Has anyone tried to turn the braking percentage down as see if that eliminates the drop?
I'm wondering why if it's software some phantoms have the issue and some phantoms not...[emoji1]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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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).
Mine doesn't climb back up I don't think.
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.
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
It's been reported on the DJI forum, and they said they are working on a fix.
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.
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.