The RAF's Gloster Meteor wound up being initial and just practical Allied jet fighter to truly enter combat in WWII. In March 1943, a jet prototype produced by the Gloster company and constructed with a De Havilland H.1 motor made its first effective test journey. In July of 1944, pilots traveling the initial manufacturing form of the Meteor, the F.1 fighter, fought fearlessly in Battle of Britain underneath the No. 616 Squadron. The F.1 housed two Rolls-Royce Welland jet machines capable of using the fighter to rates of 668km/h and was relatively effective in defending the Uk homeland against German V-1 rockets. The F.1 ended up being down the road replaced by the enhanced F.3 version featuring its Rolls Royce Derwent engines, changed canopy style, and increased fuel capability.