AD 2008-06-14

We are adopting a new airworthiness directive (AD) for certain Boeing Model 757-200, -200PF, and -200CB series airplanes. This AD requires doing an ultrasound inspection for disbonded tear straps not mechanically fastened to the skin, and related investigative and corrective actions, if necessary. This AD results from reports indicating that bonded skin panels may not have been correctly anodized in phosphoric acid before the tear strap doubler was bonded to the skin. We are issuing this AD to detect and correct a weak bond between the skin and tear strap. Such disbonding could reduce the ability of the skin to resist cracks and could adversely affect the structural integrity of the airplane.

Final rule.

2008-06-14 Boeing: Amendment 39-15426. Docket No. FAA-2007-0270; Directorate Identifier 2007-NM-211-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective April 17, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 757-200, -200PF, and -200CB series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 757-53-0077, Revision 1, dated August 6, 2007. \n\nUnsafe Condition \n\n\t(d) This AD results from reports indicating that bonded skin panels may not have been correctly anodized in phosphoric acid before the tear strap doubler was bonded to the skin. We are issuing this AD to detect and correct a weak bond between the skin and tear strap. Such disbonding could reduce the ability of the skin to resist cracks and could adversely affect the structural integrity of the airplane. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performedwithin the compliance times specified, unless the actions have already been done. \n\nInitial Inspection \n\n\t(f) At the applicable initial compliance time in paragraph (f)(1) or (f)(2) of this AD, do an external ultrasound inspection for disbonded tear straps not mechanically fastened to the skin between stations 439 to 900, and 1180 to 1621, and between stringers 10 left and 10 right, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53- 0077, Revision 1, dated August 6, 2007. \n\t(1) For airplanes with less than or equal to 21,000 total flight cycles: Before the accumulation of 24,000 total flight cycles, but no earlier than 18,000 total flight cycles. \n\t(2) For airplanes with more than 21,000 total flight cycles: Within 3,000 flight cycles after the effective date of this AD. \n\nRepetitive Inspection \n\n\t(g) If no disbonding is found during the ultrasound inspection required by paragraph (f) of this AD, repeat the inspection oncebefore 36,000 total flight cycles, but no earlier than 30,000 total flight cycles. \n\nRelated Investigative and Corrective Actions \n\n\t(h) If any disbonding is found during the ultrasound inspection required by paragraph (f) or (g) of this AD, do the applicable related investigative and corrective actions by accomplishing all the actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0077, Revision 1, dated August 6, 2007, at the applicable compliance time specified in paragraph 1.E., "Compliance,'' of the service bulletin; except as provided by paragraph (i) of this AD. \n\t(i) If any crack and/or corrosion is found during any inspection required by this AD, and Boeing Special Attention Service Bulletin 757-53-0077, Revision 1, dated August 6, 2007, specifies to contact Boeing for appropriate action: Before further flight, repair the crack and/or corrosion using a method approved in accordance with the procedures specified in paragraph (j) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(j)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. \n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\nMaterial Incorporated by Reference \n\n\t(k) You must use Boeing Special Attention Service Bulletin 757- 53-0077, Revision 1, dated August 6, 2007, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. \n\t(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_ regulations/ibr_locations.html.

Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 757-200, -200PF, and -200CB series airplanes. That NPRM was published in the Federal Register on December 17, 2007 (72 FR 71277). That NPRM proposed to require an ultrasound inspection for disbonded tear straps not mechanically fastened to the skin, and related investigative and corrective actions, if necessary. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We considered the two comments received. Boeing and Continental Airlines support the NPRM. \n\nConclusion \n\n\tWe reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are 744 airplanes of the affected design in the worldwide fleet. This AD affects 487 airplanes of U.S. registry. The required actions take about 16 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $623,360, or $1,280 per airplane. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and \n\t(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. \n\n\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \n\nList of Subjects in 14 CFRPart 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new AD: