AD 2001-25-52 Airworthiness Directives; Schweizer Aircraft Corporation Model 269A, 269A-1, 269B, 269C, and TH-55A Helicopters

Makes named: schweizer. Models named: 269A, 269A-1, 269B, 269C, TH-55A. Read the applicability below — it usually turns on serial or part numbers too.

Model 269A, 269A-1, 269B, 269C, and TH-55A helicopters, with tailboom support strut (strut) assemblies, part number (P/N) 269A2015 or P/N 269A2015-5; tailboom center attach fitting, P/N 269A2324; or with a center frame aft cluster fitting, P/N 269A2234 or 269A2235, 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 (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 failure of a strut clevis lug (lug) on a center frame aft cluster fitting (cluster fitting), rotation of a tailboom into the main rotor blades, and subsequent loss of control of the helicopter, accomplish the following: (a) Within 10 hours time-in-service (TIS), and thereafter at intervals not to exceed 50 hours TIS, for helicopters with cluster fittings, P/N 269A2234 or 269A2235: (1) Using paint remover, remove paint from the lugs on each aft cluster fitting. Wash with water and dry. (2) Dye-penetrant inspect the lugs on each aft cluster fitting. See Figure 1. (3) If a crack is found, before further flight, replace the cracked cluster fitting with an airworthy cluster fitting. Cluster fittings, P/N 269A2234 and 269A2235, are not eligible to replace a cracked cluster fitting. ER23AP02.008 (b) For helicopters with strut assemblies P/N 269A2015 or 269A2015-5, accomplish the following: (1) At intervals not to exceed 50 hours TIS: (i) Remove the strut assemblies, P/N 269A2015 or P/N 269A2015-5. (ii) Visually inspect the strut aluminum end fittings for deformation or damage and dye-penetrant inspect the strut aluminum end fittings for a crack in with accordance Step II of Schweizer Service Information Notice No. N-109.2, dated September 1, 1976 (SIN N-109.2). (iii) If deformation, damage, or a crack is found, before further flight, modify the strut assemblies by replacing the aluminum end fittings with stainless steel end fittings, P/N 269A2017-3 and -5, and attach bolts in accordance with Step III of SIN N-109.2; or replace each strut assembly P/N 269A2015 with P/N 269A2015-9, and replace each strut assembly P/N 269A2015-5 with P/N 269A2015-11. (2) Within 500 hours TIS or one year, whichever occurs first, modify or replace the strut assemblies in accordance with paragraph (b)(1)(iii) of this AD. (c) For Schweizer Aircraft Corporation Model 269C helicopters, within 100 hours TIS, serialize each strut assembly, P/N 269A2015-5 and 269A2015-11, in accordance with Schweizer Service Information Notice No. N-108, dated May 21, 1973. (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, New York Aircraft Certification Office (NYACO), FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, NYACO. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the NYACO. (e) Special flight permits may be issued in accordance with 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 inspections and modifications shall be done in accordance with Steps II and III of Schweizer Service Information Notice No. N-109.2, dated September 1, 1976 and Schweizer Service Information Notice No. N-108, dated May 21, 1973, as applicable. 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 Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New York 14902. 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 May 8, 2002, to all persons except those persons to whom it was made immediately effective by Emergency AD 2001-25-52, issued December 14, 2001, which contained the requirements of this amendment. Issued in Fort Worth, Texas, on April 12, 2002. David A. Downey, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 02-9729 Filed 4-22-02; 8:45 am] BILLING CODE 4910-13-U