LONDON, UNITED KINGDOM - DECEMBER 16: Cadet Sergeant Tommy Dade (centre) stands with the Duchess of Cambridge as she is presented with a book by Air Commodore, Dawn McCafferty Commandant of the Air Cadet organisation (right) on December 16, 2015 in London, England. The Duke of Edinburgh retired from the post of Air Commodore in Chief while the Duchess became Honorary Air Commandant of the Air Cadets. (Photo by Stefan Rousseau /WPA Pool / Getty Images)