# AD 74-02-01: Tail Rotor Trunnion Bearings - Type: Airworthiness directive - Status: Current - Products: Bell Helicopter Textron 205A-1 and 212 - Effective: February 22, 1974 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-1769 - Registered aircraft: 118 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/02D5ADA0B16A342586256A340053D76D.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/74-02-01 ## The airworthiness directive 74-02-01 BELL: Amdt. 39-1769. Applies to Model 205A-1 and 212 helicopters, certificated in all categories, equipped with tail rotor hub assembly, P/N 212-010-701. Compliance required within the next 25 hours' time in service after the effective date of this A.D., unless already accomplished within the last 25 hours' time in service, and thereafter at intervals not to exceed 25 hours' time in service from the last inspection. To detect possible cracks or excessive looseness in the tail rotor trunnion bearings, accomplish the following: (a) Using a 3 power magnifying glass, inspect the trunnion bearing (P/N 212-010- 723-1 or P/N 212-010-768-1) exposed outer races for cracking. (b) To detect any axial looseness in the trunnion bearings, grasp the hub assembly and attempt to move it towards and away from the tail boom fin assembly. If trunnion bearing movement is considered excessive, remove the tail rotor hub and blade assembly. Measure the amount of axial playin each trunnion bearing using a dial indicator. (c) If there is evidence of either trunnion bearing outer race cracking or axial play in excess of the maximum allowable .015 inch, replace the affected bearing in accordance with the instructions contained in Bell Model 212 Overhaul Manual, dated May 1, 1972, Chapter-Section 65-20-01. (Bell Helicopter Company Service Bulletin Nos. 205-05-73-5, dated August 23, 1973, and 212-05-73-4, dated August 20, 1973, pertain to this subject.) 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 the Service Manager, Bell Helicopter Company, P. O. Box 482, Fort Worth, Texas 76101. These documents may also be examined at the Office of the Regional Counsel, Southwest Region, FAA,4400 Blue Mound Road, Fort Worth, Texas, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this A.D. which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Southwest Regional Office in Fort Worth, Texas. This amendment becomes effective February 22, 1974. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H1SW](https://openairdocs.org/tcds/H1SW): Bell Textron Inc.; names 1 of 5 models: 205A-1 - [TCDS H4SW](https://openairdocs.org/tcds/H4SW): Bell Textron Inc.; names 1 of 4 models: 212 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 118 (118 by airframe model, 0 by engine model) - Makers: Bell 110, Bell Helicopter Textron 6, Bell/Southwest Florida Aviatio 2 Models with the most aircraft: - [Bell 205A-1](https://openairdocs.org/model/bell-205a-1): 56 aircraft (airframe model) - [Bell 212](https://openairdocs.org/model/bell-212): 54 aircraft (airframe model) - [Bell Helicopter Textron 212](https://openairdocs.org/model/bell-helicopter-textron-212): 5 aircraft (airframe model) - [Bell/Southwest Florida Aviatio 205 A1](https://openairdocs.org/model/bell-southwest-florida-aviatio-205-a1): 2 aircraft (airframe model) - [Bell Helicopter Textron 205A-1](https://openairdocs.org/model/bell-helicopter-textron-205a-1): 1 aircraft (airframe model) All 5 models: https://openairdocs.org/ad/74-02-01/models.md Every aircraft: https://openairdocs.org/ad/74-02-01/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.