I tried it quite a few years ago (before digital cameras were common), but didn't have very good luck.  I fly 'giant scale' aircraft (6-8 ft. wingspan) and mounted a Nikon EM 35mm with standard f1.8 / 50mm lens and an auto-winder inside the plane with the lens pointing down through the bottom of the plane.  The big planes handled the camera weight very well (just make sure you don't throw your CG way off).  A separate servo operated the shutter release.

A couple of the problems encountered were engine vibration (fuzzy pics), exhaust residue on the lens (fuzzy pics).  Engine vibration was overcome by shutting down the engine when you get high enough and then glide through your pictures and hopefully back to the landing strip.  The exhaust residue from glow engines is really a guncky crap and gas/oil burners weren't much better.  I channeled the exhaust away as best I could, but still picked up spects of crap on the lens.  Perhaps a different camera location would have been better.  (point the len up and fly inverted may have worked better for my plane, but too much work to change).

I'm more of a perfectionist when it comes to doing stuff like that, so I was unsatisfied with the outcome.  If I want to see my crop from the air, I know several pilots that will oblige me on a nice Sunday afternoon.

Could probably be perfected if you want to invest the time.  Good luck.