How far do you lean while on the ground before takeoff

James331 said:
Back till it stutters, than forward enough to smooth out, at the taxi power settings you're at for taxi you can't hurt anything leaning too much.




That.

You're going to need to lean for takeoff in high DA conditions for most any piston plane.
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Nah, it wasn't specifically "high" DAs; if I recall correctly, it was a SOP anytime - target the fuel flow (19 GPH sticks in my head, but it's been 4-5 years). Any warmish day it needed doing, though the field was at-near sea level. I do recall blasting off full rich often enough, but on plenty of just above standard days I think it required leaning for takeoff, in conditions I wouldn't be leaning a 172.
 
In typical Cessnas and Pipers I've flown, lean till it stumbles, then enriched just enough till it smooths out for all ground ops. Full rich for pre-takeoff check. Then, for high DAs (above 3,000' only), lean to the sea-level takeoff EGT value during the takeoff roll, as soon as RPMs stabilize at full power. This is what I was taught long ago. Its worked so far.
 
Sundancer said:
???? Which model? At least some 182s call for leaning for takeoff power - I seem to remember a CAP 182 I flew quite a but had that in the POH? I think/think I leaned for a certain fuel flow if I recall.
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Newer 182s with Lycosaurs that also have built in fuel flow meters will have some fuel flow “goals” in their manuals. It changes with altitude/DA in the manual as well in the 182S.

The T182T being that it has a turbo, not so much. It’ll “come from together” like Clark’s Piper engine for the same reasons if not given enough dinosaur juice at takeoff.

I believe the R182 / “182RG” also had fuel flow targets long before it was a thing in most other 182s because of its oddball engine and fuel delivery system as well, but I don’t have my book here that should be here on it.

Hmmm. Where did that thing go?

Anything Q model or earlier probably is not going to have any fuel flow targets and is just going to say “Rich” on the taxi and takeoff checklists. Folks have learned over time that full rich isn’t always the best way to operate them and therefore, don’t. The engines will tell you when they’re unhappy and you just have to pay attention to them.

Most of those models also laugh hard enough if you try to run them LOP, due to crappy air flow design, that they’ll start hiccuping with said “laughter”. You’re pretty much stuck with ROP in the big fat carb’d six banger Continental variety of 182.
 
denverpilot said:
Newer 182s with Lycosaurs that also have built in fuel flow meters will have some fuel flow “goals” in their manuals. It changes with altitude/DA in the manual as well in the 182S.
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It's on a placard, actually.
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James331 said:
Back till it stutters, than forward enough to smooth out, at the taxi power settings you're at for taxi you can't hurt anything leaning too much.
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:yeahthat: The fi big block conties pump extra fuel at full rich and that’s not good for the plugs or cylinders...:nono:
 
Sinistar said:
So both you guys speed up and slow down during taxi using the mixture control :confused2:
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Not only that I even use mixture control to reduce power as I descend and approach for landing. NOT a single drop of precious 100 LL should be wasted and I think my engine likes it a lot.
 
blueskyMD said:
Not only that I even use mixture control to reduce power as I descend and approach for landing. NOT a single drop of precious 100 LL should be wasted and I think my engine likes it a lot.
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Wish I could get away with that. In the radials, I have to enrich the mixture throughout the descent.
 
blueskyMD said:
Not only that I even use mixture control to reduce power as I descend and approach for landing. NOT a single drop of precious 100 LL should be wasted and I think my engine likes it a lot.
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Wow..as I let down I gradually go to mixture rich. Yes, it will waste fuel. But being that close to the ground I want mixture rich for any go around or need to climb.

From your description I get the sense you are actually landing with the mixture still lean? Are you based at a high elevation?
 
Sinistar said:
Wow..as I let down I gradually go to mixture rich. Yes, it will waste fuel. But being that close to the ground I want mixture rich for any go around or need to climb.

From your description I get the sense you are actually landing with the mixture still lean? Are you based at a high elevation?
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Can’t answer for him but I’m not full rich during landing here at our altitude in the 182. Some other stuff behaves better. Depends on the airplane.

At first you get a little paranoid about it and it’s further forward than when you took off, and if you’re returning from an XC and don’t really have a reference for where it was happiest today, it’s just an inch or so back even further forward.

But after a lot of hours behind this same engine, you just know and can hear when you’ve got it too rich. You stop worrying about it quite as much.

And you can always pay attention and bring the mixture up with the throttle if you’re really worried about it in a go-around. I think everyone who’s flown a while has found the mixture or prop a little back after landing once or twice and thought, hmm. That’s not supposed to be there. Someone missed both their flow and their checklist didn’t they. And their GUMPS.

Then you go beat those back into your head and behavior if you got lazy.

In the left seat I always stick out my thumb in Cessnas and close the carb heat when adding full power. I found my left hand doesn’t have a convenient thumb sticking out the correct direction when I switched seats. Dang it! :)

Switching seats will get ya to bust any bad habits about not confirming what lever or gadget or handle you’re messing with before moving it. That’s for sure.

Especially in a twin.

Making your hands do the opposite jobs of what they’re used to, is entertaining at first. Usually it’s not feeling awkward after about two flights.
 
Skyrys62 said:
The rental I fly consistently will shake horribly on the R mag check if I don't lean it pretty aggressively for a couple minutes at taxi/runup.
Apparently no one else ever leans it.
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I have a similar issue, but it is not caused by lack of leaning. The airplane stutters on 'R' because the oil pools in the lower plug and fouls it. The 'R' magneto drives lower plugs on the even bank and upper plugs on the odd bank. It was suggested to me that my valve guides are shot in one cylinder.
 
My school's C-152 checklist always said to lean the mixture 1". It wasn't until later on I started seeing, 'lean for best power'. I will say that ever since I stopped using the 1" method I have to wonder why a flight school would condone such a thing.
 
I lean until it spits and sputters, then richen enough to keep it running. Have to adjust some if you need to advance the throttle much. It's pretty hard to forget you're leaned because it'll croak when you throttle up for run-up.

I'm a bit less aggressive when I'm on mogas, which is most of the time, but if I'm running blue gas, I lean hard on the ground to keep from soaking the bottom plugs in (CH3CH2)4Pb.

Carb'd C-182.
 
Bill Jennings said:
I lean until the footpeg touches, see below!
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Most bikes have more lean left when the peg scrapes. I did have an early 90's ninja that would scrape the exhaust pipe on one side. The other guys on the track complained that the sparks were distracting so I never adjusted the suspension to stop it. :p
 
Sinistar said:
Wow..as I let down I gradually go to mixture rich. Yes, it will waste fuel. But being that close to the ground I want mixture rich for any go around or need to climb.

From your description I get the sense you are actually landing with the mixture still lean? Are you based at a high elevation?
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No I am not based at high elevation
And your guess is right. I land with leaned mixture. Now this is for most normal landing days with nice weather and normal length runway etc. If things change like making low IFR or short runway with gusty winds or increased possibility of GA then I follow regular checklist.
 
blueskyMD said:
No I am not based at high elevation
And your guess is right. I land with leaned mixture. Now this is for most normal landing days with nice weather and normal length runway etc. If things change like making low IFR or short runway with gusty winds or increased possibility of GA then I follow regular checklist.
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Thank you for clarifying. I did figure that those at elevation both took off and landed with the mixture leaned for best engine power. However, i never realized that some pilots land mixture leaned when density altitude is not a factor. In the non-DA case i figured the most precarious situation would be a throttle near idle, mixture lean, short final...GO AROUND. If the red knob doesnt go in before the throttle wouldnt the engine surely stumble due to lack of fuel and such slow, nearly windmilling rpm?
 
Thanks all for these great replies. I learn a lot from you guys. I know I am a better pilot because of POA.
 
Sinistar said:
From your description I get the sense you are actually landing with the mixture still lean? Are you based at a high elevation?
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I do the same as @blueskyMD in that I land with it still leaned. My feeling is that my hand is on the throttle quadrant and it's easy to push everything forward if needed. In the real world I am always ready for a go-around but it very rarely happens. In the last year, I had one due to traffic on the runway not far enough down and I was expecting it when tower called for it.
 
midlifeflyer said:
Slightly in North Carolina. Much more on the plains in Colorado. Almost to engine starvation in Leadville. Most guestimated.

almost 30 years flying. 20 years in Colorado, Never failed to set the mixture to the proper setting for takeoff. Not even once.
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Gotta love the 'irony' of Leadville
 
gacoon said:
What do Cirrus owners do?
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In my Cirrus NA I lean aggressively on the ground, per Deakin’s philosophy. That seems to be the consensus of what’s best here too. After startup I turn off the aux boost pump and lean back until it sputters, then enriche slightly to get it running smoothly again. During my take off flow check, boost comes back on and I sweep both the mixture and the power lever with one hand as I accelerate. It’s intersting to note that at 1000 rpm idle, when boost is on and the mixture is rich, the engine is actually running rough. Way too much fuel is going in there, I can almost see the plugs fouling up.


BTW - There’s a rule of thumb for high altitude ops for takeoff mixture setting: lean to the “R” for elevation (DA) of 6000’, to the “T” for 9000’ (mnemonic is T for Telluride).
 
Rod says lean enough so when you firewall it for takeoff it stumbles if you forget to go back rich.
 
Jorge Borbolla said:
In my Cirrus NA I lean aggressively on the ground, per Deakin’s philosophy. That seems to be the consensus of what’s best here too. After startup I turn off the aux boost pump and lean back until it sputters, then enriche slightly to get it running smoothly again. During my take off flow check, boost comes back on and I sweep both the mixture and the power lever with one hand as I accelerate. It’s intersting to note that at 1000 rpm idle, when boost is on and the mixture is rich, the engine is actually running rough. Way too much fuel is going in there, I can almost see the plugs fouling up.


BTW - There’s a rule of thumb for high altitude ops for takeoff mixture setting: lean to the “R” for elevation (DA) of 6000’, to the “T” for 9000’ (mnemonic is T for Telluride).
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There is no general rule of thumb for leaning for high density altitude operations. After operating a particular aircraft you'll get a feel for where it should be on that aircraft. There are some rules-of-thumb for number of vernier twists to be properly set rich-of-peak once peak is found. The number five (half twists) is good for many 172s and maybe even 182s.

Welcome to POA.
 
Clark1961 said:
There is no general rule of thumb for leaning for high density altitude operations. After operating a particular aircraft you'll get a feel for where it should be on that aircraft. There are some rules-of-thumb for number of vernier twists to be properly set rich-of-peak once peak is found. The number five (half twists) is good for many 172s and maybe even 182s.

Welcome to POA.
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How about 100 F over peak EGT for high DA take off? If u hav an engine analyzer u know the approx number in the air, what I don’t know is how close that will be on the ground


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WannFly said:
How about 100 F over peak EGT for high DA take off? If u hav an engine analyzer u know the approx number in the air, what I don’t know is how close that will be on the ground


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100 is close and might be okay if that is the warmest cylinder. I'm assuming you mean 100F rich of peak. I think most folks target average numbers in the 125 to 150 F rich of peak for best power.
 
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