Simplify the following text for a Grade 6 native English-speaking person.
Original: Wing Commander George Hedley Stainforth AFC RAF ( 1899 - 27 September 1942 ) was a British Royal Air Force pilot and the first man in the world to exceed 400 miles per hour .
Simplified: Wing Commander George Hedley Stainforth AFC RAF ( 1899 - 27 September 1942 ) was a British Royal Air Force pilot . He was the first man in the world to exceed 400 miles per hour in an aircraft .