AD 2000-11-52 Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76 Series Helicopters

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

Model S-76 series 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 (f) 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 main rotor blade root end pocket separation, impact with main rotor or tail rotor blades, and subsequent loss of control of the helicopter, accomplish the following: (a) Before further flight, determine the serial number of each main rotor blade. (b) Any main rotor blade identified in paragraphs (c) or (d) of this AD that has been repaired in accordance with Sikorsky Aircraft Corporation Overhaul and Repair Instructions (ORI) No. 76150-023, Revision A, dated May 26, 2000, and marked as RS-023-1 is not affected by the requirements of this AD. (c) Before further flight, remove any main rotor blade identified by serial number (S/N) in the Group 1, paragraph 1.A. Planning Information of Sikorsky Aircraft Corporation Alert Service Bulletin No. 76-65-50, dated May 25, 2000 (ASB). (d) Before each flight and at intervals not to exceed 3 hours time-in-service, visually inspect any main rotor blade, identified by S/N in Group 2, paragraph 1.A. of the ASB Planning Information, for a span-wise crack in the upper and lower root end area, in accordance with paragraph 3.B. of the ASB Accomplishment Instructions. Remove any main rotor blade with a span-wise crack and replace with an airworthy blade before further flight. (e) Accomplishing ORI 76150-023, Revision A, dated May 26, 2000, on each affected blade is terminating action for the requirements of this AD. Note 2: A crack, other than a span-wise crack, in the root end cap of the main rotor blade should be dispositioned in accordance with the applicable Maintenance Manual. (f) 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, FAA. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Boston Aircraft Certification Office. (g) 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. (h) The removal of certain serial numbered main rotor blades shall be done in accordance with Group 1, paragraph 1.A. Planning Information of Sikorsky Aircraft Corporation Alert Service Bulletin No. 76-65-50, dated May 25, 2000. The visual inspection shall be done in accordance with paragraph 3.B. of the Accomplishment Instructions of Sikorsky Aircraft Corporation Alert Service Bulletin No. 76-65-50, dated May 25, 2000. 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. (i) This amendment becomes effective on August 31, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-11-52, issued May 26, 2000, which contained the requirements of this amendment. Issued in Fort Worth, Texas, on August 7, 2000. Henry A. Armstrong, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 00-20502 Filed 8-15-00; 8:45 am] BILLING CODE 4910-13-P