Complex sentence: Typhoons were based at Lympne from March 1942 to February 1944 to counter the threat posed by the Luftwaffe's newly-introduced Focke-Wulf Fw 190s and a runway was extended across Otterpool Lane to accommodate the Typhoons.
Split into simpler sentences: Typhoons were based at Lympne from March 1942 to February 1944 to counter the thread posed by the Luftwaffe's newly-introduced Focke-Wulf Fw 190s. A runway was extended across Otterpool Lane to accommodate the Typhoons.