Air 2 flying backward on it's own!

[thereverend801]

Hey friends,
I bought a used Mavic Air 2 a few weeks ago. My first few flights were problem free... then as I was trying to take some overhead photos of my mom's house, it took off at full speed straight backwards. It was right above my head and maybe 20 feet above me when it happened. It only got about a block away before crashing into a tree. Since it was going straight backward into a large tree, I don't believe the sensors were working properly.
I brought it home, did an update, and calibrated everything.
I was able to go through one full battery with the drone performing fine. I put a new battery in, brought it up straight overhead and once again, it rocketed backwards without any controller input! I immediately hit RTH and it did stop, but it would not actually return. As soon as RTH canceled, it took off again. I tried over and over again with the same results.
Luckily I figured out that I could still rotate the drone and control altitude so I was able to fly it back home backward and gently crash land in my backyard. Once again, it seemed that none of the sensors were working properly to avoid the crash landing.
Attached are the two .txt files for the first and second flights. May 9th is the first one and the 14th is the second instance.
Any thoughts would be very appreciated... the guy who sold me the drone said... "Call me if you have any problems. I stand by what I sell." Of course he has completely stopped returning my text messages so I'm hoping I can fix this thing :-/

 

[msinger]

Attached are the two .txt files for the first and second flights

Did you forget to attach those files?

 

[thereverend801]

Did you forget to attach those files?

hmmm... it shows that it uploads the file, but when I hit save it seems to disappear!

 

[Yorkshire_Pud]

Try uploading them to DJI Flight Log Viewer | Phantom Help and post the addresses here.

 

[thereverend801]

Ok,
Here is the link for that
DJI Flight Log Viewer - PhantomHelp.com

 

[RodPad]

Wow, that works, to make sure it is the correct one, was it a 10 min flight?

I have my thoughts, but I will wait for the real people to look at.

Rod..

 

[Yorkshire_Pud]

Ok,
Here is the link for that
DJI Flight Log Viewer - PhantomHelp.com

You said there were two logs, you will need to do the same thing with the second log.

 

[slup]

...Any thoughts would be very appreciated...

So OK ... first some info regarding the chart below that covers the whole flight.

The flight starts from the left in the chart (with flight seconds along the bottom axis) and ...

-The 2 initial narrow colored background stripes are motor start & take off.
-The blue background is ordinary Normal mode.
-The pink background is when RTH was active.
-The thin white background in the middle of the chart is where you lost connection shortly.
-The red graph is the heading speed in mph (mostly backwards going).
-The black dashed graph is your elevator inputs (right stick forward or backwards). Neutral stick is value 1024 & less than that means backwards flight & more than that means forward flight.

(Click on the chart to make it larger & easier to read)


As seen (on the black dashed) ... from 129,3sec into the flight until 425,2sec the elevator stick command was for full backwards flight. Between 472sec & 544,5sec the elevator stick command was for full forward flight (that's when you flew towards home in forward flight & everything seemed to work correctly). Then in the end again full for backwards flight.

If you didn't apply those full backwards stick commands something is probably wrong with your RC... it's "sticking" on full backward. That the RTH just made your craft hover was probably due to that the "sticking" full backwards stick command was fighting the RTH flight in the opposite direction... that's why the full backwards flight started over as soon as you cancelled the RTH.

 

[Yorkshire_Pud]

Basically the same information as @slup gave but separated out a bit. I too am wondeing about the prolonged full reverse stick.
How high above the take off point is that hill at 3:43?
I think the variations in drone pitch during your full reverse stick phase are due to you stopping and starting RTH's and when the drone was not climbing to RTH height it was starting to comply with the horizontal movement commanded. When you started the next RTH and the RTH climb the drone braked quite sharply to bring it to a horizontal halt for the climb

 

[thereverend801]

So OK ... first some info regarding the chart below that covers the whole flight.

The flight starts from the left in the chart (with flight seconds along the bottom axis) and ...

-The 2 initial narrow colored background stripes are motor start & take off.
-The blue background is ordinary Normal mode.
-The pink background is when RTH was active.
-The thin white background in the middle of the chart is where you lost connection shortly.
-The red graph is the heading speed in mph (mostly backwards going).
-The black dashed graph is your elevator inputs (right stick forward or backwards). Neutral stick is value 1024 & less than that means backwards flight & more than that means forward flight.

(Click on the chart to make it larger & easier to read)
View attachment 164732

As seen (on the black dashed) ... from 129,3sec into the flight until 425,2sec the elevator stick command was for full backwards flight. Between 472sec & 544,5sec the asf elevator stick command was for full forward flight (that's when you flew towards home in forward flight & everything seemed to work correctly). Then in the end again full for backwards flight.

If you didn't apply those full backwards stick commands something is probably wrong with your RC... it's "sticking" on full backward. That the RTH just made your craft hover was probably due to that the "sticking" full backwards stick command was fighting the RTH flight in the opposite direction... that's why the full backwards flight started over as soon as you cancelled the RTH.

I think you probably nailed it… I think something is happening within the rc where it is sending the signal of full backward when it’s in the neutral position. The period of full forward was me trying to get the drone to go forward but it was actually still flying backward It never went back to normal during this flight. I basically flew it home backwards.
So does that mean I need a new RC?

 

[thereverend801]

Basically the same information as @slup gave but separated out a bit. I too am wondeing about the prolonged full reverse stick.
How high above the take off point is that hill at 3:43?
I think the variations in drone pitch during your full reverse stick phase are due to you stopping and starting RTH's and when the drone was not climbing to RTH height it was starting to comply with the horizontal movement commanded. When you started the next RTH and the RTH climb the drone braked quite sharply to bring it to a horizontal halt for the climb

Yeah, unfortunately all of that “full reverse stick” was with the stick in neutral position and even when I pressed full forward, it kept flying backward.

 

[Yorkshire_Pud]

Yeah, unfortunately all of that “full reverse stick” was with the stick in neutral position and even when I pressed full forward, it kept flying backward.

Try calibrating the controller.

 

[thereverend801]

Try calibrating the controller.

I did calibrate the RC after the first fly away… it worked great for an entire battery worth of flying and then shortly after I put in the second battery, you can see what happened.

 

[RodPad]

You said there were two logs, you will need to do the same thing with the second log.

Wow, I just figured out your question!

I didn't realize there were two events.

Rod ..

 

[Yorkshire_Pud]

Wow, I just figured out your question!

I didn't realize there were two events.

Rod ..

In post 1 he said "Attached are the two .txt files for the first and second flights. May 9th is the first one and the 14th is the second instance."

 

[Yorkshire_Pud]

I did calibrate the RC after the first fly away… it worked great for an entire battery worth of flying and then shortly after I put in the second battery

That rings a bell for some reason but I can't remember why.

 

[RodPad]

Yorkshire_Pud

mavicpilots.com

Post #1 he said "Attached are the two .txt files for the first and second flights. May 9th is the first one and the 14th is the second instance."

Long post confuse the crap out me. I still missed that I had to look again.

Rod ..

 

[thereverend801]

Sorry for the confusion.
Here is the first flight that the drone went rogue.

DJI Flight Log Viewer - PhantomHelp.com

 

[slup]

...The period of full forward was me trying to get the drone to go forward but it was actually still flying backward It never went back to normal during this flight.

That's not correct, probably you mix up the 2 flights you talk about or you don't recall the events correctly...

During below leg marked with a yellow dashed arrow you had the elevator stick fully forward & the drone obeyed & flew forward.



It's also easily seen in the log values below (within the yellow frame you have the same leg as above sat.pic.), if looking at the Pitch axis... you had the elevator on max forward (blacked dashed), the drone accelerated up to 26,9mph with a negative pitch value of about 17 degrees (negative value=drone nose down = forward flight). All is working as you command between 471,5sec-545sec.

 

[RodPad]

There is some confusion, that not I see in his last post.

Rod..