The prototype and early production Hurricanes were fitted with a Watts two-bladed fixed-pitch wooden propeller. "Flight" commented of this arrangement: "Many have expressed surprise that the Hurricane is not fitted with variable-pitch airscrews". The original two-bladed propeller was found to be inefficient at low airspeeds and the aircraft required a long ground run to get airborne, which caused concern at Fighter Command. Accordingly, trials with a De Havilland variable-pitch propeller demonstrated a reduction in the Hurricane's take-off run from . Deliveries of these began in April 1939: this was later replaced by the hydraulically operated constant-speed Rotol propeller, which came into service in time for the Battle of Britain.