The rescue of Bat 21 Bravo, the call sign for Iceal "Gene" Hambleton, a navigator aboard an EB-66 aircraft shot down behind North Vietnamese lines, was the "largest, longest, and most complex search-and-rescue" operation during the Vietnam War. Five additional aircraft were shot down during rescue attempts, directly resulting in the deaths of 11 airmen, the capture of two others, and another airman trying to evade capture.

Iceal Eugene "Gene" Hambleton was a career United States Air Force navigator who was shot down over South Vietnam during the 1972 Easter Offensive. He was aboard an EB-66 aircraft whose call sign was Bat 21. As the ranking navigator/EWO on the aircraft, he was seated immediately behind the pilot, giving him the call sign "Bat 21 Bravo". He survived for 11+1⁄2 days behind enemy lines until he was retrieved in a ground operation. His rescue was the longest and most costly search and rescue mission during the entire Vietnam War. He received the Silver Star, the Distinguished Flying Cross, the Air Medal, the Meritorious Service Medal and a Purple Heart during his career.