Complex sentence: The Midlands Air Operations Unit is a consortium of West Midlands, Warwickshire, West Mercia and Staffordshire Police which is based at Birmingham Airport and has operated since 25 July 1987.
Split into simpler sentences: The Midlands Air Operations Unit is a consortium of West Midlands, Warwickshire, West Mercia and Staffordshire Police and is based at Birmingham Airport. The Force's own Air Operations Unit has operated since 25 July 1987.