The aircraft achieved the milestone for the first time at an airforce base (AFB) in the US.
Protector flew to Creech AFB and offered an opportunity for RAF Reaper Force members to see the aircraft for the first time.
RAF No 1 Group commanding air officer air vice-marshal Harv Smyth said: “When we talk about ‘next-generation airforce’, one of the capabilities that we’re delivering is most definitely Protector.
“This idea that we’ll have an RPAS that can operate anywhere at any time in controlled airspace alongside airliners is an absolutely game-changing capability.”
39 Squadron commanding officer wing commander Colin Welsh said: “Protector for most of the team here is something which exists on paper and in pictures. So by allowing individuals to see the aircraft, to see the advanced ground control system and how the mission intelligence coordinator and the crew will interact through a new system will be a fantastic motivator for the team to have a first-hand look at the next generation of this capability.
“It takes everything that’s great about Reaper and adds a whole bundle of capabilities including the ability to sense and avoid, to be certifiable in order to fly in open airspace and a sovereign weapons payload aboard the aircraft.”
The UK is planning to purchase 16 Protector RG Mk1 aircraft to replace its existing General Atomics -built MQ-9 Reaper unmanned aircraft systems.
In July last year, RAF Waddington was named as the main operating base for the Protector aircraft, with 31 Squadron set to operate the RPAS.
General Atomics awarded contracts to UK defence suppliers for RAF Protector project in January.
BAE Systems was contracted to develop concepts of operations (CONOPS) for the project.