Hi All,

Encountered something new and strange today.  If I start the rotors of my P3S and dont take off, the rotors idle and a normal speed and the P3S does not move.  If I take off, fly for a bit, and then land, the rotors idle at first and then start to rev up.  Sometimes the Phantom even tries to lift itself up off the ground and I have to kill the motors to stop it.

I have read somewhere that this is normal after landing because the craft thinks it is still in flight and is trying to compensate.  Is this correct?

This is a real shot in the dark, but have you tried to re-calibrate your controller?  Perhaps it is sending a signal as if you were pushing the throttle stick a little, even though you aren't touching the sticks.

Also, while flying the battery gets warm --> hot and is cooled by the airflow. When you land and sit with the motors running, the battery heat may be warming the air entering the barometer which is on the under side of the MC Board just above the battery compartment. The warmer air makes the P3 think it's descending so it increases power to stabilize....

Total conjecture, but probably happening to some degree

P.S. The first thing I do after landing, ensuring the camera is not still recording, and powering off the P3, is remove the HOT battery.....

Experienced same thing, think it's normal.

It seems to be a "Feature",  because mine does the same.

Its a little scary to be honest, recalibrating the controller makes no difference.  Revving the motors is one thing but when it decides to lift itself slightly off the ground and drag itself quickly in a random direction, thats when I panic.

Kneepuck Posted at 2016-1-15 20:19
It seems to be a "Feature",  because mine does the same.

Yeah a 'feature' heh.  To be honest the Phantom has too many little surprising features that can result in damage to your expensive drone :/

terrylewis Posted at 2016-1-16 02:48
Also, while flying the battery gets warm --> hot and is cooled by the airflow. When you land and sit ...

With the props idling on the ground there is a lot of air moving under and around the drone.  I doubt what little heat off the battery and motors even come close to the pressure changes from the spinning props and ground effect.

did you put the props correctly ?  i  friend was telling me something like that ,  an i don't know how  he did it but he didnt install the props correctly and the quad was doing the same thing making a lot or air but the quad never goes up so we re install the props and then everything works fine ;)

christopherglen Posted at 2016-1-15 16:05
With the props idling on the ground there is a lot of air moving under and around the drone.  I do ...

But it does not happen right away, it idles for 15-30 sec before you hear it surging, so if it was due to airflow, I think there would be no delay.

I think it's best to shut down if your not going back up right away because it's so easy to start motors again, do a minimal pre-flight check and takeoff.

Data Ghost Posted at 2016-1-16 07:25
Its a little scary to be honest, recalibrating the controller makes no difference.  Revving the moto ...

And that's why you should always shut down completely and not leave your Phantom idling on the ground after a flight.
It's temperature change causing the barometer to drift as mentioned earlier.
There are plenty of cases recorded where the Phnatom has taken off in the same situation.

Data Ghost Posted at 2016-1-15 21:25
Its a little scary to be honest, recalibrating the controller makes no difference.  Revving the moto ...

If I don't stop the motors immediately, I have exactly the same issue after landing!

Problem is not related to the small lift of the P3 itself but rather to its strange inclination and consequent quick random dragging (that can lead to the overturning and crash)

I hope DJI analyze and puts a patch to this issue!

amadeus Posted at 2016-1-26 11:16
If I don't stop the motors immediately, I have exactly the same issue after landing!

Problem is n ...

DJI don't need to do a patch for this, it is not a fault. Simply do not leave the motors running. The aircraft does not know it has landed, and is trying to maintain it's current position. Always shut the motors off the moment you land or you are asking for trouble.

There are many cases reported where people have lifted off after sitting on the ground for a while and the aircraft has suddenly tipped over and wrecked the blades.

Geebax Posted at 2016-1-26 02:42
DJI don't need to do a patch for this, it is not a fault. Simply do not leave the motors running. T ...

I agree with you when you suggest me to turn off the motors in order to avoid problems.
This is what I do on regular basis!

But you cannot deny the fact that the sudden drag of the bird near the ground that I (and many other users...) have experimented represents an issue!

amadeus Posted at 2016-1-26 05:10
I agree with you when you suggest me to turn off the motors in order to avoid problems.
This is wh ...

No it doesn't represent an issue.  It represents poor practices in quad use.  Avoid the problem by shutting the motors off when you land and/or do not let the quad sit there in a landing position with the motors running.  That simple.

amadeus Posted at 2016-1-26 10:10
I agree with you when you suggest me to turn off the motors in order to avoid problems.
This is wh ...

It's not an issue with the Phantom, it's just the way a quad works.

If the aircraft thinks it's in the air (which it always does after initial take off), it'll always try to hold it's position & altitude & stay level.  If your landing isn't perfectly level or the gps signal varies a little (it does), or the barometer varies a little (it does), the aircraft will try to correct it.  That's what is happening, it's still trying to fly.

The "issue" doesn't lie with the Phantom...