AD 89-20-12

89-20-12 BELL HELICOPTER TEXTRON, INC. (BHTI); HERCULES; OREGON HELICOPTERS; LENAIR CORPORATION; AND SOUTHWEST FLORIDA AVIATION: Amendment 39-6664. Docket No. 89-ASW-42-AD. Final copy of Priority Letter AD.

Applicability: Model 204B, 205A, 205A-1, UH-1L, TH-1L, UH-1H helicopters, certificated in any category.

Compliance: Required as indicated, unless already accomplished.

To prevent failure of the tail rotor hub assembly, which could result in loss of control and subsequent loss of the helicopter, accomplish the following:

(a) Before further flight, determine the part number and serial number of the tail rotor hub assembly installed on the helicopter.

(b) If the tail rotor hub assembly installed is P/N 204-011-801-121 and is identified with any serial number IT0001 through and including IT0010, remove and replace the assembly with an airworthy part before further flight.

(c) If one of the tail rotor hub assemblies listed in paragraph (b) is found,report the helicopter registration, serial number, and hub assembly serial number to the Manager, Rotorcraft Certification Office, Federal Aviation Administration, Fort Worth, Texas, 76193-0170, telephone (817) 624-5170, within 10 days of the inspection. (Reporting approved by the Office of Management and Budget under OMB No. 2120-0056.)

(d) In accordance with FAR Sections 21.197 and 21.199, the helicopter may be flown to a base where the inspection and assembly replacement may be accomplished.

(e) An alternate method of compliance, which provides an equivalent level of safety, may be used if approved by the Manager, Rotorcraft Certification Office, ASW-170, Federal Aviation Administration, Fort Worth, Texas 76193-0170, telephone (817) 624-5170.

This amendment (39-6664, AD 89-20-12) becomes effective August 15, 1990, as to all persons except those persons to whom it was made immediately effective by Priority Letter AD 89-20-12, issued September 29, 1989, which contained this amendment.