AD 99-19-30 Airworthiness Directives; Sikorsky Aircraft Corp. Model S76A, B, and C Helicopters

Models named: S-76A, B, C. Read the applicability below — it usually turns on serial or part numbers too.

Model S-76A, B, and C helicopters, certificated in any category. Note 1: This AD applies to each helicopter 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 helicopters 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 (d) 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 tail gearbox forward fairing (fairing), damage to the tail rotor blades, and subsequent loss of control of the helicopter, accomplish the following: (a) Within 50 hours time-in-service (TIS), conduct a visual inspection of the attachment angle on each fairing, in accordance with the Accomplishment Instructions, paragraph A, of Sikorsky Aircraft Corp. Alert Service Bulletin 76-55-16, dated May 12, 1999 (ASB). (b) Thereafter, at intervals not to exceed 1500 hours TIS, conduct a visual inspection of the attachment angle on each fairing in accordance with the Accomplishment Instructions, paragraph A, of the ASB. (c) If the visual inspection in paragraphs (a) or (b) reveals a disbond area that equals or exceeds 1.0 square inch, prior to further flight, repair or replace the attachment angle with an airworthy attachment angle in accordance with the Accomplishment Instructions, paragraph B, of the ASB. (d) 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, Boston Aircraft Certification Office. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Boston Aircraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Boston Aircraft Certification Office. (e) 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 helicopter to a location where the requirements of this AD can be accomplished. (f) The inspection, repair, or replacement shall be done in accordance with the Accomplishment Instructions in Sikorsky Aircraft Corp. Alert Service Bulletin 76-55-16, dated May 12, 1999. 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 Sikorsky Aircraft Corporation, Attn: Manager, Commercial Tech Support, 6900 Main Street, P. O. Box 9729, Stratford, Connecticut 06497-9129, phone (203) 386-7860, fax (203) 386-4703. Copies may be inspected at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (g) This amendment becomes effective on October 4, 1999. Issued in Fort Worth, Texas, on September 7, 1999. Eric Bries, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 99-23959 Filed 9-16-99; 8:45 am] BILLING CODE 4910-13-U