Why naval aircraft needed more than raw horsepower

Carrier aircraft carried burdens that a land fighter could avoid: another crew member for navigation, over-water survival equipment, night-flying aids, extra fuel, and dependable operation far from diversion airfields. Those demands absorbed much of the performance promised by a thousand-horsepower engine. Naval services sometimes accepted less power in exchange for reliability. Twin or coupled engines could therefore remain attractive despite their added weight and complexity. The Fairey Gannet later embodied this logic through the Armstrong Siddeley Double Mamba, which coupled two engines to contra-rotating propellers.