Lake swallowd my mavic air

[MrGreen]

DJI Flight Log Viewer - PhantomHelp.com

Just started my flight and after 140 meters drone turned to the left, hit the trees and hit the water. It was a bright sunny day, drone noticed that because the ambient light is to week obstacle sensing is not working and that I am in no fly zone. Its a dark deep swamp lake so not very good place to swim.
Please someone recommend what to do and why this happened.


Sorry my native language is not English.

 

[MrGreen]

Blue dot is crash site and red areas is no fly zones

 

[sar104]

The aircraft never really had enough satellites locked, and it switched to ATTI mode when the number dropped below 8. At that point it stopped trying to control position and drifted.

 

[MrGreen]

The aircraft never really had enough satellites locked, and it switched to ATTI mode when the number dropped below 8. At that point it stopped trying to control position and drifted.

So bad luck and must buy new drone ..

 

[esta]

Sorry for your loss...

Airdata shows a notification that does NOT show up on PhantomHelp.com:

01m 39s - Motor current error. Check your propellers and fly with caution

I don't think your crash was related to GPS count... you may want to check with DJI on this.

 

[sar104]

Actually, you were flying fast and low and at 96 seconds abruptly went from full forward elevator to stick centered, at which point the aircraft dropped and possibly hit the water. The GPS count and health dropped to zero. You then applied full throttle. It took a while to respond, possibly because it was partially submerged? It did climb out but with some difficulty - that may have triggered the temporary over-current condition. If it did get wet then that would account for the unreliable baro data after the event, and the eventual loss of GPS again. Can you comment on whether you saw it hit the water?

 

[esta]

Actually, you were flying fast and low and at 96 seconds abruptly went from full forward elevator to stick centered, at which point the aircraft dropped and possibly hit the water. The GPS count and health dropped to zero. You then applied full throttle. It took a while to respond, possibly because it was partially submerged? It did climb out but with some difficulty - that may have triggered the temporary over-current condition. If it did get wet then that would account for the unreliable baro data after the event, and the eventual loss of GPS again. Can you comment on whether you saw it hit the water?

View attachment 43757

Nice graph. Maybe it hit a branch (look at satellite photo, it's just at the edge of the woods). Just after the drop in sonar altitude, Airdata reports "Downward Obstacle Sensing is not functioning.__Ambient Light is too weak." (it doesn't show this error on PhantomHelp, either..) - which may be hinting being covered by something. Not sure why it will drop 20 feet when stopping... unless you hit something.

 

[sar104]

Nice graph. Maybe it hit a branch (look at satellite photo, it's just at the edge of the woods). Just after the drop in sonar altitude, Airdata reports "Downward Obstacle Sensing is not functioning.__Ambient Light is too weak." (it doesn't show this error on PhantomHelp, either..) - which may be hinting being covered by something. Not sure why it will drop 20 feet when stopping... unless you hit something.

It almost certainly didn't drop 20 ft since it was only a couple of meters above the lake to begin with. Another reason why I think it hit the water. Water intrusion messes badly with the barometer readings.

 

[MrGreen]

Actually, you were flying fast and low and at 96 seconds abruptly went from full forward elevator to stick centered, at which point the aircraft dropped and possibly hit the water. The GPS count and health dropped to zero. You then applied full throttle. It took a while to respond, possibly because it was partially submerged? It did climb out but with some difficulty - that may have triggered the temporary over-current condition. If it did get wet then that would account for the unreliable baro data after the event, and the eventual loss of GPS again. Can you comment on whether you saw it hit the water?

View attachment 43757

No I didn't see and hear a splash. Drone was out of my eye site. If you release the throttle the drone is usually go a bit up. Not descending imo..

 

[sar104]

No I didn't see and hear a splash. Drone was out of my eye site. If you release the throttle the drone is usually go a bit up. Not descending imo..

It's appears to be more common for the aircraft to first descend on sudden stops. I've seen that many times with my aircraft, and a number of incidents posted on these forums have resulting from the same behavior.