and 54th, flying the Piasecki H-21, were assigned to the Eighteenth Air Force in 1956 and 1957. Their mission was for the purpose of providing the US Army with air support in a fashion similar to the TAC Troop Carrier Squadrons. The Army, however, declined all support from the Air Force helicopters, and the 21st/54th Helicopter Squadron turned to flying airlift support, search and recovery missions, and also cooperated with a communications group in an experiment to lay communications lines by helicopter. Prior to inactivation, the unit flew photo, airlift, and radiological survey missions during atomic testing at the Nevada Test Site. Military Air Transport Service A realignment of Troop Carrier forces in 1957 led to the Eighteenth Air Force's C-124 wings being reassigned to the Military Air Transport Service (MATS). The command's headquarters was also moved to Connally AFB, Texas on 1 September 1957 when Donaldson AFB was turned over to MATS along with the C-124s and 63d TCW assigned there. MATS C-124s from Donaldson flew the large aircraft all over the globe. Large hangars and expansive ramps were constructed to support these sizeable machines; the base became known as the "Troop Carrier Capital of the World". 1958 Lebanon crisis In 1958 the Eisenhower Administration received an urgent call for assistance from the Middle East. The government of Lebanon was being threatened with attack. Sorely needed troops and supplies had to be airlifted to Lebanon as soon as possible, and it also had to be done without public knowledge, so as not to inform a possible enemy of the deployment of US troops. A task force of 36 MATS C-124s, with a significant number from the 63d TCW based at Donaldson were dispatched from the United States to Rhein-Main Air Base, West Germany to assist in the airlift, deploying Army and Marine units along with their weapons and equipment to Beirut. 1958 Taiwan Strait Crisis Also in 1958 the Chinese Communists were shelling Quemoy and threatening Matsu. These tiny islands in the Straits of Formosa are the closest Nationalist Chinese territory to the mainland of China. By using heavy artillery fire, the Communists appeared to be softening up the islands in preparation for invasion. Tactical Air Command was ordered to organize and send a Composite Air Strike Force to Formosa (now Taiwan). C-124s, some from the 63d TCW at Donaldson, transported F-104 Starfighter aircraft from Hamilton AFB, California along