Hafner Rotabuggy

The Rotabuggy (formally known as the Malcolm Rotaplane [cite book | url=http://www.groenbros.com/history.php | title=Autogiro to Gyroplane: 1923–2003 | first=Bruce | last=Charnov | publisher=Hofstra University (as posted on the Groen Brothers Aviation web site)] ) was an experimental aircraft that was essentially a jeep (actually a Willys MB) combined with an autogyro. It was designed by Raoul Hafner of the Airborne Forces Experimental Establishment (AFEE) after their development of the Rotachute enjoyed some success.cite web | url=http://www.aviastar.org/helicopters_eng/hafner_rotabuggy.php | title=Hafner "Rotabuggy" | publisher=All the World's Rotorcraft | accessdate=2008-04-24]

The prototype was built by the M.L. Aviation Company at White Waltham in 1942. Initial testing showed that a Willys MB could be dropped from heights up to convert|2.35|m|ft|1 without damage to the vehicle. A convert|12.4|m|ft|1 diameter rotor was attached, along with a tail fairing and fins, but no rudders. Two men were required to pilot the aircraft: one to drive it as an automobile, and one to pilot it in the air using a control column.

The first trial was conducted on 16 November 1943, with the unit being towed behind a Diamond T lorry, but the lorry could not get enough speed to put the Rotabuggy in the air. A more powerful vehicle was used on 27 November to finally allow the contraption to become airborne.

Although initial tests showed that the Rotabuggy was prone to severe vibration at speeds greater than convert|45|mph|km/h|0, with improvements the Rotabuggy achieved a flight speed of convert|70|mph|km/h|0|abbr=on on 1 February 1944. The last test flight occurred in September 1944, where the unit flew for 10 minutes at an altitude of convert|400|ft|m|1 and a speed of convert|65|mph|km/h|0|abbr=on, after being released by a Whitley bomber, and was described as "highly satisfactory". However, introduction of vehicle-carrying aircraft such as the Waco CG-4 Hadrian glider made the Rotabuggy superfluous and further development was cancelled. [cite book | title=Jeeps 1941–45 | first=Steven J. | last=Zaloga | pages=37–38 | url=http://books.google.com/books?id=I_fFkOS4b_4C&pg=PA38&lpg=PA38&dq=Rotabuggy+&source=web&ots=gUKcRcQBtj&sig=tJ9T-aEYDILt_U-yXnl2aqtoRw8&hl=en#PPA38,M1 | publisher=Osprey Publishing | year=2005 | id=184176888X]

A replica of the Rotabuggy can be found at the Museum of Army Flying. Hafner also came up with the idea of a similarly outfitted "Rotatank" using a Valentine tank, but that was never built.

pecifications

* Gross weight: 1411 kg (Willys MB: 964kg; rotor unit and tail: 249kg)
* Maximum speed: 241 km/h
* Estimated rates of descent: 4.9 m/s to 10 m/s
* Minimum take-off and landing speed: 58 km/h
* Sea level rotor speed: 230 rpm (basic), 260 rpm (max)

References