Airworthiness Directive 2000-15-52
one-timeAirworthiness Directives; Bell Helicopter Textron, Inc. Model 204B, 205A, 205A-1, 205B, and 212 Helicopters
What this AD requires
This document publishes in the Federal Register an amendment adopting superseding Airworthiness Directive (AD) 2000-15-52, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron, Inc. Model (BHTI) Model 204B, 205A, 205A-1, 205B, and 212 helicopters by individual letters. This AD reduces the retirement index number (RIN) life limit for the main rotor mast (mast); increases the RIN factor for masts and main rotor trunnions (trunnions); applies standard RIN factors for all external load lifts; and requires a one-time inspection of the snap ring groove area of the mast. This AD also establishes RIN factors for masts and trunnions that have been previously installed on military or restricted category helicopters and removes from service those masts that have been previously installed with a hub spring. This amendment is prompted by an occurrence of a cracked mast at a lower value than the established RIN life limit. The actions specified by this AD are intended to preclude the occurrence of fatigue cracks in the damper clamp splined area of a mast. A crack in the damper clamp splined area could result in failure of a mast or trunnion, separation of the main rotor system, and subsequent loss of control of the helicopter.
Which aircraft AD 2000-15-52 applies to
Bell Helicopter Textron Inc (BHTI) main rotor mast/trunnion Retirement Index Number (RIN) AD; requires recalculating accumulated RIN and replacing mast/trunnion P/Ns above once RIN thresholds are reached. Text cross-references BHTI military variants (HH-1K, TH-1F, TH-1L, UH-1A through UH-1P) and various restricted-category operators only for mast/trunnion prior-installation history checks, not as this AD's own applicability list. The lead-in applicability paragraph (specific commercial Bell model designations) was not captured in retrieved text.
Whether AD 2000-15-52 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.