A top-secret stealth drone - built by BAE Systems in Lancashire - has carried out its first successful test flights, it has been announced.
Taranis, named after the Celtic god of thunder, is billed by military chiefs as the most technologically advanced aircraft ever built in the UK.
Ground testing of a demonstrator aircraft began in 2010 at BAE Systems' military aircraft factory in Warton, Lancashire, and in April last year taxi trials were carried out on the runway.
The project, which has so far cost £185 million - funded jointly by the Ministry of Defence and UK industry, will be able to launch precision strikes in hostile territory while remaining undetected.
But bosses today said that although the aircraft could fly itself autonomously, it would not be used in that way - and would not be able to set its own missions.
Taranis was first unveiled in July 2010, but has remained classified until now.
Today at a briefing in London, the MoD and BAE Systems announced that the aircraft - described as a "combat vehicle demonstrator", designed to prove that the technology it is using works - completed its first flight trials last year and said it had surpassed all expectations.
Nigel Whitehead, group managing director of BAE Systems, said in a maiden 15-minute flight in August at a secret location, Taranis carried out a perfect take-off, rotation, "climb-out" and landing, piloted remotely by former RAF pilot Bob Fraser.
Mr Whitehead said a number of flights, lasting up to one hour each, and at a variety of altitudes and speeds, were carried out last year - but could not confirm exactly how many.
Britain already uses drones, mainly for intelligence gathering, although some are armed, but Taranis - which could eventually be built and used in the 2030s - would be the first specifically-designed unmanned combat aircraft designed to fly in contested airspace.