Junkers Ju 287

From Wikipedia, the free encyclopedia

Ju 287
Type	Bomber prototype
Manufacturer	Junkers
Maiden flight	16 August 1944
Number built	2

The Junkers Ju 287 was a flying testbed built to develop the technology required for a multi-engined jet bomber aircraft. It was powered by four Junkers Jumo 004 engines, featured a revolutionary swept forward wing and was built largely from scavenged components from other aircraft. The flying prototype and an unfinished second prototype were captured by the Red Army in the closing stages of World War II and the design was further developed in the Soviet Union after the end of the war.

[edit] Development

The Ju 287 was intended to provide the Luftwaffe with a bomber that could avoid interception by outrunning enemy fighters. The swept-forward wing was suggested by the project's head designer, Dr Hans Wocke as a way of providing extra lift at low airspeeds - necessary because of the poor responsiveness of early turbojets at the vulnerable times of take-off and landing. The first prototype was intended to evaluate the concept, and was cobbled together from the fuselage of a Heinkel He 177, the tail of a Junkers Ju 388, main undercarriage from a Junkers Ju 352, and nosewheels taken from crashed B-24 Liberators. Two of the Jumo 004 engines were hung under the wings, with the other two mounted in nacelles added to the sides of the forward fuselage.

Flight tests began on 16 August 1944, with the aircraft displaying extremely good handling characteristics, as well as revealing some of the problems of the forward-swept wing under some flight conditions. Tests also suggested that the aircraft would benefit from concentrating more engine mass under the wings, a feature that was to be incorporated on the subsequent prototypes. These were to have been powered by Heinkel HeS 11 engines, but because of the development problems experienced with that motor, the BMW 003 was selected in its place. The second and third prototypes were to have six of these engines, the former with a cluster of three under each wing, the latter with two under each wing and one on each side of the fuselage, as the first prototype had. These machines were to have all-new, purpose designed fuselages, and the third prototype was also to carry armament and serve as the development aircraft for a production version.

Before the second prototype was complete, though, the Junkers factory was over-run. Wocke and his staff, along with the two prototype aircraft, were taken to the Soviet Union. There, the second prototype (returned to its original Junkers in-house designation, EF-131) was eventually finished and flown on 23 May 1947, but by that time, jet development had already overtaken the Ju 287. A final much-enlarged derivative, the OKB-1 EF 140 was tested in prototype form in 1949 but soon abandoned.