Freezing Hispano cannon presented an integration problem because Spitfire and Hurricane airframes were built tightly around the Merlin, making major redesign difficult. German engine-mounted cannon avoided the same wing-installation problem, while the British later appear to have ducted warm air from the radiators to improve reliability. Both British fighters had been ordered with provision for wing cannon, so an earlier war might sharpen the incentive to solve a known problem rather than choose an intermediate heavy-machine-gun armament. Seeing a weapon work in combat can change the priority given to an existing design option.
Notable Point · 6:48-9:09
Cannon fighters and wartime learning
Early contact with cannon-armed fighters could speed British solutions to Hispano reliability and installation problems.
20 mm Cannon.50-Calibre Machine GunsAircraft ArmamentAircraft RadiatorsCombat LearningEngine Mounted CannonFighter AircraftFighter DevelopmentHawker HurricaneHispano CannonMilitary InnovationNaval AviationRifle Calibre Machine GunsRolls-Royce Merlin EngineRoyal Air ForceSupermarine SpitfireWeapons IntegrationWing Mounted Cannon