Exhibition

Bölkow Bo 46

Since 1956, the Bölkow Entwicklungen KG had been working on several innovative rotor systems for helicopters. Emphasis of their development was placed on the high-speed rotor with controlled tilt movements, the so-called "Derschmidt" rotor system. This rotor was tested on the experimental helicopter Bölkow Bo-46.
Wind-tunnel tests with model rotors showed that cruising speeds of more than 500 km/h would be possible using this rotor system.
Three experimental helicopters of the Bölkow Bo-46 were built to test this rotor system. The first model began test flights in 1964. The main powerplant was a Turbomeca Turmo III b shaft turbine with a take-off power of 800 shp. The gearbox for the main and tail rotors was developed by Zahnradfabrik Friedrichshafen AG. The fuselage with the cabin and the engine cowling came from the Siebelwerke ATG in Donauwörth.
The Bo-46 had a take-off weight of more than 2,000 kg. It was intended to reach a speed of 400 km/h and more using two additional thrust engines. The diameter of the five-bladed main rotor was 10 m, that of the six-bladed tail rotor 1.8 m. The blades of the two rotors were made from glass-reinforced plastic. Due to technical problems in overcoming vibrations in the rotor systems development was abandoned and one prototype was transfered to the Hubschraubermuseum.

Technical Data

Type designation:	Bo-46
Usage:	High-speed experimental helicopter
Manufacturer:	Bölkow Entwicklungen KG
Country:	Germany
First flight:	1964
Length:
Height:
Rotor diameter:	10 m
Number of rotor blades:	5
Powerplant:	Turbomeca Turmo IIIb
Power:	800 shp
Max. speed:	Above 400 km/h (planned)
Service ceiling:
Empty weight:
Max. take-off weight:	2,000 kg
Range:
Crew:	1
Armament:	n/a
Manufactured:	3