AD Amdt-39-9467
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky | Aircraft-manufactured Model CH-34A | Airworthiness Directives; Sikorsky Aircraft-manufactured Model CH-34A, CH-34C, H-34A, HH-34J, HSS-1, HSS-1N, HUS-1, SH-34J, UH-34D, UH-34E, and UH-34J Helicopters |
Unsafe Condition
Failure of the main rotor shaft (shaft) results in loss of power to the main rotor system 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
Determine the maximum operational cycles-per-hour of the shaft assembly since installation. Remove the shaft assembly from the main gear box and conduct a magnetic particle inspection (MPI) for cracks within the next 50 hours time-in-service. Repetitive MPIs are required at intervals not exceeding 250 hours TIS if cycles-per-hour exceeded 20.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 hours time-in-service
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Model CH-34A, CH-34C, H-34A, HH-34J, HSS-1, HSS-1N, HUS-1, SH-34J, UH-34D, UH-34E, UH-34J helicopters with main rotor shaft assembly P/N S1635-20059-2 installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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