Background
During the Vietnam War, aircraft conducted missions over Laos. On the day in question, an AC-47 gunship, call sign Spooky 21, was tasked with a daylight mission over southern Laos, searching for targets of opportunity. The aircraft took off from Đà Nẵng. The mission occurred a few hours before a Christmas bombing halt was due to take effect.
Incident
The aircraft was flying a few miles south of Ban Bac when a mayday call from Spooky 21 was heard by other aircraft in the area. Following this distress call, there was no further radio contact with the gunship. The aircraft and its crew were subsequently lost.
Aftermath
Decades later, in 1995, some debris from the aircraft was discovered in the vicinity. In 2010, additional findings included some human remains. The crew of Spooky 21 consisted of Maj Derrell Blackburn Jeffords, 1st Lt Dennis Lee Eilers, Maj Joseph Christiano, M/Sgt Larry C. Thornton, T/Sgt William Kevin Colwell, and S/Sgt Arden Keith Hassenger. No further information regarding the cause of the loss has been formally stated.