My APM 1 is installed in a Bixler and during setup I noticed the altitude is all over the place. I'm starting to think the sensor is defective. This same APM 1 was installed in my quad but never flew right. It would flip on takeoff, after trying all of the suggestions I gave up and bought an APM2. The quad flies fine now. Any suggestions are appreciated. I was hoping to fly the Bixler soon but not until I get the altitude settled down.