I'm very sorry for your loss. I am the developer of healthydrones.com and I just looked at the log. It looks like something happened at 6 minutes 4.4 seconds. There is a severe roll to the left (not a turn – but a roll) and severe pitch forward – in a response to that the aircraft turns to the right to balance. I don't think any compass issue would cause that and GPS looks good at that time. The aircraft still maintains altitude (although it does lose gradually about 2 feet in 4 seconds or so) until you start descending at 6m 15seconds.
When this starts (6:04.4), the airplane doesn’t bump up or down, and the speed remains almost the same – so this looks less like a crash into an object, and more like a problem with motor/propeller, possibly the front-left which could cause such a response, but this is just my preliminary review. Here's more:
- At 6:07 the same exact thing happens again: strong roll to the left, strong pitch forward, aircraft corrects to the right.
- At 6:16, about 0.6 seconds after you push the throttle down (and keep it down), the aircraft miraculously balances itself, but it resumes the crazy left roll and forward pitch as soon as you release the throttle at around 6:18.
- The same ‘healing’ response happens again at 6:20 (again when you push the throttle down for a couple of seconds), and again at 6:25 or so, which continues until 6:31
- Around 6:31 you slowly bring the throttle back to the center and that’s pretty much sends the aircraft into its death spin.
All this stuff indicate more of a motor/propeller failure and not a GPS/Compass issues. When you descend, the aircraft needs less lift and therefore a partial motor/propeller failure could be more easily compensated by the other properly working motors.
I am also curious - what was the weather like when you were flying? were there any serious winds? Not that I am suggesting that this happened because of winds (it didn't), but it will help me analyze the log better if I know the environment.
I will spend more time on this over the weekend (I'm on a business trip now). A lot of this kind of analysis is on my to do list for future reports and hopefully they will help someone one day.
I hope this is helpful. Again sorry for your loss and I hope you get a new phantom from DJI quickly.