designed by Hans Wocke and Fritz Freytag, continued by Brunolff Baade after WWII
Junkers Ju287 (Final Design)
from Herwig/Rhode "Geheimprojekte der Luftwaffe I"
In 1942 the RLM asked Junkers for the development of a jet powered heavy bomber aircraft. The developement of the Ju 287 was started in autumn 1942 by Wocke. Due to aerodynamic reasons, Wocke decided to design the Ju287 with forward swept wings. Several experimental windchannel designs were developed to get conclusions about the wing design and the best positions for the jet engines:
Junkers Ju287 Design Studies
The first wind channel models were designated EF55 to EF59. The EF55 to EF57 seemed to be used for wing researches as they do not show any engines under wing or at the fuselage. The EF55 had forward swept wings, while the EF56 had positive swept wings. Also the EF56 was used for flap trials with large flap extensions, as they were needed for high speed aircraft. In October 1943 the EF57 was tested with positive swept wings again, which were folded at the outer wing areas.
Wing studies were continued with EF58, which got an elliptic forward swept wing form and EF59 with forward swept wing and nose flaps. Both wind channel models also show some engine mountings. The EF58 had classic under wing engines, while the EF59 had four engines, two under wing and two at the forward fuselage area. The EF59 of autumn 1943 was already a nearby of the later Ju287 design. However further wind channel models were used under the designator EF66 and later.
The wind channel models EF66 to EF68 were the next test steps toward the Ju 287 following the initial test series of the EF55 to EF59. Both models had already the forward swept wing, which Wocke find to be the best wing form for a larger jet aircraft. The major purpose of this test series was to find the best engine position. The EF66 combined the EF55 forward swept rectangle wing with the EF58 engine mounting under the wing. The EF68 got an engine pair at the fuselage. It seems as if this engines were movable, so that best position could be evaluated on this model.
The EF116 is a developement designator for the Junkers Ju287 of Spring 1943. This model was mainly used for evaluation of the possible forward and backward swept wings. No detailled fuselage or engines were used on this model
The final step to the Ju 287 was the EF 122 wind channel model. The EF122 seemed to be the accurate test model for the Ju287V1. Its nose section, the forward swept wings and the engine positions are exactly in the position of the V1.
The last EF model known for the Ju287 developement was the EF125. It seemed to be a model for the final Ju287 serial aircraft, but is just equipped with two Jumo 012 or BMW 018 engines. It has a forward swept span of 19,40 meters. It was the previous DFS125 design. The EF122 is very similar to the V3 and the later EF140 series.
Junkers Ju287-V1 Prototype
The above studying models were used to find the best wing design for multi engined jet aircraft. The Ju287-V1 was built to test the final wing design of the EF122. For getting quicker results, the Ju287 Prototype was built with components of several existing aircraft types. The fuselage was taken from a Heinkel He 177A-3, the tail was taken from the Junkers Ju188G-2, while the undercarriage came from an American Liberator bomber, which was captured over Germany. Two Jumo 004 engines were mounted under the rear wing, while a further two were placed at the forward fuselage near the cockpit section. When the Ju287V1 prototype was ready, it was transported to Leipzig-Brandis, as the runways at Dessau were to short for take off. On August, 16th 1944 Siegfried Holzbaur performed the first flight with Ju287V1 at Leipzig. The flight tests were satisfying and they proofed the forward swept wing design. Several tests were also performed with HWK-502 starter rockets, which should reduce the take off runway. Parachutes were used to reduce the aircraft speed after touch down. A total of six preseries Ju287 were planned:
Developement of the EF122/Ju287
up to the EF152 Passenger Airliner of 1955
While the second prototype was under construction, the RLM advised Junkers to stop the developement work of the Ju287 in advance of the "Fighter Program". But in March 1945 the program was relaunched by the RLM and a request for a serial production of 100 aircraft per month was placed. The serial production for these aircraft should have been performed by Allgemeine Transportanlagen GmbH at Leipzig and the serial aircraft should have been equipped with the Jumo 012.
The Ju287V1 was destroyed during the occupation phase of the Soviet forces in April 1945. But at Dessau the Soviets continued the construction of the V2 and V3, which were flown in summer 1945. Baade continued the developement of the Ju287 under Soviet leadership. In Dessau the EF131 was designed, which was ready for its first flight in August 1946. But before the first flight was performed, the Soviets transfered all developement and test work to Podberesje in Russia in September 1946. The first flight was performed by the German testpilot Paul Jugle on 23.05.1947 at Stakhanovo airfield in Russia. In June 1948 the Soviets advised the German team to stop further developement of the EF131. A second prototype was already under construction in Russia, but was later scrapped and used for the construction of the EF140.
The EF132 was also a developement, which was already started and of which a mockup was already built at Dessau. In contrast to the original Ju287, the EF132 had a back swept wing. The cockpit section was similar to that of the Ju288. The six jet engines were integrated within the wing structure. This design later became typical for Russian aircraft designs. But the EF132 programme was stopped before the construction of a prototype began. The EF132 was the Final Junkers-Dessau developement.
Soviet built Junkers EF140R Surveyer Aircraft
The experience of the Junkers engineering and the basic Ju287 design was used at Podberesje for further developements through the following years. The EF140 was based on the EF131. The EF131V1 prototype was converted and got two Soviet Mikulin AM2 engines. The first flight was performed on 30.09.1948 and the EF140 was further developed as a reconaissance aircraft under the designator I40-R. Due to severe vibration problems, the EF140 design was later abandoned. Further developement steps at Podberesje are not documented, but the final work of the Junkers working group at Podberesje was the EF150, which became available in May 1951. This aircraft had a back swept wing, a T-tail unit, a tandem center undercarriage with supporting wheels at the wing tips and two Soviet Ljulka AL-5 engines. Two prototypes of the EF150 were built and flown in 1951/52. Nevertheless, the Tupolew Tu-16 was put into serial production instead of the EF150. The EF150 finally marked the end of a developement line in Russia, which had been started in 1944 with the Ju287. Between 1950 and 1953 most of the Junkers employees at Podberesje returned to Germany.
But still yet in Germany, some aircraft designs were influenced by the Ju287 design. Baade returned to the German Democratic Republic in 1953. Here he became responsible for the developement of Germany's first jet airliner at Dresden, which was later named Baade 152. Of course this aircraft did not have much similarity with the Ju287, but a lot of design features were directly taken from the EF150.
Hans Wocke moved to West Germany and became the responsible design engineer at Hamburger Flugzeugbau. Here he designed the HFB320 business jet, which was characterized by its forward swept wing. This wing design of course was directly influenced by the Ju287 design, which Wocke had started at Dessau in 1944 and which was continued 20 years later with the HFB320.
More information upon Ju 287 at the WWW:
Technika WojskowaJunkers Ju287 (extensive Czech text, lots of photos)
Unsere Luftwaffe (text, images of Ju287)
Luftwaffe Resource Page (Scott Rose, data, description, interesting images)
Secret Weapons of the Luftwaffe (interesting Ju287 images)
Luft'46 (Dan Johnson, detailled EF132 review, images and detailled data)
152Homepage, EF131, EF132 by Frank Manke, infos, images, FS models about the final (EF)152
Aeronautics.ru (Sukhoi S37 History with interesting reference to EF models)
Russian Airpower (in Russian with Ju287, EF140 images)
Air+Space (Developement of the Aerospace Industry in GDR)