I have a flying wing with PixHawk "mostly" working. Sometimes it seems to have a problem with altitude when in auto mode and flying a waypoint mission. Here's what it does:
Fly RTL mode OK
Fly manual mode OK
Switch to Auto with preprogramed waypoint mission loaded. Plane accelerates and descends while heading for waypoint 1. Can't react fast enough to switch back to manual and climb. Plane hits dirt.
It's done this behavior a couple of times. One of the times I changed all my waypoint altitudes to 200M. Then the plane flew fine, way up there. Log attached. Any ideas?