Complex sentence: Gaining his Royal Aero Club Certificate in September 1916 as Flight Sub-Lieutenant, Royal Naval Air Service, he served as an Instructor at Cranwell before joining 10 Squadron RNAS in January 1918 to commence active service.
Split into simpler sentences: Gaining his Royal Aero Club Certificate in September 1916 as Flight Sub-Lieutenant, Royal Naval Air Service. He served as an Instructor at Cranwell before joining 10 Squadron RNAS in January 1918 to commence active service.