As part of the study, a full size model of the aircraft was constructed and was subjected to a rigorous test regime to determine its radar cross section.
British defense manufacturer BAE Systems, having taken an interest in the fledgling FOAS effort and keen to develop its technical experience in a relatively new field of military technology, quickly elected to participate.
[1] According to international science publication New Scientist, British stealth specialists have stated of the programme that Replica's visibility characteristics had achieved the envisioned target, which involved a balance between low observability and overall affordability.
[1] The Replica programme was received with official approval and backing, funding for proceeding with development work was provided by the Ministry of Defence, as well as self-invested by BAE Systems itself.
[1] One of the known aims of these tests was to acquire relevant data from which to evaluate the aircraft's radar cross section, which was deemed to have been a key component of its low observability characteristics.
Details on the purpose and specifics of the design's attributes have remained relatively scant, it is not known whether measures to minimise its infra-red, acoustic or visual signatures were used or of their effectiveness.
[2] According to journalists, these changes were believed to be most likely to be related to the in-development unmanned Taranis aircraft, aiding in the further refinement of its design and supporting the development of new stealth coatings for the Anglo-Franco Future Combat Air System (FCAS).
Externally, the airframe resembled the American Northrop YF-23 prototype stealth fighter, as well as the jointly-developed BAE Systems/McDonnell Douglas/Northrop Grumman proposal that was submitted for the United States Air Force (USAF) Joint Advanced Strike Technology (JAST), although Replica was developed independently of either of these aircraft.
[5] To fulfill the stringent requirements of the FOAS programme, Replica is believed to have been designed with provisions to accommodate an internal weapons bay, capable of carrying both ASRAAM air-to-air missiles for self-defence purposes and a number of laser-guided bombs within the 2, 000 lb range.