Hey guys I've never quite got this down in the sim. What is the real world way to set mixture while climbing or decending. I know when taking off; depending on elevation to set it to full rich. But what is the rule to use or chart or is it just by feel. If so then how is it done in the sim? I've noticed it can be easier with some addon planes then others to know when to adjust. Of course I've used the tool tips in the past but this can be annoying so I turned them off.I talking about piston based engines only; no turboprops.

The only reliable method of leaning your mixture is using the EGT gauge. Leaning differs a bit between engines so this is a general leaning procedure. Lean your mixture while watching the EGT gauge. As the EGT climbs, look at the RPM and note where the RPM just starts to drop. This is your peak EGT. Now look at your EGT and enrich the mixture by 15-20 degrees. This is called running rich of peak EGT. Some may say to run lean of peak EGT but regardless you have to find peak EGT to properly set your mixture.Cheers,JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.sstsim.com/images/team/JR.jpg

I wondered about this for a long time too. Then I learned that the the EGT gauge is how it's done. Only thing is, there's a lot of panels out there that don't have an EGT gauge! When that's the case, I go as best I can by sound and feel.Cheers

Thanks, I'll put this procedure to use in my DF Baron58 since it has EGT gauges and they are really the only ones I perceive to be moving whenever I change the mixture position.

There is no 100% correct answer for it, but in a GA plane, you usually lean when climbing above 3000 MSL and you richen the mixture again when descending through the same altitude.I lean the mixture by pulling back the lever slowly until you notice an increase in RPM, pull back further until the RPM peaks and then richen the mixture to have the RPM drop by around 50.There are other methods using EGT, oil temp or pressure, but that's pretty much how I use it in a small C172.Hope this helps,Pat

For aircraft without an EGT, like most normally aspirated small aircraft, you would more than likely use a chart from the POH. The Piper Warrior IIIs that I fly in in the real world have cruise charts.The way these work is that you determine whether to use 70%, 60%, or 50% power for the cruise, each has different fuel burn and often are only 2 or 3 knots TAS from each other. From there, it's a matter of interpolating charts for your cruise altitude and temperature aloft. It'll yield an RPM setting to shoot for in cruise.From there, there are two methods of leaning: Best Power, and Best Economy. This is a general rule and different engines and POHs may specify a different method for each. I'm just going to share the one I know. Best Economy leaves the throttle full and leans the mixture until the RPMs reach the desired setting. Best power, has you throttle back to 50 RPM above the desired setting then lean the mixture to the desired RPM setting.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

Think about it.. what is the purpose of leaning? What are you trying to achieve?As you climb, the air gets less denser.. So the air to fuel ratio gets out of wack. The less air : Same fuel. basically as you climb... the fuel part of the ratio keeps going up in relation to air. Which means, its fuel rich...so you need to lean it. Reduce the amout of fuel to match the less denser air.And the opposite when you descend.So.. lets say you climb after take off to 5000 feet....1. In the steam guage planes, you keep reducing the fuel mixture (Leaning) the RPM increases....and then at the peak the RPM drops...at that point give two twist of the mixture enriching it. (Basically two twist richer from the leanest). Thats it. Now climb another 2000 feet do the same....2. Second method. Look at the EGT and the RPM while leaning..(EGT would be climbing due to hotter exhaust. Fuel cools) .and at the point the RPM drops, enrichen it till the EGT cools down two notches.(with 1 and 2, you are looking at the engine as a whole..not by each cylinder)3. Garmin 1000, Avidyne...you get lean assist.http://www.avidyne.com/products/emax_entegra.shtm"EGT and CHTExhaust Gas Temperature and Cylinder Head Temperature display cylinder head and exhaust gas temperatures for each cylinder in degrees Fahrenheit. The EMax

I find that leaning needs to take place sooner in FS than in real life.

Although the 3000ft rule is often quoted, at my club we're encouraged to lean at any altitude. For example, at 2000ft in a 200HP injected Lycoming IO360 powered Socata TB200 it's the difference between 16gph and 11gph! (S&L, 75%) Now with the current price of AVGAS here in Europe (

>I find that leaning needs to take place sooner in FS than in>real life.Oooooh tell me more Ismet, experience maybe?? :-)

Good point T. About leaning while on the ground taxing.Manny

Good question and VERY GOOD answers, I have the "tips note" letting me know many times that I have the wrong mixturs, so this is helpful......one of the problems I find, is with a quadrant, the mixture levers dont respond very well........I have the paid FSUIPC and calibrate but still ot sure it is right........this is probably another subject, but just thought I would throw out to the many experts we learn from............B42L8

Thanks John, and everyone that has responded to this thread; you guys have given some real good info on this subject! This is what I love about Avsim. :-)

This is really good stuff Manny!

>I find that leaning needs to take place sooner in FS than in>real life.I've noticed the same issue. I've flown Cessna 150/152s and Piper Cadet/Warrior IIIs and neither had the performance drop at 3000 feet that I get in the sim with the corresponding payware models.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach