AD 2005-05-07

The FAA is adopting a new airworthiness directive (AD) for certain Boeing transport category airplanes. This AD requires repetitive detailed inspections to detect cracking of the aft and forward surfaces of the bulkhead web at nacelle station 180, and repair if necessary. This AD is prompted by reports of cracking of the web bulkhead at nacelle station 180. We are issuing this AD to detect and correct fatigue cracking of the web bulkhead, and consequent loss of the load path of the bulkhead at nacelle station 180, which when combined with the loss of the midspar load path, could result in the in-flight separation of the engine and strut. Such separation may result in secondary damage to the airplane and consequent reduced controllability of the airplane.

Final rule.

2005-05-07 Boeing: Amendment 39-13996. Docket No. FAA-2004-19812; Directorate Identifier 2003-NM-197-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective April 15, 2005. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 747-100, -100B, -100B SUD, - 200B, -200C, -200F, and -300 series airplanes; and Model 747SP and 747SR series airplanes; equipped with Pratt and Whitney Model JT9D- 3, or -7 (except for -70) series engines; as identified in Boeing Alert Service Bulletin 747-54A2220, dated July 31, 2003; certificated in any category. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by reports of cracking of the web bulkhead at nacelle station 180. We are issuing this AD to detect and correct fatigue cracking of the web bulkhead, and consequent loss of the load path of the bulkhead at nacelle station 180, which when combined with the loss of the midspar load path, could result in the in-flight separation of the engine and strut. Such separation may result in secondary damage to the airplane and consequent reduced controllability of the airplane. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nRepetitive Inspections and Repair \n\n\t(f) Within 9 months after the effective date of this AD, do a detailed inspection to detect cracking of the aft and forward surfaces of the bulkhead web at nacelle station 180, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2220, dated July 31, 2003.\n \n\t(1) If no cracking is detected, repeat the detailed inspection at the applicable intervals specified in the "Repeat Inspection Interval" column of Tables 1 and 2 in Figure 1 of the service bulletin. \n\n\t(2) If any cracking is detected, before further flight, repair the cracking in accordance with the service bulletin, except as provided by paragraph (f)(3) of this AD. Thereafter, repeat the detailed inspection at the applicable intervals specified in the "Repeat Inspection Interval" column of Tables 1 and 2 in Figure 1 of the service bulletin. \n\n\t(3) If any cracking exceeds the repair limits specified in the applicable structural repair manual (referenced in the service bulletin), before further flight, repair the cracking in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or in accordance with data meeting the certification basis of the airplane approved by an Authorized Representative (AR) for the Boeing Delegation Option Authorization (DOA) 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\nAlternative Methods of Compliance (AMOCs) \n\n\t(g)(1) The Manager, Seattle 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\n\t(2) 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 AR for the Boeing DOA 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(h) You must use Boeing Alert Service Bulletin 747-54A2220, dated July 31, 2003, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html\n\n\tYou may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR Part 39 with an AD for certain Boeing Model 747-100, -100B, -100B SUD, -200B, - 200C, -200F, and -300 series airplanes; and Model 747SP and 747SR series airplanes; equipped with Pratt and Whitney Model JT9D-3 or -7 (except -70) series engines. That action, published in the Federal Register on December 8, 2004 (69 FR 70936), proposed to require repetitive detailed inspections to detect cracking of the aft and forward surfaces of the bulkhead web at nacelle station 180, and repair if necessary. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public. \n\nExplanation of Change to Proposed AD \n\n\tBoeing has received a Delegation Option Authorization (DOA). We have revised this final rule to delegate the authority to approve an alternative method of compliance for any repair required by this AD to the Authorized Representative for the Boeing DOA Organization rather than the Designated Engineering Representative. \n\nConclusion \n\n\tWe have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCosts of Compliance \n\n\tThis AD will affect about 223 airplanes worldwide and 73 airplanes of U.S. registry. The required actions will take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $4,745, or $65 per airplane, per inspection cycle. \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\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\tWe have determined that this 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 128\n\n\t(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\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\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, 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 airworthiness directive (AD):