Yesterday I noticed that My Phantom would climb or descend significantly at times even though I did not give control inputs for it to.  So last night I did an IMU calibration and compas calibration and the VPS calibration and today durring two seperate flights it did the same thing.  Unfortunately on the second flight it climed as fast as if it had full up control inputs resulting in it a crash with significant damage.  While it was climbing, I was inputting full down control.  It should have been descending but it was climbing pretty fast.  Anyone ever heard of that?  Using the Beta .600 which until a couple days ago was pretty stable.  The only other thing that changed was I upgraded to the latest GO app when it came out a few days ago.  Since the P4 was purchassed almost  two years ago, I'm guessing that there isn't anything DJI would do for me.  I could repair it, new props, new shell, one new motor, but I don't think I will.  I have lots of good footage shot with this quad, but the overall experience with DJI has been pretty damn disappointing over the last year with bad firmware and all the problems and lack of prompt support.  Not sure what I will do now.  Anyone want to buy a Phantom 4 camera assembly?  It's completely undamaged.
--Jim Watkins
(Burbank, CA)

Why don't you post the flight log?  Very interesting.

ALABAMA Posted at 2018-1-17 14:18
Why don't you post the flight log?  Very interesting.

I have looked at it on Airdata UAV.   Didn't see anything remarkable.  Tell me how to post it here.

http://www.phantomhelp.com/LogViewer/Upload/ Here’s the instructions

Have you calibrated the RC Jim , just in case it is sending spurious signals to the aircraft ?

Aardvark Posted at 2018-1-17 14:35
Have you calibrated the RC Jim , just in case it is sending spurious signals to the aircraft ?

I have but its been about 2 weeks ago.  Should be good.

Okay, I have the flight log.  I uploaded it using the link and looked at the info.  How do I share it with you all?  Doesn't let me add it as an attachment.

Okay...let's try it this way.  http://www.phantomhelp.com/LogViewer/DR5O9LD983ZE8AX0T0MS/

Labroides and Endotherm are the two who can read inputs.  Wait for them.

Sorry this happened,  No storm damage in Burbank for you I hope.

Things Started going downhill @ 6.54.5 minutes, looks like you were very near heavy concrete & steel in the 2 bridges maybe causing GPS loss 0-3 satellites only, also looks like you were flying at a lower altitude than you Home Point. The AC may have initiated a Failsafe RTH causing it to want to climb to your 60 Meter RTH setting. Did the AC climb from between the 2 bridges then fall and crash into or alongside the bridges?

Hi Jim, sorry to read your post. I'm afraid that data analysis is not available for the drone that has been expired. In case that the repair is needed, you can still start a case and send it in.

Jim Watkins Posted at 2018-1-17 14:59
Okay...let's try it this way.  http://www.phantomhelp.com/LogViewer/DR5O9LD983ZE8AX0T0MS/

I've gone back for a minute before the crash and find the Phantom responding to the throttle normally except for the period from 6:52.6 - 6:53.6.
At the time you were flying under two 5-lane freeway bridges and losing GPS signal.
The Phantom rose from 3.6 - 8.9 feet in 1.1 seconds and then crashed at 6:53.6.

I can't see any obvious indication for why it climbed.
There's no sign of it ever going to RTH and you had full control signal.
Since you were flying west at the yime, I'd ask if it was afternoon?
If so it may have been that your Phantom was heading towards the sun and attempted to avoid the perceived obstacle?

Labroides Posted at 2018-1-17 23:10
I've gone back for a minute before the crash and find the Phantom responding to the throttle normally except for the period from 6:52.6 - 6:53.6.
At the time you were flying under two 5-lane freeway bridges and losing GPS signal.
The Phantom rose from 3.6 - 8.9 feet in 1.1 seconds and then crashed at 6:53.6.

The Flight was at 12:05 PM.  Not looking into the sun.  I have flown under that freeway many times and losing GPS  never caused this before.  And like I said, it happened the day before in an open park with nothing around.  Very strange.  I could repair it myself.  I have replaced the shell before, but I am not sure I want to do it again.  It's a project.  I wonder how much it would cost to have it repaired.

You can send it in and receive a quote before repairs are started.

I was not recording video at the time of the crash into the bottom of the 5 freeway, but I do have video from the flight just minutes earlier.  That flight too had vertical control issues and in that case it wanted to keep descending despite neutral or some opposite control inputs.  You will notice that as I return to land I am not maintaining a constant smooth rate of descent.  I am in fact fighting with the joystick to try, but the quad wants to keep descending or descending faster than my inputs would suggest.    I also post this video to give you a better idea of the location.   I could upload the logs for that flight if anyone thinks it would be useful.   Video here

--Jim

Jim Watkins Posted at 2018-1-18 06:57
The Flight was at 12:05 PM.  Not looking into the sun.  I have flown under that freeway many times and losing GPS  never caused this before.  And like I said, it happened the day before in an open park with nothing around.  Very strange.  I could repair it myself.  I have replaced the shell before, but I am not sure I want to do it again.  It's a project.  I wonder how much it would cost to have it repaired.

As I said, the log doesn't point to the cause so I'm only guessing what might have happened.
Obstacle avoidance is something that could cause the Phantom to ascend in flight even if you are trying to descend.
Did you have OA enabled at the time?
You were flying in an uncommon situation, in a dark area under the freeway bridge that blocked GPS.
I suspect that the incident is not random and was related to the environment there at the time.
It might be that your Phantom was trying to avoid an "obstacle" and it might not have been the sun but could have been a bright area on something the sun was shining on ... a white car, a bright piece of concrete or something like that?

The obstacle sensing system has several limitations.
Here are some from the manual:
The performance of your Vision System and Infrared Sensing System are affected by the surface being flown over.
Ultrasonic sensors may not be able to accurately measure distances when operating above sound-absorbing materials and the camera may not function correctly in suboptimal environments.
The aircraft will switch from P-mode to A-mode automatically if neither GPS nor Vision System and Infrared Sensing System are available.  
Operate the aircraft with great caution in the following situations:
a) Flying over monochrome surfaces (e.g. pure black, pure white, pure red, pure green).
b) Flying over a highly reflective surfaces.
c) Flying at high speeds of over 31mph (50kph) at 2 meters or over 11mph (18kph) at 1 meter.
d) Flying over water or transparent surfaces.
e) Flying over moving surfaces or objects.
f) Flying in an area where the lighting changes frequently or drastically.
g) Flying over extremely dark (lux < 10) or bright (lux > 100,000) surfaces.
h) Flying over surfaces that can absorb sound waves (e.g. thick carpet).
i) Flying over surfaces without clear patterns or texture.
j) Flying over surfaces with identical repeating patterns or textures (e.g. tiling).

Note particularly F & G.

The .dat file recorded in your Phantom gives more information than the .txt file in the app.
It would probably indicate whether obstacle avoidance was triggered.
You could try looking into that to get more detail.

Labroides Posted at 2018-1-18 15:26
As I said, the log doesn't point to the cause so I'm only guessing what might have happened.
Obstacle avoidance is something that could cause the Phantom to ascend in flight even if you are trying to descend.
Did you have OA enabled at the time?

Yes, but this has happened on 3 different flights in 3 different locations.  Collision avoidance was on in all cases.  

Jim Watkins Posted at 2018-1-18 17:50
Yes, but this has happened on 3 different flights in 3 different locations.  Collision avoidance was on in all cases.

Was that three flights in extreme lighting conditions or were the others out in the open?
Data from the other incidents might be useful

Labroides Posted at 2018-1-18 18:10
Was that three flights in extreme lighting conditions or were the others out in the open?
Data from the other incidents might be useful

The other two were in normal out in the open, in an open field in one case.  One is the flight video I posted.  Same launch location, but not under the bridge.  It was mostly at 200' or so.

my p4 went up to 1400+ wile i was  pulling down on controls
http://app.airdata.com/main?share=WfVFis    3 http://app.airdata.com/main?share=Wupczo  2
http://app.airdata.com/main?share=xOTcTS  1

jackodogandroid Posted at 2018-1-19 12:35
my p4 went up to 1400+ wile i was  pulling down on controls
http://app.airdata.com/main?share=WfVFis    3 http://app.airdata.com/main?share=Wupczo  2
http://app.airdata.com/main?share=xOTcTS  1

Very strange.

jackodogandroid Posted at 2018-1-19 12:35
my p4 went up to 1400+ wile i was  pulling down on controls
http://app.airdata.com/main?share=WfVFis    3 http://app.airdata.com/main?share=Wupczo  2
http://app.airdata.com/main?share=xOTcTS  1

Well they're all Litchi flights, and in two out of the three they were in waypoint mode, so under control of Litchi ?

Aardvark Posted at 2018-1-20 10:31
Well they're all Litchi flights, and in two out of the three they were in waypoint mode, so under control of Litchi ?

these were all 1 mission.   i had all control except up-down.
i had had problem with p4 not coming down before, full decent and slowly descends.
that mission had been flown at least 5 times before.
something had control, it wasnt me.

Do you guys use Gimbal protectors, the type across the legs?

Bashy Posted at 2018-1-20 22:17
Do you guys use Gimbal protectors, the type across the legs?

nothing aftermarket on p4

jackodogandroid Posted at 2018-1-22 07:19
nothing aftermarket on p4

Nothing aftermarket.

I decided to send my P4 in for an estimate with the intention of repairing it if it cost less than $200.00.  They gave me an estimate of $185.00 so I had them proceeded.  I will say that the turn around time was impressive.  I sent it in less than a week ago and it's shipping back today.  I am very glad to see that we have firmware .700 official now.  I wouldn't want the same thing to happen again.  It will be interesting to see if they update the firmware before returning it.  It will also be interesting to see if they repaired my unit or simply sent me a different one.  I'll keep you posted.

Jim Watkins
(Burbank, CA)

Jim Watkins Posted at 2018-1-24 11:50
I decided to send my P4 in for an estimate with the intention of repairing it if it cost less than $200.00.  They gave me an estimate of $185.00 so I had them proceeded.  I will say that the turn around time was impressive.  I sent it in less than a week ago and it's shipping back today.  I am very glad to see that we have firmware .700 official now.  I wouldn't want the same thing to happen again.  It will be interesting to see if they update the firmware before returning it.  It will also be interesting to see if they repaired my unit or simply sent me a different one.  I'll keep you posted.

Jim Watkins

Good luck with your new bird