Bf 109E and Bf 110C

Louis Sheehan Notes

The Luftwaffe's Messerschmitt Bf 109E and Bf 110C fought against the RAF's workhorse Hurricane Mk I and the less numerous Spitfire Mk I; Hurricanes outnumbered Spitfires in RAF Fighter Command by about two to one when war broke out.^[46] The Bf 109E had a better climb rate and was up to 40 mph faster in level flight ^[47] than the Rotol (constant speed propellor) equipped Hurricane Mk I, depending on altitude. The speed and climb disparity with the original non-Rotol Hurricane was even greater. In spring and summer 1940, all RAF Spitfire and Hurricane fighter squadrons converted to 100 octane aviation fuel,^[48] which allowed their Merlin engines to generate significantly more power and an approximately 30 mph increase in speed at low altitudes^[49][50] through the use of an Emergency Boost Override.^[51][52][53] In September 1940, the more powerful Mk IIa series 1 Hurricanes started entering service in small numbers.^[54] This version was capable of a maximum speed of 342 mph (550 km/h), some 20 mph more than the original (non-Rotol) Mk I, though it was still 15 to 20 mph slower than a Bf 109 (depending on altitude).^[55]