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 Federal Register Information
 Header Information
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39 [66 FR 21855 5/2/2001]
Docket No. 99-NM-124-AD; Amendment 39-12206; AD 2001-09-01
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200 and -300 Series Airplanes
PDF Copy (If Available):
Preamble Information
Regulatory Information
2001-09-01 BOEING: Amendment 39-12206. Docket 99-NM-124-AD.
Applicability: Model 757-200 series airplanes as listed in Boeing Alert Service Bulletin 757-32A0135, Revision 1; and Model 757-300 series airplanes as listed in Boeing Alert Service Bulletin 757-32A0138, Revision 1; both dated November 30, 2000; 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 request approval for an alternative method of compliance in accordance with paragraph (c) 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 prevent stress corrosion cracking, leading to fracture of a main landing gear (MLG) truck beam during ground operations, which could result in either reduced controllability of the airplane or a fire, accomplish the following:
Repetitive Clearing Procedure
(a) Within 4 years since the last overhaul of the MLG truck beam, since the date of airplane delivery (for MLG truck beams that have not been overhauled), or since the date of installation of new truck beams; or within 90 days after the effective date of this AD; whichever occurs latest: Insert a wooden probe, or similar non-metallic object, into the aft drain hole of the MLG truck beam, to clear the drain passage and ensure it can properly drain, in accordance with Boeing Alert Service Bulletin 757-32A0135, Revision 1 (for Model 757-200 series airplanes), or 757-32A0138, Revision 1 (for Model 757-300 series airplanes), both dated November 30, 2000, as applicable.
(1) If the aft drain hole is found unclogged, repeat the clearing procedure thereafter at intervals not to exceed 18 months.
(2) If the aft drain hole is found clogged, repeat the clearing procedure thereafter at intervals not to exceed 6 months.
Note 2: Accomplishment of the clearance of the drain passage prior to the effective date of this AD in accordance with Boeing Service Letter 757-SL-32-060, dated March 31, 1999; Boeing Alert Service Bulletin 757-32A0135 (for Model 757-200 series airplanes), or 757-32A0138 (for Model 757-300 series airplanes), both dated June 8, 2000; as applicable; is considered acceptable for compliance with the requirements specified in paragraph (a) of this AD.
Internal Inspection
(b) For Group 1 airplanes as listed in Boeing Alert Service Bulletin 757-32A0135, Revision 1, dated November 30, 2000: Within 8 years since the date of airplane delivery (for MLG truck beams that have not been overhauled), or since the date of installation of new truck beams; or within 6 months after the effective date of this AD; whichever occurs latest: Perform an internal inspection of the truck beam protective finish (plating and primer) to detect discrepancies (flaked, cracked, missing finish, or corrosion), as illustrated in Figure 2 of the alert service bulletin.
Corrective Action
(1) If no discrepancy is detected, prior to further flight, apply corrosion preventive compound in accordance with the Accomplishment Instructions of the alert service bulletin.
(2) If any discrepancy is detected, prior to further flight, overhaul or replace the truck beam, as applicable, in accordance with the Accomplishment Instructions of the alert service bulletin.
Note 3: Accomplishment of the internal inspection and overhaul of the MLG truck beam, as applicable, prior to the effective date of this AD, in accordance with Boeing Alert Service Bulletin 757-32A0135, dated June 8, 2000, is considered acceptable for compliance with the requirements specified in paragraph (b) of this AD.
Alternative Methods of Compliance
(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, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.
Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.
Special Flight Permits
(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.
Incorporation by Reference
(e) The actions shall be done in accordance with Boeing Alert Service Bulletin 757-32A0135, Revision 1, dated November 30, 2000; or Boeing Alert Service Bulletin 757-32A0138, Revision 1, dated November 30, 2000; as applicable. 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 Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
Effective Date
(f) This amendment becomes effective on June 6, 2001.
Footer Information
Issued in Renton, Washington, on April 20, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate,
Aircraft Certification Service.
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