for example, i don't talking about of only sparks. In a burning hurricane , the little pieces of fuselage that impact in the 109 that we flying. Or the dornier that dispread pieces of fire. they are not only aluminum structure and heavymetal pistons. there are so much things around of a engine that can dispends pieces of fire over our glass. like one said before, depend the aircraft. Hurricanes and gladiators have a particularly fuselage.
when we are so close of a plane that we shot down, for example, a hurricane or spitfire whit small guns, is obvious that we will see sparks, burning fragments and pieces of fire and shit and effects like that very close to us
pics of that time don't say so much
anyway, is a little detail the sparks in the burning aircraft or sparks coming of our engine and for a damage cylinder/piston and we can see this in the left/right of the canopy .
if oleg team don't put this, someone maybe , in a far away future will do a mod. that mod will call: "spark and pieces of shits coming on an burning plane"