Flight simulation HELP!!

Thank you for all your help, guys!! The engine sound and flying stopped after the crash to the ground, but it didn't do that to the barn nor to the windmill. I changed the radius of both the barn and the windmill. Instead of using a number, I used the object's depth + 2 and IT WORKED!! I can't get my effects to work (the smoke and all), but I'm happy with how it is now.

Also, when the plane crashes to the barn or the windmill, I've put "plane move down [biplane distance to ground]", but it gets burried under the ground. I'll play around with it...if you have any suggestions, that would also be very much appreciated.

I will post the working world now in case someone out there also goes through the same problem as I did. Thank you so much!