DF-107 - Dong Feng / East Wind fighter
The East Wind 107 project began with the "East Wind 104". In March 1958, with Soviet expert's help, China proposed to indedpendently develop one kind of light frontline fighter plane, with a top speed of about Mach 1.4. In May and June 1958, the design team started inquiries into improving the DF-104 design speed. In August 1958, the aircraft industry administrative bureau held the technical meeting, at the meeting proposed surpassed the world advanced level the design program, resolved that the DF-104 the design goal should be improved to Mach l.8 with a ceiling of 20,000 meters. This new model was designated "East Wind 107".
On August 6~15, 1958, the aircraft industry technical meeting convened in Shenyang. This was after JJ-1 test flight success. They planned an ideological mobilization of the population to independently design in the broad technical aeronautics field. Simultaneously the meeting proposed to surpasses the world advanced level the design program, resolved that improves the east wind 104 design indices to the Mach number 1.8, the ceiling 20000 meters, the new model is called east wind 107. The DF-107 planned to use two new research and development elements: the "Red Flag 2" jet engines, and in the entire design to refer to American Chance-Vought Fort Worth company's F-8 "Crusader" ship-borne fighter, including the F-8's variable incidence wing.
The DF-107 technical advisory work carried on about 8 months, and in September 1958 it was finished. In the consultation it was detected that the design proposal had significant technical questions, mainly that the maximum speed cannot be achieved. The drag had been under estimated because the of the angle of attack of the variable wing intensity. The aircraft performance could not meet the predetermined requirements. Moreover, more importantly, the Soviet Union continually criticized the side mounted air ducts that had already been used in the in JJ-1. The Soviets said that an aircraft length smaller than 20 meters was not suitable for side mounted air ducts. The led the DF-107 to change from the side mounted air ducts and drop the variable angle of attack wing. This corresponded with an enlargement of the design of the RD-9B the engine that was the foundation the Red Flag 2 engines. This was the situation after the June 1958 report of the aviation industry bureau. In August 1958, the DF-107 pre-designs were basically complete.
When the DF-113 fighter plane plan examining committee convened, management's representative proposed that to avoid a dispersion of energy, the Mach 2.5 DF-113 and Mach 2.0 DF-107 programs merge to do research on a single Mach l.8 fighter plane. This evoked the intense discussion at the meeting, which finally approved both projects. After the meeting, Chen Geng opposes this matter, thinking that "to do both two, would also do them inadequately. Can do one advanced only, should not do backwardness". This opinion was accepted by Peng Dehuai, who cancelled the original meeting conclusion. Therefore in October 1958 the central report mentioned only the DF-113.
Although the Minister of the First Ministry of Machine Building authorized the aviation industry bureau to stop the trial production of the DF-107, but the design modification work still continued. The engine's experimental work also continued to carry on. Since the DF-107 plans had already started and had made certain progress, if it were suspended as a result of the DF-113, it would be rather a pity. Although therefore holds the examining committee once more which manages by air force Commander Liu Yalou, at the meeting has the argument, but the conclusion was agreed the DF-107 would continue trial production, and this was authorized by the national aviation trial production group's name. This resolution caused the DF-107 design teams to dance with joy, as a result of its early preparatory work development, therefore as soon as authorized by the higher command, the experimental work comprehensively unfolded, the very quick blueprint originating comprehensively and starting the experimental work.
The experimental work unfolded comprehensively, and very quickly the blueprint were completed and and the experimental work started. In December 1958, the Shenyang aircraft design office basically completed the DF-107 working drawing designs. In January 1959 the DF-107 trial production blueprints were completed.
Subsequently, in accord with the technical assistance protocol, the Soviets decided on 27 February 1959 to review the design. Led by aviation industry bureau Assistant Commissioner Xu Changyu, the designers brought the DF-107 blueprint information to consult with the Soviets. At the same time, they also took the DF-107 models to the Soviet Union. The original DF-107 was the first Chinese fighter plane which had not only high measures of performance but also used many new technologies. Therefore China wanted to keep it strictly secret from the Soviets, to avoid the Soviet Union knowing China's new model.
The Soviets detected the existence of a major issue in the design proposal, that the angle of attack of the variable wing was unstable, the drag estimates were too low, and the design cannot meet the performance requirements. In February-May 1959, the aircraft design office modified the blueprint examination. In May 1959, the office modified the DF-107 blueprint into the DF-107A, which cancelled the variable angle of attack wing design, changed the fixed high delta wing, but preserved the side mounted air ducts. After the modification the aircraft needed wind tunnel testing, however at that time China had only the HK-2 transonic wind tunnel which had been imported from East Germany.
In August 1959, by authorization, DF-107 experimental work stopped. In September 1959 the office designed DF-107Z tactic reconnaissance aircraft according to the factory party committee's resolution, simultaneously with the DF-107A testing machine. Later there were designed transition plans, so the DF-107J ground attack trainer aircraft was not put into trial production. By October 1959 the aircraft's expected use of the Red Flag 2 engines faced difficulty according to the plan. The aircraft design office modified the design to the DF-107S, to change to the Soviet RD-9B engine (used in the Mig-19 / J-6). The DF-107 made a full size wooden model, and then stopped the development.
The plan was postponed repeatedly, the most basic reason being the design's requirements were a very great distance from China's aircraft industry's existing technology and craft production.
Of the many novel technology used for the DF-107 was a variable angle of attack wing design similar to the F-8 Crusader or some of the Mikoyan Ye-series fighter prototypes. Otherwise this fighter closely resembles a twin engined Starfighter fuselage with a standard tail and sharply ranked wings. The two engines were to be fed by two lateral air intakes and seem to have been much improved and up-rated engines derived from the WP-6 called "Hong Qui-2" ("Red Flag-2"). This was the second indigenous turbojet designed by the Shenyang Aeroengine Design Office (SADO) following the initial success of the PF-1A developed for the JJ-1. Even after early ground test runs seem to have been successful or at least quite promising, it was once again decided to stop all development work on the engine and the fighter itself from November 1959 on and to develop another engine called "Type-814" for the next project the DF-113.
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