The Pa28R Turbo Arrow III is my favorite aircraft, and so my constant choice. I have quite a few hours in it, and find it quite comfortable to command. I have only standard piston experience in real life and have learned in sim only how to operate this plane, by reading the manuals, and tutorials. The manual describes a mixture control, and there’s a nice EGT gauge, so I’ve been controlling mixture above 3000’ to max egt.
Then I read on the forum that turbo aircraft do not use a mixture control. I’m hoping the manual of the Arrow is correct, and perhaps there are a variety of turbo equipped aircraft that can clarify the validity of a mixture control on the Arrow Turbo.
There is indeed a mixture control on the Turbo Arrow. I flew the Turbo Arrow IV in real life for my commercial and CFI training. The turbo has a fixed wastegate so max MP can be achieved all the way up to 12,000 feet density altitude. So as long as that is possible, the engine thinks it is at sea level up to 12,000 feet. Above that, it can’t maintain sea level rated power anymore and the engine will start to act like a normally aspirated engine at that point. In cruise, the checklist does say to lean the mixture. When I flew it, if I remember correctly it was leaned to a particular EGT with a digital readout.
I’d venture to guess it uses the mixture to a lesser extent than a normally-aspirated piston engine (someone correct me), as that’s kinda the point of the turbo: to get more air into the fuel-air mixture. And a good rule of thumb for all engines is 125 degrees rich of peak EGT. You’ll basically never damage an engine running it like that.
Yes. The first item on the cruise climb checklist is MIXTURE - FULL RICH. Section 4.33 CLIMB in the Turbo Arrow IV POH states “The mixture control should remain at full rich during the climb.” The Turbo Arrow by JustFlight is different than that and DOES need to be leaned, but not because of JustFlight’s programming, but because of the way MSFS is programmed.
Turbo Prop - jet engine, often mounted backwards, with a gearbox and prop attached to the turbine shaft. Examples - Cessna Caravan, TBM, Quest Kodiak, PC6, Piper Cheyenne
Turbocharged Engine - traditional piston engine with a turbo charger to compensate at high altitude, Example - PA28 Turbo Arrow, Turbo Normalised variants of the Bonanza
I’ll slightly hijack this post since it’s about mixture control.
Is EGT is the only way to determine proper mixture? Cause according to EGT it’s always really low mixture for the highest temperatures…
I try to really closely watch RPM needle while changing the mixture. There are slight movements of the needle that possibly show if I’m doing something positive or negative for the engine.
Turbo charger mixture is incorrect in the sim. The game does not take into account the normalised pressure that results from boost and looks for the super lean mixture a normally aspirated engine would need at the same altitude.
There are otherways to determine the mixture, leaning till the prop RPM starts to drop then increasing a bit appears to be the standard technique in a fixed-prop aircraft without an EGT gauge.
While other people adjust the mixture to get a specific fuel flow rate they are looking for.
Must be a forum goof of some kind.