Adney helicopter


Small, homebuilt single-seat experimental helicopter built in 1948 by Eric Adney, an accountant from the Black Rock suburb of Melbourne, Australia, with no prioflying experience or formal engineering education. So far this is the earliest known homebuilt helicopter in Australia to successfully take flight, in a time when information on such machines were scarce throughout the country.

It is powered by a 20hp (15kW) 750cc side-valve JAP engine arranged in front of the pilot position, powering two-blade main and tail rotors. The main rotor utilizes a semirigid teetering hinge design similar to Bell products of the time, except reversed with the flybar below the rotor hinges and gyroscopic action instead of cyclic control. It is hypothesized that shifting of the pilot's body weight controlled the sideways, forward, and backward flight, while it was found that aluminum handles on each side of the frame behind the engine controlled the rest of it - the left handle served to control the throttle, and the right controlled both collective and tail rotor pitch. There are no foot pedals like on conventional designs; the pilot's feet rest in small bracing under the main wheel struts. The engine could also be disengaged from the main rotor during an emergency with the use of a one-way sprag clutch, constructed from bob-weights of an automotive distributor shaft.

It appears that the airframe was entirely hand-made. It consists of a wooden spar with bolted aluminium tubing, probably taken from surplus aircraft judging by the quality. The rotor blades are of hollow wooden construction. Two alternate tailbooms were also built, one of which would eliminate the pilot seat when installed, thus rendering it an unmanned platform.

It was concluded that the small scale is likely due to Mr. Adney being relatively short and lightweight, though the danger of the overhead main rotor relative to the pilot's head was still a concern should it flap downward in flight. It is also likely that the flight tests were conducted in a pilotless configuration via tether.

The machine is still in flyable condition, with original engine still operable and all original parts intact. It was rescued from a neighbor when Mr. Adney's children decided to scrap it after his death, later to be obtained by its present owner, at the time primarily interested in the engine it used. However, it was decided to preserve the machine rather than salvage the engine from it.

Ian Drysdale of the 
Drysdale Motorcycle Company in the pilot seat, demonstrating the small scale of Mr. Adney's machine.

Alternate tailboom configurations.

A closer look at the engine and airframe.