AD 92-27-21

92-27-21 BELL HELICOPTER TEXTRON, INC. (BHTI): Amendment 39-8575. Docket Number 92-ASW-45.

Applicability: Model 205A-1 and 205B series helicopters, with increased diameter tail rotor drive shaft (drive shaft), P/N 204-040-620-011, installed, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the drive shaft, loss of tail rotor control, and subsequent loss of control of the helicopter, accomplish the following:

(a) Within 25 hours' time-in-service after the effective date of this AD:

(1) Conduct a one-time inspection of the helicopter and the drive shaft in accordance with paragraphs 1 through 4 of the Accomplishment Instructions of BHTI Alert Service Bulletin (ASB) 205-92-49, dated October 5, 1992, for BHTI Model 205A-1 helicopters, and ASB 205B-92-13, dated October 5, 1992, for BHTI Model 205B helicopters.

(2) Reassemble the tail rotor drive shaft assembly in accordance with paragraph 5 of the pertinent ASB to ensure a minimum of 0.50 inch clearance is obtained between the tail rotor drive shaft tunnel (drive shaft tunnel) and the drive shaft.

(b) Each time the starter generator is installed after maintenance, ensure a minimum of 0.50 inch clearance is maintained between the drive shaft tunnel and the drive shaft. Adjust the position of the drive shaft tunnel in accordance with paragraph 5 of the pertinent ASB to obtain proper clearance.

(c) Remove unairworthy parts found during the inspection required in paragraph (a) and replace with airworthy parts before further flight.

(d) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Rotorcraft Certification Office, FAA, Rotorcraft Directorate, Fort Worth, Texas 76193-0170. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished.

(f) The inspection, removal, and replacement, if necessary, and reassembly shall be done in accordance with the applicable BHTI ASB 205-92-49 or 205B-92-13, both dated October 5, 1992. 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 Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101. Copies may be inspected at the FAA, Office of the Assistant Chief Counsel, 4400 Blue Mound Road, bldg. 3B, room 158, 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 July 7, 1993, to all persons except those persons to whom it was made immediately effective by Priority Letter AD 92-27-21, issued January 7, 1993, which contained the requirements of this amendment.