Complex sentence: The first unit in the USAF of this nature was the 4400th Combat Crew Training Squadron, sometimes referred to as "Jungle Jims" or Air Commandos.
Split into simpler sentences: The first unit in the USAF of this nature was the 4400th Combat Crew Training Squadron. As such, 4400th CCTS personnel were sometimes referred to as "Jungle Jims" or Air Commandos.