The Raven forward air controllers provided crucial support to the Laotian forces in the fight against the communist Pathet Lao and North Vietnamese attempts to take control of large parts of Laos, particularly the Plain of Jars in the north of the country and the Southern Panhandle through which ran parts of the Ho Chi Minh Trail. Although strike aircraft flying missions against enemy forces in Laos were based mainly in Thailand, South Vietnam and US Navy aircraft carriers, forward air controllers were needed to be based closer to the combat zone but politically it was not possible to establish an overt American military presence in Laos itself. A way around this problem was to send a small number of USAF pilots to Laos ostensibly working as civilians under a highly classified covert programme called Steve Canyon. The pilots did not wear military uniform (although they carried military ID) and, initially, they flew aircraft borrowed from the Royal Lao Air Force or Air America but later USAF aircraft were supplied, primarily the O-1 Bird Dog, the U-17 Skywagon and the T-28 Trojan. Usually the aircraft carried no markings and wore bogus serial numbers. The Steve Canyon programme was born out of a very small-scale project which started in May 1966 with just three non-commissioned FAC pilots who used the radio call sign Butterfly. The programme expanded gradually and in September 1967 the radio call sign was changed to Raven, the name which became familiar from then on. Administratively the Ravens pilots later came under the 56th SOW’s Detachment 1 based at Udorn but operationally they had a number of ‘masters’ including the US Ambassador and Air Attaché in Vientiane, the CIA, and Hmong Generals. The Ravens operated out of five forward airfields: Pakse and Savannakhet in the Southern Panhandle; Long Tien near the Plain of Jars; Luang Prabang further north and Wattay airfield at the capital Vientiane. However they also operated from small airstrips throughout the country. The majority of the Raven FACs operated out of Long Tien in support of General Vang Pao’s indigenous force of Hmong (or Meo) tribesmen. The observers carried by the Ravens were often Hmong or Laotian officers. A total of 177 pilots have been identified serving as Raven FACs between 1968 to 1972 with 23 being killed during that period. Due to the highly classified nature of their operations, information about Raven losses is often vague and sometimes contradictory.