Israeli ducted-fan robo sky-jeep in hover trials

Manned version offering "comfortable access" to high-rise windowsills

Admittedly this was tethered and to heights of only two feet, but Urban Aero says that this is "just outside of ground effect for this particular configuration"*. The firm goes on to say that the trials have confirmed the AirMule's potential ability to hover rock-steady in 50 knot gusty winds. The statement adds:

Based on the success of these initial hover tests the vehicle is now being readied for the next phase which will include vehicle position stabilization in X,Y and height above ground. During this upcoming phase the safety wires that are now connected to the tarmac will be removed.

The initial idea for the unmanned AirMule is that it could airlift crucial supplies to troops fighting in built-up areas where helicopters would struggle to reach them. It might also extract battle casualties; obviously nobody would normally be keen to ride in an unpiloted aircraft, but if the alternative was avoidable deaths from wounds the decision might be made. Israeli troops do more fighting than most in urban areas, so Urban Aero may find a market if the AirMule can be made to work.

In the event of success, the AirMule is intended to develop into manned, multi-purpose "X-Hawk" craft. These would have most of the attributes of the long-coveted flying car: VTOL, robo-autopilot requiring almost zero skill from the pilot, "comfortable access to... the window of a high-rise building".

However, though Urban Aero claims that "the aircraft’s ducted-fan design makes it significantly quieter than any helicopter", one might doubt whether a turbine-powered craft is ever going to really be quiet enough for residential areas. Furthermore, the need to keep the fan discs large for reasonable efficiency is such as to dominate the design of the craft - perhaps to the point of making it unsuitable for many tasks.

Still, though: one to watch. ®

*Vertical-thrust craft gain additional lift and stability when "in ground effect", ie close enough to the ground that its presence affects the behaviour of the air blasted down through the thrust disc. In helicopters, ground effect drops away sharply to insignificance above a height of half the rotor-disc diameter; the Urban Aero statement chimes roughly with the dimensions of the craft's fans.