P4P Complete Loss of control, til crash

[bsartist]

Sounds like what happened to me. Read my story here:

Lost total control of the AC. What happened here?

TLDR; Running Go4. Lost connection momentarily and RTH initiates. Thereafter the AC would not take ANY commands - from app (command timeouts) or RC. Returned to home but stopped landing at about 9+ ft due to “unsafe landing area.” Had to wait for batt to get to basically zero before it came down...

phantompilots.com

 

[RodPad]

@bsartist,

Yo!
This is almost 2 years old, and there is four pages.
I will read it, and very close, when I'm at work.

Thanks for the post.

Rod

 

[bsartist]

@bsartist,

Yo!
This is almost 2 years old, and there is four pages.
I will read it, and very close, when I'm at work.

Thanks for the post.

Rod

It wasn’t for you, Rod. :eyeroll:

 

[Bone4Drone]

Hi Guys,
While in the process of downloading the DAT files from the drone I had a reoccurrence of the disconnection issue! Please view the attached video and you can clearly see the Aircraft Disconnected warning, yet I had complete control of the gimbal. Exactly as was the case on Monday...

The problem appears to be repeatable and I think that's good news. If it were me, I'd download and save all flight data, then re-install all firmware on drone and controller. Then see if you can repeat the problem, as you did here, while drone is NOT in the air. If problem persists, ship it to DJI. Since the problem isn't from abuse or pilot error, I would argue with them as to who is responsible for cost of repair. Always worth a try. For instance, I had a Meade telescope 8 years out of warranty that they repaired free just for asking nicely and a defective used Celestron camera I bought on eBay 2nd hand which they replaced by sending me 2 NEW ones!

 

[RodPad]

It wasn’t for you, Rod. :eyeroll:

I liked your before picture, you looked snarky.
You used that on a post, still makes me laugh!

Rod

 

[RodPad]

The problem appears to be repeatable and I think that's good news. If it were me, I'd download and save all flight data, then re-install all firmware on drone and controller. Then see if you can repeat the problem, as you did here, while drone is NOT in the air. If problem persists, ship it to DJI. Since the problem isn't from abuse or pilot error, I would argue with them as to who is responsible for cost of repair. Always worth a try. For instance, I had a Meade telescope 8 years out of warranty that they repaired free just for asking nicely and a defective used Celestron camera I bought on eBay 2nd hand which they replaced by sending me 2 NEW ones!

Yes, save the data and more testing!

I think It is out of warranty.


Rod

 

[RodPad]

@Fly Dawg, @Meta4,

I think there is still some twisted stuff.

Would you guys want to take another look see?
Even though the pay scale is kinda low.

Rod

 

[Bone4Drone]

Hi,
Would appreciate some experienced assistance. In the middle of a roof inspection (still photos only) my P4P indicated a compass error (I think) then attempted to land. As it was not safe to do so, the drone just hovered in place. I tried to cancel the landing but the response from the app was a " request time out". I tried to return to home; nothing. I restarted DJO Go4; nothing. I restarted the remote; nothing. I restarted my iPhone 7; nothing. In short I had no control of the drone but still had return vision and control of the gimbal. I could tilt up and down and see live vision, just not motor / servo control. Eventually the battery went flat, the drone tried to land on the sloping roof, and obviously tumbled to the gutter.
I'm wondering if anyone else has experienced the same. I have done at least 100 jobs like this in the past 9 months without issue. Flight records attached for anyone who can understand them.
Any clues to the issue would be appreciated...
Fausto

I was flying my drone above my roof last year when a bunch of bluebirds started attacking it. A few of them flew right into the props. Had blue feathers on my chimney and in my trees for weeks. Little buggars darn near knocked me out of the air a couple of times but I got the drone back on the ground safe. Didn't lose control of the drone except for a few momentary heart attacks but I did lose control of my bladder a few times when the feathers were too thick to see my screen for a while. This story has nothing to do with Fausto's problem but his story just brought it to mind.

 

[Fausto]

Sounds like what happened to me. Read my story here:

Lost total control of the AC. What happened here?

TLDR; Running Go4. Lost connection momentarily and RTH initiates. Thereafter the AC would not take ANY commands - from app (command timeouts) or RC. Returned to home but stopped landing at about 9+ ft due to “unsafe landing area.” Had to wait for batt to get to basically zero before it came down...

phantompilots.com

Hi Rod,
Thanks for the heads up. I have read the entire thread (I think) and it just seems to end without a resolution... Did you ever resolve the issue?
Thanks Fausto

 

[bsartist]

Hi Rod,
Thanks for the heads up. I have read the entire thread (I think) and it just seems to end without a resolution... Did you ever resolve the issue?
Thanks Fausto

@Fausto, it was my post.

No, it was never resolved. I included it here to show that on one hand, your experience was not a one-off - it did happen to someone else. On the other hand it has not reoccurred in a couple of years so that should give you some sense of comfort for flying again. Also to avoid reinventing the wheel in case some of the analysis could be relevant.

 

[RodPad]

@Fausto, it was my post.

No, it was never resolved. I included it here to show that on one hand, your experience was not a one-off - it did happen to someone else. On the other hand it has not reoccurred in a couple of years so that should give you some sense of comfort for flying again. Also to avoid reinventing the wheel in case some of the analysis could be relevant.

Now, that's funny.
He thanked me for your post.

Rod

 

[Andy9]

If DAT file doesn't show anything then it is imposible to say something relevant.
It must had been something that you overlooked unintentional stick movement, the wind, etc.

 

[bsartist]

If DAT file doesn't show anything then it is imposible to say something relevant.
It must had been something that you overlooked unintentional stick movement, the wind, etc.

Or an obscure/infrequently tickled bug in the firmware.

 

[Fausto]

Or an obscure/infrequently tickled bug in the firmware.

Hi Bill,
Sorry I was clearly confused when I responded... Thank you for the heads up very much appreciated.
I also understand the frustration you vented in your thread. It seems (with me as with you) that in the post above people just assume human error and that the drones are infallible. I'm not sure how it is even possible to initiate a RTH accidentally, and even if it was, it is still possible to cancel it.
As I said previously, I am happy to accept that I either made a mistake or didn't make the correct decisions when dealing with to the problem.
Anyway, enough said.
I'm glad you had no more issues. It'll be a while before I trust this drone over someone or something.
Cheers,
Fausto

 

[bsartist]

Hi Bill,
Sorry I was clearly confused when I responded... Thank you for the heads up very much appreciated.
I also understand the frustration you vented in your thread. It seems (with me as with you) that in the post above people just assume human error and that the drones are infallible. I'm not sure how it is even possible to initiate a RTH accidentally, and even if it was, it is still possible to cancel it.
As I said previously, I am happy to accept that I either made a mistake or didn't make the correct decisions when dealing with to the problem.
Anyway, enough said.
I'm glad you had no more issues. It'll be a while before I trust this drone over someone or something.
Cheers,
Fausto

Given the “command timeout” and the total inability to get the aircraft to respond to *anything*, at least in my case, I’m fairly convinced it’s some kind of nasty but rare bug in the firmware. Some parts of the FC state machine was working perfectly (thankfully). But other parts were stuck. Command timeout tells me the commands were being sent but not received and acknowledged by the aircraft.

 

[Andy9]

Look in search for 'command timeout'. Several times we had similar issues when after this message the drone stoped responding and just hoover few m above the ground or something like that. And nobody has clearly explained what that issue can be or how to override it.

 

[quaddamage]

Command timeout tells me the commands were being sent but not received and acknowledged by the aircraft.

That's good thinking.

The next step is figuring out which module isn't responding.

Dji Hardware is a collection of modules, and when commands are sent to the AC they're really DUML packets sent to a specific module.

Here's some more info on that.

 

[bsartist]

Look in search for 'command timeout'. Several times we had similar issues when after this message the drone stoped responding and just hoover few m above the ground or something like that. And nobody has clearly explained what that issue can be or how to override it.

Yes. I was one of them.

 

[Andy9]

I remember that case!

It seems and have been told in previous posts the situation is not the same as the more common signal lost. Although the result is - uncontrolable drone in both cases. But at 'timeout' don't expect an activating RTH, the signal isn't lost, only the drone because of some unknown reason will ignore all inputs from RC.
So this is much worse than signal lost. At the end it will go into a landing procedure because of the battery depletion and it will go to land wherever it is even into the water.
What is the point of such stupid and unreasonable action? What triggers it.
Maybe the drone decides not to obey the RC any more.

 

[bsartist]

What is the point of such stupid and unreasonable action? What triggers it.
Maybe the drone decides not to obey the RC any more.

There is never a point to a software bug. They are unintentional. And, yes, that’s exactly what’s happening as I’ve mentioned. The RC is trying to send commands and the aircraft is ignoring them. This obviously can’t be intentional. The drone gets “stuck” in a bad state. In my case the RTH was initiated first. It appeared as though it *may* have been momentary signal loss. Drone was far and turning around. After that I tried to cancel RTH and it wouldn’t obey. I