Airbus Defence and Space has unveiled its Low Observable UAV Testbed (LOUT), a secretive programme which has been in development since 2007. It was unveiled during a Trade Media Briefing (TMB) on November 5, with a scale model and presentation shown to visitors.
With the project starting more than ten years ago, the presentation states that Airbus had taken a "[Lockheed Martin] 'Skunk Works' approach" in developing the LOUT. In 2010, the Bundesministerium der Verteidigung (German Ministry of Defence) contracted the LOUT for use as a ground-based very low observable (VLO) testbed for "wideband signature reduction technologies" and for "further VLO integration bringing together simulation and measurement based on a potential configuration for a VLO-platform." Work since 2010 has been carried out at Airbus facilities in Manching and Bremen.
In early 2016, the programme finalised LOUT's basic configuration with a set radar cross section (RCS) and Airbus has since been working on providing the UAV with iterative camouflage optimisation, also known as virtual motion camouflage.
Airbus Defence and Space has given a broad overview of the LOUT's key features. The company says that the UAV takes a "holistic approach to stealth," with a focus that covers signature reduction, electronic countermeasures (i.e. jamming, deception and signature augmentation) and electromagnetic emission control - which provides new sensors with lower detectability.
The company has opted for a multispectral diamond-shaped design configuration, which covers radar, infrared (IR), visual and acoustic stealth techniques. The LOUT also features an integrated flat nozzle design, giving Airbus the options to equip it with thrust vectoring capabilities and/or the cooling of the platform's structural parts. As with many other stealth aircraft, the engine inlet is designed to have a very low RCS and the LOUT is no different. The platform features a diverterless inlet with "provisions to suppress IR radiation." It will also have a radar absorbing intake duct and a "broadband leading edge LO design." The presentation also showed Airbus' LO coating contributions including surface wave attenuation, which will decouple mutually spaced scattering effects and shielding "optically transparent and electrically conducting" transparencies.
The platform has reduced its IR and acoustic signature, switching from a VHF radio frequency to Ka-Band. It utilises passive sensing and is aware of its own signature when linked to a mission management system. The company adds that other projects have complemented the LOUT with regards to electromagnetic emission control.
Pictures released by Airbus Defence and Space show LOUT to have a transparent canopy, which raised questions about the company's possible intentions to produce it as an optionally manned fighter. According to journalists at the FMB, that is not the case.
The LOUT is a "demonstration of LO properties" employed on a full-scale VLO platform and further research and development into the testbed will be used in the development of other planned VLO projects, including FCAS and other stealth manned/unmanned aircraft produced by the company in the coming decades.