Question Leave mixture "set" on landings or go full rich?

[Neal]

I've seen conflicting "techniques" on the mixture control. Mike Busch mentioned in his EAA AirVenture seminar this past year about leaving the mixture set vs throwing cold fuel into the engine. In the spirit of not fouling plugs, I can also see leaving the mixture "set" and also for various density altitude's. The downside though is you may be "set" for lean of peak (LOP) which is also for a power setting and you do a go around, then what? Yeah, you could just push the mixture in for that.

Plenty of pro's/con's on mixture control, leaving it "set" as you come in for landing or going full rich. What do you do and what's your opinion on why?

 

[Waldom]

I would want the mixture control in full rich in most cases. At high density altitudes, you would need to keep in mind that leaning immediately after applying power during a go around could be necessary. With a rich mixture, you can be assured that the engine won't stumble with the application of full throttle in that situation.

The exception would be if the density altitude was so high at the landing airport that the airplane is at the edge of its performance envelope and/or if you are dragging the runway for an inspection knowing you will be doing a go-around. In that case, you might want to take the time to run up to full throttle and lean for best power at pattern altitude prior to making the approach.

 

[Neal]

I can see a difference depending on how you lean. If you run ROP such as leaning to 100 degrees ROP as some do, that could probably be something you could leave set. I run LOP and that's typically for a power setting and probably not ideal to be relying on for a go around at WOT. I'll probably stay with going full rich entering the pattern but interested in what people do.

 

[Cubonaut875]

Great topic, in the FX3 fuel injected i've been going to full rich for landing. In my Supercub with a carb I left it lean since if you rapidly went to full throttle it definitely would stutter. I love the fuel injection as you can go to wide open much more rapidly. A few years ago I almost hit a deer, listen to the throttle lag at about 1:30 in the video - you will be happy you have fuel injection. Lucky I was with my flight instructor who spotted the deer, we were going to help with a balloon launch.

 

[Neal]

Wow - my biggest nightmare in plane, car, and RV!

 

[ve6yeq]

My personal EX-3 approach checklists contain mixture rich, prop high rpm and aux fuel pump on to reduce the number of things that I need to deal with on go-around (red knob, blue knob, yellow light).
I find that trimmed for best glide and with full flaps as in go-arounds after forced approach practice, I already have to handle a multiple phase go-around with adding enough power to level off, reduce flaps to 16 deg, full power, raise flaps otherwise holding both the stick forward enough which is heavy and a heavy flap handle due to full power can be a lot at once. If I had to handle mixture and aux fuel pump as well it would be just two extra steps to remember.
In the Grob G115C that I did my initial training in, the mixture was right next to the throttle so it was easy to simultaneously with one hand motion push mixture rich slightly ahead of throttle full so I did not go mixture rich on approach but I still had boost pump on as in really cold conditions and negative DA, the engine driven fuel pump was not quite enough at full power.

 

[midlifeflyer]

Mike Busch mentioned in his EAA AirVenture seminar this past year about leaving the mixture set vs throwing cold fuel into the engine

What was he talking about at the time? Mike often talks about knowing the best power EGT number and setting the mixture for that rather than blind adherence to “mixture rich.” It’s in effect what is done for landing at high D-Alt airports (although most locals are guesstimating landing throttle position based on experience).

 

[Neal]

What was he talking about at the time? Mike often talks about knowing the best power EGT number and setting the mixture for that rather than blind adherence to “mixture rich.” It’s in effect what is done for landing at high D-Alt airports (although most locals are guesstimating landing throttle position based on experience).

I don't remember the full context of the seminar.