UAVs

BattleHog and Excalibur make first appearances

Two new vertical take-off and landing (VTOL) unmanned air vehicles were unveiled at the AUVSI show. Aurora Flight Systems is building its Excalibur unmanned tactical strike aircraft as a technology demonstrator for the US Army, while previously unknown American Dynamics says its company-funded BattleHog close air-support UAV made its first flight in July.

Aurora expects to fly a proof-of principle aircraft next year, under a contract from the US Army Aviation Applied Technology Directorate. The 1,180kg (2,600lb) Excalibur has electrically driven fans in the forward fuselage and wing tips that provide a third of the lift, with the remaining two-thirds provided by a centrally mounted tilting turbofan.

After a vertical or short take-off, the Williams turbofan tilts forward to provide propulsion, the tip fans retract into the wing and the vehicle flips over into its normal flying configuration.

The 6.4m (21ft)-span vehicle is designed to reach 300kt (550km/h) at sea level, 460kt at 30,000ft and fly at up to 40,000ft. A 545kg payload from a short take-off could include four wing-mounted AGM-114 Hellfire air-to-surface missiles.

American Dynamics' BattleHog 110X would be capable of carrying two Hellfires and an M134 minigun. The 5.2m-span, 1,450kg BattleHog 100X demonstrator is powered by a Rolls-Royce T63-720 turbine engine driving a ducted lift-fan in the centre fuselage, says Paul Vasilescu, technology development director.

The fixed-wing UAV has no control surfaces, and instead uses fan speed and pitch variations to provide directional control. Speeds of up to 270kt are anticipated.

A larger BattleHog 350X with an afterburning engine driving twin lift fans in a 12.2m-span wing, is in manufacture and will fly in 2008, says Michael Koegler, marketing strategist.