Peter wrote:
There might be a certification issue, BTW. For example the KFC225 autopilot is certified to accept altitude data from a KEA130A and probably little else. So if you put in a GAE12, you end up with two sources of pressure altitude in your aircraft, which could give interesting results, which could be quite irritating too… since they won’t exactly match.
Peter,
Multiple sources are supported. The GTN uses a priority scheme to determine which is used. Here is a screenshot of the install manual.
Sure; what I was thinking about was the KFC225 pressure altitude, which cannot (IMHO, just being regulatory-anal 
) come from a GAE12.
