Hercules dumping water
This is a standard C-130H belonging to the 302nd Airlift Wing, AF Reserve Command at Peterson AFB, Colorado. It is seen here dumping 8000 gallons of water onto the grass next to Fairford's main runway, as part of its display.
This unit is one of four who have in addition to their routine transport duties, the task of carrying the Modular Airborne Fire-Fighting Sysytem (MAFFS). The particular aircraft has no modifications. All of the fire-fighting equipment is palletized and will fit in any C-130.
More of:
This event (Air Tattoo 1999)
This aircraft type (c130)
Image #83