Lessons learned from the LOUT will be available for potential adaptation during a long-term evolution activity on the Eurofighter Typhoon, and on a proposed French-German-Spanish FCAS development.
On Nov. 4, 2019 at Manching, Airbus Defence & Space has revealed LO UAV testbed (LOUT) a more than decade-long research and demonstration effort into very low observable (LO) technologies, conducted as a classified effort for the German defence ministry.
Mario Hertzog, Airbus future combat air system (FCAS) programme manager, explained that the company began initial concept work in 2007. A contract to refine configuration and material choices was awarded in 2010 and the production of a diamond planform demonstrator was completed in 2014.
According to Flight Global, the chosen configuration used for aerodynamic and anechoic chamber testing since 2014 is described as a 4t-class vehicle and has a roughly 12m (39.3ft) wingspan and similar length. The subsonic design would use a conventional engine concealed behind a diverterless inlet, and has twin intakes blended into its upper fuselage. A cockpit transparency and sensor apertures also formed part of the testing.
The aircraft’s exhaust nozzle also is shielded from beneath.
Such a vehicle would be optimised for use against ground-based air-defence systems, Hertzog pointed out. He also added that this mission requirement also led the company to hone LO techniques for the vehicle’s landing gear doors and centerline internal weapons bay.
Focus areas have included testing LO materials, including a radar absorbent structure for engine intake ducts, and on assessing radar frequency and infrared signature performance. Modelling work has also been conducted to analyse the likely acoustic characteristics of such a design.
Even though Airbus has completed contracted work on LOUT, the company says additional activities could be conducted. Hertzog did not reveal if Berlin could seek a flight-test campaign with such a system.
However, lessons learned from the LOUT programme will be available for potential adaptation during a long-term evolution activity on the Eurofighter Typhoon, and on a proposed French-German-Spanish FCAS development, Hertzog says.
“Stealth is and will remain an enabler for survivability,” he notes.
Photo credit: Airbus