# Airworthiness Directives; Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, and SW205A-1 Helicopters Manufactured by Bell Helicopter Textron Inc. for the Armed Forces of the United States
> **Rule** · Final rule; request for comments. · Published 2000-12-11 · Effective 2000-12-26 · 65 FR 77263
## Document
- **Document number:** 00-31012
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 65 FR 77263
- **Publication date:** 2000-12-11
- **Effective date:** 2000-12-26
- **FAA docket:** Docket No. 2000-SW-42-AD
## Abstract

This document publishes in the Federal Register an amendment adopting superseding Airworthiness Directive (AD) 2000-22-51, which was sent previously by individual letters to all known U.S. owners and operators of Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH- 1H, UH-1L, and UH-1P; and Southwest Florida Aviation SW204, SW204HP, SW205, and SW205A-1 helicopters manufactured by Bell Helicopter Textron Inc. (BHTI) for the Armed Forces of the United States. This AD requires establishing a retirement life for certain main rotor masts, creating a component history card or equivalent record, and identifying certain masts as unairworthy. This AD also requires removing the hub spring, if installed, and determining whether a main rotor mast (mast) has ever been installed on a helicopter while operated with a hub spring. Conducting certain inspections based on the retirement index number (RIN) and on whether the helicopter was ever operated with a hub spring is also required. Replacing any mast that has inadequate radius or a burr in the damper clamp splined area is also required. Finally, this AD requires sending information concerning the mast to the FAA. This amendment is prompted by the discovery of a crack in a mast with a lower RIN value than the established life limit. This action is necessary to preclude the occurrence of a fatigue crack in the damper clamp splined area of a mast. This condition, if not corrected, could result in failure of a mast or main rotor trunnion (trunnion), separation of the main rotor system, and subsequent loss of control of the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2000/12/11/00-31012/airworthiness-directives-model-hh-1k-th-1f-th-1l-uh-1a-uh-1b-uh-1e-uh-1f-uh-1h-uh-1l-and-uh-1p-and)
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