Hi there,

Yesterday I've tested my Phantom 3 indoors in a large open hall, and I didnt' think of changing the mode switch on the remote.

The GPS signal was not available so the P3 was in the P-OPTI mode first and also switched to P-ATTi  (probably at higher altitudes) when I check the flight records.
It was possible to fly but it took a lot more steering skills, I noticed the Phantom 3 was not 100% stable and started to drift a bit with both sticks untouched compared to flying outside.

Is this the best way to fliy indoors, or should I change the position on the remote to another mode to increase stability?

If anybody has experience with flying indoors, can you confirm if the way it behaves remains about the same during a flight?
Or can it do unexpected things other then a bit of drifting, like dropping a lot causing it to crash?

My goal is to use it to chase a bowling ball, like in 'The Big Lebowski' , but I dont want it to crash into the wall or something.

That's funny. Bowling, yet you actually don't want a 'strike', after all? ;-)

RedHotPoker

In ATTI you phantom is locked into altitude but not into position. It will maintain its height but you have to control its movements and these movements will continue until you stop them. So it requires some flight practice to keep yourself in control.

ATTI and practice is probably your best option  I'd say...

VPS is good to maintain a hover of a surface that has details/patterns it can work with, but may not help that much if you're over a bowling alley.

Either way, if VPS doesn't do it for you, ATTI is what you've got so practice in that. :-)