Complex sentence: After the war, the RAF High Speed Flight was based at Tangmere and in September 1946 a world air speed record of was set by Group Captain Edward Mortlock Donaldson in a Gloster Meteor.
Split into simpler sentences: After the war, the RAF High Speed Flight was based at Tangmere. In September 1946, a world air speed record of was set by Group Captain Edward Mortlock Donaldson in a Gloster Meteor.