Collett was in Britain when the First World War broke out. He joined the
Royal Flying Corps in 1914. He earned his
Royal Aero Club Pilot's Certificate number 1057 at a private flying school on 29 January 1915. He was transferred to
Brooklands on 17 February. He successfully repeated the experiment several days later. A
Bar followed shortly thereafter, on 18 October 1917. When recovered, Collett was assigned to
No. 73 Squadron RFC as they prepared their Camels for combat. On 23 December 1917, Collett was test-flying a captured German
Albatros over the Firth of Forth, which inexplicably dived into the sea. He was buried in grave K903 in
Comely Bank Cemetery in Edinburgh. ==Honors and awards==