AD 2013-26-13
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky | S-70 | Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters |
Unsafe Condition
A critical engine part remaining in service beyond its fatigue life due to the current life limit being based on hours time-in-service (TIS) instead of fatigue cycles, which could result in fatigue failure of an engine rotor part, engine failure, 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
Insert LCF limit diagrams into the airworthiness limitations section of the maintenance manual or instructions for continued airworthiness. Obtain actual LCF1 and LCF2 counts from the engine history recorder, calculate the LCF1 and LCF2 fatigue retirement life for each GGT rotor part, and replace any GGT rotor part that has reached the new fatigue cycle life limit with an airworthy rotor part.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
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Affected Aircraft
Sikorsky Model S-70, S-70A, S-70C, S-70C (M), and S-70C (M1) helicopters with General Electric (GE) T700-GE-401C or T700-GE-701C engines installed.
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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