An Air Force Reserve C-130 Hercules aircraft expels water during a capabilities demonstration April 23, 2012, here as part of annual Modular Airborne Fire Fighting System II certification. The training is held annually to ensure the military aircrew members and ground crews are prepared for the upcoming firefighting season. The U.S. Forest Service sponsored training was hosted by the Air Force Reserve's 302nd Airlift Wing. The MAFFS program is a joint U.S. Forest Service-Department of Defense effort, where the U.S. Forest Service supplies the MAFFS units, while the U.S. Air Force provides both aircraft and fully-qualified aircrews. Air Force Reserve MAFFS-equipped C-130s can be requested by the National Interagency Fire Center, then activated through U.S. Northern Command.
Wikipedia: Modular Airborne FireFighting System