BAE Systems Demon

Lore & Background

During the early 21st century, BAE Systems initiated a five-year research programme known as flapless air vehicle integrated industrial research (FLAVIIR), with a declared budget of £6.5 million financed by BAE Systems and the UK's Engineering and Physical Sciences Research Council. The programme aimed to develop and test a new aerodynamic circulation-based aircraft flight control system, manipulating airflow via non-traditional means. Participants included various British aeronautics companies, specialists, and academic institutions including Cranfield University and nine other British universities. An American patent for elements of the control system was filed in August 2007 and granted in July 2011.

The conventional BAE Systems Eclipse UAV was selected as the basis for the demonstrator. Ahead of the flight test programme, the Demon was subjected to various ground-based tests, including the use of wind tunnels and scale models. On 17 September 2010, the Demon performed its first flight in which all of its conventional control surfaces were deactivated during a portion of the flight off the coast of Cumbria, having flown out of Barrow/Walney Island Airport. Richard Williams, BAE's programme director for future capability, stated: 'I feel sure I have witnessed a significant moment in aviation history.'

Reader's Guide

The Demon's significance lies in its demonstration of fluidic flight controls, a system that uses engine exhaust gas redirected via a thrust vectoring nozzle and bleed air precisely controlled to provide control over aerodynamic forces traditionally provided by flaps, ailerons and elevators. The arrangement reportedly functions by directing air from a rectangular exhaust nozzle over upper and lower surfaces, using the Coandă effect to establish control over pitch, while bleed air is blown over a Coanda surface on the wing's trailing edge for roll control. By controlling boundary layer conditions, the fluidic controls can also generate greater lift or drag during take-off and landing.

In late 2010, BAE Systems stated that the Demon would not be followed up by a direct production aircraft, but its technologies would be filtered through to other platforms. Aerospace periodical Flight International speculated that the circulation control system could one day be employed in civilian aviation to reduce the size of the wing on widebody airliners. Its developers expressed hopes that the technology could reduce noise, cut fuel consumption, and lower maintenance costs. In military applications, the technology might enable future combat aircraft to achieve greater levels of stealth than conventionally equipped counterparts. Beyond the flight control system, the Demon trialed a fully bonded structure with low-cost material reinforcing features that reportedly achieved roughly 50% cost savings over conventional manufacturing processes.

Did You Know?

• The Demon has been referred to as the world's first 'flapless' aircraft.
• Its first flight without conventional control surfaces occurred on 17 September 2010 off the coast of Cumbria.
• The Demon was developed from the conventional BAE Systems Eclipse UAV.
• The FLAVIIR programme had a declared budget of £6.5 million.