| English term or phrase: fixed-pitch prop | I'm not taking sides on the LOP question. If your airplane manual or the documents that accompany any STC engine modifications say LOP is approved, I have no problem flying the engine that way. The crossflow head engines in the Continental 550 family are particularly happy at LOP.
However, some engines just don't sound smooth at LOR They stumble or shake mote at that setting, and that tells me they aren't happy even if the procedure is approved. I want the engine to sound smooth and happy, so if it's not when at LOB I put in the extra fuel. And, of course, at power settings above cruise, the engine should always be well rich of peak.
In Continental's computer-controlled engines (fadec), the computer has control of the precise mixture hi each cylinder individually and sets it at LOP for cruise power, but as soon as you advance the throttle past cruise, the computer switches back to rich of peak. For pilots who want the extra power of rich of peak operation, that mode could be selected on the fadec control Continental engineers were fine with LOP under certain cruise conditions, and that is what they programmed into the fadec computer.
A piston engine typically makes die most cruise power with the mixture set about 150° F rich of peak. However, for takeoff and initial climb, the mature should be even richer to maintain the greatest defense against detonation. The fuel systems are set up to deliver that detonation margin at lower-elevation airports, but when the airport is high and the temperature hot, the pilot has to lean the mature on takeoff to produce maximum power. The standard advice in that situation is to lean enough for smoothness, or for maximum rpm with a fixed-pitch prop.
>> Increased airspeed is an obvious cooling advantage because a greater mass or air is forced over the engine. |
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The translation workplace 
peer agreement (net): +3
