N967MD

The Air Data Attitude Heading Reference System, or Garmin GSU 25C needs to be mounted very securely to the airframe, and it needs to be mounted +/- 1 degree either longitudinally or laterally. There is not a pre-determined location or mount for this. Midwest Panel Builders gave me a plate they had cut based on a general idea of where we wanted to put it... but I ended up cutting about 1/3 of the plate off, and drilling a bunch of new holes in it.

The end result is very solid, and I think it came out very clean.

Leveling and calibration... once I had everything mounted, I needed to go into the configuration and tell it how it was mounted... then I had to level the aircraft and run it through its calibration. Now everything reflects the actual attitude of the aircraft. Before this my displays were showing nose low and a slight bank.