Mavic Pro Mishap. No Idea what happened?

[MyrtleManiac]

Maybe someone can tell me what happened. I really don't know how to interpret these logs. Mavic Pro, I was about 250 ft AGL taking pics when the screen went black. I immediately hit RTH and it never made it back. I recovered the aircraft but it is pretty tore up. Just trying to figure out if I did anything wrong.

The incident starts with "speed error" at 6 min 45.9 sec.

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[Meta4]

Maybe someone can tell me what happened. I really don't know how to interpret these logs. Mavic Pro, I was about 250 ft AGL taking pics when the screen went black. I immediately hit RTH and it never made it back. I recovered the aircraft but it is pretty tore up. Just trying to figure out if I did anything wrong.

The first hint of any issue is the Speed Error warnings that popped up while the drone was hovering at 6:45.9.
But there was nothing in the flight data to show a probelm at that point.
RTH began at 6:48.9 and started normally until a series of Speed Error warnings showed at 7:01.3 and the drone started to slow down and go off course.
At about 7:08 the drone starts to yaw slowly but things get crazy around 7:09.9 when the drone goes into a spin and starts losing height.
The compass error warnings at that time are probably due to the rapid spinning rather thn a genuine problem with the compass.
A second later the drone is rolling and tumbling as it spins and falls.
It appears that the collision was at about 7:17.9 and all data after then can be ignored.

The spinning and losing height suggests that either a prop or motor failed.
The speed error prior to that suggests a hardware fault might have been responsible for losing a motor.
There's nothing in the data that suggests operator error.

 

[MAvic_South_Oz]

Is the DAT needed to get motor info ?
Maybe grab that in case a more in depth alalysis is needed ?
Get that following instructions in section 3. here . . .

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

@Meta4 good to see you getting into this log reading, are you using same tools as @sar104 @slup and @BudWalker or just reading the txt info from the Phantom help page ?
Just curious as to how you are doing your flight dissemination.

 

[MyrtleManiac]

Thanks Meta4! I checked the motors when I got back and all 4 seem to be operating correctly. I guess I would have to assume prop failure or bird strike at this point. I didn't know what the speed error warnings were but I assume that was the indication that would occur if I lost a prop (or a part of one anyway). I did notice after recovery that all of the props were still intact except for one which was half gone. I assumed originally that it happened during the crash but now it would appear more like the cause of the crash instead.

Again, thanks for looking at this for me. In 3 years I've had my Mavic I have never had a failure or crash. I guess it was bound to happen sometime.

 

[sar104]

This looks like a lost or broken prop at 428 seconds, probably rear left from the initial attitude excursion and the CCW rotation:



The mobile device DAT file will confirm the exact cause if you can retrieve it - it will have a filename ending in FLY341.DAT.

The speed and compass errors were recorded as non-GPS errors, which occur when the IMU inertial solution starts to diverge from the GPS data. They both started before the mechanical issue, so it's not clear exactly what was going on there. Again - the DAT file may shed more light on that.

 

[MyrtleManiac]

That's some great info sar104! Thanks. Thinking back on the flight I did have some strange yawing control problems a little earlier in the flight but just attributed it to the wind. I guess I'll be a lot more conscience of it if it ever happens in the future. If something doesn't feel right, land immediately and give the aircraft a good thorough examination. Hopefully, I've learned a little something.