This bust is of a female pilot of the Air Transport Auxiliary. This almost forgotten arm of the RAF were responsible for delivering aircraft from factories to the front line.
These pilots had little training on the specific aircraft, it was not unusual for the only familiarisation to be the aircraft handbook. there is one story of Jackie Moggridges propping up the handbook of Supermarine Walrus in the windscreen while taking off!
The bust was inspired by reading the biography of Mary Ellis, who sadly died recently but delivered 76 different type of aircraft including hundreds of Spitfires.