Originally Posted by
The500man
It sounds from reading my Lycoming manual like they would rather provide a one-size fits all solution with regards leaning to keep things relatively simple. They don't recommend operating at LOP and they don't recommend leaning above 75% power, although they make some exceptions along the lines of if the POH says so! I can quite believe there are more efficient ways to operate an engine in the various conditions that may be encountered in flight than the fairly hard line of the POH, but for most private pilots in single pilot aircraft, ultra-fine engine management is probably a little too much to ask. It's good to aspire to fly as well as possible though, so for anyone that wants to learn how to improve on the manufacturers operational recommendations it's probably definitely worth spending money on extra education even if you aren't going to recover the cost through fuel savings. There probably should be a disclaimer here about not ignoring your POH because you THINK you know better. Make sure you KNOW what you are ignoring and more importantly why.
Anyway this thread was about engine checks and someone mentionecd a static RPM check.
I think there is a subset of pilots who are LOP nerds and I mean that in the nicest possible way. That is they have spent the big bucks to buy and install an engine analyzer and learned how to understand what it is saying so that they can achieve measurably more efficient flying with respect to the only metric that really matters, Miles of flight per Pound of fuel.
However for the average PPL flying a trainer/tourer with a simple carburated engine IMO 80% of the maximum possible fuel efficiency can achieved by simply leaning to engine roughness and then pushing the mixture knob up to smooth operation plus a little bit. But most people just seem to fly around with the mixture full rich all thr time
. The engine should be leaned
anytime the aircraft is in cruise. I don't think it is well understood that excessively rich mixtures can be just as bad for the engine as too lean a mixture.
With respect to the static RPM check I will abort any takeoff where I do not see the initial RPM within the POH range. Yes it could be a out of tolerance RPM gauge but it could be something more serious and if it is the gauge the unit should be fixed as it will be impossible to accurately set any power.