The Croatian Home Guard reached its maximum size at the end of 1943, when it had 130,000 men. It also included an air force, the Air Force of the Independent State of Croatia , the backbone of which was provided by 500 former Royal Yugoslav Air Force officers and 1,600 NCOs with 125 aircraft. By 1943 the ZNDH was 9,775 strong and equipped with 295 aircraft.
Question: Where did most of the Air Force come from?
Answer: former Royal Yugoslav Air Force