AD Amdt-39-9789
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | McDonnell Douglas | Helicopter Systems Model MD-900 | Airworthiness Directives; LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H |
| aircraft | Pilatus | PC-12 | Airworthiness Directives; LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H |
| aircraft | Sikorsky | Aircraft Model S-76 | Airworthiness Directives; LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H |
| aircraft | Textron | Various | Airworthiness Directives; LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H |
| aircraft | Bell | Helicopter Textron | Airworthiness Directives; LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H |
Unsafe Condition
Unusual AHRS reaction to certain radio frequency signals causing misleading roll and pitch information.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Install a placard limiting flight to VFR operations only, or modify and inspect AHRS wiring cables, perform repetitive inspections of cable shielding, and insert a statement into the aircraft flight manual.
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Compliance Time
Before further flight
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Affected Aircraft
LITEF GmbH AHRS Unit Models LCR-92, LCR-92S, LCR-92H installed on Sikorsky S-76, McDonnell Douglas MD-900, Bell 412 helicopters, and Pilatus PC-12 airplanes.
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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