -Compliance: Required as indicated, unless accomplished 
    previously. -
        To prevent loss of fuel from one fuel tank during normal 
    operating conditions or loss of fuel from both main fuel tanks 
    during fuel cross feeding operations, due to chafing and eventual 
    failure of the fuel crossflow tube, accomplish the following: -
        (a) Within 10 hours time-in-service after the effective date of 
    this AD, perform a visual inspection to detect bends in or damage to 
    the fuel crossflow tube, and perform an inspection to determine 
    whether the clearance between the fuel crossflow tube and the flight 
    control cables is at least 0.150 inch; in accordance with Learjet 
    Alert Service Bulletin SB A60-28-3, dated May 12, 1995. -
        (1) If the tube is not found to be bent or damaged, and a 
    minimum clearance of 0.150 inch exists, no further action is 
    required by this AD. -
        (2) If the tube is not found to be bent or damaged, and a 
    minimum clearance of 0.150 inch does not exist, within 10 hours 
    time-in-service after the effective date of this AD, replace the 
    tube with a new tube in accordance with either paragraph (a)(2)(i) 
    or (a)(2)(ii) of this AD, as applicable. Prior to further flight 
    following replacement of the tube, perform an inspection to 
    determine whether the clearance between the fuel crossflow tube and 
    the flight control cables is at least 0.150 inch, in accordance with 
    Learjet Alert Service Bulletin SB A60-28-3, dated May 12, 1995. -
        (i) For airplanes having serial numbers 60-001 through 60-055, 
    inclusive: Replace the fuel crossflow tube with a new tube in 
    accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
    1995. -
        (ii) For airplanes having serial number 60-056 through 60-058, 
    inclusive: Replace the fuel crossflow tube with a new tube in 
    accordance with paragraph 2.B. of Learjet Alert Service Bulletin SB 
    A60-28-3, dated May 12, 1995. -
        (3) If the tube is found to be bent or damaged, prior to further 
    flight, replace the tube with a new tube in accordance with either 
    paragraph (a)(3)(i) or (a)(3)(ii) of this AD, as applicable. Prior 
    to further flight following replacement of the tube, perform an 
    inspection to determine whether the clearance between the fuel 
    crossflow tube and the flight control cables is at least 0.150 inch, 
    in accordance with Learjet Alert Service Bulletin SB A60-28-3, dated 
    May 12, 1995. -
        (i) For airplanes having serial numbers 60-001 through 60-055, 
    inclusive: Replace the fuel crossflow tube with a new tube in 
    accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
    1995.
        -(ii) For airplanes having serial number 60-056 through 60-058, 
    inclusive: Replace the fuel crossflow tube with a new tube in 
    accordance with paragraph 2.B. of Learjet Alert Service Bulletin SB 
    A60-28-3, dated May 12, 1995. -
        (b) If a minimum clearance of 0.150 inch does not exist on the 
    new fuel crossflow tube that was installed in accordance with the 
    requirements of paragraph (a) of this AD, prior to further flight, 
    repair in accordance with a method approved by the Manager, Wichita 
    Aircraft Certification Office (ACO), FAA, Small Airplane 
    Directorate. -
        (c) 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, Wichita ACO. Operators shall submit 
    their requests through an appropriate FAA Principal Maintenance 
    Inspector, who may add comments and then send it to the Manager, 
    Wichita ACO.
    
         -Note 2: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Wichita ACO. -
        (d) 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. -
        (e) The inspections and certain replacements shall be done in 
    accordance with Learjet Alert Service Bulletin SB A60-28-3, dated 
    May 12, 1995; and certain other replacements shall be done in 
    accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
    1995. 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 Learjet, P.O. Box 7707, 
    Wichita, Kansas 67277-7707. Copies may be inspected at the FAA, 
    Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
    Washington; or at the FAA, Wichita Aircraft Certification Office, 
    Small Airplane Directorate, 1801 Airport Road, Room 100, Mid-
    Continent Airport, Wichita, Kansas; or at the Office of the Federal 
    Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 
    -
        (f) This amendment becomes effective on August 3, 1995.
    
        Issued in Renton, Washington, on June 28, 1995.
    Darrell M. Pederson,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 95-16377 Filed 7-18-95; 8:45 am]
    BILLING CODE 4910-13-U
    
    

Document Information

Effective Date:
8/3/1995
Published:
07/19/1995
Department:
Transportation Department
Entry Type:
Rule
Action:
Final rule; request for comments.
Document Number:
95-16377
Dates:
Effective August 3, 1995. -
Pages:
36984-36986 (3 pages)
Docket Numbers:
Docket No. 95-NM-119-AD, Amendment 39-9303, AD 95-14-09
PDF File:
95-16377.pdf
CFR: (1)
14 CFR 39.13