Hey guys, Thought I'd put a record of my experience to help anyone out who has the same issue. On my new P3P, the motors weren't starting unless the phantom was about 1.5m off the ground being held by someone. Here's the story: So after unboxing my new phantom 3 professional, updating firmware, calibrating the remote, charging the batteries, and calibrating the compass, I thought I'd start the motor without props on to check its working. However all the CSC combinations wouldn't start the motors. I didn't want to do an IMU calibration at this point yet as I've seen some people complaining that it flew better out of the box, and drifted after an IMU calibration. The gimbal horizon was straight, and the values coming from the gyro and accelerometer on a level surface appeared good. So I thought maybe I'd try the auto takeoff feature outside with the props on. Nothing happened. The app said successful takeoff immediately, and yet no motors started to spin. Being my first DJI product, I thought there might be some in-built precautions or errors that are preventing it starting. Thought perhaps it was a software error so tried on a few different platforms. Nada. Then while my friend was holding the phantom at about chest height I thought I'd try a CSC (without props). Voila! The motors started spinning! So turned them off, put it back on the ground, tried CSC and nothing. Turns out the bird would only start its motors when off the ground. Tried flying it after starting it in the air and putting it down carefully and taking off manually. Flew very well. Very stable, no symptoms of a bad IMU. Anyways so I thought I'd do an IMU calibration finally, and it solved the whole issue! Done quite a few flights since and am very happy with the bird. I thought I had a defective bird for awhile, so if anyone else is having trouble with the motors starting do an IMU calibration.