Why reliable aircraft can outperform better paper designs

Why did reliable radial engines matter so much to British wartime air power?

Lower maintenance demands kept more aircraft serviceable and produced more flying hours than superior but maintenance-intensive designs.

Bristol Pegasus radial engines illustrate the operational value of reliability. Compare aircraft needing four maintenance hours per flying hour with aircraft needing only two while holding the available workforce constant. Liquid-cooled inline installations also carried radiator and coolant weight and generally demanded more maintenance per flying hour than radials at this stage. The more maintainable fleet can generate far more daily flying time even if each individual aircraft looks less impressive on a specification sheet. Repeated over several days, that serviceability advantage becomes combat power because more machines remain available for patrols, strikes, and fleet defence.