AD 48-17-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-51 | Airworthiness Directives; Sikorsky Model S-51 Helicopters |
Unsafe Condition
Wear in the primary and secondary planet pinion shafts (Sikorsky P/N S-535524) may cause malfunctioning of the main rotor gearbox.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Rotate the planet pinion shafts 180 degrees or replace them with new parts after 800 hours of operation. If rotated, replacement must be done after an additional 800 hours.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
at each 800-hour inspection
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Model S-51 Helicopters
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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