As an engineer like as all when we have a problem we look for a cause. Ie mags timing plugs etc. it not a case of change a cly and all be ok. We look at eve eying that May have cause that. And guess what. The fella behind the controls is to blame nearly all off the time. If what Walter has just said is true we would not see the damage that we see. The little red knob is a major problem in the wrong hands. A 210 in around 1985 out bankstown crashed a killed all on board just after takeoff. Reason pilot though he was pulling pitch he pulled the red knob instead and crashed. I keep saying fuel is cheap.
Cheers