Adventurous motorcyclists might be familiar with the thrill of getting airborne at the top of a rise, but the Hoverbike is set to take catching some air to a whole new level.
With a 1170 cc 4-stroke engine delivering 80 kW driving two ducted propellers, the inventor of the Hoverbike, Chris Malloy, says with its high thrust to weight ratio, the Hoverbike should be able to reach an estimated height of more than 10,000 feet and reach an indicated airspeed of 150 knots (278 km/h or 173 mph). At the moment these are only theoretical figures as the Hoverbike hasn’t been put through its paces yet, but Malloy has constructed a prototype Hoverbike and plans to conduct real world flight tests in a couple of months.
By day, Malloy works in the mechanical design of airborne and ground based hyperspectral sensors at an optical engineering company in Australia. But after work and on weekends Malloy has spent the past two and a half years slaving away in his garage working on his Hoverbike. His efforts were prompted when his helicopter instructor likened a Robinson R22 light utility helicopter to an airborne motorbike. Disagreeing, Malloy set about building something closer to an actual flying motorbike.
The result is a prototype Hoverbike that seats a single pilot on a Kevlar reinforced carbon fiber with foam core frame in between two horizontal spinning propellers constructed from Tasmanian Oak with a carbon fiber leading edge. Instead of the complicated swash plate setup found in single rotor helicopters, the Hoverbike employs the same basic flying principles as a tandem-rotor Chinook helicopter. As with the Chinook, the counter-rotating rotors cancel out each other’s torque reaction, eliminating the need for an anti-torque vertical tail rotor and increasing the efficiency of the vehicle.
Control of the Hoverbike is done completely via the handlebars. Forward and reverse movement is controlled via the motorbike-like handlebar grips. The right grip increases the thrust, while the left grip controls the angle of the control vanes positioned under the rotors to pitch the nose of the Hoverbike down – for forward movement – or up – for moving backwards. Meanwhile, turning is achieved by turning the handlebars left and right, just like a motorbike but with an extra axis that lets them rotate up and down a little, which alters the angle of the front and rear control vanes.
With safety an obvious concern for airborne vehicles, Malloy says he has given as many components as possible triple redundancy and made the Hoverbike design as simple as possible. The current prototype doesn’t feature adjustable pitch propellers so it cannot autorotate in the case of an engine failure, but Malloy says the ability to add two explosive parachutes to the Hoverbike’s airfarme or have the rider wearing a parachute is a safer option.
Malloy also says he plans to have the whole system controlled by gyros and he has already designed and partially tested the circuits and code required. But he initially wants to fine-tune the controls mechanically first to ensure he produces the most stable design. Eventually however, he says there will be room for a computer override of sorts to stop amateur pilots tipping over. The propellers, which are currently largely exposed, will also be fully covered in a mesh to ensure limbs don’t get too near the blades.
