Airworthiness Directive 99-04-13
recurringAirworthiness Directives; Bell Helicopter Textron, Inc. Model 214ST Helicopters
What this AD requires
This amendment adopts a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214ST helicopters. This action requires a reduction of the never-exceed velocity (Vne) limitation until an inspection of the tail rotor yoke (yoke) assembly for fatigue damage and installation of a redesigned yoke flapping stop are accomplished. Recurring periodic and special inspections to detect occurrences of yoke overload are also required. This amendment is prompted by reports of inflight failures of yokes installed on civilian and military helicopters of similar type design. The actions specified in this AD are intended to prevent fatigue failure of the yoke that could result in loss of the tail rotor and subsequent loss of control of the helicopter.
Which aircraft AD 99-04-13 applies to
Tail rotor yoke fatigue prevention. Review yoke incident history; if a bending-load incident history exists, replace immediately. Pending permanent fix, install a 145 KIAS Vne red-line placard/RFM temporary revision. Within 180 days, replace the yoke assembly (P/N 214-011-802-105 or -111) with a zero-time or X-ray-diffraction-passed unit per Bell ASB 214ST-96-75, and install flapping stop P/N 214-011-809-109.
Whether AD 99-04-13 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.