Leaning on taxi

One thing that wasn't covered too well in my private pilot training was leaning the mixture on taxi, should I run lean during ground operations? What are the benefits vs. running full rich? How far should I lean?

Finally, what if I forget to put the mixture back onto full rich prior to take-off, is it dangerous?

airframe-and-powerplant

asked Feb 04 '10 at 21:22

JoeSEL ♦♦
213●1●2●13

edited Feb 05 '10 at 16:01

Patrick Pohler ♦♦
1337●18●41●117

3 Answers:

oldest newest most voted

Consult your POH. Some engines are susceptable to plug fouling when near idle on the ground, and "leaning for taxi" is suggested in these cases. For a normally aspirated engine - all I can speak to - there is no danger leaning as much as you want at very low throttle settings. IF the engine gets rough, enrich slightly. It is very important to go to full rich before the run-up, and especially before takeoff power, or you run a small risk of too-lean detonation damaging cylinders &/or exhaust components...

answered Feb 05 '10 at 21:57

Sarah
146●3

I'm with Sarah, first step is to check your POH. Next, if this is an aircraft owned by someone else (FBO, flight club, owner) check the owner's preference for leaning on taxi and ask what they do.

What I do in the Piper Warrior is set my RPM to 1000, then lean, watching the rpm increase. When the rpm starts to decrease, I note what the highest rpm was and enrich until I get the highest rpm back. That's the mixture setting I use for taxi.

Its a very good idea to full rich for run-up (it should be on your checklist). But if you accidentally forget, you'll know when you apply power, the engine will sputter and struggle. Just back off the throttle and enrich your mixture. There's a small risk of detonation, but if you catch it immediately and don't keep the power on for a long period of time I think you'll be fine. Again consult your POH and the aircraft owner.

answered Feb 09 '10 at 06:26

Patrick Pohler ♦♦
1337●18●41●117

Did you mean 2000 RPM or what you wrote as 1000 RPM. I don't think you'll get very good results with an "idle" setting.

(Apr 28 '10 at 15:03) wbeard52

Leaning for taxi will help prevent plug fouling. Full rich is appropriate for take off except in some situations such as high altitude take offs where you want maximum power. For this, during run-up, I go full throttle and lean to max RPM then enrich slightly. The POH should provide whatever info you need for your aircraft.

answered Aug 03 '10 at 19:36