The Junkers Ju 252 was one of a number of aircraft designed in an attempt to replace the aging Ju 52/3m, but only a small number were produced, and for most of the Second World War the Luftwaffe was left without a modern transport aircraft.
The Ju 252 had the same general layout as the Ju 52/3m, including its three engines, one under each wing and one in the nose. The corrugated skin of the older aircraft was replaced with a smooth skin. The new aircraft had retractable undercarriage, and a pressurized cabin.
The most impressive feature of the Ju 252 was the Trapoklappe hydraulic rear loading ramp. When this ramp was lowered it raised the back of the aircraft, making the cargo floor level. Small vehicles could then easily drive up the ramp and be stowed inside the aircraft. It also made it easier to drop parachute retarded cargos from the aircraft, and was a great improvement on the cargo handling capabilities of the Douglas Dakota.
Work on the first three prototypes began in July 1940. They were powered by three 1,340hp Junkers Jumo 211F liquid-cooled engines, and could carry up to twenty one passengers. The V1 made its maiden flight in October 1941, followed early in 1942 by V2 and V3.
Originally twenty five Ju 252s had been ordered by Lufthansa, but by the start of 1942 the Luftwaffe urgently needed new aircraft. The V4 was built as a military prototype, and was armed with a single 13mm MG 131 machine gun carried in a power-operated gun turret mounted above and behind the pilot's cabin.
The Ju 252 didn't impress in service tests, and after work had begun on eleven aircraft the project was cancelled. The eleven aircraft were completed as the Ju 252A-1, although with prototype designations. All fifteen aircraft had been built by the end of 1942. The Allies first gained knowledge of the aircraft after a reconnaissance flight over the Rechlin testing grounds on 28 June 1943.
A number of alternative versions of the Ju 252 were proposed but never built. The Ju 252B was to have carried more guns. The Ju 252C was to have been powered by Bramo 323 radial engines. The Ju 252D was to have been given floats.
The aircraft that were built were used by Transportstaffel 5 as normal transport aircraft, and by I/KG 200 for covert missions, including agent drops.
Engine: Three Jumo 211J engines
Power: 1,400hp each
Wing span: 111ft 10 1/3in (34.09m)
Length: 82ft 4 1/4in (24.1m)
Empty weight: 28,885lb
Loaded weight: 48,510lb
Max Speed: 273mph at 19,686ft
Cruising Speed: 260mph at 18,801ft
Service Ceiling: 22,674ft
Range: 2,485 miles (normal), 4,101 miles (maximum)