Brian Allen first went to sea as a naval aviation officer cadet aboard HMS Indefatigable in 1952, bound for Gibraltar. In 1954 he was appointed to Lossiemouth for fighter training and flew the Vampire T22. In December 1955 Brian joined 737 Squadron where he was attached to the Anti-Submarine Training Course flying the Fairey Barracuda. On completion he was destined to fly the then new Fairey Gannet twin turbo prop anti-submarine aircraft. July 1955, and now with 825 Squadron, saw his introduction of the new aircraft, a very different machine to the Barracuda. The Squadron joined HMS Albion on 10 January 1956, as she preceded down Channel in the company of her sister ship HMS Centaur, outwards bound for the Far East. After this tour was completed 825 Squadron was disbanded and Brian was transferred to 751 Squadron aboard HMS Warrior, an old WWII carrier with none of the latest facilities of his previous ship and on its final commission. However, his greatest shock was to discover that he would not be flying a Gannet, but the rather elderly Grumman Avenger, a very different airplane with a tail wheel and a piston engine. This would require a great change in take-off and landing technique.

In February 1957 Warrior sailed west for the Panama Canal and thence into the Pacific where she and her aircraft would assist in Operation Grapple, the tests of Britain's first atomic bombs. During this operation Brian's adventures included dislodging the padre's kidney stone upon a catapult launch, denting the flight deck by a heavy landing and ditching close to the beach after an engine failure. Having converted to helicopters Brian was posted to 815 Squadron aboard HMS Albion in 1960 flying the Whirlwind Mk 7. During this posting he survived another ditching when his helicopter lost power and sunk. Having returned from a long Far Eastern voyage, Brian was now posted into The Helicopter Trials and Development Unit and it was whilst experimenting in a prototype Wasp that an accident, in which his crewman perished, was to injure him so severely that he was unable to fly again. He completed his commission as an Air Traffic Control Officer