Advancing Throttle Shuts Down Engine Issue
Here is a solution to the issue that has worked for me. But first a bit of background:
Purpose of Mixture Control: (credit goes to Google AI) The mixture control in a Cessna 172 allows the pilot to adjust the ratio of fuel to air entering the engine by controlling the amount of fuel delivered, which is crucial for maintaining optimal engine performance at different altitudes, primarily by “leaning” the mixture at higher altitudes to compensate for the thinner air and maximize fuel efficiency.
Key points about the mixture control:
Pulling the mixture control lever “leans” the mixture, reducing the amount of fuel entering the engine, while pushing it forward “enriches” the mixture, adding more fuel.
As you climb in altitude, the air becomes thinner, so you need to lean the mixture to maintain the correct fuel-air ratio.
Leaning the mixture at higher altitudes improves fuel economy and engine efficiency.
Auto Mixture in the sim will do this for you; but I think there are some hardware setup conflicts that cause the controls to not behave as in reality. In real life in a C172, if you do the shutdown procedure and the engine is still running, you pull out the mixture control and the engine quits (the mixture gets too lean to burn). So I started to think that perhaps I was not paying enough attention to Mixture Control, because I had Auto Mixture turned on!
How to fix it: Turn Auto Mixture to OFF, on the Assistances Page (see below). In FS2000 this issue arose, and pilots had suggested that the yoke or throttle hardware was sending multiple signals, and in combination with Auto Mixture setting, were causing the engine to shut down when the throttle setting is changed (because the resulting conflicting signals caused the mixture to maximum lean). So first turn off Auto Mixture.
I do like some auto settings, mostly auto rudder, in real life it seems easier to do then in the sim, so I like the assistance in FS2024. Auto rudder will make your turns much better and smoother. I likey!
- Many of us use throttle quadrants, and that’s probably where the conflicts happen. On a lot of training missions, you start out at altitude. The instructor tells you to reduce power to decend or increase power to climb. As soon as I would change the throttle setting, for some reason the engine would quit, and doing a “Control E” to restart the engine, while the plane is sinking takes up time and then you fail for not being at altitude. Bummer. [However its good training if your engine really fails in flight! If it happens for real, you go down that checklist pretty quickly!] Soooooo, try setting your throttle and mixture levers to one of these settings:
½ way up the quadrant! (red knob). The blue knob is propellor control, which is not applicable in C172, but will become applicable as you fly more complex airplanes.
When I start a training mission, and I expect to be flying at altitude to start, I make sure my throttle is full on and the mixture is between half and full (usually full) as measured on the quadrant. If I am starting from the end of a runway, and my throttle is not advanced, the mixture is between half and full on the quadrant (usually full, but ½ seems to work as well) Explanation of why to follow below.
Even after Auto Mixture is turned off, you still may stall the engine, if the mixture on the throttle quadrant is not adjusted properly. So if it’s less than ½ down the quadrant you probably will shut down the engine. So be on 100%.
I cannot account for why the throttle and mixture are having a conflict, but I did notice one thing about the mixture setup that I do not understand. See next pic…….
The span of the mixture axis is from -100 to 100%, meaning that if the lever is full down its -100% and full up 100%. -100% is pretty lean (I think impossible in reality) , and would surely stall the engine. Soooo I think that the midpoint of the quadrant is actually 0, soooo if you have a mixture setting greater than 0 and or less than 100% the engine will be receiving the correct fuel/air mixture and you won’t stall the engine. You should have the mixture set at 100% (full on), [until you get to higher altitude]; because full OFF will cause the engine to quit; and of course lower than 0 surely will cause the engine to quit. Perhaps this is where the glitch is in the software, if your mixture lever is at the bottom of your quadrant, you are giving -100% mix to the engine – surely your engine will quit! I don’t even think this is reality. The span of the mixture axis should only be from 0% to 100%, so be sure your mixture level is at full on, or no less than ½ on the quadrant.
- Perhaps the easier way to fix this issue is to stay on Auto Mixture, then disconnect the mixture control in the throttle quadrant!!! I have also noticed that there are other mixture controls associated with my yoke controls, perhaps it might be a good idea to review all Power Management settings on all the yoke and throttle quadrant hardware, and make sure that your hardware is not sending conflicting signals. I have not tried these two fixes yet, but it seams reasonable.
I mostly fly C172 in sim, and have a lot of real time hours in a C172. I am working my way up to the big stuff (in sim), but I cannot see a reason for the span of the mixture control to be 100% to -100%. Perhaps this is something Asobo should fix??? Bottom line is, turn off auto mixture, and make sure your mixture control is full on, or no less than ½, as per the pictures above. I’ve tried this on missions and on ground starts and it works. Also, in real life this is how the mixture control works, the mixture is rich to start, and lean it out as you get to altitude.
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