AD 74-16-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Erickson Air-Crane | S-64A | Airworthiness Directives; Sikorsky Models S-64A, S-64E, and S-56 Helicopters |
| aircraft | Erickson Air-Crane | S-64E | Airworthiness Directives; Sikorsky Models S-64A, S-64E, and S-56 Helicopters |
Unsafe Condition
Fatigue failures of the main rotor head spindle lock nut, part numbers S1510-23031-0 and S1510-23031-1.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the main rotor head spindle lock nut with a serviceable part of the same part number before specified time-in-service hours. Repeat replacement at intervals not exceeding 750 hours for P/N S1510-23031-0 or 10,500 hours for P/N S1510-23031-1.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before the accumulation of 750 hours time in service (for P/N S1510-23031-0) or 10,500 hours time in-service (for P/N S1510-23031-1), or within the next 25 hours time in service after the effective date of this AD, whichever occurs later.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Sikorsky Models S-64A, S-64E, and S-56 helicopters certificated in all categories.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.