No harm done here, but I had my bird flying directly across and away from me, I stopped, oriented it left to fly in that direction then it lost connection with GPS (I had had an 18 sat connection) The drone suddenly drifted, but more accurately it started moving very quickly backwards without any orders from the sticks. Now I thought it might have been RTH being triggered, but it was going in a completely new direction and luckily it reconnected with the 18 sats and I was able to regain control. I know you probably want my flight logs, and I am new to that, but has this occured with anyone else while flying?

When you lost GPS, the aircraft likely went into ATTI mode. In this mode, only vertical stabilization is provided through the onboard barometer. So with no horizontal stabilization, the aircraft drifted with  the wind and any turbulence caused by the aircraft itself.

QiiFlight Posted at 2017-4-10 11:53
When you lost GPS, the aircraft likely went into ATTI mode. In this mode, only vertical stabilization is provided through the onboard barometer. So with no horizontal stabilization, the aircraft drifted with  the wind and any turbulence caused by the aircraft itself.

Thanks for the insight. I didn't realize that you get no horizontal stab. in ATTI..

It's not clear from your original post, when you say 'regain control' do you mean that while GPS was off you couldn't control it with the sticks either? If that's the case there must be something seriously wrong and I suggest you investigate with DJI. Otherwise, if you were still able to control by stick (ok, of course not as easy as in P mode), then for now assume it was a glitch of the moment, but better keep monitoring it.

betonven Posted at 2017-4-10 12:28
It's not clear from your original post, when you say 'regain control' do you mean that while GPS was off you couldn't control it with the sticks either? If that's the case there must be something seriously wrong and I suggest you investigate with DJI. Otherwise, if you were still able to control by stick (ok, of course not as easy as in P mode), then for now assume it was a glitch of the moment, but better keep monitoring it.

That actually happened to me once with a P3P. I'm not even sure I lost GPS. I do recall having a strong transmitter connection but the quad did not respond to stick movements at all for about 5 seconds. It was only about 90 feet up and perhaps 50 feet away from me. Never happened again though.

thatguy Posted at 2017-4-10 11:53
Thanks for the insight. I didn't realize that you get no horizontal stab. in ATTI..

There's a little more information on ATTI mode on page 13 of the P4P manual:

https://dl.djicdn.com/downloads/ ... _User_Manual_EN.pdf

I would concur with QiiFlight as well that the unit temporarily going into ATTI mode is the likely culprit. Just to clarify, though, were you trying to move the aircraft at all while it was drifting? If so, did it seem like it was trying to 'fight' the drift at all?

DJI-Jamie Posted at 2017-4-10 14:34
There's a little more information on ATTI mode on page 13 of the P4P manual:

https://dl.djicdn.com/downloads/phantom_4_pro/20170314/Phantom_4_Pro_Pro_Plus_User_Manual_EN.pdf

No I didn't touch the sticks. The GPS locked on at about the time I was reaching for them. It happened fast.

thatguy Posted at 2017-4-11 07:02
No I didn't touch the sticks. The GPS locked on at about the time I was reaching for them. It happened fast.

Just to clarify, what kind of area were you flying in? The quick drop in satellites hasn't happened again so far, correct?

DJI-Jamie Posted at 2017-4-11 07:28
Just to clarify, what kind of area were you flying in? The quick drop in satellites hasn't happened again so far, correct?

I was by a lake in a mountainous area by a major freeway. Not near any towns or cities.

thatguy Posted at 2017-4-11 13:58
I was by a lake in a mountainous area by a major freeway. Not near any towns or cities.

Were you close to the freeway when this happened?

This ís why you should always practice flying in atti mode regulary.

DJI-Jamie Posted at 2017-4-11 14:17
Were you close to the freeway when this happened?

Nope, I wasn't around any obstacles it could have struck.  The only hazard was the water...

thatguy Posted at 2017-4-18 06:35
Nope, I wasn't around any obstacles it could have struck.  The only hazard was the water...

If it was just for a quick moment and the change from GPS to ATTI didn't reoccur, it's most likely just a "one off" situation. Since satellites generally aren't static, temporary drops in satellites can happen. If the drop in satellites like this becomes more consistent, however, you may want to look into sending it in for further evaluation and potential repair.