the first production Hurricane I flew at Brooklands on 12th Oktober 1937 fitted with an early example of the Rolls Royce Merlin II that was rated at 1.030hp at 16.250feet (4.955m). this power unit drove a fixed pitch two bladed propeller and at a weight of 5,459kglb (2,476kg), the aircraft attained a maxium speed of 318mph (512km/u) at 17,400 feet (5,305m).
In January 1939 the Merlin II gave way to the Merlin III with the fixing of a constant speed three bladed propeller and it was this amanded specification that was adopted and all Hurricane Mark I`s were constructed using this configuration. Other alteratlons being the armament wich was four Browning .303 machine gun mounted in the wings.
By the 27th September 1939 ,Hawker had deliverd 497 Hurricanes to the RAF against the intial order of 3.500 and was enough to equip 18 Fighter Command squadrons.
