[Boris The Spider]

I remember in the original IL-2 that you would occasionally experience fouled plugs at startup and have to re-fly the mission after the "mechanics fixed the problem."

I think this is an excellent idea, having a engine problem every X number of hours or X number of missions. Say a drop in oil pressure, a bad sparkplug, magneto or a blown cylinder. Not always enough to put you in the slik, you could still limp home.
I'll give this a big +1