You can earn this on the first Japanese mission, Attack on Pearl Harbor, in phase three when you control a torpedo bomber, as long as you don’t switch planes during the phase. Drop your first torpedo on the West Virginia and keep heading across the airbase as you reload. The Monaghan will be headed right-to-left across your screen, and then turn towards you as it chases the mini-sub. Drop a torpedo on it from 0.3 to 0.2 miles out and the destroyer will sink straight away. After that, circle back right and drop your third torpedo on the West Virginia, ending the phase and earning Hat Trick.