Mavic Crash - Compass Error

drewdrones · Apr 4, 2020

Hello Guys [I am looking at you @sar104]

I have a friend who took his drone out to fly and yes took off from concrete. I have attached the .DAT and .TXT files.

From what I can tell, there were a few GPS errors early on as well as just before the crash, but I was wondering if he hit the building or anything as such?

If you guys can shed some light i'd appreciate it!

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Meta4 · Apr 4, 2020

drewdrones said:
From what I can tell, there were a few GPS errors early on as well as just before the crash, but I was wondering if he hit the building or anything as such?

There's nothing in the flight data to suggest any compass errors or any malfunction during the flight.
The GPS Position NoMatch warnings at 0:21.9 are a common false alarm and mean nothing.
He was lucky with the concrete but not so lucky with his piloting.
The drone was flying under control and at 8:50.8 collided at low speed with something 209 feet above launch height.

sar104 · Apr 4, 2020

There were no compass errors until it was flown backwards into the building at around 1 m/s - everything looks fine in the txt log. That's the wrong DAT file - the applicable file is FLY555.DAT, not FLY558.DAT - but it's unlikely to show any sensor problems.

slup · Apr 4, 2020

As already said both by @Meta4 & @sar104 your friend backed the drone into the building ... nothing mysterious by that, it was a Mavic Pro without rear OD so nothing there to stop it in time. The navHealth & sat count also dropped continuously the closer he came that building ... all errors showing up were just a result of the impact.

If you want to have it more visualized I have attached one 3D view of the flight path showing the impact at the red cross at 64m (which sounds like a reasonable building hit height), after that it was virtually free fall.

Then also the flight telemetrics in the very end ... note what happens with Yaw, Pitch, Roll & Z-speed (in this case descend which max out at 22,1m/s) were the impact occurs there the markers are in the chart.