Complex sentence: The fourth, prior 22 Wing evolved out of a unit called the "Radar Control Wing", which was created by the air force in 1987 to run day-to-day air defence operations in the Underground Complex for the Canadian NORAD Region.
Split into simpler sentences: The fourth, prior 22 Wing evolved out of a unit called the "Radar Control Wing". The Radar Control Wing was created by the air force in 1987 to run day-to-day air defence operations in the Underground Complex for the Canadian NORAD Region.