AD 85-17-08

85-17-08 SIKORSKY AIRCRAFT: Amendment 39-5196. Applies to Model S-58A, B, C, D, E, F, G, H, J, BT, DT, ET, FT, HT, and JT helicopters certificated in any category and CH- 34 series HH-34 series, SH-34 series, UH-34 series, and VH-34 series helicopters certificated in the restricted category.

Compliance is required as indicated, unless already accomplished.

To prevent the separation of the stationary star and rotating star, accomplish the following:

(a) Within the next 10 hours time in service after the effective date of this AD, and thereafter at intervals not to exceed 25 hours time in service from the last inspection, visually inspect the 12 main rotor head star assembly retainer bolts, Part Number lP/N) MS20074-04-04 or P/N AN74A4, for damage and for security of fastening in accordance with Section 2, Paragraph A, of Sikorsky Alert Service Bulletin (ASB) No. 58B10-19, dated May 31, 1985, or later FAA-approved revision.

(b) If damaged or loose bolts are found, fluorescent magnetic particle inspect the bolts for cracks and visually inspect the bolt threads for crossed, stripped, or flattened threads in accordance with Section 2, Paragraph A, of Sikorsky ASB No. 58B10-19, dated May 31, 1985, or later FAA-approved revision.

(c) If a cracked bolt is found, or if the bolt threads are crossed, stripped, or flattened, replace with a new (zero time) bolt prior to further flight in accordance with Section 2, Paragraph A, of Sikorsky ASB No. 58B10-19, dated May 31, 1985, or later FAA-approved revision.

(d) Within the next 100 hours time in service after the effective date of this AD, unless already accomplished within the last 1,000 hours time in service, replace the 12 main rotor head star assembly retainer bolts with new (zero time) bolts in accordance with Section 2, Paragraphs A(7)(c), (d), and (e) and Paragraph B, of Sikorsky ASB No. 58B10-19, dated May 31, 1985, or later FAA-approved revision; thereafter, install new (zero time) main rotor head star assembly retainer bolts at intervals not to exceed 1,100 hours time in service.

(e) Render unairworthy any bolts removed in accordance with the requirements of paragraph (d) of this AD by crushing the threads.

(f) Aircraft may be ferried in accordance with the provisions of FAR Sections 21.197 and 21.199 to a base where the AD can be accomplished.

(g) An alternate method of compliance or adjustments of the compliance time which provide an equivalent level of safety may be used when approved by the Manager, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, Massachusetts 01803, telephone number (617) 273-7118.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Sikorsky Aircraft Division, United Technology Corporation, North Main Street, Stratford, Connecticut 06601. These documents also may be examined at the Rules Docket, Office of the Regional Counsel, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas 76106.

This amendment becomes effective January 13, 1986, as to all persons except those persons to whom it was made immediately effective by priority letter AD No. 85-17-08, issued August 30, 1985, which contained this amendment.