P4P doesn’t come down

[Centaurius]

Hi,

During my most recent flight with my P4P the drone wouldn’t descend further than 60m, not even using auto land. Only after minutes of fiddling with the controls, switching between flight modes and sliding the auto land button about ten times it descended to the ground. I’ve checked all of the sensors afterwards but none of them were dirty or blocked.

Any thoughts on how to fix or prevent this?

 

[Fly Dawg]

Any thoughts on how to fix or prevent this?

I have seen a similar incident, which I wont go in to at the moment. If you can upload the log from this flight to the link below, we might be able to determine if the issue is control aor AC related. Instructions are on the link. If you do upload this, place a link back here to the uploaded file.

Phantom Help Upload

 

[Meta4]

During my most recent flight with my P4P the drone wouldn’t descend further than 60m, not even using auto land. Only after minutes of fiddling with the controls, switching between flight modes and sliding the auto land button about ten times it descended to the ground. I’ve checked all of the sensors afterwards but none of them were dirty or blocked.

Any thoughts on how to fix or prevent this?

The few similar reports were due to an issue with the bottom sensors.
You would need to check the flight data to see if this was the case in your incident.
Disabling the VPS in the app settings should solve the issue if nothing else does.

 

[Fly Dawg]

The few similar reports were due to an issue with the bottom sensors.

@ 60 meters? The VPS should not be active at that altitude.

 

[Meta4]

@ 60 meters? The VPS should not be active at that altitude.

If enabled, the VPS is active.
At 60 metres, it shouldn't be reporting anything, but if it is (as would be shown in flight data) that is likely to be the issue.

 

[Fly Dawg]

If enabled, the VPS is active.
At 60 metres, it shouldn't be reporting anything,

Agreed, that is why I mentioned the Log it it were not disabled.

 

[Centaurius]

The VPS didn’t report anything, I already tried switching it off during the flight but it still wouldn’t come down. By the way, my P4P is currently on an older firmware version because I wanted to change some flight parameters, perhaps that could be of influence?

 

[Fly Dawg]

I already tried switching it off during the flight but it still wouldn’t come down.

As I mentioned in Post#2, I have seen a similar incident. To explain that, it was from the flight log, which is why I suggested that you upload the log from that flight and share that upload back here. To be exact, the incident I am speaking of was a "Stuck" RC throttle which took the aircraft to the maximum allowable altitude and no inputs from the RC were effective in bringing it back down. It was un-recoverable. My thought was that it could be a similar thing, but we need to see the logs to verify that.

 

[Meta4]

The VPS didn’t report anything, I already tried switching it off during the flight but it still wouldn’t come down. By the way, my P4P is currently on an older firmware version because I wanted to change some flight parameters, perhaps that could be of influence?

Without recorded flight data, all you will get will be guesses and you've probably seen everything that will be guessed at by now.
If you want to find out what caused the issue, post your flight data.
Go to DJI Flight Log Viewer - Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
Come back and post a link to the report it gives you.

 

[Centaurius]

The reason I’m a bit reluctant to post the flight logs is that I flew past the max. altitude limit in this particular flight and I didn’t want to start yet another discussion about the dangers of that action. However, as I’d also like to know the cause of the malfunction, I will try to post them today.

 

[Fly Dawg]

The reason I’m a bit reluctant to post the flight logs is that I flew past the max. altitude limit in this particular flight

Hence why I mentioned the stuck throttle event. Nothing the pilot could do in that instance.

 

[Centaurius]

Here’s the link to the flight log:
DJI Flight Log Viewer - PhantomHelp.com

At 14m 19s you can see that I put my left stick all the way down but nothing happened. At 4m 24.7s it was going down, but extremely slowly.

 

[Meta4]

From 13:36.5 till 13:41.5 your data shows the VPS registering an altitude of less than 1 ft, despite the barometer showing you were much higher than that.

From 13:37.8 till 13:42.1 you had the left stick hard down but no descent happened.
You then centred the left stick and pulled it back down again and the drone descended normally.

The issue appears to be due to a temporary problem with your downward facing sensors.

 

[Centaurius]

From 13:36.5 till 13:41.5 your data shows the VPS registering an altitude of less than 1 ft, despite the barometer showing you were much higher than that.

From 13:37.8 till 13:42.1 you had the left stick hard down but no descent happened.
You then centred the left stick and pulled it back down again and the drone descended normally.

The issue appears to be due to a temporary problem with your downward facing sensors.

Alright so that means everything should be fine if I just recalibrate the sensors right?

 

[Meta4]

Alright so that means everything should be fine if I just recalibrate the sensors right?

Maybe ... That depends on what caused the temporary glitch.
You would expect it to be permanent if it would require recalibration to fix it.

 

[Centaurius]

Maybe ... That depends on what caused the temporary glitch.
You would expect it to be permanent if it would require recalibration to fix it.

Alright, then I’ll just test it first without recalibrating and see if the glitch keeps showing up. If so, I’ll recalibrate them and see what that does. Thanks for the help.

 

[Fly Dawg]

Alright, then I’ll just test it first without recalibrating and see if the glitch keeps showing up

For a visual of Meta4's comment. There appears to be some issue with the VPS. Try a test both with the VPS on and off to see if there is any difference in response. The VPS levels in the graph below are no where near correct, and they should not even be there at all over, give or take 30 feet in altitude.

 

[Centaurius]

For a visual of Meta4's comment. There appears to be some issue with the VPS. Try a test both with the VPS on and off to see if there is any difference in response. The VPS levels in the graph below are no where near correct, and they should not even be there at all over, give or take 30 feet in altitude.

View attachment 104213

I’ll try that, thanks.