Milisav Semiz was the leading Yugoslav combat in his IK-3 on date 06.04.1941

Milisav Semiz , Yugoslav pilot on IK-3 

Captain Vasilije J. Stojanovic (Royal Yugoslavian Air Force)
The three pips and the single stripe indicate a captains rank. He wears the royal air force badge on his visor and the pilot badge on his right breast. This uniform would have been a medium blue color. Note the square pocket flaps with the pleat...Black & white is original, color painted by me

Captain Vasilije J. Stojanovic (Royal Yugoslavian)

The Czechoslovak army had only 70 of these "mobile machinegun positions". Behind them you can see two LT35s.