Complex sentence: In early 1910 he began fly his designs and in September 1910 he occupied one of the first hangars at Hendon Aerodrome and his Valkyrie design started test flying from there in October 1910.
Split into simpler sentences: In early 1910 he began fly his designs and in September 1910 he occupied one of the first hangars at Hendon Aerodrome. His Valkyrie design started test flying from there in October 1910.