Is AD 99-17-19 a recurring Airworthiness Directive?

No — AD 99-17-19 is a one-time directive. Verify it was complied with in the aircraft's records.

Which aircraft does AD 99-17-19 apply to?

AD 99-17-19 applies to Bell Helicopter Textron, Inc. — models 206L-1, 206L-3, 206L-4, 206L. Serial/part conditions may narrow it to specific aircraft.

Airworthiness Directive 99-17-19

one-time

Official AD 99-17-19 · FR doc 99-21573 · 1999-08-20 · airframe

Airworthiness Directives; Bell Helicopter Textron, A Division of Textron Canada, Model 206L, L-1, L-3, and L-4 Helicopters

What this AD requires

This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron, A Division of Textron Canada (BHTC), Model 206L, L-1, L-3, and L-4 helicopters, that currently requires the creation of a component history card or equivalent record using the Retirement Index Number (RIN) system for certain mast and trunnions and a system for tracking increases to the accumulated RIN. That AD also establishes retirement lives for the mast and trunnion. This amendment requires the same actions required by the existing AD but increases the RIN multiplier for the mast and corrects a helicopter model number. This amendment is prompted by further tests and analyses that indicate the RIN multiplier for the Model 206L-4 helicopters needs to be increased and the discovery of an error in a model designation in the existing AD. The actions specified by this AD are intended to prevent fatigue failure of the mast or trunnion, which could result in loss of the main rotor system and subsequent loss of control of the helicopter.

Which aircraft AD 99-17-19 applies to

MakesBell Helicopter Textron, Inc.

Models206L-1, 206L-3, 206L-4, 206L

Applies to Model 206L, 206L-1, 206L-3, and 206L-4 helicopters. Establishes a Retirement Index Number (RIN) life-tracking system for the main rotor mast and trunnion per Bell Helicopter Textron Alert Service Bulletin No. 206L-94-99, Revision A, dated May 1, 1995. RIN increases by 1 per torque event (takeoff or external-load lift) for Model 206L/206L-1/206L-3 mast and trunnion; increases by 2 per torque event for Model 206L-4 mast and trunnion. Trunnion retirement life = 24,000 RIN; mast retirement life = 44,000 RIN or the flight-hour service life limit, whichever occurs first.

Whether AD 99-17-19 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:

Method of compliance — The specific action taken (inspected, replaced, modified) and to what revision.

Date — When the work was done.

Aircraft time — Total time in service / tach at compliance — how recurring next-due is computed.

Signature & certificate — The A&P/IA who returned it to service, with certificate number.

Is AD 99-17-19 complied with on your aircraft?

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.