Mavic Went CRAZY!... CRASHED

[Simmo]

It has all that!
However, as @sar104 said, the information given to the FC was flawed, so it tries to do what its programmed to do, which was to hold position.
It couldn't with the flawed data. (Even with dual sensors...)
Same as some lost RPA's are from extreme wind events, the FC is doing its best, but cant compete....

 

[Toyotamdt]

Wow guys, like I said,I’m new here and I never expected you to break this down do well.

So essentially it wasn’t clear cut ‘pilot error’ but DJI likely won’t take the blame here either?

Sorry to be such a rookie but I am.... I don’t even know what Atti is.... sounds like it needed to be in Atti, but wasn’t because I couldn’t switch it and it didn’t do it on its own???

 

[sar104]

There have been several similar crashes. Would this be considered pilot error?

In the notifications it says:
Warning:In Flight, working compass encounters magnetic-field interference,please switch to atti mode if craft behave abnormally

Warning:In Flight, working IMU encounters heading exception,please switch to atti mode if craft behave abnormally

I don't think we can manually switch to ATTI mode even if we wanted to, right?

Why did the drone not switch to ATTI mode after these warnings? It seems like the drone correctly determined the issue, but asked the operator to take an action that was impossible (switch to ATTI).

lets hope the Mavic II will have a ATTI switch...

It's arguably pilot error to launch from a magnetically distorted location but, on the other hand, DJI's instructions don't really explain the hazard or the solution - i.e. to check that the aircraft arrow is pointing in the correct direction on the display. In addition the FC will throw these compass errors but then not actually switch to ATTI, or switch too late to prevent these uncontrolled flights. The more recent firmware versions seem to try harder to fix the heading problems and wait longer before switching.

The message makes no sense on a Mavic of course, and I'm not even sure whether it is really an instruction or a badly worded warning about what might happen. The Mavic really does need an ATTI switch. I sacrificed Sport mode on mine to have that available, but that only works with earlier firmware, I think.

The FC cannot itself detect, prevent, or fix the problems of taking off with an incorrectly initialized heading, but until DJI provide better guidance I think there is a reasonable case to be made for at least shared responsibility in these kinds of events.

 

[sar104]

Wow guys, like I said,I’m new here and I never expected you to break this down do well.

So essentially it wasn’t clear cut ‘pilot error’ but DJI likely won’t take the blame here either?

Sorry to be such a rookie but I am.... I don’t even know what Atti is.... sounds like it needed to be in Atti, but wasn’t because I couldn’t switch it and it didn’t do it on its own???

In P-GPS mode the FC controls position, attitude and altitude. To control position, correct for drift etc., it has to know its heading (which way it is facing). In ATTI mode it gives up trying to control position and just holds the aircraft level and maintains altitude. It will drift with the wind if the pilot doesn't apply stick inputs to correct it, but it will not cause any of these uncontrolled flights.

 

[Toyotamdt]

So, do I have an argument with DJI, that it never went into ATTI mode??

 

[sar104]

So, do I have an argument with DJI, that it never went into ATTI mode??

Maybe. I think that what I wrote above in post #23 is a fair assessment of the situation, but it's somewhat subjective. I would give them the data and make the case that (1) they don't provide instruction on how to check that there is no magnetic interference at launch and (2) that the ATTI switch did not happen and there is no user override.

 

[Toyotamdt]

Do they extract the info from the drone? I filled out the paperwork on line and boxed it up. I have the flight data on my computer. I'm guessing it's in the drone too?

BTW, that you all so much. I don't typically reach out for advice on the internet but this has been awesome. One way or another I'll be piloting another Air soon.

 

[Tinmania]

This appears to be at least the second time in a month that this has happened with an Air. Have read similar cases for the MP, though perhaps not as frequently lately.

I think dji needs to step up here and come up with an adequate solution. I can understand trying to hold back switching to ATTI mode, especially on models where owners have no simple way to practice flying in ATTI mode. There would no doubt be people complaining they crashed due to the aircraft doing so (regardless if the alternative was worse).

On the other hand, it is bordering on negligent to show a warning, that to most reasonable people, advises switching to ATTI mode when that is patently impossible for the pilot to do, and then continues to fly resulting in a likely crash--all without switching to ATTI on its own

Meanwhile I think it is becoming apparent that the physical heading of the Mavic absolutely should be checked to ensure it complies with its reported heading before even considering lifting off. It's no longer just a good idea; it should be done before every flight.



Mike

 

[Toyotamdt]

This appears to be at least the second time in a month that this has happened with an Air. Have read similar cases for the MP, though perhaps not as frequently lately.

I think dji needs to step up here and come up with an adequate solution. I can understand trying to hold back switching to ATTI mode, especially on models where owners have no simple way to practice flying in ATTI mode. There would no doubt be people complaining they crashed due to the aircraft doing so (regardless if the alternative was worse).

On the other hand, it is bordering on negligent to show a warning, that to most reasonable people, advises switching to ATTI mode when that is patently impossible for the pilot to do, and then continues to fly resulting in a likely crash--all without switching to ATTI on its own

Meanwhile I think it is becoming apparent that the physical heading of the Mavic absolutely should be checked to ensure it complies with its reported heading before even considering lifting off. It's no longer just a good idea; it should be done before every flight.



Mike

Again I am very new to this but you all made perfect sense. If I can't switch to ATTI, don't waste my time telling me to switch.

 

[RayOZ]

They should prevent the AC from taking off in the first place. And newbies might not be familiar with flying in ATTI, they might panic and crash anyway. If AC starts to drift, orientation not facing away from pilot, they wouldn’t know how to pilot correctly. If AC is facing them, move right joystick left will roll AC right, let go of joystick, it’ll continue to drift.
OP, don’t argue with DJI customer support. Talk to them nicely and they’ll response better.

 

[rfc]

DJI's instructions don't really explain the hazard or the solution - i.e. to check that the aircraft arrow is pointing in the correct direction on the display.

Is the important takeaway here that the ONLY indication that a pilot might have that the IMU/Compass are not on the same page before he takes off, is the aircraft arrow? That's it?
No other screen warnings or alerts on the initial "status" page?

If so, I'm adding this to my Before Takeoff Checklist!

 

[Slowcaptain]

I would not be surprised people start using analysis done by @sar104 in their defense when they file a case with DJI. I mean it just all makes sense!
Pretty sure DJI will soon be wary of mavicpilot/sar104 cases and I hope they actually implement changes in FW/software from all the learning and suggestions here.

 

[Tinmania]

They should prevent the AC from taking off in the first place.

The AC may not even know its actual heading is incorrect, so preventing takeoff is easier said than done. It has an EMU not AHRS so compass is critical to heading. In some cases there was a compass warning before flight but not always.

And newbies might not be familiar with flying in ATTI, they might panic and crash anyway. If AC starts to drift, orientation not facing away from pilot, they wouldn’t know how to pilot correctly. If AC is facing them, move right joystick left will roll AC right, let go of joystick, it’ll continue to drift.

I'm not sure I agree with this logic. We are in a situation where the aircraft is in charge of holding position and it cannot do that without knowing heading. That leads to a cascade of incorrect corrections that will likely result in a crash should there be anything around to hit--and this can happen at a relatively high speed. You would seemingly prefer this to switching to ATTI where, in my opinion, you at least have a good chance of controlling the aircraft (ATTI is not as hard as many seem to imply--I have drones where I would be happy to have just ATTI).

Beyond that, we have an actual warning to switch to ATTI, yet that is not possible. Surely you can agree that is not acceptable.

OP, don’t argue with DJI customer support. Talk to them nicely and they’ll response better.

Always good advice, but I don't think the OP nor anyone else was suggesting arguing with dji.



Mike

 

[sar104]

They should prevent the AC from taking off in the first place. And newbies might not be familiar with flying in ATTI, they might panic and crash anyway. If AC starts to drift, orientation not facing away from pilot, they wouldn’t know how to pilot correctly. If AC is facing them, move right joystick left will roll AC right, let go of joystick, it’ll continue to drift.
OP, don’t argue with DJI customer support. Talk to them nicely and they’ll response better.

Is the important takeaway here that the ONLY indication that a pilot might have that the IMU/Compass are not on the same page before he takes off, is the aircraft arrow? That's it?
No other screen warnings or alerts on the initial "status" page?

If so, I'm adding this to my Before Takeoff Checklist!

That's the entire point - there is no way for the aircraft to detect that the local magnetic field is distorted, and that its initialized heading is wrong. It has to rely on the operator, who presumably knows which way it is really pointing, to check if it is correct.

 

[HoozierDroneDaddy]

It's arguably pilot error to launch from a magnetically distorted location but, on the other hand, DJI's instructions don't really explain the hazard or the solution - i.e. to check that the aircraft arrow is pointing in the correct direction on the display. In addition the FC will throw these compass errors but then not actually switch to ATTI, or switch too late to prevent these uncontrolled flights. The more recent firmware versions seem to try harder to fix the heading problems and wait longer before switching.

The message makes no sense on a Mavic of course, and I'm not even sure whether it is really an instruction or a badly worded warning about what might happen. The Mavic really does need an ATTI switch. I sacrificed Sport mode on mine to have that available, but that only works with earlier firmware, I think.

The FC cannot itself detect, prevent, or fix the problems of taking off with an incorrectly initialized heading, but until DJI provide better guidance I think there is a reasonable case to be made for at least shared responsibility in these kinds of events.

If you search DroneU on Youtube, there is a vlog showing how to replace the sport mode with ATTI mode. You would then have this preferred option.

 

[sar104]

If you search DroneU on Youtube, there is a vlog showing how to replace the sport mode with ATTI mode. You would then have this preferred option.

I did replace sport mode with ATTI mode, as I mentioned above.

 

[thongbong]

Sounds like an IMU error. And it sounds like the classic flyaway from the old phantom days. DJI did finally admit fault and fixed it through firmware. Exactly why I don't update if everything works. Hear that? That's the firmware and pilot error police coming .

 

[Peter Barnes]

Meanwhile I think it is becoming apparent that the physical heading of the Mavic absolutely should be checked to ensure it complies with its reported heading before even considering lifting off. It's no longer just a good idea; it should be done before every flight.



Mike

How do you check that the correct heading is being reported?

 

[sar104]

How do you check that the correct heading is being reported?

You compare the direction of the aircraft arrow on the map with the direction that the aircraft is actually facing.

 

[Plainview]

could have been crazy interfiernece from all the metal, theres one spot i have flown from and i get a interfernce warning and my bird did some weird things with no stick movement from me, i dont fly there any more as its happend 2 times same thing, i bet it was interernce and affected your compass and it didnt know where it was going

I agree of all my drones the Mavic is most susceptible to metal!