SYNOPSIS: The Lockheed C130 Hercules was one of the most versatile aircraft used in the Vietnam War because it served many purposes. Among them were: airborne command and control, weather reconnaissance, search/rescue/recovery, transport, tanker, gunship, drone controller and electronic reconnaissance. The US Marines employed the KC130F version, nicknamed the "Dasc" tanker, primarily as a probe-and-drogue refueling plane, although when the 70,000-gallon rubber fuel bladders were removed from the cargo compartment, the aircraft also served as a transport. The KC130F was capable of refueling two aircraft simultaneously.
On 1 February 1966, 1st Lt. Albert M. Prevost, pilot; Maj. Richard A. Alm, pilot; SSgt. Russell B. Luker, 1st mechanic; GSgt. Galen Humphrey, navigator; SSgt. Donald L. Coates, radio operator; and SSgt. Peter G. Vlahakos, flight engineer; comprised the crew of a KC130F (aircraft #804). The aircraft was conducting a "Dasc" tanker refueling mission for Navy and Marine F4B fighters enroute to bomb the major northern port city of Haiphong. Throughout the mission this aircraft was under direct radar control of the DaNang Control Center.
After the mission to refuel the strike aircraft was cancelled due to poor weather conditions in the target area, the tanker was returning to DaNang Airbase. At 1845 hours, as the aircraft neared Hon Co Island, known to American personnel as "Tigre Island," the crew "saw some unusual flashes on Tigre Island," and they were going to "make another pass to take a look-see." It was standard operating procedure for aircrews to investigate any unusual activity sighted when flying over enemy held territory. Since Tigre Island was believed to be uninhabited at the time, gathering intelligence about new activity on the island was vital. DaNang Control was not unduly alarmed when radio contact was broken.
At 1849 hours, the DaNang Control Center attempted to make radio contact with the tanker, but received no response. Shortly thereafter, the aircraft disappeared from DaNang's ground control radar. A search and rescue (SAR) operation was immediately launched. An extensive search of the water surrounding Tigre Island and the island itself failed to locate any trace of the aircraft and crew. At the time the formal search was terminated, and because the last known position of the tanker was over water, Richard Alm, Galen Humphrey, Peter Vlahakos, Albert Prevost, Donald Coates and Russell Luker were listed Killed in Action/Body Not Recovered.
Later US intelligence learned the NVA had secretly moved several radar-controlled 37mm anti-aircraft artillery (AAA) guns onto the island for the express purpose of trying to shoot down American aircraft that routinely flew over or near the island on their way to and from missions over mainland North Vietnam. Further, they determined this aircraft was lost due to direct enemy action.At the time of last contact, the tanker's location was approximately 48 miles east and slightly south of Dong Hoi, another major enemy port city, less than 10 miles north of Tigre Island and on a direct heading toward it. It was also 23 miles north of the demilitarized zone (DMZ), 105 miles north-northwest of DaNang in the Gulf of Tonkin adjacent to Quang Binh Province, North Vietnam.