Mavic Air…may it rest in pieces!!

[Inthenash]

i tried to fly today and almost immediately after takeoff the drone started to fly weird and not respond. Hard crash from about 150 feet into concrete. I found most of it the drones pieces. My question is what caused this to happen? The memory card will not access and gets really hot when inside a computer. Worst thing is the insurance expired in June 2021. Any ideas on what to provide for diagnostics?

 

[MAvic_South_Oz]

Hmmm, that's a sorry story, and hope you can get another Air (perhaps 2nd hand) to make use of your existing equipment.

It sounds like a compass / IMU disagreement, a classic cause of erratic incontrollable flight, where no amount of effort by a pilot can save it.
If you want to get to the bottom of this, find and post your flight TXT log, either the TXT file itself from the device folder, or post it into phantomhelp flight programme online and post the link to that report back up here.

All explained in section 3 of this post . . .

Mavic Flight Log Retrieval and Analysis Guide

With the introduction of the Mavic Mini there has been a noticeable uptick in the number of posts requesting help with lost or crashed aircraft. While there is plenty of help and advice available on this forum, and detailed guidance and options on several other websites, I thought that perhaps a...

mavicpilots.com

 

[tlswift58]

i tried to fly today and almost immediately after takeoff the drone started to fly weird and not respond. Hard crash from about 150 feet into concrete. I found most of it the drones pieces. My question is what caused this to happen? The memory card will not access and gets really hot when inside a computer. Worst thing is the insurance expired in June 2021. Any ideas on what to provide for diagnostics?

Until we can see the flight logs - all pure speculation. Did you have GPS lock or not? If no, then ATTI is an unstable flying condition; but should not crash unless pilot error or maybe high winds - none of which we know at this point. Even where you were flying - a lot of magnetic interference can be an issue.

Post the logs and let the pro's let you know.

 

[Inthenash]

i think this is the link needed.

 

[GFields]

So sorry for your loss.

 

[eEridani]

Launched without having any GPS satellites in view. And the VPS was obstructed or it was too dark to be effective.

 

[MAvic_South_Oz]

..

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

No sat locks at all for 45 seconds, quite unusual.
Totally manual control required without the VPS functioning.
Was this flight at 1:45am ?

edit - added phantomhelp flight log view

 

[slup]

Yeah ... as already said, you didn't have any GPS assisted horizontally hold & it was too dark in order for the VPS sensor to be able to lock on to the ground surface giving you OPTI mode's horizontally hold. All this means ATTI mode with only height hold but no horizontally hold at all & no auto brake after stick release.

If unused to ATTI it can be very confusing ... the last thing you want to do is to use full stick deflections, but you did & your MA1 speed up & you lost control.

All this is clear when going into the TXT log message stream ... most of these messages was shown on you screen device also, so you should have been aware of the risk.

(Click on all pics below to make them larger)


Looking at your flight with some chosen telemetry data depicted on a chart where:

The pink & grey background color to the left is motor start & take-off
The blue background color is ATTI mode
& the grey background color to the right in an error message saying "notEnoughForce"
The red graph is the height
The green graph is pitch angle
The blue graph is roll angle
The purple & yellow graph (invisible as they have value 0) is the satellite count & navHealth

... shows this.



It confirms that this flight was only in ATTI mode ... 0 satellites locked with 0 in navHealth as the flight controller didn't have any GPS positional data to evaluate.

Starting at 38sec into the flight you hit something ... the roll angle goes to 94,4 degrees but it recovers, but at 41,4sec you either hit something again or a prop became damaged earlier & now failed completely & your MA1 turns upside down, loses height fast & a "notEnoughForce" error flag comes up.

But ...

Besides that you took the risk to launch even though all the warning messages ... I suspect something else can be going on regarding your GPS, Have marked that in blue in the TXT log message stream shown above. This can indicate that your GPS unit wasn't functioning as it should.

 

[MAvic_South_Oz]

Besides that you took the risk to launch even though all the warning messages ... I suspect something else can be going on regarding your GPS, Have marked that in blue in the TXT log message stream shown above. This can indicate that your GPS unit wasn't functioning as it should.

Exactly, I don't ever recall not having a GPS locked take off being established within say 5 - max 10 seconds after the drone, controller, and app all come on line.
I know satellite availability worldwide can vary somewhat, but almost everywhere should get a GPS lock a lot sooner than 44 seconds, shouldn't it ?

 

[slup]

... almost everywhere should get a GPS lock a lot sooner than 44 seconds, shouldn't it ?

The thing is that it says that Satellite positioning is OFF ... so think it's not even trying to get a sat lock, usually it just say "weak GPS signal".

 

[MAvic_South_Oz]

The thing is that it says that Satellite positioning is OFF ... so think it's not even trying to get a sat lock, usually it just say "weak GPS signal".

Thought that was the case, indicates it could be faulty, and the OP might have a case for warranty, depending on date of purchase etc.
Battery hours indicate zero miles, so might have even been first flight.

 

[eEridani]

An initial GPS lock can take some time, even minutes, especially if the software/firmware was just installed and the fast lock cache for GPS sats was cleared during update. But if the GPS was turned off, well, that's a different issue.

 

[eEridani]

Figured out the no gps satellite and darkness thing:

The launch was from an underwater sea mount:

 

[Inthenash]

Yeah ... as already said, you didn't have any GPS assisted horizontally hold & it was too dark in order for the VPS sensor to be able to lock on to the ground surface giving you OPTI mode's horizontally hold. All this means ATTI mode with only height hold but no horizontally hold at all & no auto brake after stick release.

If unused to ATTI it can be very confusing ... the last thing you want to do is to use full stick deflections, but you did & your MA1 speed up & you lost control.

All this is clear when going into the TXT log message stream ... most of these messages was shown on you screen device also, so you should have been aware of the risk.

(Click on all pics below to make them larger)
View attachment 136608

Looking at your flight with some chosen telemetry data depicted on a chart where:

The pink & grey background color to the left is motor start & take-off
The blue background color is ATTI mode
& the grey background color to the right in an error message saying "notEnoughForce"
The red graph is the height
The green graph is pitch angle
The blue graph is roll angle
The purple & yellow graph (invisible as they have value 0) is the satellite count & navHealth

... shows this.

View attachment 136609

It confirms that this flight was only in ATTI mode ... 0 satellites locked with 0 in navHealth as the flight controller didn't have any GPS positional data to evaluate.

Starting at 38sec into the flight you hit something ... the roll angle goes to 94,4 degrees but it recovers, but at 41,4sec you either hit something again or a prop became damaged earlier & now failed completely & your MA1 turns upside down, loses height fast & a "notEnoughForce" error flag comes up.

But ...

Besides that you took the risk to launch even though all the warning messages ... I suspect something else can be going on regarding your GPS, Have marked that in blue in the TXT log message stream shown above. This can indicate that your GPS unit wasn't functioning as it should.

Thanks for the detailed analysis! I agree it was 95% pilot error. I have several hours at the controls yet have deleted logs at DJI. So ultimately I learned the hard way.

Yes, I hit a wall 38 seconds in and did try to recover using all stick controls.