AD 99-20-09 Airworthiness Directives; Boeing Model 747 Series Airplanes

Models named: 747 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747 series airplanes, as listed in Boeing Alert Service Bulletin 747-71A2277, dated November 29, 1995; or Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998, or Revision 2, dated January 14, 1999; 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)(1) 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 separation of the engine from the airplane, accomplish the following: Restatement of Requirements of AD 96-03-01 R1, Amendment 39-9538 Inspections and Corrective Actions (a) Within 90 days after February 16, 1996 (the effective date of AD 96-03-01 R1, amendment 39-9538), accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD in accordance with Boeing Alert Service Bulletin 747-71A2277, dated November 29, 1995, or Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998, or Revision 2, dated January 14, 1999. (1) Perform a visual inspection to ensure that installation of the tangential link upper bolt nut is on the forward side of the engine mount fitting. (i) If the tangential link upper bolt nut is installed on the forward side of the engine mount fitting, repeat the visual inspection at intervals not to exceed 18 months. (ii) If the tangential link upper bolt nut is not installed on the forward side of the engine mount fitting, prior to further flight, remove the nut, bolt, and washers, and reinstall the nut, bolt, and washers in accordance with the service bulletin. Thereafter, repeat the visual inspection at intervals not to exceed 18 months. (iii) If the tangential link upper bolt is missing from the engine mount fitting, prior to further flight, perform the various follow-on actions in accordance with the service bulletin. (The follow-on actions include visual inspections, magnetic particle inspections, replacement of the lower engine mount fitting with a serviceable part, if necessary; installation of new safety links, bolts, and nuts; and installation of a new tangential link upper bolt.) Thereafter, repeat the visual inspection at intervals not to exceed 18 months. (2) Perform an inspection to verify that the torque value of the tangential link upper bolt (on both sides of the mount) is within the limits specified in the service bulletin. (i) If the torque value of the tangential link upper bolt nut is within the limits specified in the service bulletin, repeat the inspection (verification) at intervals not to exceed 18 months. (ii) If the torque value of the tangential link upper bolt nut is outside the limits specified in the service bulletin, prior to further flight, perform a visual inspection of the tangential link upper bolt and washer for any damage or discrepancy, in accordance with the service bulletin. (A) If no damage or discrepancy of the tangential link upper bolt and washers is found, prior to further flight, replace the bolt nut with a new or serviceable part in accordance with the service bulletin. Thereafter, repeat the inspection (verification) specified in paragraph (a)(2) of this AD at intervals not to exceed 18 months. (B) If any damage or discrepancy of the tangential link upper bolt and washers is found, prior to further flight, replace the damaged or discrepant part with a new or serviceable part, and replace the bolt nut with a new or serviceable part, in accordance with the service bulletin. Thereafter, repeat the inspection (verification) specified in paragraph (a)(2) of this AD at intervals not to exceed 18 months. New Requirements of This AD Replacement (b) Within 18 months after the effective date of this AD, accomplish the requirements of either paragraph (b)(1) or (b)(2) of this AD. Accomplishment of either paragraph (b)(1) or (b)(2) of this AD constitutes terminating action for the repetitive inspection requirements of this AD. (1) Replace the safety links on the aft engine mount with modified safety links in accordance with Boeing Service Bulletin 747-71-2206, dated April 16, 1987; or Boeing Service Bulletin 747- 71-2206, Revision 1, dated November 12, 1987, as revised by Boeing Notice of Status Change No. 747-71-2206 NSC 1, dated December 4, 1987, and Boeing Notice of Status Change [[Page 53623]] No. 747-71-2206 NSC 2, dated March 17, 1988. (2) Replace the tangential link upper bolt on the aft engine mount with a reworked bolt and a new nut retainer, in accordance with Parts 2 and 3 of Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998, or Revision 2, dated January 14, 1999. Alternative Methods of Compliance (c)(1) 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, 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. (c)(2) Alternative methods of compliance, approved previously in accordance with AD 96-03-01 R1, amendment 39-9538, are approved as alternative methods of compliance with this AD. Note 2: 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 Secs. 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 747-71A2277, dated November 29, 1995; Boeing Service Bulletin 747-71A2277, Revision 1, dated May 21, 1998; Boeing Service Bulletin 747-71A2277, Revision 2, dated January 14, 1999; Boeing Service Bulletin 747-71-2206, dated April 16, 1987; or Boeing Service Bulletin 747-71-2206, Revision 1, dated November 12, 1987, as revised by Boeing Notice of Status Change No. 747-71-2206 NSC 1, dated December 4, 1987, and Boeing Notice of Status Change No. 747- 71-2206 NSC 2, dated March 17, 1988; as applicable. (1) The incorporation by reference of Boeing Service Bulletin 747-71A2277, Revision 2, dated January 14, 1999; Boeing Service Bulletin 747-71-2206, dated April 16, 1987; or Boeing Service Bulletin 747-71-2206, Revision 1, dated November 12, 1987, as revised by Boeing Notice of Status Change No. 747-71-2206 NSC 1, dated December 4, 1987, and Boeing Notice of Status Change No. 747- 71-2206 NSC 2, dated March 17, 1988; as applicable is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Boeing Service Bulletin 747-71-2206, Revision 1, dated November 12, 1987, contains the following list of effective pages: ------------------------------------------------------------------------ Revision level Page No. shown on page Date shown on page ------------------------------------------------------------------------ 1-5, 9, 10, 12.............. 1.............. November 12, 1987. 6-8, 11, 13-18.............. Original....... April 16, 1987. ------------------------------------------------------------------------ (2) The incorporation by reference of Boeing Alert Service Bulletin 747-71A2277, dated November 29, 1995, was approved previously by the Director of the Federal Register as of February 16, 1996 (61 FR 10270, March 13, 1996). (3) 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. (f) This amendment becomes effective on November 8, 1999. Issued in Renton, Washington, on September 22, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 99-25218 Filed 10-1-99; 8:45 am] BILLING CODE 4910-13-P