The work of the
Airborne Forces Experimental Establishment at Ringway, Manchester, on
the Rotachute from 1940 onwards led to the suggestion that the
free-wheeling autogyro principles employed could also be applied to
larger loads. The designer, Raoul Hafner, suggested the Rotabuggy,
a Jeep (or "Blitz Buggy") with rotors, and the Rotatank,
a similarly modified Valentine tank. A development contract was
placed with the M.L. Aviation Company at White Waltham in 1942, covered
by specification 10/42.
Preliminary tests involved loading a Jeep with concrete and
dropping it from heights of up to 7 ft. 8 in. (2.35 m.), demonstrating
that the standard vehicle could survive undamaged from impacts of up to
11g. A 46 ft. 8 in. (12.4 m.) dia. two-blade rotor was then fitted, as
well as a streamlined tail fairing with twin rudderless fins. Other
additions were Perspex door panels, a 'hanging' rotor control next to
the steering wheel and a rotor tachometer and glider navigational
instruments.
The Rotabuggy, camouflaged, carrying RAF roundels and a
prototype "P", was tow tested behind a 4½ litre supercharged Bentley,
and achieved gliding speeds of up to 65 mph (105 km/h) IAS.
The first flight was made on November 16, 1943. Later, some flights
were made behind a Whitley bomber from Sherbourne-in-Elmet.
One witness described how she watched a Whitley take off with a
Jeep in tow, circle and land. The Jeep, still in tow, did
not touch down at the same time, and the witness realised that its
occupants "were unhappy". With the pilot holding the hanging control
column and the driver clutching the steering wheel, the Jeep
made a series of up and down movements, whilst the audience hoped it
would stall on a 'down' rather than an 'up'.
This it fortunately did, the driver taking over and driving flat-out
after the Whitley, to which it remained attached. When it
stopped, nobody got out for a while; the pilot was then assisted out
and lay down beside the runway to recover. Apparently he was exhausted
from trying to control the joystick, which had whipped in circles for
the whole flight.
Apparently this flight was one of the worst, and the handling and
flying qualities of the Rotabuggy were officially recorded as
"highly satisfactory", especially when large tail fins had been fitted
and greater rotor blade articulation provided. However, development of
Horsa II and Hamilcar vehicle carrying gliders made further development
of the idea unnecessary.
Rotabuggy data: |
ROTOR SPAN:
46 ft. 8 in. (12.4 m.)
GROSS WEIGHT:
3,110 lb. (1411 kg) including
550 lb. (241 kg) for rotor unit |
DESIGN MAX. SPEED:
150 mph (241 km/h)
EST. RATE OF DESCENT:
960-1,980 ft/min
(4.9-10 m/sec) |
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