I've put around 3 hours on my Mavic Air, so I'm fairly comfortable with the controls, but am by no means a veteran pilot.  This afternoon I took off in my front yard using the precision RTH mode.  It was in GPS mode, it said it did not need a compass calibration, so I didn't do it; the last compass calibration was last weekend at a park ~2 miles away, it was also in sport mode (more on this below).   The takeoff went perfectly fine, I turn the drone and look towards the sunset, climb a little (~45' is the max altitude for the flight), and all of a sudden the drone starts floating backwards while I am giving no steering input.  I never even looked at the screen, I was flying by sight.  There was no wind, it was completely calm, the street is lined by trees that are much taller than my max flight altitude, and they weren't moving at all. Right after taking off I turned and flew a few feet towards the sunset, according to the flight viewer in DJI Go 4, the drone was flying backwards, but steering input was forwards, so I now believe the compass was off. Shortly thereafter I started to climb from 18 to to 45' with no more steering input, and the drone started to slowly drift away from the sunset (backwards).  Within a few seconds I started providing 100% steering input towards the sunset, which did nothing as it continued floating backwards, and then I tried to bring the drone down towards the ground to prevent a crash, however, it continued to drift backwards before entangling itself in a tree and gravity did it's thing, culminating in several seconds of the drone sitting upside down on the ground, props spinning.  I had to carefully pick it up, and without losing any fingers, struggled to hit the power button so it would stop trying to de-finger me.  Fortunately there was no major damage to the drone, or my fingers.  One arm ended up folded in which scratched the top quite a bit, and all 4 props were heavily damaged.  I swapped props, brought it outside, it asked to calibrate the compass, which I did, and I was able to take off and land, I didn't fly around because I no longer trust it. The main issues here are WHY did the drone drift backwards with no input and no wind, why did it not ask for a compass calibration if it was nearly 180 degrees off, why did it seemingly completely ignore directional steering input, and what SHOULD the drone do when it's upside down on the pavement spinning at full RPM? How is one supposed to turn it off without risking limbs?  It seems like it should be able to realize it's upside down and turn itself off. Mistakes I know I made: * It was in sport mode.  Last time I flew it I was playing around in a wide open, drone safe area, so played a bit with sport mode.  I didn't flip it back off.  Without sport mode MAYBE it wouldn't have crashed in to a tree?  But who knows, it thought it was flying the other direction... Possible mistakes: * I didn't calibrate the compass; but it didn't ask me to.  Should I not bother trusting the compass calibration notification, and always calibrate?  Why bother having the notice? * I was running an older firmware because the last time I updated the firmware I was affected by the RC connectivity bug and the controller wouldn't connect to the drone.  I ended up following the instructions in this forum to downgrade and factory reset the controller and drone, and had not yet tried to perform a re-upgrade. The result: a scuffed up drone and 4 destroyed props, but more importantly, a now very concerned flier. Between my experience with the firwmare updates, and the several hours I spent trying to get the drone usable, and now the drone apparently ignoring steering input leading to a crash, leave me concerned about the product, and question whether I should keep it.  Granted, now that it's scratched up I'm pretty sure I can't return it.. Is this an isolated incident and calibrate the compass every time and pretend it was a fluke?  Should I feel confident/safe flying my drone?  Should I try and return or RMA it?

Hi there, I'm sorry to hear about the accident. Please kindly start a case and send it in for diagnosis: https://www.dji.com/support. If the drone is still in warranty period, the local team will arrange data analysis after they received the package. If you encounter any difficulties during the repair progress, feel free to contact us with your case number, we'll be here for help. Thanks!

How long will the process take?  I'm flying to Hawaii tomorrow and was planning on practicing with it there, and then am travelling to Iceland ~4 weeks from now, which is the reason I purchased the drone in the first place.

I have now tried to submit a case in two separate web browsers, multiple times each, and the web form appears to be unable to submit a case.  I tried in chrome, and then when that didn't work I.E.
  

citywok Posted at 2018-3-26 20:48
I have now tried to submit a case in two separate web browsers, multiple times each, and the web form appears to be unable to submit a case.  I tried in chrome, and then when that didn't work I.E.
  [view_image]

So sorry for the inconvenience. The picture that you attached is not clear to read what happened to your page, could you please provide a more clear photo? Have you contacted our support for a help to get a case number? Thanks!

If you want other operators to provide input as to what went on in our opinion. You will need to post flight logs. (txt file from your device)

Can you put up your flight log to link below it might help you understand what happened.
Just click on link and follow instructions come back here and post your link.


http://www.phantomhelp.com/LogViewer/Upload/

Here's a link to the flight log: https://www.dropbox.com/s/alo9t8ijg4zphx9/DJIFlightRecord_2018-03-19_%5B18-40-06%5D.txt?dl=0

@DJI Diana,
When I click submit the button greys out and nothing happens.  If I uncheck/recheck the checkbox I can click submit again, and it still doesn't do anything.  I'll call DJI to get a case number.

citywok Posted at 2018-3-27 06:47
Here's a link to the flight log: https://www.dropbox.com/s/alo9t8ijg4zphx9/DJIFlightRecord_2018-03-19_%5B18-40-06%5D.txt?dl=0

@DJI Diana,

Here is the flightrecord: http://www.phantomhelp.com/LogViewer/18D2X2LOWK7SWR6FHHU6/
First diagnosis: You took off with a very weak satellite link (11 should be minimum) and soon after take off you seem to have touched a tree as described above by you. I am not sure whether something was wrong with the compass or if you might have been confused about its heading.
Others here will analyse the stick movements etc. and might be able to tell you more.

Orientation problems when using eyes on a distant drone in silhouette.  Flying the rear end instead of the nose after a turn that was really a turn and a half?  Does that flight record show the drone obeying stick inputs.  It not being responsive would be my worry since I don't know of any digitally linked RC aircraft that ignore stick commands when in radio range of the pilot.

It looks very much a problem with weak gps probably being blocked by the trees, coupled by you making incorrect stick inputs, you can go through all your stick movements and you will see that your aircraft corresponded to all your stick movements, so Watchberger may have put his finger on the fact that you were somehow disoriented.

In weak gps aircraft may be slow in reacting to stick movements, but having said that it looks like it wasn’t to far off according to these logs.

Try to make sure as Watchberger said that you have minimum 11 sats when flying and be careful when flying under the cover of trees..

A few more thoughts that hopefully will help you:
- In my opinion it was not a good idea to not have updated the firmware. Thus should there have been any malfuntions at all with your MA (which we can't verify on the basis of data available to us) it cannot be excluded that outdated firmware has been a factor. Firmware updates by their nature are issued to fix problems that have been identified. If after an update you experience problems you rightfully can blame the company or the product. But by not updating you accept to potentially run into problems that ottherwise would have been fixed.
- Taking off in Sport mode in a narrow environment is indeed risky.
- You definitely don't need to calibrate the compass before each flight. DJI since recently recommends to do it after significant changes of location. But I believe compass has not been an issue in your case.
- It is correct, that normally the MA should have auto shut off as soon as it was upside down. Here again outdated firmware can have played a role but impossible to verify now.
- I would strongly recommend you to do all updates (incl. for all batteries) and then thoroughly test all functions of your MA in an open area in P-Mode. Also turn it upside down to check if it will auto switch off.
- For navigation make use of the red arrow you seen on the compass and the map of DJI GO 4. Its nose indicates the heading of your AC.
- If in all these tests you observe anything abnormal, you should indeed send it in for check and repair as appropriate.

I always wait for a song GPS connection before take off with the latest FW installed and always best to take off out of Sport mode. Good to see that you acknowledge your errors.

Hey Bud, sorry for your crash.
Here's my totally amateur analysis of your crash.
You did indeed apply throttle to gain altitude, you also applied forward elevator to move slightly toward the sunset.
There was a wind, however as you say, quite light. Just under 4 mph .
At first, I thought that as you were looking into the sunset, that forward collision sensors where trying to avoid that big yellow object.
But no, the flight log confirms no collision sensors enabled as you were in Sport mode.
Seemingly then the AC drifted in the slight wind over your head and toward the trees. (Remember no GPS hold in Sport mode.)
Here's where I believe it all went wrong, you wanted the AC to come back, and gave it a fist full of throttle, and reverse elevator (as in the flight log)
Unfortunately, as the drone was facing the other way, you actually increased its speed into the tree.
My conclusion is that being in sport mode, with no automated assistant, the operator became disorientated and applied incorrect stick input. Therefore pilot error.
Sorry bud.