AD 2010-16-12

We are adopting a new airworthiness directive (AD) for certain Model 777-200LR and -300ER series airplanes equipped with GE90-100 series engines. This AD requires replacing the insulation blanket fasteners of the lower aft cowl of the thrust reverser. This AD also requires inspecting the oil scavenge tube on the turbine rear frame of the engine for damage, and replacement if necessary. This AD results from a determination of insufficient clearance and subsequent interference between the oil scavenge tube on the turbine rear frame of the engine and the bolt on the aft cowl insulation blanket of the thrust reverser. We are issuing this AD to prevent damage and possible puncture of the oil scavenge tube and consequent oil loss, which could result in an in-flight shutdown of the engine.

Final rule; request for comments.

2010-16-12 The Boeing Company: Amendment 39-16389. Docket No. FAA- 2010-0704; Directorate Identifier 2010-NM-037-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective August 30, 2010. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to The Boeing Company Model 777-200LR and - 300ER series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 78: Engine exhaust. \n\nUnsafe Condition \n\n\t(e) This AD results from a determination of insufficient clearance and subsequent interference between the oil scavenge tube on the turbine rear frame of the engine and the bolt on the aft cowl insulation blanket of the thrust reverser. The Federal Aviation Administration is issuing this AD to prevent damage and possible puncture of the oil scavenge tube and consequent oil loss, which could result in an in-flight shutdown of the engine. \n\nCompliance \n\n\t(f) 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\nFastener Replacement \n\n\t(g) Within 180 days or 300 flight cycles after the effective date of this AD, whichever is later: Replace the insulation blanket fasteners of the lower aft cowl of the thrust reverser, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008. \n\nInspect and Replace \n\n\t(h) Before or concurrently with accomplishing the requirements in paragraph (g) of this AD: Do a detailed inspection of the oil scavenge tube on the turbine rear frame of the engine for damage, in accordance with the Accomplishment Instructions of General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008. If any damage is found, before further flight, replace the tube, in accordance with the Accomplishment Instructions of General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008. \n\n\tNote 1: For the purposes of this AD, a detailed inspection is: "An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.'' \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Margaret Langsted, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6500; fax (425) 917-6590. Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC- Requests@faa.gov. \n\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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008; and General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008; as applicable; to do the actions required by this AD, unless the AD specifies otherwise. \n\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\n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221. \n\n\t(4) You may also review copies of the service information that is incorporated by reference 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\tBoeing has determined that insufficient clearance and subsequent interference exists between the oil scavenge tube on the turbine rear frame of the engine and the bolt on the aft cowl insulation blanket. This location could encounter interference under flight loads. Damage to the oil scavenge tube was confirmed after flight on undelivered airplanes. Several in-service airplanes had sustained damage (dents, gouges, or chafing) because of the interference condition. This condition, if not corrected, could result in possible puncture of the oil scavenge tube and consequent oil loss, resulting in an in-flight shutdown of the engine. \n\nRelevant Service Information \n\n\tWe reviewed Boeing Alert Service Bulletin 777-78A0070, dated November 20, 2008. This service bulletin describes Procedures for replacing the insulation blanket fasteners of the lower aft cowl of the thrust reverser. \n\n\tBoeing Alert Service Bulletin 777-78A0070, dated November20, 2008, specifies prior or concurrent accomplishment of an inspection of the oil scavenge tube on the turbine rear frame of the engine for damage, and replacement if damage is found, in accordance with General Electric GE90-100 Service Bulletin 79-0017, dated March 3, 2008. \n\nFAA's Determination and Requirements of This AD \n\n\tNo airplanes affected by this AD are on the U.S. Register. We are issuing this AD because the unsafe condition described previously is likely to exist or develop on other products of the same type design that could be registered in the United States in the future. This AD requires replacing the insulation blanket fasteners of the lower aft cowl of the thrust reverser. This AD also requires inspecting the oil scavenge tube on the turbine rear frame of the engine for damage, and replacement if necessary. \n\n\tSince no airplanes are affected by this AD, notice and opportunity for public comment before issuing this AD are unnecessary. \n\nComments InvitedThis AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2010-0704; Directorate Identifier 2010-NM-037-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\n\tWe will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \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\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 governmentand 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\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\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD docket. \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\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: