Messerschmitt Me 408

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Messerschmitt Me 408
Model of the Me 408
Model of the Me 408
Type: Convertible plane
Design country:

GermanyGermany Germany

Manufacturer:

Messerschmitt AG

Commissioning:

Project draft

The Messerschmitt Me 408 Rotor-Jet was the design of a convertible aircraft by the German manufacturer Messerschmitt AG from the 1960s. The implementation of the project only led to the demonstration of models at aviation shows .

history

The background to the development of the Me 408 was the urgent need in the 1960s for feeder aircraft that were supposed to connect the large airports outside the cities with small city airports. Examples were the helicopter line from the Heliport in Duisburg , which was operated by Sabena , and the New York Airways connection between the PANAM building in New York and John F. Kennedy International Airport . The main disadvantages of using helicopters were the high levels of noise and fuel consumption compared to fixed-wing aircraft.

An alternative are convertible airplanes (also called transformation helicopters), which Messerschmitt dealt with in the mid-1960s. In October 1967 the company presented a first draft project. For several years, measurements were then carried out in the wind tunnel , foldable rotors were built and tested in the stand, and combined control systems were designed. The manageability of the transition phases between vertical and horizontal flight was examined in great detail. Furthermore, theoretical investigations on flight mechanics and dynamics were carried out in the MBB helicopter departments.

There was no real development phase of the rotor jet, because at the end of the 1960s it was recognized that the development of VTOL aircraft is very costly and that the operating costs of such a device are not competitive with those of pure helicopters.

A drawing of a variant Me 508 is shown on the Popular Rotorcraft Association website , but no further literature is available for this.

construction

The Me 408 was designed as a six- to seven-seater touring aircraft with additional foldable rotors that were located at the ends of a straight rectangular wing. In the first stage of development from 1966/67, two shaft turbines were built into the fuselage fairings on both sides of the stern. The large propulsion fan (fan) was arranged centrally in the rear and was to be driven mechanically via gears and long-distance shafts. The rotors were also connected to the turbine output, which first transferred the power to a central transfer case and then to the rear to the fan or to the front to a bevel gear, which was supposed to drive a continuous long-distance shaft connecting both rotors. This ensured that even if one engine failed, there would be no asymmetrical loading of the rotors.

In the second variant of the project from 1968, two fans were to be located under the engines, with the blowers being driven by the hot gases from the gas generator . With regard to the mechanical requirements, this concept was designed to be much simpler than the first solution. In both variants, the 6 m spanning lift rotors should be stowed in a casing above the engine nacelles after they have been folded up. Torque compensation was not provided because the flapping and swivel jointless rotors should rotate in opposite directions.

In both versions, T58 shaft turbines were used as gas generators. In the second version, these could either be used to drive the working turbines of the rotors and, after switching over by means of appropriate flaps in the gas line, to drive the so-called tip turbines of the propulsion fan. Here, too, the two rotors should be connected by a shaft running through the wing. A model of this version was shown at the Hanover Aviation Show in 1968 , the drive concept being largely identical to that of the Me P 2020 transporter project, which was also shown .

Technical specifications

Parameter Data
crew 2
Passengers 6-8
Maximum rate of climb 20.5 m / s
Max. Takeoff mass 5000 kg
Cruising speed 750 km / h at 9000 m
Range 1700 km with 720 kg payload
Engines two General Electric T58 shaft turbines,
each with 1360 kW (1850 hp) takeoff power

See also

literature

  • Kyrill von Gersdorff, Kurt Knobling: Helicopter and Gyrocopter - Die deutsche Luftfahrt Vol. 3. Bernard & Graefe Verlag, Munich 1982, ISBN 3-7637-5273-0 , p. 184 ff.
  • Messerschmitt Me 408 rotor jet. In: Flug Revue , June 1967, p. 120 ff.

Individual evidence

  1. ↑ Kyrill von Gersdorff, Kurt Knobling, 1982, p. 188
  2. ↑ Me 508 at Popular Rotorcraft Association (PDF; 1.7 MB)
  3. ^ Photo of the first project variant in FLIGHT from May 18, 1967
  4. ↑ 7th German Air Show. In: Flug Revue, June 1968, p. 28 f.

Web links