I've tried flying indoors my mode is on P. Seems like it flys good untill it links up to GPS then it seems to drift. Should I be in the A or F mode. I know the book says VPS and GPS are best used together indoors. So I'm guessing this is the P mode. Any ideas?

When we fly indoors at events we just leave them on P-GPS.  We do not get GPS lock because of metal roofs most of the time.  The drift you may be seeing could be of the spotty nature of the GPS or the VPS is having difficulty getting a lock on the floor.  It requires a lighted surface with details/patterns to work the best.

Make yourself a Heliport landing/take off pad. Or purchase one.
There are many makers and designs available if you aren't handy...

Cut out a stencil, and spray paint the pattern, which you design. ;-)
I like this awesome home job.


And another...


RedHotPoker

Maybe the carpet does not have a good pattern. Will try later. RedHodPoker, don't know what to say, really nice. Make a video landing on it

The Phantom 3 is equipped with accurate ultrasonic sensors for indoor flight use but its recommend only to fly in larger indoor areas.
To work properly the sensor needs some distance to recognize different ground surfaces.
The P3 is not designed to fly inside normal small living rooms.

The indoor option is meant for use on sports events, concert halls etc.

thanks for the info