Ok, I've just upgraded from a phantom 2 to 3 pro. Second flight today, go to start the motors, it does it's quick 2 rev thing with the motors and slowly flips on it's side. No damage, just some dirty props, but annoying.
Why? It was a bit windy, will a gust while it revs the motors cause this to happen? With the phantom 2 there was no rev so you could just wait until there where no gusts. kind of annoying if this is the case.
I calibrated the controller and did a compass calibration and tried again and it seemed to be ok. It hovers very steady but should I do an IMU calibration to be sure? I noticed my gimbal is a little tilted. Just don't want it to flip again.
running latest 1.40010 firmware
Oh man! I had the same thing happen. I also came from a P2V+ and never had an issue. I love the P3P, so don't get me wrong. But the "double rev" makes me nervous every time, and this is why... I was about to launch from the roof of a 4 story parking garage. There was a 3' x 3' concrete pillar that looked like a great spot. It's not like I just pulled this thing out of the box... I had over 300 flights with my P2, and was on about the 40th flight with this P3. I started the motors manually, and "rev-rev" and a gust of wind, and it tipped over in slow motion as I launched myself towards it from about 15' away. I was thinking, "I hope I have a spare set of props with me" as I watched them spin into the concrete pillar. I didn't mention this above, but this concrete pillar was on the outside edge of this 4-story parking garage. Again, still in slow motion, like in the movies... another gust, and the P3 continued it's roll past thrashing the props, and over the side of the building she went. As I got to the edge, I saw her hit the sidewalk some 40' below. Pieces were flying off of it like a watermelon drop from old school Dave Letterman. After a few tears, I gathered the pieces. A cable was sticking out of the seam between the upper and lower halves of the shell; the landing gear was broken, the gimbal didn't look as bad as I thought it would, but surely was fried; the battery case was cracked open, and of course the props were jagged and broken. When I got home, I took the shell apart. The small cables plugged into the main control board were not just pulled out, the whole sockets were ripped from the main board. It was a mess. The whole thing was a "basket-case"! So I did what most Phantom loving people would do... I got on Amazon Prime and ordered another one...ouch on the wallet, but can't live without her!
Lessons Learned: I always use auto take-off now. This is because in retrospect, the bird would have probably lifted off and avoided the tumble had I not been attempting to launch manually (even though I'd done it hundreds of times before, I wasn't quick enough to thing "FULL THROTTLE" as she started to tip, which "might" have saved her. Second Lesson Learned: Don't take off from the side of a building/structure even though there's a seemingly perfect spot for it. THIRD LESSON LEARNED: Be more cautious in "gusty" conditions. It sure seamed benign at the time... just a slight 5-7 knot breeze, but a few gusts for sure, probably to 15 knots.
I talked to Eric Cheng from DJI when I met him at a NASA UTM (UAS Traffic Management) workshop. He said the "double-rev" is a prop tightening measure for the P3. It's there because in aggressive flying, there are instances where the motors actually stop momentarily. If the props are not tight, they theoretically could loosen up and fall off.... another thing that could ruin our day!
