by Brett_Henderson » Tue Jun 26, 2007 6:36 am
A book, or at least a chapter, can be written about mixture settings.. Unfortunately, one of the shortcomings in MSFS realism, is the gauges that center around mixture adjustment; EGT and fuel-flow, specifically. There is more than one method, and more than one proper setting.
Since you, as a pilot, will know what your fuel-flow will be at a given altitude and power setting; the fuel-flow gauge is more like a confirmation gauge to cross check after leaning. The EGT (or ITT on a turbo-charged engine) is the primary mixture gauge.
"By the book", after you're level and trimmed, you'd lean SLOWLY until the EGT peaks, and then richen by one increment colder. Now.. some pilots (plane owners) believe it's better to lean to peak and stay there. The logic is that even though you'll shorten engine life by a tad; the money saved in fuel more than makes up for it. You can pretty much duplicate this by leaning until you lose power audibly and then richen slightly (how many students are taught in planes with no EGT).
The big rule of thumb is... Full rich under full power until 3000msl, then lean just enough to see a slight temp increase on the EGT and try to keep it there (never letting it peak) until you level for cruise and then lean accordingly.
Richening for descent is an in-exact science. Just try to richen in proportion to your altidude (if you were cruising at 6000msl, have the mixture 1/2 way in by 3000, etc.) and have the mixture at max power before landing.
Now.. max power can be a tricky thing when you're taking off or landing at a high-altitude (or high density altitude) airport. If, for example, the density altitude is 3000feet, and your plane is at maximum gross takeoff weight, a full rich setting will yield way less than the maximum power you'll need. Finding that sweet-spot is important. You can't just do a run-up and lean like you would for cruise,
Last edited by
Brett_Henderson on Tue Jun 26, 2007 6:38 am, edited 1 time in total.