Su-15VD FLAGON / T-58VD V/STOL

There is some confusion on the Su-15VD designator. Some sources report it was an upgraded version of the basic Sukhoi all-weather interceptor, alias Flagon-E, that began to enter service with the IAP-VO Strany from late 1973. This sub-type was essentially similar to the current Flagon-F apart from its conical (as opposed to ogival) radome. Other sources report it was a V/STOL demonstrator designated Flagon B.

The T-58VD machine was not intended to improve the actual Su-15. Instead it was used as a flying laboratory for the creation of the program strike aircraft short takeoff and landing T6-1, which became the Su-24. The idea was to install additional lift engines (PD), which was at that time very popular in the world. For example, in England tested prototype Short SC.1, and in France - Dassault Balzac. For the improvement of short-field performance, the designs had to pay a substantial reduction in range and payload reduction, but inefficiency of the chosen scheme did not seem obvious. It was the "growing pains" of military aviation, the symptoms of which were recorded in different countries.

Su-15 provided the bulk of the Soviet air defense over the years; its development was due to the threat of US strategic bombers, in particular, the possibility of mach 3 bombers developed (for example, the XB-70). In response, the Soviet authorities quickly raised the possibility of all weather interceptor and designs, such as the "MiG-25" Foxbat and MiG-23 Flogger been developed. "Mig" Sukhoi Design competitors are already all-weather interceptor, which entered service Su-9, which was improved in 1966 - Su-11. When in 1962 the requirements of an interceptor was installed to reflect any mach 3 US bombers may develop (they never did) Sukhoi went about developing an interceptor with a much better, higher performance than all that was before, but instead of trying something or radical "dry" followed the path of least resistance and adapt existing technology, making it bigger and better.

This fast, heavy delta aircraft required long runways, but this was never been considered as a problem for the Soviets. Landing speed is as high as 186mph (300km / h), which required a long distance to stop, especially with a heavy titanium-reinforced body.

May 6, 1965 order was issued the MAP, for which Sukhoi given the task to build a flying laboratory to full-scale test modes KVP. The aircraft was given the designation T-58VD, and it was created on the basis of the first prototype of the Su-15. This had dorayuotat fuselage. Between the air channels in a row at an angle of 10° to the vertical lift installed three RD-36-35 thrust of 2540 kgf. In the upper part of the fuselage were placed two air intake opening shutters: the front one and the rear for two engines. At the bottom of the profiled fuselage controlled blinds that have two positions, providing gas jet deflection. Construction T-58VD completed in December 1965 and then began working out on a special stand. It was a metal-coated pad to which moored plane, and NK-12 engine mounted in the front as in certain similarity fan shaped wind tunnel. The flow at the outlet of the pipe allows you to simulate the run of the aircraft to a speed of 400 km / h. Tests on the stand allowed to completely fulfill all the basic system T-58VD.

Unfortunately, there was an emergency in February 1966 which killed the propulsion laboratory mechanic Ukhov, who inadvertently approached the nose of the aircraft during the installation of the fan.

On April 26, 1966 the aircraft was moved to LIiDB. Lead engineer for testing remained fair, and leading pilot was appointed Solovyov. In June, taxiing and podlety to include lifting motors have been carried out. The first flight of the T-58VD Soloviev performed on July 6 with the lifting motors are not involved, and flight tests have begun with their inclusion at the end of the same month. Before the end of the year took place on 37 flights, 19 rulezhek and the approach, including taxiing on a dirt strip. It has been found that the included PD takeoff speed decreased from 390 to 285 km / h and landing - from 315 to 225 km / h, the run length is reduced from 1170 to 500 m, and the path - from 1000 to 560 m Behavior aircraft. PD included in the take-off is practically no different from the usual Su-15. However, performed at lower speeds greatly hampered land significant pitching moment, which had to remove the front disable RD-36-35.

The tests continued until the end of 1967, and showed that the benefits of improved field surgery with more than deficiencies overlap. Hot gas stream from the PD adversely affect the aircraft elements, and did not allow the WFP to suspend under the fuselage payload. It was very significant reduction in the weight and recoil reduction in fuel capacity on board (up to 3970 kg). Also Solovyov, T-58VD flew only Ilyushin, who performed in March 1967 at its 3 flights in preparation for the test by the experienced T6-1. In 1968-69, the flying laboratory occasionally rose into the air, then stood for a long time. In 1976 it was transferred to the MAI for use as a teaching tool. But there the career was short-lived: in 1980, it was cut into scrap metal.