Hank Adlam began his naval flying career in 1941, his first operational posting was to the newly-formed No. 890 Squadron. The squadron's first operational role was to protect a convoy sailing from New York and bound for Greenock. Their major task was to protect the ship's squadron of Fairey Swordfish anti-submarine aircraft and to destroy any long-range Lufwaffe Fw Condor reconnaissance patrols that were transmitting convoy positions to the waiting U-boat wolf-packs. During this first operational voyage he lost his best friend who was shot down. Later, on this same initiation to front-line operational flying, Hank was forced to ditch into gale-torn Atlantic Ocean. In the autumn of 1942, 890 Squadron joined the fleet carrier HMS Illustrious, again involving convoy protection. During one patrol he helped destroy an enemy Blohm und Voss Bv 138 Seaplane. Illustrious sailed for the Mediterranean arriving in Malta, with the objective of providing air cover for the landings at Salerno. 1944 saw the Squadron pilots despatched aboard HMS London and then they briefly joined HMS Atheling, to provide air cover for a strong fleet attacking Japanese shipping around the Andaman Islands.
When 890 was disbanded he joined 1839 Squadron flying the new Grumman Hellcat.