[TteFAboB]

I don't know how to do it in Tactical Engagements, but to fly anything in any of the campaigns rename the ValidAC.bin file present in each campaign folder.

For instance, to fly A-10s in Korea, go to ...\Lead Pursuit\Battlefield Operations\Campaign\Korea and rename the ValidAC.bin file to anything else, like ValicAC1.bin or ValicACnot.bin, or inValidAC.bin, or allyourbasearebelongtoValidAC.bin. You get the idea.