In the other Hand..
I will give you a simple lesson about this.
At First We Make The Ground
make object plain 2,10000.0,10000.0
position object 2,0,-25,100
xrotate object 2,90
color object 2,rgb(0,100,100)
After That We bring Your Plane To The Scence
load object "pp.3ds",1
position object 1,0,30,10
color object 1,rgb(100,100,100)
We Change The Camera Settings
position camera -900,10,10
yrotate camera 90
We Fix The Object Pivot
We Begen the Loop
Use A Few Commands to move our plane
if upkey()=1 then up=up+1
position object 1,0,up,10
if downkey()=1 then up=up-1
position object 1,0,up,10
We use a command to detect if our plane has reached the Ground
if object position y(1)<-10
end
endif
And Finaly
We update Screen
Follow the white rabbit