Airbus Defence & Space has revealed 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.

Airbus Defence & Space has revealed 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.

Showing its LO UAV testbed – or LOUT – platform at Manching on 4 November, Airbus future combat air system (FCAS) programme manager Mario Hertzog said the company began initial concept work in 2007. This led to a contract award in 2010 to refine configuration and material choices, and the production of a diamond planform demonstrator was completed in 2014.

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Airbus

Pointing to the company’s long involvement with LO reseach, Hertzog says: “Bringing all our experience into one programme was a logical conclusion.”

The chosen configuration used for aerodynamic and anechoic chamber testing since 2014 has a roughly 12m (39.3ft) wingspan and similar length, and is described as a 4t-class vehicle. 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, with Hertzog noting that such a vehicle would be optimised for use against ground-based air-defence systems. This mission requirement also led the company to hone LO techniques for the vehicle’s landing gear doors and centerline internal weapons bay, Hertzog notes.

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Airbus

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.

Airbus confirms that it has completed contracted work on LOUT, but says additional activities could be conducted. However, Hertzog declines to say whether Berlin could seek a flight-test campaign with such a system.

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.

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Airbus