He flew in the Battle of Britain before his unit was transferred to Sicily in December 1940, participating in the attack on the Royal Navy aircraft carrier HMS Illustrious on 10 January 1941.
HMS Beagle | HMS Victory | HMS M31 | HMS Bounty | HMS M23 | HMS ''Humber'' | HMS ''Bounty'' | HMS M27 | HMS M25 | HMS Investigator | HMS M33 | HMS ''Beagle'' | HMS Plumper (1848) | HMS Endeavour | HMS ''Victory'' | HMS Royal Charles | HMS Queen Mary | HMS ''Plumper'' | HMS Britannia | HMS ''Investigator'' | HMS ''Express'' | HMS Duke of Wellington | HMS ''Britannia'' | HMS Ark Royal | Yangtse Incident: The Story of HMS Amethyst | HMS ''Winchelsea'' | HMS Volage | HMS ''Trincomalee'' | HMS Trincomalee | HMS Sultan (establishment) |
According to the Oxford Dictionary of National Biography, Grant's other inventions included "a naval fuel (briquettes known as Grant's Patent Fuel), a steam kitchen, which was given its first trials in the warship HMS Illustrious. He also constructed a new type of lifebuoy, and a feathering paddle wheel."
The raid was launched at 5.30am on 19 April, with 17 Barracuda bombers and 13 Corsair fighters from HMS Illustrious and 29 Dauntless and Avenger bombers and 24 Hellcat fighters from USS Saratoga.
He served with 806 Squadron (November 1940), 805 (early 1941), 806 Squadron (March 1941) & 801 Squadrons FAA at HMS Illustrious (aircraft carrier), HMS Heron (RN Air Station, Yeovilton, Somerset), HMS Eagle (aircraft carrier), HMS Victorious (aircraft carrier), HMS Indomitable (aircraft carrier) and at Crete and North Africa.