Focke-Wulf drive wing

Focke-Wulf drive wing
Type:	VTOL - interceptor
Design country:	German Empire
Manufacturer:	Focke-Wulf
First flight:	Wasn't built
Number of pieces:	-

The Focke-Wulf Triebflügel , or Triebflügeljäger , was a German concept aircraft from 1944, the final phase of World War II, planned to protect against the increasing threat from the Allied bomber commands. It is designed as a vertical takeoff and landing stern takeoff to be used as an interceptor for local defense of critical areas that had small or no airfields.

The development of the power wing only reached the level of wind tunnel tests when the Allies took over the production facilities. No prototype was completed.

construction

Focke-Wulf drive wing (shortened rotors)

A completely new concept was used for the Focke-Wulf drive wing. According to this, no wings provided the lift, but all the lift and thrust should be generated by a rotor / propeller arrangement that made up a third of the entire length of the aircraft. The drive wing would have been roughly in the middle of the aircraft's longitudinal axis, between the cockpit and the horizontal stabilizer . Before take-off, the aircraft should stand vertically on its tail, in this position the rotors functioned like a helicopter . When flying horizontally, they would function more like a giant propeller. The three rotor blades were to be mounted in a ring arrangement on a segment that could freely rotate in the aircraft fuselage. At the end of each rotor blade a ramjet engine would have been provided, a so-called blade tip drive . In order to set the rotors in motion until the ramjet engines work, simple jump starters should be used on the rotor tips. If the speed had then been high enough to start the ramjet engines by means of air flow, the empty jump start rockets would have been dropped. The angle of attack of the rotor blades could be varied to adapt to the flight position and speed and the required lift. Because the ramjet engines are arranged at the ends of the rotor blades, there is no reaction torque and no counter-rotation of the fuselage. The fuel should be carried in hull tanks and directed through the center of the rotating ring and along the rotors to the ramjet engines.

A cross-shaped tail at the rear part of the fuselage of four control surfaces, with moving aileron , also known as combined vertical stabilizers and elevators would have worked, formed the rear of the Focke-Wulf Triebflügel. The tailplane would have been a means for the pilot to control the tilt of the fuselage in the same direction as the direction of rotation of the rotor caused by the centrifugal force of the rotor ring. Influencing the pitch, roll and yaw moments during flight was also provided by this tail unit construction. A single large sprung wheel at the far end of the fuselage formed the main landing gear . Four small trailing wheels on retractable struts were placed at the end of each tail unit to stabilize the aircraft on the ground and so that it can be moved on the ground. The main landing gear and the support wheels were covered in flight by aerodynamic landing gear fairings.

When taking off, the rotors would be angled so that they generate more lift, just like a helicopter or, more precisely, a helicopter . Once the aircraft reached a sufficient height, it would be angled into level flight. A slight angle of attack is necessary for level flight so that the rotors provide the required downward thrust as well as the forward thrust. As a result, the four automatic cannons in the front fuselage are angled slightly downwards in relation to the center line of the fuselage. The rotors are the only components that generate lift in level flight.

To land, the aircraft is pulled up until it is vertical in the air, then the thrust is reduced until the aircraft begins to descend backwards until it touches the ground with the landing gear. This would have been a delicate and probably dangerous maneuver, as the pilot is sitting in the cockpit with his line of sight looking up and cannot see the ground behind him directly in this position (at most limited by the rearview mirror). In contrast to some other tail takeoff aircraft, the pilot's seat was fixed in the direction for forward flight. The spinning rotor would also impair rearward visibility.

This design of the Focke-Wulf Triebflügel was unique among the VTOL designs from the 20th century, and also unique in comparison to other German projects. Some early design studies for the Roton (rocket) in the 1990s showed Roton with a rotor system similar to that of a helicopter, with which Roton was supposed to land again.

In the 1950s, the US built a prototype rear-starter (the Lockheed XFV-1 and Convair XFY-1 ), but these were powered by conventional turboprops , with nose-mounted counter-rotating propellers to counter torque. They also used conventional wings for lift, their cross-shaped tails with integrated landing gear were largely comparable to that of the Focke-Wulf drive wing .

Technical specifications

Parameter	Data
crew	1
length	9.15 m
span	11.5 m
height
Gross mass	2500 kg
Minimum steering speed	230 km / h
Maximum speed	1000 km / h
maximum permissible speed	2700 km / h
Service ceiling	15,300 m
Rate of climb	50 m / s
Engines	3 Pabst ramjet engines , 8.9 kN each 3 Walter liquid rockets 2 Walter HWK 109-500 start-up rockets, 14.71 kN each
Armament	2 × 30 mm MK 103 each 100 rounds + 2 × 20 mm MG 151 each 250 rounds

See also

• Coleopter

Web links

Commons : Focke-Wulf Fw Triebflügel  - Collection of images, videos and audio files

• Paper model (Wolfgang Holzinger)
• Paper Model (Fiddlers Green)
• Air '46 Pictures
• NASA dancing wing VTOL UAV Concept

Individual evidence

1. ↑ David Myhra: Dragonfly: the Luftwaffe's experimental Triebflü̈geljäger Project . Schiffer Publishing, 2003, ISBN 0-7643-1877-2 , p. 47.
2. ↑ David Myhra: Dragonfly: the Luftwaffe's experimental Triebflü̈geljäger Project . Schiffer Publishing, 2003, ISBN 0-7643-1877-2 , p. 36.