"In reality, they operated as members of the USAF Circuit Rider teams from the 1st Mobile Communications Group based at Udorn Royal Thai Air Force Base who rotated to the site every seven days.Personnel working at the TACAN site were supplied by weekly flights of the 20th Special Operations Squadron, based at Udorn RTAFB in northeastern Thailand operating under the code name Operation Pony Express, using Lima Site 85, the airstrip constructed by the Central Intelligence Agency (CIA) in the valley below.