Complex sentence: During his time as CAS Burnett's prime focus was EATS but he also founded the Women's Auxiliary Australian Air Force (WAAAF) and RAAF health services, the latter having previously been provided by the Army.
Split into simpler sentences: During his time as CAS Burnett's prime focus was the EATS. However, but he also founded the Women's Auxiliary Australian Air Force (WAAAF) and RAAF health services, the latter having previously been provided by the Army.