# AD 89-20-12: Tail Rotor Hub Assembly - Type: Airworthiness directive - Status: Current - Products: Overseas Aircraft Support 204B, 205A, 205A-1, TH-1L, UH-1L, TH-1L, UH-1H, UH-1H, TH-1L, UH-1L and UH-1H - Effective: August 15, 1990 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-6664 - Docket: 89-ASW-42-AD - Registered aircraft: 86 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/133528D8A999C9F886256A4D0073E6CE.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/89-20-12 ## The airworthiness directive 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. ## 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 3 of 5 models: 205A, 204B, 205A-1 - [TCDS H7SO](https://openairdocs.org/tcds/H7SO): Overseas Aircraft Support Inc.; names 2 of 5 models: TH-1L, UH-1L ## 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: 86 (86 by airframe model, 0 by engine model) - Makers: Bell 63, Northwest Rotorcraft 6, Williams Helicopter 6, Southwest Florida 3, Bell/Southwest Florida Aviatio 2, Richards Heavylift Helo 2, Rotorcraft Development 2, Bell Helicopter Textron 1, Precision Helicopters 1 Models with the most aircraft: - [Bell 205A-1](https://openairdocs.org/model/bell-205a-1): 56 aircraft (airframe model) - [Bell 204-B](https://openairdocs.org/model/bell-204-b): 7 aircraft (airframe model) - [Northwest Rotorcraft UH-1H](https://openairdocs.org/model/northwest-rotorcraft-uh-1h): 6 aircraft (airframe model) - [Williams Helicopter UH-1H](https://openairdocs.org/model/williams-helicopter-uh-1h): 6 aircraft (airframe model) - [Southwest Florida UH-1H](https://openairdocs.org/model/southwest-florida-uh-1h): 3 aircraft (airframe model) - [Richards Heavylift Helo UH-1H](https://openairdocs.org/model/richards-heavylift-helo-uh-1h): 2 aircraft (airframe model) - [Bell/Southwest Florida Aviatio 205 A1](https://openairdocs.org/model/bell-southwest-florida-aviatio-205-a1): 2 aircraft (airframe model) - [Rotorcraft Development UH-1H](https://openairdocs.org/model/rotorcraft-development-uh-1h): 2 aircraft (airframe model) - [Precision Helicopters UH-1H](https://openairdocs.org/model/precision-helicopters-uh-1h): 1 aircraft (airframe model) - [Bell Helicopter Textron 205A-1](https://openairdocs.org/model/bell-helicopter-textron-205a-1): 1 aircraft (airframe model) All 10 models: https://openairdocs.org/ad/89-20-12/models.md Every aircraft: https://openairdocs.org/ad/89-20-12/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.