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up-stick stopped working at high altitude, did not improve

jimbo1969

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I flew up a ridge on a steep slope, such that the drone was about 100 ft above the ground, but 1000 ft above its takeoff point. At around 1025 ft above starting point, it suddenly stopped increasing altitude. It would maintain altitude fine, and all other inputs worked. I flew it around a bit at this new ceiling, then returned home and did a bit of roaming around near home. All the controls worked fine EXCEPT up-stick. So I could not go up even a few feet to get over the roof ridge of the house or above the power lines to get the last few feet home.

Is there some kind of 'circuit breaker' type of deliberate function that just turns off the ability to go upward after a certain limit is reached? Perhaps at 1024 ft above take-off point, for example? And shouldn't the functionality return after you bring it back to a very low altitude?

Thanks for any insight into how it works.
 
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Hi there & welcome to the forum 👋 :D

The only 'circuit breaker' you have is the maximum altitude setting in the DJI Fly app ... which can be set at max 1640ft above the recorded HP.

The other thing that can stop your drone to ascend is a altitude zone according to the DJI FLY Safe material included in your drone ... you will not be able to go higher than what the zone allows.

If your drone during your flight was below the 'circuit breakers' I've mentioned above but couldn't go higher anyway ... something appears to be malfunctioning.
 
What do you have the maximum flight altitude set to in the Fly app?
~1600 ft. That was the first thing I monkeyed with, as it was originally set to something around 400 ft, which was way underground, of course, as I flew it towards the mountain. Thanks much for that link. It actually points to a great in-depth discussion of IMUs, Euler angles, etc. Somebody put some real effort into that guide.
 
Hi there & welcome to the forum 👋 :D

The only 'circuit breaker' you have is the maximum altitude setting in the DJI Fly app ... which can be set at max 1640ft above the recorded HP.

The other thing that can stop your drone to ascend is a altitude zone according to the DJI FLY Safe material included in your drone ... you will not be able to go higher than what the zone allows.

If your drone during your flight was below the 'circuit breakers' I've mentioned above but couldn't go higher anyway ... something appears to be malfunctioning.
Thank you.
I actually just did an experiment in a safe location wherein I put it in sport mode and flew it straight up to see if I could reproduce the error. It went above the ceiling where it had stopped earlier and I let off the stick around 1100 ft. I focused on other stuff for a bit, and then noticed that it was still climbing fast (as if it still thought the stuck was pushed up 100%). It reached the ~1640 ft ceiling before it stopped ascending. I'll study up on what telemetry gets logged and post back if I find anything interesting. I wonder if it simply keeps operating on the last known state of the controls when it loses connectivity. That wouldn't explain the original issue, but it'd be good to know (and it would explain the behavior during my test).
I'm task-loaded right now because I'm a newbie, so I'm probably missing some obvious indicators.
 
Would the following summarize your story of post #1?

EDIT ........I had not seen post #5 when I first made this post. (#5 & #6 both have the same time stamp)

The drone, following your commands, climbed to a certain height, which, incidentally, was below the height you had set as the maximum, the drone would go no higher than that even if commanded to climb.
After that, even if you first descended, the drone would not climb again.
 
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~1600 ft. That was the first thing I monkeyed with, as it was originally set to something around 400 ft, which was way underground, of course, as I flew it towards the mountain. Thanks much for that link. It actually points to a great in-depth discussion of IMUs, Euler angles, etc. Somebody put some real effort into that guide.
In that case I'd take a look at the flight log to see if that indicates what was happening.

Thank you.
I actually just did an experiment in a safe location wherein I put it in sport mode and flew it straight up to see if I could reproduce the error. It went above the ceiling where it had stopped earlier and I let off the stick around 1100 ft. I focused on other stuff for a bit, and then noticed that it was still climbing fast (as if it still thought the stuck was pushed up 100%). It reached the ~1640 ft ceiling before it stopped ascending. I'll study up on what telemetry gets logged and post back if I find anything interesting. I wonder if it simply keeps operating on the last known state of the controls when it loses connectivity. That wouldn't explain the original issue, but it'd be good to know (and it would explain the behavior during my test).
I'm task-loaded right now because I'm a newbie, so I'm probably missing some obvious indicators.
That certainly suggests a problem, although it sounds like a different one. Definitely needs a look at the logs.
 
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... I let off the stick around 1100 ft. I focused on other stuff for a bit, and then noticed that it was still climbing fast (as if it still thought the stuck was pushed up 100%)
That really sounds like a malfunction ... share your flight log & let us see what's going on.

Follow the instruction further down here --> DJI Flight Log Viewer | Phantom Help to retrieve the mobile device .TXT log from the mobile device you flew with ... then upload it to the same site & take note of the link they provide once you have uploaded the log. Come back here and share that link.
 
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Thank you.
I actually just did an experiment in a safe location wherein I put it in sport mode and flew it straight up to see if I could reproduce the error. It went above the ceiling where it had stopped earlier and I let off the stick around 1100 ft. I focused on other stuff for a bit, and then noticed that it was still climbing fast (as if it still thought the stuck was pushed up 100%). It reached the ~1640 ft ceiling before it stopped ascending. I'll study up on what telemetry gets logged and post back if I find anything interesting. I wonder if it simply keeps operating on the last known state of the controls when it loses connectivity. That wouldn't explain the original issue, but it'd be good to know (and it would explain the behavior during my test).
I'm task-loaded right now because I'm a newbie, so I'm probably missing some obvious indicators.
As long as the drone does not go above 400 ft above the ground - you are legal. If you fly straight up from takeoff and go above 400 ft - you are breaking the rules for drone flight. Adjusting the max height is mainly for when you are at a fly point of a mountain and want to climb the mountain with your drone - but keeping it no higher than 400 ft above the ground it is following.

My Air2 started throwing out warnings at high altitude in Colorado near Mt. Evans, which is approx 14,000+ feet high. I was not at the summit, but over by Echo Lake and once up about 200 ft, got the high altitude warning. Drone still flew fine and would go higher, but that altitude makes the drone work harder, so shorter battery life.

When the drone loses connectivity for more than approx 10 seconds - it's set to auto Return Home (from your take off point or wherever it set the HomePoint on take off - which can be very different). You'll want to make sure YOU know where your RTH / homepoint set is or the drone will return to that spot, not where you took off from if it did not set there. RTH works off GPS and if low GPS at that location, it won't set the RTH / homepoint till it does get enough satellites and in some places - that won't happen at all. Search the forum for ATTI Mode, as you'll experience it sooner than later - esp when no GPS is found with the drone. Then you are flying manually with no stabilization / etc - that GPS gives the drone.

If you have not done your FAA TRUST Test, you should do it soon. It's required of ALL drone pilots. Easy test, but does go over main points / rules like VLOS and other things most newbie pilots don't know about and so they break the law / rules by doing so.

You'll want / need an app like Aloft or B4UFLY to make sure your areas you fly in are legal to do so as well. Many places in Colorado, esp around Denver do not allow drone flight from their properties - esp city / state parks. You can legally fly over said parks by taking off / landing from outside their boundaries if you can do so within VLOS / rules.

Lots of YouTube videos as well. Some good, some bad. Bad ones are the ones where they fly 4 -5 miles downrange and such - which in the US and most countries is illegal. Fly safe & smart to help keep the drone community out of hot water and regulators who want to restrict drones even more than they currently are.
 
With post #5 in mind.

I really suggest you upload the .txt logs for these two flights to "PhantomHelps log viewer", which can be found at DJI Flight Log Viewer | Phantom Help
Then down load the csv output from that page and browse it or perhaps 'give it ' to the software CsvView, see CsvView Downloads

If you want the likes of Sar104 or Slup to have a look the log then post the link to your log on PhantomHelp.

I would most definitely reduce the maximum height set in the app to, at the most 400ft, for the moment at least. But, to be honest, until you find out the cause of this misbehaviour, I would be wary of flying the drone out of doors.

If you feel compelled to fly it out of doors look up how to change the response to the CSC position and be prepared to use the CSC stop the drone motors in midair and cause the drone to drop.
You might even then have the opportunity to see if another CSC would restart the motors before the drone hits the ground.
Should you attempt the midair restart and it works, be prepared to throttle up just in case the motors restart at idle.
I did a mid air motor stop and restart with a Phantom 3 and the motors restarted at idle, it took me a second or two to realise it was still falling and why and to give it full throttle.
 
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@PhiliusFoggg thanks for the heads up on the CSC emergency stop/restart and the reminder that the motors only restart to the regular idle speed. I think it would have taken me longer than "a second or two" to realize why it was still falling and would only figure the "why" after the descent came to a sudden stop...
 
MIGHT, the Mavic's may be more intelligent than the Phantom and go "oh dear, I am in the air, I better give it some Welly"
They most probably are, at least the later iterations ... it's plenty of clips on YT showing hand launching's by a CSC command with the AC in a flat hand, motors goes idle ... then quickly lower the hand, & the AC goes to a hover without the throttle moved.

Here's one example with a Mini 2 ...

 
I'd still be ready to throttle up, just in case. lol
The Phantom came awfully close to deep sea diving lol
 
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