A variable-speed drogue designed to allow air-to-air refuelling of fixed- and rotary-wing aircraft from the same unit has undergone initial flight tests in California, USA.

The Chico-based Conversion Tank Works (CTW) of Aero Union is developing the multi-role drogue for several applications, including a forthcoming requirement from Lockheed Martin for a new drogue for a tanker version of its C-130J. "That is what is driving it," says CTW engineering manager, Mike Hutter. Lockheed Martin is "-trying to justify having a competition", for the work which is aimed initially at a US Marine Corps and, possibly, a UK requirement, Hutter says.

Leading competitors could include Flight Refuelling, through its Sargent-Fletcher subsidiary, and California-based West Coast Netting, which makes a low-speed, soft drogue for helicopter applications.

The Aero Union unit is spring balanced "-so the forcing function is the air speed at which it is being dragged. The basket therefore gets smaller with high speed for fighters and opens up for low- speed helicopters", says Hutter. Current systems need to be reconfigured on the ground before they can be switched from fuelling rotary craft to fixed-wing craft, and vice-versa, the company says.

Source: Flight International