Frankly, for the type of wars we're likely to fight in the foreseeable future, the most common mission would call for something like a cheap prop-driven plane with a ton of ordnance hardpoints. Take the flight surfaces off, stuff 3-4 of them into a C-17 and fly them to the theater of operations, go to work.
Pilot here. The aviator community loves pretty much anything that flies and won't get us killed doing it. :)
The role you're describing is currently filled - very well, I might add, by the A-10. It can fly low and slow (has a stall speed of right around 140mph), it's heavily armored and can carry massive amounts of armament. Not to mention an enormous gun that can decimate pretty much anything in its path.
They're slated for retirement soon, though. Long term, I think this role will eventually be filled by drones.
I'm not 100% sold on drones. Yes, they work, they're cheap, and they don't expose squishy & expensive pilots to danger. But even with frequency-agile radios, they're vulnerable to jamming and ASAT missiles taking out important stuff in orbit.
I was expecting someone to jump in with the dog-fight argument against using low & slow aircraft. Unlike in Vietnam, today's missiles are reliable and effective, so even a prop plane can engage and defeat a jet at extended ranges... as long as positive hostile ID can be made early enough.
AC-130 is significantly more of a sitting duck to infantry-deployable surface to air missiles. They have to be fairly low and fly in slow circles with the broadside facing the target. It would be hard to imagine a better missile target. One was shot down in the gulf war by one such infantryman/SAM and all 14 crew were killed. A-10s can loiter and provide extended ground support, but can come in/leave quickly, maneuver well, use terrain to hide from ground fire, etc.
I agree with you, but the original description was that of a cargo plane turned into an assault platform. I was assuming the intention was creating something more along the lines of the Flying Fortress, but the AC-130 was the closest thing I could think of that's still in service.
