OKB-1 EF 126

OKB-1 EF 126
Type:	Experimental attack aircraft
Design country:	German Empire / Soviet Union
Manufacturer:	Junkers / OKB-1
First flight:	May 21, 1946 (without drive) March 16, 1947 (with drive)
Commissioning:	-
Production time:	October 1945 - June 1946
Number of pieces:	5 prototypes

The OKB-1 EF 126 was a German attack aircraft with pulso drive . The project planning work originally carried out to create a fighter aircraft began in the final phase of the Second World War at Junkers in Dessau . After the development work was initially interrupted by the end of the war in Europe , it was continued and completed by a German specialist group under Soviet supervision, and the aircraft was then briefly in the Soviet zone of occupationtried. The actual test flights took place in the Soviet Union. A series production did not take place.

prehistory

The EF 126 was part of a series of projects to create aircraft that were easy to produce and easy to use, mass-produced and intended to help turn the war that was unfavorable for Germany. Up until the end of the fighting, however, she had only made architectural drawings. Then US troops occupied the Dessau Junkers factory and subsequently confiscated all plans and documents that they could get hold of. After their departure and the transfer of the city under Soviet control on July 1, 1945, there were not many of the original drawings of the various projects, but in this situation the former head of the Junkers test department, Brunolf Baade , with the help of former employees, offered missing ones To recap documents for the Soviet occupying power. This recognized the favorable opportunity and ordered the establishment of a "Special Technical Office 1" (Ossoboje technitscheskoje bjuro, OTB), in which the activities should be bundled. Further former Junkers employees could be conscripted and on April 17, 1946 the name was changed to OKB-1, which was divided into an aircraft and an engine development group and whose workforce comprised a total of 2,992 employees, including 20 members of the Ministry of Aviation Industry of the USSR ( MAP). Brunolf Baade took over the management of the aircraft department, and Dr. Disc responsible. The military commissioner Nikolai Olechnowitsch, previously a research assistant at the Central Institute for Aircraft Engines, was appointed director . Two days later, the Minister for the Aviation Industry, Mikhail Khrunichev, issued Order No. 228 on “the use of German engine technology and German specialists”. This instructed Baade's group to continue the development of the EF 132 , EF 131 and EF 126 projects and, in the case of the latter two, to conclude with the construction of test samples. After completion of production, the EF 126 was to be transferred to the Soviet Union in May / June 1946, along with subsequent testing. Only one project study was to be carried out for the six-engined long-range bomber EF 132. It is no longer possible to understand why the EF 126, which was actually designed as a fighter, was intended for use as an attack aircraft. Baade probably tried to make the design more interesting for the Soviet side in this way, fearing that the project would not be approved due to the large number of similar studies or existing types.

The EF 126 was to be equipped with a Jumo 226 pulse engine, which had been in development as As 044 since 1944. Now the department working in the Otto Mader factory in Dessau under Manfred Gerlach received the order to build and test the unit.

construction

The design of the EF 126 was based closely on the Fi 103 winged bullet . Similarities were the relatively short trapezoidal wing and the arrangement of the Argus thrust tube over the rear fuselage. The use of a vertical stabilizer on two end plates to the right and left of the horizontal stabilizer was new. In contrast to the cabin of the already existing manned version of the Fi 103 ( Reichenberg device ), which was located directly under the entrance of the thrust tube, the bubble-shaped hood was moved further forward. An extendable runner served as the chassis. The EF 126 was supposed to start either with the help of the aircraft tow or under its own power with the support of start-up missiles . Two 20 mm automatic cannons were provided in the bow as armament.

Construction and testing

After the production of the EF 126 had been demanded by a ministerial resolution, at a management meeting on October 1, 1945, factory director Olechnowitsch gave Baade the order to produce five test samples by February next year. Despite the simple structure of the aircraft, this appointment could not be kept. In January 1946, the construction of the first dummy was completed, in May the first machine was ready for testing. The remaining four prototypes were completed by the end of June. The tests with the EF 126 V1 began on May 21, 1946 in Dessau in a sliding tow behind a Ju 88 . While the first flight was still carried out satisfactorily, the next one disaster occurred on the same day. The German pilot Hans-Joachim Matthies, a former Junkers works pilot, intercepted the aircraft too strongly, so that after the first touchdown it ricocheted off the ground and after about 100 m with a steep bank angle touched the ground again, whereby the right wing came loose , the plane overturned and broke. Matthes was killed in the process.

Although the accident was due to a pilot's error, the remaining four aircraft had to be revised, which was done, among other things, by changing the wing profile. Testing was then resumed in the summer of 1946. Around the same time, a Soviet delegation from the MAP under the direction of the designer Alexander Jakowlew visited the Dessau OKB-1 to find out about the status of the work. It certified that the EF 126 was unsuitable as an attack aircraft due to its light, non-armored design, weak armament and limited range due to the low fuel supply. Nevertheless, it was decided to continue the experiments, but this time in the USSR. In September 1946 the planes were dismantled and shipped. In addition, a Ju 88 was equipped for tests with a Jumo 226 under the wing and transferred by a German crew. This combination was tested for the first time on December 31, 1946, and around 30 more tests are expected to be carried out next year.

These broadcasts were made as a prelude to Aktion Ossawakim , the sending of German specialists and their relatives to the Soviet Union. The OKB-1 itself was housed during this operation in October 1946 on the site of the former aircraft factory No. 458 on the Ivankovo ​​reservoir north of Moscow. Since this was damaged by bombing during the war and the reconstruction was not yet completed when the Dessau employees arrived, the tests with the EF 126 could not be resumed until the following spring.

The flights began, as already practiced in Germany, in the sliding tow of a Ju 88 and were satisfactory. The first flight with activated propulsion was made by the EF 126 V5 on March 16, 1947 and lasted about 30 minutes. The tests were so successful that the Soviets considered taking three EF 126s in the traditional Tushino air parade, but ultimately the date for August 18 could not be kept. For example, the restrictions that the reconstruction of the plant, which dragged on until the end of 1947, also had consequences for the test program. Another point was the lack of reliability of the engines, whose number of operating hours was only about 15 hours instead of the required 40. These impairments ensured that only twelve flights with a total flight time of 3 hours 15 minutes were carried out during the whole of 1947. A corresponding instruction ensured that the flights were terminated in October 1947. The test samples were parked in the open and were exposed to the onset of cold spells without protection, which is why all rubber cables and electronic components had to be replaced in the following spring. Since interest in the EF 126 had already waned, only a few more ground tests were carried out in May 1948 and the program was officially discontinued on June 21, 1948.

Technical specifications

Performance data calculated
Conception	Light attack aircraft
Constructor (s)	Brunolf Baade
Construction year	1946
crew	1
span	6.85 m
length	8.33 m
Wing area	8.93 m²
Preparation mass	1420 kg
Takeoff mass	2760 kg
drive	a Jumo 226 pulse engine (Argus As 044)
power	4.9 kN each
Top speed	780 km / h
Landing speed	185 km / h
Service ceiling	7200 m
Range	320 km
Armament	two 20 mm MK

literature

• Reinhard Müller: Brunolf Baade and the aviation industry of the GDR . Sutton, Erfurt 2010, ISBN 978-3-86680-721-1 .
• Dimitri Alexejewitsch Sobolew: German traces in Soviet aviation history . The participation of German companies and professionals in aviation development in the USSR. Mittler, Hamburg 2000, ISBN 3-8132-0675-0 .

Individual evidence

1. ^ Lew P. Berne: Mikulin and the "Baade" bomber. In: Flieger Revue Extra. No. 18, Möller, Berlin 2007, ISSN  0941-889X , p. 28