I'm not sure whether these are cheats or just some programing errors, but I consider them cheats. This is one of the discoveries I found in Janes F-15:

When you are in the mission builder YOU can fly any plane in the list.

Make a new mission, edit a campiagn mission, etc. Choose the human plane (your plane) and choose a plane other than F-15 (eg. SU-27, Mig-29, etc.) when you fly the mission campaign or whatever, the cockpit will look like the F-15's, but press F8 (exterior view) and see the difference!!!

Note: My F-15 is version is 1.02F and I don't know whether it applies to newer versions.