Urban Aeronautics has delayed the first untethered hover of its AirMule ducted fan propelled unmanned air vehicle until mid-year to ensure that all systems are functioning.

Urban had planned to achieve the milestone this month, but company president Rafi Yoeli says: "We are now preparing the craft for the next phase, and are moving slowly to ensure all the systems function. When we complete this we will go to free flight."

The Israeli firm is fitting the UAV's sensors to support free flight activities, Yoeli says. These include a laser altimeter, differential GPS and an inertial measurement unit.

Mule near hover - Urban Aeronautics 
 © Urban Aeronautics

AirMule is an all-composite single-engined vertical take-off and landing cargo and medical evacuation UAV. With a fuel consumption of up to 150kg (330lb) per hour depending on its speed, the useful payload for a 1h mission will be about 400kg.

The UAV's flight control will be achieved using an Urban system that relies almost entirely on inertial measurements augmented by GPS signals.

Powered by a 730hp (544kW)-rated Turbomeca Arriel-1D1 engine, the ducted fan AirMule should deliver a top speed of 100kt (185km/h), with a climb rate of 6,000ft/min (30.4m/s). The air vehicle is 5.9m (19.3ft) long and 2.15m wide, with a maximum take-off weight of 1,090kg.

Source: Flight International