In Nazi Germany, many different designs were developed for vertically taking off fighter-interceptors, most of which had a vertical fuselage position during take-off and landing. Perhaps the most unusual of these is the Focke-Wulf Triebflugel interceptor project, which was developed in 1944 by the famous aircraft designer K. Tank together with D. Klucheman and H. Haliman.
Triebflugel - translated from German as a wing-propeller, which most accurately reflects the design of the aircraft, which did not have a wing in the usual sense. For vertical take-off and landing on the tail, as well as for horizontal flight, the plane had to use a three-blade propeller wing with a diameter of 11,4 m, which was set in motion by the O. Pabst design installed at its ends with an 839 kgf thrust. It was assumed that the engine will run on non-deficient fuels. For the promotion of the wing should have been used one small rocket engine company "Walter".
After a vertical take-off, the aircraft must go to a horizontal flight, which was to be made with a small tailing angle so that the propeller worked on the oblique-blowing mode and created, in addition to the horizontal one, the necessary lift (lateral force on the propeller).
Control of the aircraft should be carried out using aerodynamic rudders mounted on the cross tail. The pilot was to be located in the nose in a well-glazed cockpit. Armament - two guns MK-103 and two MG-151 with ammunition also located in front. The fuel tank was located in the central part of the fuselage.
The design characteristics of the aircraft: take-off weight 5175 kg; empty weight 3200 kg; maximum equivalent power at the ground 10200 el.s.s., maximum climb rate at the ground 125м / s, speed 1000km / h. As can be seen from these data, the project of the fighter was given a huge power supply, unattainable when using other engines - almost 2 hp / kg, which should provide not only a high rate of climb, but also a high speed of flight.
The vertical position of the fuselage during takeoff and landing required the development of a special chassis with one main and four auxiliary supports. The main landing gear located in the rear fuselage, and retractable - auxiliary support in the fairing at the ends of the cruciform tail. All supports were equipped with caster wheels.
Work on the aircraft design was limited not only by the stage of preliminary design and experimental research, but also by detailed design study. Because of its novelty and complexity, the project remained unfulfilled, but many of the solutions incorporated into it later found their application in other projects, both in Germany (FW-860, He-231), and in other countries.