The USAF still operates (62) 2-engined UH-1Ns for ConUS ops... they are devoted to ferrying operational crews (and Security Tactical Response Teams) to/from isolated MinutemanIII ICBM silos, to ferry VIPS around Washington DC, and to fly basic utility and search and rescue missions at a handful of sites around the globe.
They
were planning to replace them with a new helo, but that got scrapped in the FY2012 budget, so they just got 3 from the USMC as attrition replacements and are overhauling them.
As the USMC's UH-1Ys are new-builds, the USAF is now expecting to take on a "significant number" of ex-USMC Twin Hueys in order to expand their "service helicopter" fleet.
The USMC is replacing their 100 UH-1Ns with "up to 160" UH-1Ys.
http://www.dodbuzz.com/2012/02/24/af...-from-marines/