This heat exchanger works by being surrounded by fuel. Thus if shrapnel is entering the vicinity of this part, the vehicle and it's occupants are probably alre

This heat exchanger works by being surrounded by fuel. Thus if shrapnel is entering the vicinity of this part, the vehicle and it's occupants are probably already toast. Caveat / plot twist: If it's a kerosene or diesel chopper (common with Jet powered helicoptes), the fuel is much less susceptible to igniting due to a spark. Even still, how often does the outcome land on "If only the heat exchanger was more robust and impenetrable, everything would've turned out significantly better!" ?