Not sure what it means but the reason for the 5 props:
"Several rectifying design changes were made by Hawker in response to feedback from the test pilots, including the adoption of a five-bladed Rotol propeller to greatly reduce overspeed tendencies;....."
"The Hawker Sea Fury is a British fighter aircraft designed and manufactured by Hawker Aircraft. It was the last propeller-driven fighter to serve with the Royal Navy and one of the fastest production single reciprocating engine aircraft ever built.[2] Developed during the Second World War, the Sea Fury entered service two years after the war ended. It proved to be a popular aircraft with a number of overseas militaries and was used during the Korean War in the early 1950s, and by the Cuban air force during the 1961 Bay of Pigs Invasion."