The rescue of Bat 21 Bravo, the call sign for Iceal "Gene" Hambleton, from behind North Vietnamese lines was the "largest, longest, and most complex search-and-rescue" operation during the Vietnam War.
On April 2, 1972, the Easter Offensive, the largest combined arms operation of the entire Vietnam War, was in its third day. An early morning flight of two United States Air Force EB-66 aircraft was led by Bat 20, piloted by Lt. Col. Robert Singletary. Hambleton was a navigator aboard Bat 21. The two aircraft were escorting a cell of three B-52s. Bat 21 was configured to gather signals intelligence, including identifying North Vietnamese anti-aircraft radar installations to enable jamming. Bat 21 was destroyed by an SA-2 surface-to-air missile and Hambleton was the only survivor, parachuting behind the front lines into a battlefield filled with thousands of North Vietnamese Army soldiers.
Hambleton had Top Secret access to Strategic Air Command operations and was an expert in surface-to-air missile countermeasures. The North Vietnamese Army may have possessed information about his presence in Vietnam and his capture would have meant a huge intelligence bonanza for the Soviet Union.