Complex sentence: On 21 June 1940 the Central Landing Establishment was formed at Ringway airfield near Manchester; although tasked primarily with training parachute troops, it was also directed to investigate using gliders to transport troops into battle.
Split into simpler sentences: On 21 June 1940 the Central Landing Establishment was formed at Ringway airfield near Manchester. Although tasked primarily with training parachute troops, it was also directed to investigate the use of gliders to transport troops into battle.