Mitsubishi Stuka and Thunderbolt

[JtD]

Whatever the ignition component on top of the hub was, it's crucial for the engine and there's no backup system. I'm nowhere near my sources, so you'll have to look at the details yourself. One hit in the right spot, the component's dead, and the engine dies with it. You can also try in game and shoot the engine into other parts, you'll see it keeps working.