Troubleshooting Intermittent G5 Sensor Failure on Twin-Piston Aircraft
An intermittent sensor failure affecting a Garmin G5 backup PFD on a twin-piston aircraft can be a frustrating and potentially serious issue. The G5, a highly reliable unit in its own right, relies on its internal or external sensors to provide accurate attitude, airspeed, and altitude data. When a sensor fails intermittently, it often points to a problem with power, wiring, or grounding, rather than a failure of the G5 unit itself. This article will provide repair tips to diagnose the issue and highlight the importance of professional service.
Diagnosing the Problem: A Methodical Approach
A flickering screen, a sudden loss of attitude data (“Red X”), or erratic airspeed and altitude readings are all signs of an intermittent sensor failure. A methodical diagnosis is the first and most crucial step.
- Check Power and Grounding: The G5 is extremely sensitive to voltage fluctuations. The first step is to check the aircraft’s electrical system, specifically the power and ground wires leading to the G5. A loose or corroded terminal on the circuit breaker, a frayed wire, or a poor ground connection can cause the system to drop power momentarily, leading to a reboot or a sensor failure. This can be exacerbated by engine vibration.
- Inspect the ADAHRS Module: For G5 systems, the internal sensor is an ADAHRS (Air Data, Attitude, and Heading Reference System). For systems with an external G5, the ADAHRS is in its own box. The ADAHRS is a solid-state unit, but it’s sensitive to vibration. Ensure the unit is securely mounted and not subject to excessive movement.
- Check Pitot-Static Connections: The G5 receives airspeed and altitude data from the aircraft’s pitot-static system. An intermittent sensor failure could be caused by a loose connection in the pitot-static lines. A qualified technician will perform a leak check to ensure the system is airtight and that the connections to the G5’s pressure ports are secure.
Professional Repair and The Aero Center’s Commitment
While some of these troubleshooting steps can be performed by a skilled owner, a professional avionics technician is required to perform a full diagnosis and repair. They have the specialized tools, such as a digital multimeter and a pitot-static test set, to accurately diagnose these issues.
At The Aero Center, our technicians have extensive experience with Garmin G5 systems on a wide variety of piston aircraft. We have the authority and expertise to work on these sensitive avionics systems and can quickly and accurately pinpoint the source of an intermittent sensor failure. We believe in providing our customers in California, Arizona, and Nevada with the social proof of a job done right.
As the only 24/7 maintenance center in the region, we are uniquely positioned to minimize your aircraft’s downtime. We understand that a failing backup PFD is a significant safety concern, and our goal is to get you back in the air safely and efficiently.
Footnotes:
- https://www.garmin.com/en-US/p/576615
- https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/media/19_phak_ch17.pdf
- https://www.aopa.org/news-and-media/all-news/2012/october/1/avionics-g1000-updates
- https://www.textron.com/brands/textron-aviation
The Aero Center is located at William J. Fox Airfield KWJF | Lancaster, CA. Contact us at 209.885.6950 for questions or appointments.