98-07-21: Engine Tailpipe V-Band Coupling

98-07-21 LOCKHEED AERONAUTICAL SYSTEMS COMPANY: Amendment 39-10442. Docket 97-NM-93-AD. Applicability: Model 1329-25 series airplanes equipped with an engine tailpipe V-band coupling, part number (P/N) NH1002299-10; and Model 1329-23 series airplanes that have been modified in accordance with Supplemental Type Certificate (STC) SA2326SW, equipped with an engine tailpipe V-band coupling, P/N NH1002299-10; certificated in any category. NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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. Compliance: Required as indicated, unless accomplished previously. To prevent displacement of the engine tailpipes, which could result in escape of hot exhaust gases from the engine tailpipe, and consequent damage to adjacent structure, accomplish the following: (a) Within 12 months after the effective date of this AD, replace the tailpipe V-band coupling having P/N NH1002299-10 with a new, redesigned coupling having P/N NH1003605-10, in accordance with Step 1, Figure 71-1, of Lockheed JetStar II Handbook of Operating and Maintenance Instructions, undated (for Model 1329-25 series airplanes); or Step 8, Figure 71-1(S), of Garrett Airesearch Aviation Company 731 JetStar document, undated (for Model 1329-23 series airplanes); as applicable. NOTE 2: Installation of P/N NH1003605-10 prior to the effective date of this AD is considered acceptable for meeting the replacement requirement of paragraph (a) of this AD. Compliance may be demonstrated by confirmation that the airplane maintenance records reflect installation of P/N NH1003605-10 V-band couplings. (b) As of 12 months after the effective date of this AD, no person shall install a tailpipe V-band coupling, P/N NH1002299-10, on any airplane. (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, Atlanta Aircraft Certification Office (ACO), FAA, Small 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, Atlanta ACO. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta 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) This amendment becomes effective on May 18, 1998.