Hey guys, I'm now flying a Cessna 206 a lot. I joined something called FS Economy, it's very cool you may want to check t out. Well back to my question, this FSE thing requires that I fly long distances with my 206, so I was wondering, once I reach my cruise altitude what settings would you recommend for my fuel mixture, props attitude and throttle??
Any other advice on how you would operate a 206 in real life is appreciated since the way I fly the plane has an impact on how much I'll get charged on the 100hrs maintenance.
I am sure there are more qualified individuals to post on this than I, but I do believe you want to adjust the mixture for optimum "EGT" (exhaust gas temperature). Then you adjust your prop for optimum prop RPM whilst keeping an eye on indicated airspeed. Through all of these "tweaks" watch for lowest fuel flow rate as you try to achieve a nice neutral trim....watch for stable altitude. The reference sheet in the kneeboard should give some basic settings for cruise to start from.
Thank you sir. I also got this advice from another forum, I thought I'd share with you guys:
Quote:
I've flown a C206, got a few hours in a C210, got many hours in a C182, and many MANY hours in C177rg.. They're all pretty much the same when it comes to prop RPM, and mixture.. The only differences might be in RPM settings, that will vary 100-200 RPM depending on the specific engine, and specific prop.
Assuming a max take-off RPM of 2700 (very common for all these planes) and a sea-level take-off... you'd start with maximun manifold pressure, maximun RPM, and full rich. As soon as the climb is established and the flaps are up, a dutiful pilot will reduce RPM by no more than 100 and continue climbing. If your cruising altitude will be at least 5000msl you'll not need to touch the throttle at all, as the manifold pressure will come down on its own.. As you go through 3000msl you'll lean slightly. In a real plane, you do this by the EGT gauge getting it come up just a bit. You want a mostly rich mixture under a full-power climb, so leaning is ever so slight until you're level and cruising.
75% cruise power is around 25" of manifold pressure and 2500 RPM with the mixture leaned to where the EGT gauge peaks, and then richened slightly (normally 2 notches on the EGT gauge). The problem with FS9/X EGT gauges, is that they aren' very accurate or responsive (though some 3rd party gauges are), so you need to lean by fuel-flow. Lean until the fuel-flow peaks, and then continue leaning just a tad more. That gives a pretty realistic fuel-flow (if the plane is modeled accurately).
If you cruise at much higher than 5000msl, you won't be able to hold 25" of manifold pressure. The trick here is to keep the prop RPM and manifold pressure "squared"... i.e.. 24"/2400rpm ... 23"/2300rpm.. never going below 2250rpm and NEVER setting the prop RPM lower than the manifold pressure ( 24"/2300rpm).. That's like bogging a car down with too high a gear (like starting out in 4th gear) and is hard on the engine.
When descending (or slowing), the ideal situation is to lower manifold pressure by 1 inch per minute (this avoids shock cooling), but in a pinch you can reduce power more quickly.. just don't go below 21" until you've been near 21" for a good minute(or two). As for leaning during descent, it's up to you to try to keep it proportional. Once you're below 3000msl, it's OK to go full rich; either to prepare for landing, or to re-lean at your new altitude.
Just remember to have the prop-rpm back to full before you turn final, in case you need to go around...
Now.. for other than sea-level take-offs/landings, an already leaned mixture might be called for. If you take off from a Denver airport, in a C206, you'll have the mixtured leaned significantly from the start. You can find that sweet spot during your run-up (because it can vary depending on the density altitude that day), by adjusting the mixture for an RPM peak, and you'll hear it, too.
Those are the basics, and should be all you need to know for simming with a constant-speed prop, and a normally aspirated, piston engine..
ALMOST FORGOT embarrassed
Cowl flaps !.. Open while taxiing and climbing , closed while cruising... DO NOT forget to open them after landing.. if the next pilot forgets to check them, and takes off, it'll will take some life out of that engine Angry
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