Mixture rich on approach?

Cessna vs Piper POH. Lean until the engine stumbles then richen it back up at all temps. The engine doesn't care if its hot or cold outside.
 
Timbeck2 said:
Cessna vs Piper POH. Lean until the engine stumbles then richen it back up at all temps. The engine doesn't care if its hot or cold outside.
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Hmm guess I will need to check my POH again...thought it said to be full rich below 3000
 

I fly a fuel injected Mooney out of South Valley but have flown various aircraft. I always lean for altitude. I have had an engine die from running full rich on a hot day. So I learned to give the engine the mixture ratio that will make it run most efficiently. Why at take off would you want your engine to run less efficiently than it could? It is a simple matter to look at the rpms being produced to determine the mixture that is optimal.


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Jozu said:
I fly a fuel injected Mooney out of South Valley but have flown various aircraft. I always lean for altitude. I have had an engine die from running full rich on a hot day. So I learned to give the engine the mixture ratio that will make it run most efficiently. Why at take off would you want your engine to run less efficiently than it could? It is a simple matter to look at the rpms being produced to determine the mixture that is optimal.


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I totally agree...I used to lean always before takeoff and at altitude of course...then the PoA changed my mind forever
 
Timbeck2 said:
You're in Phoenix right? Here, I'm only 367' below 3000' when I'm sitting on the ground.
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Yea deer valley is at 1500, but on a hot day could be close to that 3000 mark. Just wasn't sure if it would be better to give it that extra cooling from running mixture rich
 
Pilawt said:
Hm. U42 = 4600' MSL elevation. Even on a 65 F day, density altitude > 6000'. It's the CFI's call, of course, but I'm not a fan of partial-power takeoffs in my C-172N/180 hp.
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It is not a partial power take off. It is a full power take off with an optimized fuel to air mixture ratio. Full rich does not mean full power. Look at your engine performance metrics.


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Jozu said:
It is not a partial power take off. It is a full power take off with an optimized fuel to air mixture ratio. Full rich does not mean full power. Look at your engine performance metrics.


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zactly.....full power requires the proper mixture ratio.....which is often "not" full rich mixture.
 
I'm gonna start leaning before takeoff...if my engine burns up I'm blaming PoA forever
 
Handling the mixture knob is too much responsibility for me
 
CC268 said:
I'm gonna start leaning before takeoff...if my engine burns up I'm blaming PoA forever
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Go by the book. The book will take into account altitude etc. Play with a big fuel injected Continental for example at your peril if you do it wrong.
 
Jozu said:
It is not a partial power take off. It is a full power take off with an optimized fuel to air mixture ratio. Full rich does not mean full power. Look at your engine performance metrics.
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Taking off in a 172 at >5000' DA with the mixture knob all the way in is not an optimized mixture ratio. The engine is producing less power than it can, safely, in those conditions. That's a partial-power takeoff.

And I think you and Checkout_My_Six misunderstood my earlier post (my inartful prose, no doubt). We have a report of a CFI at a warm-weather 4600' MSL field mandating full rich in a 172 in all flight regimes except cruise. I'm saying it should be leaned appropriately even on takeoff and climb; to arbitrarily leave it "full rich" results in power loss, among other problems.
 
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denverpilot said:
Up here, the 182 isn't full rich for takeoff so it isn't full rich on approach either.

It would blub and sputter and carry on like a moonbat on Facebook like it was going to die, with a combo of full rich and carb heat.

Definite nope. I just twist it back up to about where it was for takeoff on the way down from cruise.
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What he said. I never ever use full rich not even at sea level.
 
The plane is supposed to be set up so you go full rich at full power at sealevel (density altitude sea level). One way to check is fuel flow. Fly it at sealevel (ok 500') at full rich and see if you are getting the fuel burn specified in the POH.
 
MAKG1 said:
Taking off leaned in a 182 at sea level is not a good thing. Minimum 18 GPH at full throttle, 15 at 23 inches.
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It's a TR182 and try 31" and 20+ gph.

In any case leaning for peak EGT or peak RPM is not "a bad thing"


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petrolero said:
It's a TR182 and try 31" and 20+ gph.

In any case leaning for peak EGT or peak RPM is not "a bad thing"


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And peak CHT. Don't forget that. And the limitation to not exceed 70% power leaned in the POH of many Cessna singles.

It's irresponsible as hell to introduce turbocharged operations into a thread clearly about natural aspiration, without qualification. Do you really want some student pilot to apply your statement to a 172? THINK.
 
MAKG1 said:
And peak CHT. Don't forget that. And the limitation to not exceed 70% power leaned in the POH of many Cessna singles.

It's irresponsible as hell to introduce turbocharged operations into a thread clearly about natural aspiration, without qualification. Do you really want some student pilot to apply your statement to a 172? THINK.
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GFY, interweb tough guy! Who made you the arbiter of what threads are about?

I'm sure students across America are hanging on your every word but not mine.

Cessna 182s of many varieties are notorious for fouling plugs and leaning for taxi and takeoff prevents that. I've lost a plug in flight. Not fun.

Also did you see the many other posts about the same thing?

You are why I stopped posting here anyway.

Petrolero out! Again. smfh


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Does anyone have any links or resources about leaning and overall engine management? Having done my primary training a long time ago and just getting back into the game my leaning knowledge is basically full rich under 3000 and lean to engine roughness with three turns in above that. With everything that's been posted I feel like I'm way behind the knowledge curve! If I remember right avweb had some great articles that I'll have to dig through again.
 
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Skid said:
Does anyone have any links or resources about leaning and overall engine management? Having done my primary training a long time ago and just getting back into the game my leaning knowledge is basically full rich under 3000 and lean to engine roughness with three turns in above that. With everything that's been posted I feel like I'm way behind the knowledge curve! If I remember right avweb had some great articles that I'll have to dig through again.
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Yes. Look for the early Pelican's Perch articles on AvWeb. Great stuff. "Manifold Pressure Sucks!" is the best description of constant-speed prop operations I've ever seen, and I frequently point people to it.
 
Skid said:
Does anyone have any links or resources about leaning and overall engine management? Having done my primary training a long time ago and just getting back into the game my leaning knowledge is basically full rich under 3000 and lean to engine roughness with three turns in above that. With everything that's been posted I feel like I'm way behind the knowledge curve! If I remember right avweb had some great articles that I'll have to dig through again.
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Here's the index to the John Deakin articles you're thinking about: https://www.avweb.com/news/pelican/182544-1.html

Those articles mostly talk specifically about operating larger, fuel-injected engines with good balance of fuel distribution among the cylinders, and good instrumentation. But the principles are good to understand, regardless what kind of engine you have. In a smaller carbureted engine, without all-cylinder CHT/EGT information, your technique (with 3,000' density altitude as the benchmark) works about as well as any.
 
simtech said:
I have read mike busch where he says the only time you should be full rich is start up and climb below 3k feet unless high DA airport. I have tried leaving it lean during approach but my instincts always have me richen it. Ive tried both but my brain says full rich. As soon as wheels touch down and I slow to taxi speed I lean aggresivly.
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Ignore mike. Read the manufacturers recommendation and follow.
 
CC268 said:
Hmm guess I will need to check my POH again...thought it said to be full rich below 3000
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Most often that only applies to full power (e.g. takeoff and climb). With most airplanes there is NO altitude where proper leaning won't improve efficiency and engine longevity. A lot of misunderstanding WRT the use of the red knob stems from CFIs and flight school owners trying to keep students and renters from abusing engines. If you want to learn the science behind engine mixture management attend the live APS course or at least try the online version.
 
Pilawt said:
Hm. U42 = 4600' MSL elevation. Even on a 65 F day, density altitude > 6000'. It's the CFI's call, of course, but I'm not a fan of partial-power takeoffs in my C-172N/180 hp.
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My first few lessons he showed me how to lean for altitude after the run-up. Then someone burned up the valves in the 152. After that he decided to change the app on his planes.
 
korben88 said:
My first few lessons he showed me how to lean for altitude after the run-up. Then someone burned up the valves in the 152. After that he decided to change the app on his planes.
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What was he teaching and did the student actually do it that way?

It's nearly impossible to fly non-turbo airplanes up here without leaning for takeoff and there's no "burning up" of valves going on.
 
denverpilot said:
What was he teaching and did the student actually do it that way?

It's nearly impossible to fly non-turbo airplanes up here without leaning for takeoff and there's no "burning up" of valves going on.
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Honestly I don't remember the specifics, just that he sent out a bulk email to everyone that said from then on he wanted full rich for takeoff, climb and decent. He also updated the checklists in the planes.
 
korben88 said:
Honestly I don't remember the specifics, just that he sent out a bulk email to everyone that said from then on he wanted full rich for takeoff, climb and decent. He also updated the checklists in the planes.
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His airplanes, his rules... but if he thinks *properly* leaning above 3000 MSL for takeoff, caused burnt valves, he's not right.

Someone is teaching something wrong, or someone is doing something wrong, to have that happen. That's all I'm sayin'.
 
denverpilot said:
His airplanes, his rules... but if he thinks *properly* leaning above 3000 MSL for takeoff, caused burnt valves, he's not right.

Someone is teaching something wrong, or someone is doing something wrong, to have that happen. That's all I'm sayin'.
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I don't remember the procedure that he taught at the time. I might have an old checklist somewhere.

I've been considering changing CFIs.
 
denverpilot said:
What was he teaching and did the student actually do it that way?

It's nearly impossible to fly non-turbo airplanes up here without leaning for takeoff and there's no "burning up" of valves going on.
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I've seen two engines quit from the mixture being too rich. Fortunately both were silk on the ground at the time, although one of them had just been cleared for takeoff.

I agree something weird is going on if a CFI is insisting on full rich takeoffs at high density altitude due to burning engines.
 
Like many others, from the entry to the pattern and right down to wheels on the ground it is flown with the mixture leaned. As I reduce throttle I automatically lean it a bit more (mixture goes richer as you close the throttle plate) This is not done by EGT, it is just pull the levers back another half inch.
As soon as the wheels touch it gets really leaned out (blubber blubber, shake like a wet dog, passengers scream and faint)
I have had maybe one fouled plug in the past 20 years - probably longer than that even (but then i'm not sure what I had for breakfast, eh)
My engines make TBO (way past)

Now, if I need to go around I will HAVE to advance the throttle to do it (I can't think of any other way to do it)
If I am worried that I cannot remember to also advance the mixture and props, I have no business flying. A tiny delay between full throttle and full mixture is meaningless - Especially given the windmilling engine at part throttle has cooled the head temperatures significantly.
In my case, I have levers, so everything goes forward at the same time. ymmv
 
Lotta opinions but it really only matters what the POH says.

@CC268 I owned a Piper for a year and here in FL with sea level operations or even 2K DA's I would use full rich to start, lean aggressively for taxi, full rich takeoff. IF I was climbing above 5,000 ft I would leave it on full rich until I climbed past that and then lean because RPM would start to drop. My POH recommended AGAINST full power and anything but full rich when < 5,000 feet.

If I was going somewhere less than 5,000 feet (which was 90 % of the time) I would use full rich until my destination altitude and lean for cruise, because for me cruise <> full power. I had a fuel flow meter so, it was easy to get the GPH target I wanted (while monitoring CHT's, no EGT in that plane).

Landing would be full rich and I'd have it there usually at TPA. I totally disagree with anyone saying I'll just firewall it (the mixture) on the go around. When you need power to go around, you need it now. A leaned mixture (depending where you are) may NOT GIVE you full power.

Why do you need one more thing to do on a go-around? Just push power, cleanup the plane as necessary and go. Prop and mixture should be where they need to be to give you FULL power at the moment you need it, not as you slowly increase to it.

Just my 2 cents...
 
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midlifeflyer said:
I've seen two engines quit from the mixture being too rich. Fortunately both were silk on the ground at the time, although one of them had just been cleared for takeoff.

I agree something weird is going on if a CFI is insisting on full rich takeoffs at high density altitude due to burning engines.
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I've had an engine quit in the flare at high DA, due to flooding. It wasn't full rich, either, just too rich. Probably close to 10,000 DA that day. It's a good thing I didn't need a go-around, but as it was, it was an uneventful landing. Clearing the runway, on the other hand, was a lot more difficult (especially since that airport didn't have taxiways). Flooded hot starts on an IO-360 are not fun....and there was no mechanic within 50 miles, so I really didn't want to drain the battery.
 
Tarheelpilot said:
Ignore mike. Read the manufacturers recommendation and follow.
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Ignore Mike at your own peril.

I'm not a big fan of the guy, but on matters of engine management, he's right.

Caramon13 said:
I owned a Piper for a year and here in FL with sea level operations or even 2K DA's I would use full rich to start, lean aggressively for taxi, full rich takeoff. IF I was climbing above 5,000 ft I would leave it on full rich until I climbed past that and then lean because RPM would start to drop. My POH recommended AGAINST full power and anything but full rich when < 5,000 feet.
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5,000 is pretty high to start leaning in the climb, IMO. The Mooney has an EGT gauge with a handy "Climb" range marked on it which makes leaning in the climb really easy. It's amazing how much difference it can make in performance even as low as 1500-2000 feet to keep leaning it during the climb instead of staying full rich. By 4500 feet, I'll lose a good 1/3 of my climb performance if I leave it full rich!

It doesn't take much - Maybe a half twist of the knob every 1000 feet or so at most - but it does make a big difference in performance.

If I was going somewhere less than 5,000 feet (which was 90 % of the time) I would use full rich until my destination altitude and lean for cruise, because for me cruise <> full power.
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Absolutely. The old "Don't lean below x feet" thing has bitten some people. *ALWAYS* lean for cruise, regardless of altitude.
 
remember....they are referencing a "density altitude"....not AGL or MSL. Big difference folks.

...and regardless you can't harm your engine by over leaning when the power settings are lower than 70-75%.
 
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