Andrzej Jeziorski/MUNICH

Industrial partners in the tri-national X-31 VECTOR research programme expect the signature in March of an inter-government memorandum of understanding (MoU) signalling the restart of the successful thrust vectoring work.

Following the approval of the US portion of the programme's funding in mid-January, similar clearance is expected from the German and Swedish Governments before the MoU is signed and the programme's six-month first phase gets under way, say programme sources.

The first phase would involve the preparation and evaluation of the hardware, including the one remaining Boeing/Daimler-Benz Aerospace (Dasa)X-31A thrust vectoring research aircraft, a new thrust vectoring nozzle and air data system and the definition of overall goals for the programme.

Flight testing will begin in the second phase, which will focus on reducing the aircraft's tail size with the aim of eventual tailless flight.

According to the sources, Sweden has expressed particular interest in work on the thrust vectoring nozzle, expected to be based on General Electric's AVEN axisymmetric vectoring engine nozzle, and the integrated flight control system. JAS39 Gripen builder Saab and engine company Volvo Aero will be in the vanguard of the Swedish effort.

Germany is to focus more on designing a new advanced air data system for post stall flight, while the tailless elements of the programme will be US led.

The division of programme costs and workshare has yet to be finalised among the partners.

Dasa military aircraft division president Aloysius Rauen, a keen advocate of thrust vectoring, says that he would like to see the results of the VECTOR programme applied eventually to the Eurofighter EF2000 or JAS39 Gripen thrust vectoring technology demonstrators, letting Europe "-catch up with Russia" in this field.

Rauen argues that thrust vectoring has many benefits beyond those of enhanced manoeuvrability and post stall flight. These include weight and stealth gains from removing an aircraft's tail fin and improved short take off and landing performance.

The VECTOR effort is the long awaited follow-up to the X-31 Enhanced Fighter Manoeuvrability (EFM) programme, which ended in 1995. The closing phases of the project included a series of quasi-tailless flights, simulating the elimination of the aircraft's fin.

The aircraft still has half its useful life left, and has been mothballed since the completion of the EFM programme.

Source: Flight International