It was normally loaded with high-explosive shells, but could also be loaded with the M80 armor-piercing shell which could penetrate 1 inch (25 mm) of armor plate at 500 yd (460 m)

HTC (or anyone) knows what shells we got ingame ? If thats the AP, then its shells could go through the plane, leaving a big hole, but dealing limited dmg(if not piercing engine or any critical part), compared to a 37mm HE, which would have blown the plane, whatever part it landed on...