Set an entpnt, assign the type as Veh Ent for now.
Rotate the entry point arrow until it points in the direction the plane would be facing at launch, which also determines the keypad key, i.e. point it NE and keypad NE will launch you to that spawn point.
Now select the properties again and reasign the object type as Ftr Entry instead of a Veh Ent.
At the end of this process, if you want an air start, tweak the 'Y' value to the alt you want.