flight simulator help

im making a flight simulator game and i need help because i want to be able to choose a plane than takeoff, but i cant seem to get the plane from falling through the runway help please

[jediaction]

Falling through the run way. Thats ground detection. The choosing a plane. Put any extra planes set vehicle to the main plane that moves. Make it showing = false. Then when a button is clicked to select the new plane. Make it showing = true, and the main plane = false. Got it?