AD 2010-26-09
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Sikorsky | helicopters | Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S76A, B, and C Helicopters |
Unsafe Condition
An anomaly in the LITEF Attitude Heading and Reference System (AHRS) related to the 26 volt AC inverter could result in a decoupling of both autopilots, potentially leading to loss of control during Instrument Meteorological Conditions (IMC) or night flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the AHRS unit to determine if it is at Mod Status '18'. If identified, install placards on the instrument panel to prohibit single pilot Instrument Flight Rules (IFR) and single pilot night flight. Insert limitations into the Rotorcraft Flight Manual (RFM) to require a minimum flight crew of 2 pilots for IFR and night flight, and reduce airspeed to 120 knots indicated airspeed (KIAS) if both autopilots uncouple during IMC or night flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 5 days of the effective date.
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Affected Aircraft
Sikorsky Aircraft Corporation Model S76A, B, and C helicopters equipped with LITEF LCR-100 AHRS units at Mod Status '18'.
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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