For the first one, its set in the world created by Chris Wooding, whos first book was Retribution falls, set on the world of Vardia. I would be the pilot of a V-22 tilt rotor, with ten marine recon soldiers in the back which is somehow sent from Earth, to Vardia, where they encounter the Century knights, and have to adapt to a new world, with no way to return home, adjusting to a world thats more steampunk than modern.
The second one is where the same event happens, but my V-22 goes through an invisible crack between realities just over New York, and we find ourselves on a parallel earth,again, to adapt with no way home.
If either of these two appeal, let me know.