Dear people,
An unfortunate situation happened today to my drone while flying it I lost a signal and drone activated return home mode, at some point, it regained the signal and immediately after tried to land and landed in trees, it was still about 60% charged and was still sending video feed to the controller, but it was tilted up so footage was not useful. Gimble was not responding to the controller and drone was not able to get back to fly, so I had screenshots of what DJI GO4 app was showing, also GPS coordinates from the flight record in the app. The one thing I was able to do is to activate gimble calibration which moved the gimble and I've got to see a bit more useful image from the drone, but then gimble stuck for and also app in fly mode was showing constantly 10% gimble calibration overlay so at the end it didn't help much. We did scout the area where last GPS coordinates were recorded, and couldn't find a drone. Now we are back at the computer analyzing the data from drone what is strange is that crash coordinates are very close to the home position and we were physically close to it and couldn't hear the drone (to be clear around was loud too, but still). Would anybody please with experience be able to look at the log data and tell what is the most probable location we should scout?

The exact same thing happened to me while filming in lake tahoe.  I was flying with no problems with 20 satellites locked in and my communication with the drone was excellent with full bars. Distance was about 1800 feet when all of the sudden the screen went black and my app was completely useless.  The controls were not responding,  my mavic zoom initiated return home and just stayed up there waiting to land but was close to trees and the sensors refused to let it land.  Luckily my son has dji go 4 app installed in his pixel phone and I asked him to lend it to me. Somehow with his phone I was able to get stick control and give my drone to safe landing.  I have to say very scary situation,  I keep thinking maybe someone was missing with my transmission.

Here is the flight log: phantomhelp.com/LogViewer/HKANEDI9CV4DD330YSRR/
As you can see it do not record HOME POINT until after 2 min.
So the log is not right. If you remember what you did the first 2 min
the home point is set where the drone was after 2 min flight not where you took off.

Hi essenciya,

Your flight started with zero 5 satellites but no recpeption.
So your MA was in OPTI mode, with a height limitation of 5 meters.

at 32 second you applied forward pitch, so i assume you flew away from your starting point.
at 1m24s MA in P-GPS mode ; 8 sats and 3 bars reception.
HP not yet set!at 2m1s HP is set, guess it is not your take-off position! But it was not that far away, about 12 meters?
See the map with position of your recorded HomePoint.

Can be really bad because with a RTH it will fly not to the take-off position!at 5m47s at 51 meters away from HP (not take-off point) a disconnect, so MA starts a RTH procedure.
RTH went OK, at HP it starts to autoland.

Autolanding start at height of 129 meters, descending to 108 and remain at that height, 3 motors obstructed. Was it in top of trees?

But as said, its not where you are

Always wait for enough sats and reception and HP set at take-off position before you fy away.

cheers
JJB

JJB*: Thanks for this analysis. So I have flown out from where takeoff position, and then I've realized that HP is not set, then I've brought the drone back so HP will set close by, not exactly takeoff pos but I'd say within 12 meters is correct assumption.
G_Sig: I've also used that webapp to analyze, what is not clear to me is why part of the path on the way back to HP is red? should I start looking when the red started, because it means that's where last strong GPS signal was? If I play the flight then after this position drone jumps to the HP and then start landing procedure, could it be that it never got to the HP and started to land before then?

MagicRide Posted at 3-18 08:03
The exact same thing happened to me while filming in lake tahoe.  I was flying with no problems with 20 satellites locked in and my communication with the drone was excellent with full bars. Distance was about 1800 feet when all of the sudden the screen went black and my app was completely useless.  The controls were not responding,  my mavic zoom initiated return home and just stayed up there waiting to land but was close to trees and the sensors refused to let it land.  Luckily my son has dji go 4 app installed in his pixel phone and I asked him to lend it to me. Somehow with his phone I was able to get stick control and give my drone to safe landing.  I have to say very scary situation,  I keep thinking maybe someone was missing with my transmission.

Best to start your own thread and not HIJACK someone else’s. Just common curtesy.

Hello and good day essenciya. I am sorry to know what happened to your previous flight with your DJI Mavic Air. We highly recommend syncing your flight records using the DJI GO 4 app and contact our support for our team to provide an appropriate solution and initiate the investigation. The repair fee would depend on the warranty of the product and the outcome of the investigation. Just a reminder that if the warranty of the said drone has already expired then DJI will not be able to perform a data analysis for the said drone. You may refer to the link below to contact our DJI Support Team. Thank you.

www.dji.com/support

essenciya Posted at 3-18 08:50
JJB*: Thanks for this analysis. So I have flown out from where takeoff position, and then I've realized that HP is not set, then I've brought the drone back so HP will set close by, not exactly takeoff pos but I'd say within 12 meters is correct assumption.
G_Sig: I've also used that webapp to analyze, what is not clear to me is why part of the path on the way back to HP is red? should I start looking when the red started, because it means that's where last strong GPS signal was? If I play the flight then after this position drone jumps to the HP and then start landing procedure, could it be that it never got to the HP and started to land before then?

The red part is when the connection is lost and that trigger the go home and then auto landing
when the drone think its at home. There is lost connection for 25.6s
Did you use Find My Drone in the app? It should work as the last location is right.

essenciya Posted at 3-18 08:50
JJB*: Thanks for this analysis. So I have flown out from where takeoff position, and then I've realized that HP is not set, then I've brought the drone back so HP will set close by, not exactly takeoff pos but I'd say within 12 meters is correct assumption.
G_Sig: I've also used that webapp to analyze, what is not clear to me is why part of the path on the way back to HP is red? should I start looking when the red started, because it means that's where last strong GPS signal was? If I play the flight then after this position drone jumps to the HP and then start landing procedure, could it be that it never got to the HP and started to land before then?

Hi,

RTH brings it back to HP, so it landed there.

at "6" = 60% batt level, landing position.

cheers
JJB

At 6m43.4s, the drone hit something and caused it to pitch and roll violently.  1 second later at 6m44.4s, there is a message indicating "Motor Obstructed".  We can also see in the log that from 6m43.4 to 6m43.9, the VPS sensors were registering a value of 0 instead of a null value.  I assume this is because it suddenly saw something.  

It doesn't look like it fell down hardly at all after this initial contact.  Maybe you can use the GPS coordinates from the image below to be able to help with your search!

Best of luck!


p.s. As others have mentioned, I highly recommend waiting for a solid GPS lock and the home point to be recorded before taking off.

KlooGee Posted at 3-18 10:22
At 6m43.4s, the drone hit something and caused it to pitch and roll violently.  1 second later at 6m44.4s, there is a message indicating "Motor Obstructed".  We can also see in the log that from 6m43.4 to 6m43.9, the VPS sensors were registering a value of 0 instead of a null value.  I assume this is because it suddenly saw something.  

It doesn't look like it fell down hardly at all after this initial contact.  Maybe you can use the GPS coordinates from the image below to be able to help with your search!

yes, landed / soft crash top of the tree`s.

But are those tree really 108 meters high??

JJB* Posted at 3-18 11:19
yes, landed / soft crash top of the tree`s.

But are those tree really 108 meters high??

Maybe trees are above take off point .

hallmark007 Posted at 3-18 11:24
Maybe trees are above take off point .

probably yes, tall tree`s on a hill,  take off point waterfront. make sense...
But if  you look in GE that is doesn`t look that high.

JJB* Posted at 3-18 11:19
yes, landed / soft crash top of the tree`s.

But are those tree really 108 meters high??

Hard to tell for sure when looking at Maps or Google Earth.  Seems like there is a tall & steep area right next to that area.  When looking at Maps/Earth, the GPS coords don't necessarily look like its on the steep area, but hard to tell for sure.

KlooGee Posted at 3-18 11:54
Hard to tell for sure when looking at Maps or Google Earth.  Seems like there is a tall & steep area right next to that area.  When looking at Maps/Earth, the GPS coords don't necessarily look like its on the steep area, but hard to tell for sure.

yep, its bad luck for a MA to stay on top of those dense treetops!

Thank you all. I went back to the spot today, scouted all around the last gps location without luck. But what strange is that it shows 108m of altitude at the crash spot. So I assume its just way above the HP. And that's where rock climbers will be useful. The only question, should i trust that altitude reading?