I loaded the BB Maps before I entered the plane. If you load them and change the zoom to see the area you'll be flying above you don't need reception.

Another thing I noticed while flying. I use Holux and I have to get the satellites before I get on the plane. For some reason if I don't have the satellites' position fixed there is no way to do it while flying. So I get the position fixed before I enter the plane and then I don't turn off my Holux.