Replica was a design study for a British military aircraft with stealth capabilities, developed by BAE Systems. It was associated with the Royal Air Force's now cancelled Future Offensive Air System. The Replica project is known to have run from 1994 to 1999 building a full size model and subjected to a rigorous test regime to determine its radar cross section. It is widely believed that Replica may have been intended to replace the Panavia Tornado from 2017 onwards. Experience from the program was later rolled into the Joint Strike Fighter program, which essentially replaced Replica.
Replica was a twin-seat strike fighter that sported a V-tail arrangement to reduce radar cross-section and weight. The design of the aircraft is similar to the Northrop YF-23 and the joint BAE/McDonnell Douglas/Northrop Grumman proposal for the Joint Strike Fighter although Replica was independent of either aircraft. To fulfill the FOAS requirements, Replica was probably designed to accommodate an internal weapons bay capable of carrying ASRAAMair-to-air missiles for self-defence and laser-guided bombs in the 2 000 lb range. Replica was a twin engine design, but as it did not pass the mock-up stage no engine was selected. The design hints at the use of 2D Thrust vectoring however this is unconfirmed. The design of the mock-up also suggests that it may have featured AESA radar in leading edges on the wings of the aircraft as the nose is too small to house Radar. The advantages of the leading edge AESA radar would be a wider coverage area. It could also be the case that the mock-up was unrepresentative of any potential production aircraft in regards to radar housing. Many of Replica's design features are classified by the BritishMinistry of Defence. Due to the sensitive nature that Stealth aircraft have in the UK, it is unlikely that detailed information on Replica is to be released into the public domain for the foreseeable future.
In February 2014, the testbed model of Replica was seen being transported around the BAE Warton test facility in Lancashire, England. During the brief 2014 sighting, the aircraft was sporting a new low-visibility coating and minor structural changes and was upside down on a platform being taken into an enclosed hangar. These changes are most likely to be related to the Taranis aircraft, further refining design and aiding in development of new stealth coatings for the Anglo-Franco Future Combat Air System. As of March 2014, the Replica testbed is back on its infamous radar testing plinth at BAE Warton but now in its new paint scheme.