Mavic Pro 2 Sea crash - Maldives

Tarik_abdellah · Oct 22, 2020

Hi,
Hoping to seek some group expert analysis here to help me come to a conclusion on the cause of the crash of my drone into sea. Best efforts to recover drone but unable to locate under waters I Was doing a drone shot above sea water drifting backwards from the land and when returning back, it just disconnected from remote (assuming collided with water). I was flying low in the Maldives, but just want to know if I pressed something prior to crashing that helped secure its fate.
I have uploaded a zip file of all the flight data I could obtain.
Thanks all for your help in advance

Meta4 · Oct 22, 2020

Tarik_abdellah said:
I was flying low in the Maldives, but just want to know if I pressed something prior to crashing that helped secure its fate.

Here's what a summary of that flight data looks like:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

Here's the relevant parts of the recorded flight data:

You were flying low over a shallow reef lagoon.
VPS is showing a height of 2 metres above something ... but was that above the water surface, or above the bottom seen through clear water?
The two blue highlighted areas are you pulling down on the the left stick to descend and fly lower.
The yellow highlight that immediately follows is the sudden big change in the pitch angle indicating a crash with something (the water surface).

When flying close to obstacles, it's helpful to realise that the wideangle lens makes objects appear further away from the lens than they actually are.

The crash location was at 5.69365 73.34284 and the drone should be somewhere close to there unless there are strong currents.

new2mavic · Oct 22, 2020

It was quite windy as can be seen from the amount of sideway tilting when only forward elevatore was applied :

Things were still OK 1.5 seconds before the disconnection but in the last 0.5 sec, the craft descended despite the application of some up throttle. It also appears that there was a big wave beneath the drone as the IR sensor at the bottom detected a change in height over water surface from 2.1m to 0.8m . I would suspect that there was some strong local air turbulence that pushed the drone into the water.

Do you have any video? May be in the cache ?

Meta4 · Oct 23, 2020

new2mavic said:
Things were still OK 1.5 seconds before the disconnection but in the last 0.5 sec, the craft descended despite the application of some up throttle./QUOTE]
The up throttle had no effect because it was 1.5 seconds after the drone had hit the water and the damage was done.

new2mavic · Oct 23, 2020

Meta4 said:
The up throttle had no effect because it was 1.5 seconds after the drone had hit the water and the damage was done

Both barometer and IR sensor readings indicate that the drone has not yet hit the water.

The big pitch change mentioned in your post was not due to collision but the craft automatically braking because the choppy water surface was seen as an obstacle. I have seen that on my M2P when flying close to water surface.

Such obstcale avoidance action has occurred a number of times thoughout the flight :

slup · Oct 23, 2020

new2mavic said:
Both barometer and IR sensor readings indicate that the drone has not yet hit the water.

The big pitch change mentioned in your post was not due to collision but the craft automatically braking because the choppy water surface was seen as an obstacle. I have seen that on my M2P when flying close to water surface.

Such obstcale avoidance action has occurred a number of times thoughout the flight :

View attachment 115652
View attachment 115653

Yeah, support that, the water touch down isn't shown in the log ... the pitch movements originate clearly from OD breaking. Furthermore the yaw is mainly unchanged, which should be impossible if the AC was plowing into the water. Actually I think a wave took the AC out from beneath, this as the waveheight abruptly change -1,5m, the barometric sensor just -0,1m & the Z-speed is fairly constant.

Flying this low over disturbed water is to beg for trouble unfortunately ...

Tarik_abdellah · Oct 23, 2020

Hi all,
Thank you so much for everyone taking the time to add value to this unfortunate situation. I have added some cache files so you can see what happened just before and the video we were trying to capture. Yes looking back at this, was a not so bright thing to do - but when the aircraft left the hotel room - we felt that it was at a height safe over water and don't recall taking any action to reduce the altitude - although it may seem this was the case in the error log - which is indisputable. Anuawus - hope the video files provide some insight - and once again - really grateful for everyone's input!

We have since purchased a replacement - we had one delivered to the island a few hours later but definitely wont be planning the same trick again lol

Click to Download - File size was quite large, so uploaded them into iCloud drive - where I hope you can see the 3 video files.

slup · Oct 23, 2020

Tarik_abdellah said:
Hi all,
Thank you so much for everyone taking the time to add value to this unfortunate situation. I have added some cache files so you can see what happened just before and the video we were trying to capture. Yes looking back at this, was a not so bright thing to do - but when the aircraft left the hotel room - we felt that it was at a height safe over water and don't recall taking any action to reduce the altitude - although it may seem this was the case in the error log - which is indisputable. Anuawus - hope the video files provide some insight - and once again - really grateful for everyone's input!

We have since purchased a replacement - we had one delivered to the island a few hours later but definitely wont be planning the same trick again lol

Click to Download - File size was quite large, so uploaded them into iCloud drive - where I hope you can see the 3 video files.

Yeah ... could have been striking, to bad that you lost your AC in the process. And unfortunately the clips doesn't shed any further light on what happened than what we already have said ... some OD breaking is visible in there though.