During the AC3.2 testing an issue has come up especially with a few IRIS copters where it's gotten a bad gyro calibration.

The likely cause is that right after the pilot plugs in the battery they shut the battery door.  This is totally natural but the problem is that a few seconds after the battery is plugged in ArduCopter does the gyro calibration (red and blue flashing lights).  If the vehicle is moved during this period it can lead to a bad gyro calibration which can lead to a heading error slowly building up after take-off.  It can take a minute or two for the heading error to build up but after that loiter and especially auto missions could go badly because it won't know it's heading properly.

So please be careful not to jostle the vehicle whenever the red & blue lights are flashing.  Do that and the gyro calibration will be fine.

Thanks and there are new pre-arm checks in AC3.2 to enforce this.