Altitude drops during flight...

Has anyone posted this on the DJI forum site to see if they will respond officially?


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Has anyone tried to turn the braking percentage down as see if that eliminates the drop?
 
FYI, according to Peter at Acesdeals.biz, "DJI is aware of this altitude drop problem in some but no all P4s and a software fix is forthcoming"


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FYI, according to Peter at Acesdeals.biz, "DJI is aware of this altitude drop problem in some but no all P4s and a software fix is forthcoming"


Sent from my iPhone using Tapatalk
I'm wondering why if it's software some phantoms have the issue and some phantoms not...[emoji1]
 
I have the same issue as well. Hope they fix it soon! Would love a gimble calibration fix too. Slow to recover level horizon when turning ect.
 
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I believe the problem is the vision system on the bottom of the craft. It's not broken, it's just how it operates. Try flying around at 100 feet and see if the altitude changes as badly (it shouldn't).


I have flown mine from zero to 400', and everything in between, and you can even see the "sinking" in my videos... So, unless the VPS is somehow superseding the GPS then I don't think it is the VPS. One suggestion I saw earlier was to test in atti mode. I'll do this on my next flight, and report back...
 
I have a theory. I'm not sure how valid it is, but I'll share it. My P4 has exhibited this phenomena also. The air circulation of the craft is quite clever, and quite different than P3P. Air enters the belly of the craft using a fan, as we have all seen by now in photos. The air is pushed up through the craft, then out the motor pod vents. The air circulation through these vents is helped with suction created by the venturi of the propeller thrust racing downward over the top of the motor pod (I think that's so clever). When the rushing air is split by the motor pod arm, it's compressed slightly. As the air goes past the arm, it's uncompressed and speeds up, causing a venturi suction affect. This draft of the passing air helps by sucking air out of the motor arm bottom vents. My theory is the pressure differentials of this rushing air at different throttle levels is affecting the barometer sensor inside, causing the craft react with altitude changes, unpredictably. Turning left or right happens to amplify these pressure changes (negative or positive) because of the change in pressure from the craft spinning to turn. This could potentially change the venturi, and change in craft's interior barometric pressure, ever so slightly, affecting the accuracy of the barometer sensor readings. Again, it's just a theory.


But one HELL of a theory! I'm COMPLETELY convinced!! :)
 
I found a video on Youtube that demonstrates the altitude drop. Skip to 12:23 unless you want to see the review/demo.

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Yeah, I saw this video as well. I think it's quite obvious that there is definitely a problem here. It should be interesting to see how DJI addresses this issue. There appears to be far too many people experiencing this drop in altitude for DJI to just ignore it, or claim they haven't heard about it.
 
I've had this drop in altitude since I started flying my new bird on Monday.
 
I called DJI this morning regarding this problem. They basically told me this is not a firmware issue and they wanted me to send them a video showing the drop in altitude.


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I called DJI this morning regarding this problem. They basically told me this is not a firmware issue and they wanted me to send them a video showing the drop in altitude

That is even worse news! If it isn't a firmware issue and solvable by an update then it is a hardware issue; which means a fix is unlikely or would require you to return your P4 to DJI.

They don't need your video, this has been reported by too many (with posted examples) for them to unaware. And considering this seems to be a not uncommon issue they could duplicate themselves by flying some of the assembly line.

Sound like more delay and deny or at least don't acknowledge.
 
It's been reported on the DJI forum, and they said they are working on a fix.

They have been "working" on the horizon issue since the P3 and it is obvious how well that is going. Again if it is not firmware a quick inexpensive fix seem to be unlikely.

I hope that they are wrong and can correct with a firmware update.
 
That is even worse news! If it isn't a firmware issue and solvable by an update then it is a hardware issue; which means a fix is unlikely or would require you to return your P4 to DJI.

They don't need your video, this has been reported by too many (with posted examples) for them to unaware. And considering this seems to be a not uncommon issue they could duplicate themselves by flying some of the assembly line.

Sound like more delay and deny or at least don't acknowledge.

Yes I am sure they are aware of it and they are just stalling by asking for a video. "Natalie" acted like this was the first she has heard of this issue. When I specifically asked if they were working on a firmware update to address the problem she told me flat out this was not a firmware issue. I assured her that I had performed all the calibrations possible for the bird. By the way I initially sent them an email four days ago and got no response so I had to call. I am not holding my breath on this one.
 
I've noticed mine doing this, however this is my first phantom. So i was unsure if it was normal or what. Guess it's not.


It is not normal for previous Phantoms, but, unfortunately, it is beginning to appear that it IS normal for the Phantom 4!! :(
 

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