AD 2000-05-16 Airworthiness Directives; Sikorsky Model S-61 Helicopters

Models named: S-61. Read the applicability below — it usually turns on serial or part numbers too.

Model S-61 helicopters with pylon, part number (P/N) S6120-76265-001 or S6120-76266-507, installed, 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 (b) 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 structural failure due to a crack or corrosion of pylon upper and lower hinge web fittings (web fittings), P/N S6120-76261-012, -013 (upper) or S6120-76262-012, -013 (lower), and subsequent loss of control of the helicopter, accomplish the following: (a) Within 25 hours time-in-service (TIS), (1) Determine the alloy-temper of the web fittings in accordance with Sikorsky Aircraft Corporation Alert Service Bulletin No. 61B20-33, dated September 3, 1999 (ASB), Accomplishment Instructions, paragraph 3.A. (2) Prepare the web fittings for inspection in accordance with the ASB Accomplishment Instructions, paragraph 3.B. (3) Inspect the web fitting in accordance with the ASB Inspection Plan, Chart A, and the Accomplishment Instructions, paragraphs 3.C., 3.D, and 3.E. Nicks, scratches, corrosion pitting or prior rework beyond the limits specified in paragraph 3.C.(5) require approval by the FAA. (4) Repair or replace web fittings, as necessary, in accordance with the ASB Accomplishment Instructions, paragraph 3.C.(3) through (6). Nicks, scratches, corrosion pitting, or prior rework beyond the limits specified in paragraph 3.C.(5) require approval by the FAA. (5) If replacing an unairworthy web fitting with an airworthy web fitting, replace it in accordance with the ASB Accomplishment Instructions, paragraph 3.F., prior to further flight. (6) Create a log card for the pylon, if none exists. Make an entry on the log card or equivalent record implementing recurring inspection intervals in accordance with Chart A of the ASB. (b) 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 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. (c) Special flight permits may be issued in accordance with §§ 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. (d) The inspection, repair, and replacement shall be done in accordance with the Inspection Plan, Chart A, and the Accomplishment Instructions of Sikorsky Aircraft Corporation Alert Service Bulletin No. 61B20-33, dated September 3, 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. (e) This amendment becomes effective on March 30, 2000. Issued in Fort Worth, Texas, on March 6, 2000. Henry A. Armstrong, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 00-6036 Filed 3-14-00; 8:45 am] BILLING CODE 4910-13-U