AD 2005-24-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | Vertol Model 107-II | Airworthiness Directives; Boeing Vertol Model 107-II Helicopters |
Unsafe Condition
Cracking on the ends of the spline teeth of the quill shaft, around the pinhole, occurs due to a wear step in the mating pinion gear splines. These cracked spline teeth can provide stress concentrations that may lead to fatigue cracks, resulting in separation of the quill shaft between the aft transmission and the mix box assembly, loss of rotor synchronization, and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove the aft transmission assembly, separate the mix box assembly from the aft transmission, and remove the quill shaft from the pinion gear assembly. Visually inspect the external spline of the quill shaft for a chipped or cracked tooth around the pinhole. Magnetic particle inspect the quill shaft for a crack. Replace any quill shaft that has a crack or a chipped or cracked tooth with an airworthy quill shaft before further flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 hours TIS if the pinion gear has 700 or more hours TIS, unless accomplished within the previous 350 hours TIS. If the pinion gear has less than 700 hours TIS, comply on or before reaching 750 hours TIS.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Vertol Model 107-II helicopters, all serial numbers, with a quill shaft, part number (P/N) 107D2067, all dash numbers, and a pinion gear, P/N 107D2215.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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