Welcome Mavic Pilot!
Jump in and join our free DJI Mavic community today!
Sign up

Strange drone behaviour resulting in a crash

maccboy

Member
Joined
Aug 27, 2019
Messages
13
Reaction score
1
Age
56
Location
England
Hi.

First post so be gentle!
I've had an Air for around 6 months and had an unexplained crash on Friday. I fired it up intending to go up a hundred feet or so to take a photo of the sunset. That's all. The screen said it was flying on Vision, but it was just a straight up and down flight so I carried on. I put Sport on and sent the drone up. There was a pause before it started to go up and then it shot off eastwards, disappearing from view. I hit the RTH button but the family saw it fly off towards the sea, crash, and then take off and fly away from the beach before crashing again. Having searched this forum, I've found and converted the flight log ( I think), which I've attached.
Any information or help to explain what happened would be amazing!
Thanks.
Andy.
 

msinger

DJI Drone Expert
Approved Vendor
Premium Pilot
Joined
Oct 12, 2016
Messages
20,672
Reaction score
11,148
Location
Harrisburg, PA (US)

msinger

DJI Drone Expert
Approved Vendor
Premium Pilot
Joined
Oct 12, 2016
Messages
20,672
Reaction score
11,148
Location
Harrisburg, PA (US)
Can you upload your DJI GO TXT flight log here and link it back here?
 

maccboy

Member
Joined
Aug 27, 2019
Messages
13
Reaction score
1
Age
56
Location
England
Wow, that's a smorgasbord of errors...:eek: Can you indicate the wind conditions at the time?
Thanks for your reply, but I don't like the sound of it! There was virtually no wind. If there had been anything more than a strong breeze, I wouldn't have put the drone up.
 

dbyantis

Well-Known Member
Joined
Feb 8, 2017
Messages
667
Reaction score
294
Location
Western suburbs of PHL
Er, thanks. I was planning to go straight up and straight down. Appreciate your view.
Still, the GPS is the safety net, without a good home point set, RTH will not be available. I understand that you intended a short flight. But if you go into sport mode to get somewhere, it didn't sound like a short flight. Sorry for the loss/expensive lesson.
 

Northwood Mediaworks

Active Member
Joined
Apr 23, 2019
Messages
36
Reaction score
40
Age
61
Location
Canada
Site
northwoodmediaworks.com
Thanks for your reply, but I don't like the sound of it! There was virtually no wind. If there had been anything more than a strong breeze, I wouldn't have put the drone up.
Ya, sorry for your loss, but as the others are saying, you indicate not the wisest of choices for flying that day. I guess my next question would be where you took off, any possible causes of magnetic interference? Concrete with rebar in it? Do you check your sensors (compass/imu) before each take off? I was trying to avoid calling out all the preventables here as you asked us to be gentle :oops:
 
Last edited:

maccboy

Member
Joined
Aug 27, 2019
Messages
13
Reaction score
1
Age
56
Location
England
Thanks for all the replies. I did find it with just a broken prop. I was on a beach so there was nothing obvious that could have caused a problem with interference. As I said, I was aiming to fly vertically upwards, take some shots, and fly back down. It wasn't really that big a deal, in my view.
I was hoping someone could discover what the cause of the strange flight path was from the data. I did nothing to create the problem. Flying without GPS wasn't the cause, inference wasn't the cause, flying GoVision wasn't the cause. The sensors were fine. That's it, really!
 

Bigbird48

Well-Known Member
Joined
May 13, 2018
Messages
1,054
Reaction score
866
Age
69
Location
Phoenix ,AZ
SOUNDS LIKE YOU DIDN'T HAVE GPS LOCK you went up and the wind took it. with out gps your in atti mode and a slight brezze will wisk it away.
 

BudWalker

Well-Known Member
Premium Pilot
Joined
Oct 24, 2016
Messages
1,358
Reaction score
827
Age
71
Location
Arroyo Grande, California
Hi.

First post so be gentle!
I've had an Air for around 6 months and had an unexplained crash on Friday. I fired it up intending to go up a hundred feet or so to take a photo of the sunset. That's all. The screen said it was flying on Vision, but it was just a straight up and down flight so I carried on. I put Sport on and sent the drone up. There was a pause before it started to go up and then it shot off eastwards, disappearing from view. I hit the RTH button but the family saw it fly off towards the sea, crash, and then take off and fly away from the beach before crashing again. Having searched this forum, I've found and converted the flight log ( I think), which I've attached.
Any information or help to explain what happened would be amazing!
Thanks.
Andy.
I looked at the .txt. It's likely that the problem was a compromised Yaw at launch. With a .txt I usually look at a comparison between GPS data weighted position and position computed mostly from accelerometer data and gyro data. That can't be done here because GPS data wasn't available at launch

The curved trajectory in combination with a constant Yaw (aka toilet bowling) is almost always the result of a compromised Yaw. The Yaw data indicates that the MA was facing east at launch. Was the MA actually facing west, into the sunset?

I saw your comments about a clean launch site. There are other ways Yaw can become compromised. Did you power up in the presence of ferrous metal (car hood, steel picnic table, etc..) and then move it to the launch site?

The .DAT would help figure out more if you want to retrieve it.
How to retrieve a V3.DAT from the tablet

There seems to be a lot Monday morning armchair quarter backing in this thread. None of it based on an analysis of the log. My advice is to ignore it.
 

sar104

Dic mihi solum facta, domina.
Premium Pilot
Joined
May 27, 2017
Messages
8,220
Reaction score
8,915
Location
Los Alamos, NM
I looked at the .txt. It's likely that the problem was a compromised Yaw at launch. With a .txt I usually look at a comparison between GPS data weighted position and position computed mostly from accelerometer data and gyro data. That can't be done here because GPS data wasn't available at launch

The curved trajectory in combination with a constant Yaw (aka toilet bowling) is almost always the result of a compromised Yaw. The Yaw data indicates that the MA was facing east at launch. Was the MA actually facing west, into the sunset?

I saw your comments about a clean launch site. There are other ways Yaw can become compromised. Did you power up in the presence of ferrous metal (car hood, steel picnic table, etc..) and then move it to the launch site?

The .DAT would help figure out more if you want to retrieve it.
How to retrieve a V3.DAT from the tablet

There seems to be a lot Monday morning armchair quarter backing in this thread. None of it based on an analysis of the log. My advice is to ignore it.
Agreed - this has a number of the hallmarks of a yaw error after takeoff leading to TBE:

Delta_V.png

That kind of error generally seems to be associated with a 90° yaw error, so I'd expect that it was actually facing north(ish).
 

maccboy

Member
Joined
Aug 27, 2019
Messages
13
Reaction score
1
Age
56
Location
England
I looked at the .txt. It's likely that the problem was a compromised Yaw at launch. With a .txt I usually look at a comparison between GPS data weighted position and position computed mostly from accelerometer data and gyro data. That can't be done here because GPS data wasn't available at launch

The curved trajectory in combination with a constant Yaw (aka toilet bowling) is almost always the result of a compromised Yaw. The Yaw data indicates that the MA was facing east at launch. Was the MA actually facing west, into the sunset?

I saw your comments about a clean launch site. There are other ways Yaw can become compromised. Did you power up in the presence of ferrous metal (car hood, steel picnic table, etc..) and then move it to the launch site?

The .DAT would help figure out more if you want to retrieve it.
How to retrieve a V3.DAT from the tablet

There seems to be a lot Monday morning armchair quarter backing in this thread. None of it based on an analysis of the log. My advice is to ignore it.
Thanks for your reply. I'll get the DAT file later today when I get home. I don't think I started the drone until I got to the beach as I'm usually very careful about battery usage.
 

maccboy

Member
Joined
Aug 27, 2019
Messages
13
Reaction score
1
Age
56
Location
England
Agreed - this has a number of the hallmarks of a yaw error after takeoff leading to TBE:

View attachment 81849

That kind of error generally seems to be associated with a 90° yaw error, so I'd expect that it was actually facing north(ish).
Thanks. I can't remember which way it was facing. Hopefully the DAT file will help explain a bit more.
 

New Threads

Forum statistics

Threads
70,619
Messages
817,629
Members
97,752
Latest member
Rustyshackleford1