AIRCRAFT SEE-THROUGH PROBLEM

hello, i am in need of help. i have a airplane i made in Gmax, and when i fly it in FSX and i go to locked spot right behind the airplane. i can see through the cockpit, its like there is a big hole in the front. but it is closed up.

Two possibilities that I can think of.
It's made for FS9 not FSX, or not for FSX Acceleration.

Or, your card isn't fast enough to handle the graphic intensive aircraft.
If it's the second, turn down some of your settings, get a newer card, clean the cards fan, it may be overheating.