AD 87-25-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky Aircraft Corporation | S-76A | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A and S-76B Series Helicopters |
| aircraft | Sikorsky Aircraft Corporation | S-76B | Airworthiness Directives; SIKORSKY AIRCRAFT Model S-76A and S-76B Series Helicopters |
Unsafe Condition
Possible loss of AC electrical power due to 26 VAC transformer single ground connection failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Provide separate ground connections for 26 VAC transformers 1 and 2. Compliance may be achieved through Sikorsky Service Bulletin No. 76-24-5.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 25 hours' time in service after the effective date of this AD
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Affected Aircraft
Sikorsky Aircraft Corporation Model S-76A and S-76B series helicopters through and including serial number 760350
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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