AD 2015-20-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky | Various | Airworthiness Directives; Various Sikorsky-Manufactured Transport and Restricted Category Helicopters |
Unsafe Condition
Main rotor shaft (MRS) structural failure, loss of power to the main rotor, 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 whether the MRS was used in repetitive external lift (REL) operations, perform a nondestructive inspection (NDI) for cracks, replace any unairworthy MRS, establish new retirement lives for each REL MRS, and remove from service any MRS with oversized dowel pin bores.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 12 months of the effective date (November 24, 2015).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Aircraft Corporation Model S-61A, D, E, L, N, NM, R, and V; Croman Corporation Model SH-3H; Carson Helicopters, Inc., Model S-61L; Glacier Helicopters, Inc., Model CH-3E; Robinson Air Crane, Inc., Model CH-3E, CH-3C, HH-3C, and HH-3E; and Siller Helicopters Model CH-3E and SH-3A helicopters.
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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