After the Korean War ended and the B-29 and B-36 bombers were retired, the United States Air Force no longer had an aircraft that could drop the M-121, and the bombs were put in storage. Production of the T-10 ended in 1955. The B-36 was the last operational aircraft that could drop a fully assembled Tallboy type bomb in the conventional way. During the Vietnam War, some M-121s, minus their rear streamlined shrouds and tail fin assemblies, were shipped to Vietnam for Commando Vault missions where the warheads were incorporated into the BLU-82 weapons dropped by C-130s using radar control in order to clear a helicopter landing zone. The warheads were mounted on a platform and pulled by parachutes from the rear-loading ramp of C-130s. After clearing the aircraft the large extraction chutes and pallets were cut away and small triangular chutes stabilized the large warhead until impact. A three-foot nose probe detonated the bomb at the correct stand-off distance. One of the last of the World War II Tallboy designs was dropped during a Commando Vault mission to clear a landing zone for helicopters on a ridge during the 1969 Battle of Hamburger Hill in Vietnam. Dropping from , the bomb hit exactly where it was needed. The Commando Vault missions were more accurate in bomb delivery on target than the more modern B-52s.