Garmin GRS 77/77H AHRS — Temporary Loss of Heading and Attitude Display
- Published
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators should avoid moving the aircraft on the ground during the first 10 seconds after powering on the pilot’s and co-pilot’s primary flight displays. If a noticeably drifting heading is observed, do not take off; instead, power down and reinitialize the AHRS. Any occurrences of this issue should be reported to Garmin Aviation Product Support with detailed information as outlined in the SAFO.
Summary
SAFO 14004 is a Safety Alert for Operators issued by the FAA addressing a temporary loss of heading and attitude display in aircraft equipped with Garmin GRS 77/77H AHRS systems. This issue affects several Garmin integrated flight deck systems including Garmin G1000, G1000H, G950, G900X, G500, G500H, G600, Cirrus Perspective™, and Embraer Prodigy®. The alert informs operators about potential heading drift and temporary loss of attitude information during critical phases of flight.
What changed
SAFO 14004 introduces awareness of a specific issue where moving the aircraft within 10 seconds of powering on the AHRS or magnetic interference near the magnetometer during initialization can cause heading drift and temporary loss of heading and attitude displays. It provides guidance on identifying the problem and recommended preventative measures to avoid it.
Why it matters
This alert is important because inaccurate or lost heading and attitude information can compromise flight safety during takeoff and climb. Operators, maintenance personnel, and repair stations must understand the conditions that cause this issue to prevent inadvertent flight with unreliable flight instrument data, ensuring compliance with safety standards and maintaining situational awareness.
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