Complex sentence: He joined No 41 Squadron in Aden flying Demon fighters, which returned to England later that year to be re-equipped with the Hawker Fury, and again in 1940 with Spitfires.
Split into simpler sentences: He joined No 41 Squadron in Aden flying the Hawker Demon fighter. The squadron returned to England later that year to be re-equipped with the Hawker Fury, and again in 1940 with Spitfires.