"A B-29 assigned to the 581st Air Resupply Squadron, 580th Air Resupply and Communications Wing (ARCW), based at Mountain Home AFB, Idaho, conducted trials at Eglin AFB, during the summer of 1951 to determine if the aircraft could be used to extract personnel utilizing the prototype Personnel Pickup Ground Station extraction system. The test aircraft was modified with a 48-inch diameter opening in place of the aft-belly turret and with an elongated tailhook at the rear of the aircraft. The system was similar to the one adopted in 1952 by Fifth Air Force for the C-47 Skytrains of the Special Air Missions detachment in Korea. The tests proved technically feasible, but the project was dropped for the B-29 aircraft due to aircraft size and safety considerations of flying it so close to the ground."