AD 97-08-08 Airworthiness Directives; Boeing Model 777-200 Series Airplanes

Models named: 777-200 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 777-200 series airplanes powered by General Electric (GE) 90 engines having serial number 900-104, -105, -106, - 108, -109, -110, or -111; certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been [[Page 19482]] otherwise 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.

Required as indicated, unless accomplished previously. To prevent fatigue cracking in the bolts that attach the yoke of the forward mount of the engine to the fan case of the engine, which could lead to failure of these bolts and consequent separation of the engine from the wing, accomplish the following: (a) For airplanes powered by GE90 engines having serial numbers 900-105 and -110: (1) Within 125 landings after the effective date of this AD, conduct a visual inspection of the yoke of the forward mount of the engine to detect damaged, missing, or failed attachment bolts, or failed engine mount links, in accordance with GE Aircraft Engines Service Bulletin 72-183, dated February 28, 1997. (i) If no discrepancy is found, repeat this inspection thereafter at intervals not to exceed 125 landings. (ii) If any discrepancy is found, prior to further flight, modify the engine in accordance with GE Aircraft Engines Service Bulletin 72-275, dated March 4, 1997. No further action is required by this AD for that engine. (2) Within 1,000 landings after the effective date of this AD, modify the engine in accordance with GE Aircraft Engines Service Bulletin 72-275, dated March 4, 1997. Accomplishment of this modification constitutes terminating action for the repetitive inspections of that engine required by paragraph (a)(1)(i) of this AD. (b) As of the effective date of this AD, no operator shall install on any airplane any GE90 engine having serial number 900- 104, 900-106, 900-108, 900-109, or 900-111 unless that engine has been modified in accordance with GE Aircraft Engines Service Bulletin 72-275, dated March 4, 1997. (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, Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle 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 modification shall be done in accordance with GE Aircraft Engines Service Bulletin 72-183, dated February 28, 1997, and GE Aircraft Engines Service Bulletin 72-275, dated March 4, 1997. 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 General Electric Aircraft Engines, GE90 Product Support, One Neuman Way, Cincinnati, Ohio 45215-6301. 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. (f) This amendment becomes effective on May 7, 1997. Issued in Renton, Washington, on April 10, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-9881 Filed 4-21-97; 8:45 am] BILLING CODE 4910-13-U