Australian Engine Technology in UAV

The Australian Orbital Corporation's FlexDI Heavy Fuel Engine has been chosen for the Australian designed Aerosonde UAV for USN/US Special Forces Operations Command ("Driving Force", Beth Stevenson, page 31, Unmanned Vehicles, Sheppard Publications, June/July 2012). The Aerosonde was originally powered by an Avgas engine, which limited the range and required a special supply in the military environment.

In 1999 I visited Aerosonde, in Victoria and looked at early models of the robotic aircraft under construction.

The Aerosonde was interesting in being small enough to be carried by one person, but having enough range to cross an ocean, and do so autonomously. This cuts across the usual division between small short range UAVs which are flown by an operator like a model airplane, and large long range UAVs which are semi-autonomous.

The Aerosonde would be a useful complement to the RAN's new amphibious warfare fleet, offering a low cost option to extend ship's sensors.

Australian Diesel UAV

The Aerosonde UAV was originally designed in Australia for the Bureau of Meteorology. It is now owned by US defence company Textron and marketed as a small but long range surveillance aircraft for the military. The latest announced is the Aerosonde RG. This is no larger than previous models (being light enough to pick up with one hand). The most significant change is to use a "heavy fuel" engine. This is a deseil engine, which has advantages of increased fuel economy and compatibility with the fuels used by the military.

The aircraft is also reinforced for catapult launching and recovery. The original Aerosonde was launched from a rack on the roof of a moving vehicle and recovered by making belly flop on the ground (there is no landing gear). This required a large open area for launch and recovery. The new system uses a catapult for launch and a net for recovery. The wings are reinforced to attach the catapult to and also to survive flying into a net.

The Aerosonde was significant as it broke with previous conventional wisdom for UAVs, which held that the aircraft were either small and short range or large and long range. The Aerosonde is small, but also has an long range. As sensors, navigation and communications electronics become smaller, the scope of such UAVs increases. The Aerosonde has only a 6.8 kg payload, but that is now sufficient for high resolution imaging equipment, intelligent autonomous flight control and a satellite terminal.