Few details of the still highly sensitive project have been cleared for release, but more information may become available later. What is known is that the GBP 20 million programme, codenamed ‘Replica’ was jointly funded by BAE SYSTEMS and the Ministry of Defence via the Defence Evaluation and Research Agency (DERA).
The project was initiated in 1994 and completed what is described as a rigorous test programme in 1999. The full scale model was intended to demonstrate the UK’s capability to design and build an affordable, low observable [stealth] aircraft with good survivability for future Royal Air Force and Royal Navy requirements
Replica was never intended to be as difficult to detect as the exotic and highly expensive pure stealth aircraft such as the American F-117a and B-2. However, UK stealth specialists are said to have achieved their goal of striking a balance between low observability and cost. They have also sent out a strong message regarding British expertise.Source: youtube.com