Curtiss-Wright C-76 Caravan

under C-76 Caravan's wing at Curtiss-Wright in 1943. In 1941, Curtiss-Wright was contracted by the United States Army Air Forces to design and construct an all-wood military transport aircraft, with performance specifications meeting or exceeding that of the Douglas C-47 Skytrain then in service. The Curtiss-Wright CW-27 was designed by Curtiss-Wright's chief designer George A. Page, Jr. as a high-wing, twin-engine, cargo transport aircraft, utilizing plywood construction with a tricycle undercarriage. Though the British de Havilland Mosquito had successfully employed a ply construction using a balsa wood core and birch hardwood exterior, Curtiss-Wright engineers, using research provided by Forest Products Laboratory, rejected this approach, insisting instead on a ply construction of dense mahogany, which greatly increased the plane's weight. At Curtiss' request, Army Materiel Command laid in large supplies of mahogany, and a number of furniture manufacturers, including the Baldwin Piano Company, were subcontracted to build components for the aircraft, which would be assembled at Curtiss-Wright's new defense plant in Louisville, Kentucky. The original contract called for 11 YC-76 preproduction aircraft, and the first aircraft would be built and tested at Curtiss-Wright's St. Louis, Missouri Division plant. To keep the plywood flexible during construction the factory was kept hot and damp. The prototype YC-76 first flew on 1 May 1943. Only five production aircraft were completed in 1943: three from Curtiss-Wright's St. Louis Division, and two from a new plant at Louisville, Kentucky, which was finished in May 1942. The Higgins Aircraft Co. contract was cancelled by the Army on 3 August 1943 before the Higgins factory in New Orleans had been completed, and Higgins was awarded another contract to produce the C-46 Commando. ==Operational history==

The first flight of the YC-76 prototype took place on 3 May 1943. It was discovered in testing that the C-76 was unstable when not carrying a cargo load; in order to obtain a stable center of gravity, the plane had to be ballasted beyond its maximum permissible gross takeoff weight. The wing failures were attributed by some sources to the failure of the fasteners used to secure the wood components of the aircraft. As war priority measures designed to increase aluminum production proved successful, the feared shortage of light alloys never materialized. The Sara Clark Collection, National Archives, Record Group 342, Box 2719, document the disposition of the 25 YC-76 aircraft as Articles #1, #3, # 4, and #5 were placed in the "Z" category, ZC-76, due to the poor gluing conditions and assembly procedures by subcontractors found through a Material Division inspection of the subcontractors work. These aircraft were assigned to the Technical Training Command and used for ground purposes only. Article #2 was destroyed in static testing at Wright Field. Article #6 was lost in a crash. Article #9 was under repair, but repairs were stopped and the airplane placed in Class 26, non-operational status. Air Service Command operated 12 YC-76s on a service test basis for nine months and found that they required excessive man hours to maintain. It was suggested that these be placed into Class 26 or Survey. The final disposition of the aircraft as of 1 October 1945, by letter of the Air Technical Service Command; 1-Washout upon delivery from factory, 5-Class 26, 10-Survey, 1-Condemned, 8-Reconstruction Finance Corp. to be sold as surplus. In the interim, the Curtiss-Wright plants at Buffalo, New York and Louisville, Kentucky went over to full production of the Curtiss C-46 Commando. USAAF Materiel Command later estimated the entire C-76 project cost the U.S. government $400 million and several months in lost production time. ==Variants==

;YC-76 :Prototypes, 11 built. ;C-76 :Production aircraft built at St Louis, five built. ;YC-76A :Production variant, nine built. ;C-76A :Production variant, order for 175 cancelled, none built. ==Specification==