Engines dont catch fire in AH.
Well I'm not a historian but I believe most American aircraft in WWII had self sealing fuel tanks to prevent fuel leaking from the tanks do to gunfire. Now obviously if you take a hit by a bunch of 20mm rounds its gonna leave one hell of a hole and fuel will leak but with an aircraft traveling 200 miles an hour or so, the fuel vapors would be too oxygen enriched by the air passing over the wing of the aircraft and therefor be above the fuel's UEL (upper explosive limit). If fuel still had a high chance of igniting under these conditions, modern jet aircraft would not have the option to dump fuel as it would pose too much of a hazard when the fuel vapors came into contact with super heated gasses from the aircrafts engines. If you don't believe me, drive your car down the highway, light a match and hold it out the window.
Something else to consider is that military grade or any aviation fuel for that matter has a substantially higher flashpoint than standard automotive fuels. I wouldn't recommend trying it but I could probably stand in a lake of JP-8 (standard fuel for most U.S.A.F aircraft today) with a lit road flare, drop it at my feet and not have a care in the world about having it light off. Now this one is up for criticism because I've been trying to find out what fuel WWII bombers used back then and so far haven't had much luck (I believe it was just a modified version of standard AvGas for the time.) so if someone could get back to me on that, I'll try to find its LEL and UEL for reference.
Another fact you all seem to be overlooking (like no one back in WWII could think of ways to solve these problems) is that just like the aircraft we have flying around today, even the gas tanks were equipped with fire suppression systems that would flood the said tank with foam were it to catch on fire. I believe the company mainly responsible for manufacturing these systems was the Walter Kidde Company out of Belleville, NJ. Here is a quote taken from a web page discussing the fire systems as well as other life support systems they made to support the Allied war effort;
"Somewhere out in the far Pacific, a wounded Grumman Hellcat is spiraling down. As the pilot ditches the plane in the sea, he pulls the cord on his Belleville-made flotation vest and escapes along with a Belleville-made inflatable raft. The vest and raft keep him afloat until he is rescued. A distance away, on the deck of an aircraft carrier, asbestos clad men, known as "Asbestos Joes", watch as a smoking war bird tries to set down on the deck. A Kidde fire suppression unit prevented the gas tanks of the plane from exploding in air giving the pilot a chance to come in. When the skidding craft bursts into flames on touchdown, the "Asbestos Joes" rushed straight into the flames, armed with Belleville-made flight deck equipment, doused the flames and saved the pilot. Wherever there was combat, Belleville was present in carefully crafted equipment to protect the fighting men."
Now with everything considered about the fuel, the engines WOULD be the most likely culprit for a fire on a plane and that is why WWII bombers were equipped with fire bottles.
Why don't people gather all the facts before going berserk?
I could keep going because hey, I only do this for a living and your the one sitting behind your computer playing a video game.
