Mavic 2 pro crash, help needed

[paulatkin73]

At this stage I'm not really sure what to suggest. There have been a few reports of somewhat similar events recently, and the cause is not clear. Perhaps install the new firmware update and run a couple of controlled test flights:

Power up the aircraft on the ground and don't move it before takeoff. Check that the aircraft orientation arrow in the app agrees with the direction that the aircraft is facing. Takeoff and climb to 10 meters or so and then do a couple of full CW and CCW rotations. Then post the DAT file back here.

for more technically advanced users it would make sense to take drone apart and make sure there is nothing at all inside the drone bouncing around imu1 - no broken pieces of plastic, dirt, leaves, etc.
with no signs of board overheat or any other external factors it is not usual for IMUs to produce garbage data like this.
and, yet again, it just proves again that 2 IMUs design is not enough - if there was 3 of them, then a task of choosing correct data set would be way more reliable.

 

[Civics69]

for more technically advanced users it would make sense to take drone apart and make sure there is nothing at all inside the drone bouncing around imu1 - no broken pieces of plastic, dirt, leaves, etc.
with no signs of board overheat or any other external factors it is not usual for IMUs to produce garbage data like this.
and, yet again, it just proves again that 2 IMUs design is not enough - if there was 3 of them, then a task of choosing correct data set would be way more reliable.

Very good point. I do however always launch from a mat or hand launch and land. This thing is always flown in perfect conditions. I'm an aerospace engineer and could take apart but I think that would void my warranty, unfortunately.

 

[paulatkin73]

Very good point. I do however always launch from a mat or hand launch and land. This thing is always flown in perfect conditions. I'm an aerospace engineer and could take apart but I think that would void my warranty, unfortunately.

it does not apply if you have bought the optional dji refresh program, i think. but, i agree, it is a risk to take this stuff apart for people who are not sure of how to put it all back together. disassembly is not very difficult, but, one needs to know what to do.
blower fan design is done there in the way where it may get some debris into the board. if there is even a small spec of something hitting gyros and accelerometer chips - it may act up, but, a probability of such event is not very high.
it is just odd to see the issues as described, and, i believe it usually IMU1 that produces that, so, it has to be something mechanical, most likely, to cause it. go figure. i looked at mine - did not see anything obvious there, but, my drones never had IMU1 acting up yet, knock on wood.

 

[Civics69]

Ok Guys, firmware updated, everything calibrated and performed the test Sar104 suggested with no issues. Decided at that point to put the drone through its paces just to make sure (log attached) and all seemed fine, as usual.
Could you tell me what .DAT file you require for the log and i will upload straight away.

Thanks Guys

 

[sar104]

Ok Guys, firmware updated, everything calibrated and performed the test Sar104 suggested with no issues. Decided at that point to put the drone through its paces just to make sure (log attached) and all seemed fine, as usual.
Could you tell me what .DAT file you require for the log and i will upload straight away.

Thanks Guys

FLY089.DAT

 

[Civics69]

FLY089.DAT

Strange to have two i think but both attached.
Interested to see what comes from it.

 

[DanMan32]

When I was flying low testing my batteries, IMU altitude went quite a bit negative.
At one point VPS said 5ft but height said -0.5. Later it was 7ft vs -7 ft. Can atmospheric pressure change that much in less than 10 minute period in calm, stable weather?
It took a minute or two before it would get past "cannot fly". Attempting engine start in that state to try and see why said "no altitude from IMU".

Not trying to hijack the thread, just throwing observations that might be related.

 

[Civics69]

Which brings me to article 94- small unmanned aircraft requirements: paragraph 2) The remote pilot of a small unmanned aircraft may only fly the aircraft if reasonably satisfied that the flight can safely be made. After my incident I can't guarantee that so legally unable to fly. (UK CAA regulations)

 

[dannybgoode]

Which brings me to article 94- small unmanned aircraft requirements: paragraph 2) The remote pilot of a small unmanned aircraft may only fly the aircraft if reasonably satisfied that the flight can safely be made. After my incident I can't guarantee that so legally unable to fly. (UK CAA regulations)

I think you’d be fine under this reg. You had a one off issue, looked into it thoroughly and updated the craft’s firmware etc.

You now believe that due to the actions you’ve taken the flight can be made safely.

Flight safety also factors in things like the area you are flying in so go to a big open space and if there are issues you’ve mitigated them.