Remember those ....... just recently there was a proposal to bring em back.
http://4.bp.blogspot.com/_8DAL7gPYBiM/TU4WybaTy5I/AAAAAAAAAvI/BWqYySw6Z-4/s1600/ACH-47A.jpg
Maybe the CV-22 the next generation of tiltroters can provide such a platform.
Sort of a CV-22 with ...1 each GAU-19B’s on each side and one on the back ramp with a 25mm Chain gun on the chin slaved to the pilots helmet like the apache or cobra gunships add 2 more side gunners positions with M134DT’s. 5 gunners and the pilots 25mm would be pretty good firepower for a CSAR rig ..... sort of like the old MH53 Jolly Greens possibly.
3 of those in a rescue package would be impressive.
Stay Safe !