Do you lean as you climb ?

[pagirard]

Hi everyone,

I have a question for the Mooney experts here: do you lean in climb ?

I fly in Florida, low density altitude most of the time and MSL is almost AGL. I typically lean for taxi (by ear), take off full rich. Climb 25inMP/2500RPM and I start leaning "a bit" every thousand feet starting at 4000ft. I choose my IAS to keep the CHT below 405F, it's usually 105-107kts, when the sky is clear, I also engage the RAM boost air to help with cooling and the additional inch of MP.

When I reach my cruise altitude and the plane is configured for cruise: 24inMP/2400 and trimmed. I then go back to full rich and then do a big lean pull to find the peak EGT and try to lean around -10F/-20F LOP while carefully observing the CHTs.

 

My climb performance isn't great so my question is: is it better to leave the mixture full rich in climb and only lean when reaching cruise or leaning as you climb ?

 

Bonus question: how about in places with much higher density altitude, do you ever take off with mixture not full forward? How about the climb ?

 

Thanks in advance for your help.

 

Pierre

[Greg Ellis]

@pagirard  Go to here:  Advanced Pilot   Download the Target EGT power point presentation.  It should help understand the leaning as you climb concept.  You are fortunate that it will be easy for you to put this into practice since you are at sea level.  It will also give you a good reference for when you are departing from any airport at any density altitude.

It is for normally aspirated engines such as your E model.  And, yes, I do lean as I climb.

 

[Ragsf15e]

46 minutes ago, pagirard said:

Hi everyone,

I have a question for the Mooney experts here: do you lean in climb ?

I fly in Florida, low density altitude most of the time and MSL is almost AGL. I typically lean for taxi (by ear), take off full rich. Climb 25inMP/2500RPM and I start leaning "a bit" every thousand feet starting at 4000ft. I choose my IAS to keep the CHT below 405F, it's usually 105-107kts, when the sky is clear, I also engage the RAM boost air to help with cooling and the additional inch of MP.

When I reach my cruise altitude and the plane is configured for cruise: 24inMP/2400 and trimmed. I then go back to full rich and then do a big lean pull to find the peak EGT and try to lean around -10F/-20F LOP while carefully observing the CHTs.

 

My climb performance isn't great so my question is: is it better to leave the mixture full rich in climb and only lean when reaching cruise or leaning as you climb ?

 

Bonus question: how about in places with much higher density altitude, do you ever take off with mixture not full forward? How about the climb ?

 

Thanks in advance for your help.

 

Pierre

I would also recommend keeping full throttle and 2700rpm as you climb in addition to the target egt mentioned above.  Additionally, most people will climb at a little higher airspeed to keep temps a little lower than your 405.  Say maybe 115-120kts for below 390.  The old 25/2500 thing has been mostly discredited at this point as full power is quickest to climb and not harmful to the engine.

[McMooney]

max rpm and throttle to altitude

 past 3000 ft, pull mixture just enough to get the egt to wiggle  and adjust every thousand feet or so.

don't really touch much until cruise, where i set rpm to say 2300 and adjust mixture to peak or below.

when flying distance,  i generally cruise at an altitude when mp falls to below 23in

 

Edited February 12, 2024 by McMooney

[skydvrboy]

7 hours ago, pagirard said:

Bonus question: how about in places with much higher density altitude, do you ever take off with mixture not full forward? How about the climb ?

At several airports in Colorado if you leave your mix full forward you'll just flood the engine.  For high density altitude run up, you go full throttle, lean until max RPM, then enrichen the mix a bit and release the brakes.  You can then adjust the mix a little on the roll, if needed, to hit your target EGT.  Finally, lean in climb for target EGT just as you would anywhere else.  Bonus answer: At high density altitudes all takeoffs should be no-flap takeoffs.

[Echo]

I used to climb full throttle and RPM (and still climb mixture full in climb), but I have a prop limitation with my current Mooney.  What say all regarding a "fullpower climb to altitude" with this placard?

[Ragsf15e]

4 minutes ago, Echo said:

I used to climb full throttle and RPM (and still climb mixture full in climb), but I have a prop limitation with my current Mooney.  What say all regarding a "fullpower climb to altitude" with this placard?

I question where your red lines are and why the range is red?  The continuous operation one is yellow on mine and the max is 2700.  Are you talking about the markings on the tach or the note under it limiting your climb?  I don’t think either of them do?

[EricJ]

17 minutes ago, Echo said:

I used to climb full throttle and RPM (and still climb mixture full in climb), but I have a prop limitation with my current Mooney.  What say all regarding a "fullpower climb to altitude" with this placard?

Your engine redline (acccording to the M20E TCDS) is 2700 rpm.   With the prop full forward you should have well over 2550 rpm at full throttle.

[0TreeLemur]

I live close to Sea Level.   On takeoff, full power with full rich EGT on my IO-360 is about 1250F with a fuel flow of about 19 gph.    I climb full throttle, full rpm (2700) to cruising alt.   Once I get to 5000 ft, I'll lean until the EGT rises to about 1250F.   I'll lean every 1000 ft or so to keep it at 1250.

I fly out west quite a bit.   In fact, I learned to fly there.   At density altitudes greater than 4000 ft I was taught to take off with the mixture pulled to an extent that kind of comes with experience.  My instructor during my pp training had me pull it about an inch in a C152.  

Last summer I took off from a field with a D.A. over 9000 ft.   I had the mixture pulled about 2 inches on takeoff, and used that 1250 EGT to adjust it once the engine got up to full power.   It took forever to get off the ground and I was on a 6000 ft runway so I had time to watch it.

I agree with @EricJ, your redline should be 2700, and that red arc should be a yellow arc.  If your engine is not making 2700 on takeoff, you should have your governor adjusted so that it does.

If you don't have one, a great first upgrade for an older Mooney is an engine monitor.

[Ragsf15e]

25 minutes ago, 0TreeLemur said:

I live close to Sea Level.   On takeoff, full power with full rich EGT on my IO-360 is about 1250F with a fuel flow of about 19 gph.    I climb full throttle, full rpm (2700) to cruising alt.   Once I get to 5000 ft, I'll lean until the EGT rises to about 1250F.   I'll lean every 1000 ft or so to keep it at 1250.

I fly out west quite a bit.   In fact, I learned to fly there.   At density altitudes greater than 4000 ft I was taught to take off with the mixture pulled to an extent that kind of comes with experience.  My instructor during my pp training had me pull it about an inch in a C152.  

Last summer I took off from a field with a D.A. over 9000 ft.   I had the mixture pulled about 2 inches on takeoff, and used that 1250 EGT to adjust it once the engine got up to full power.   It took forever to get off the ground and I was on a 6000 ft runway so I had time to watch it.

I agree with @EricJ, your redline should be 2700, and that red arc should be a yellow arc.  If your engine is not making 2700 on takeoff, you should have your governor adjusted so that it does.

If you don't have one, a great first upgrade for an older Mooney is an engine monitor.

One thing I have learned from MS is that your governor shouldn’t be affecting your rpm during the takeoff roll.  At full power and zero kts, the prop is on the low pitch stop.  At some point ~60-90kts the governor Will start to increase pitch to hold it at 2700.  Point is, full power and initial part of the roll you should see 2600+ regardless of your governor (i see about 2675 initially).  If you don’t, your engine isn’t making full rated hp or the low pitch stop is set poorly which i heard was less likely.  Maybe one of the A&Ps will clear up or correct my rudimentary knowledge of this…

[Utah20Gflyer]

Yes I lean as I climb.  I almost never take off full rich unless it is very cold but I’m as rich as I can be while still keeping the engine running smoothly and making good power.  There’s a big difference in power between full rich and pulling the mixture out 1/4 inch when DA is 5k.  
 

The big pull is unnecessary if you are flying a normally aspirated engine.  Just wait until WOT and your prop setting equals 65 percent power or less and then find your mixture setting at your leisure.  Once your below 65 percent you can’t harm the engine using the mixture knob.   

[Ragsf15e]

1 minute ago, Utah20Gflyer said:

Yes I lean as I climb.  I almost never take off full rich unless it is very cold but I’m as rich as I can be while still keeping the engine running smoothly and making good power.  There’s a big difference in power between full rich and pulling the mixture out 1/4 inch when DA is 5k.  
 

The big pull is unnecessary if you are flying a normally aspirated engine.  Just wait until WOT and your prop setting equals 65 percent power or less and then find your mixture setting at your leisure.  Once your below 65 percent you can’t harm the engine using the mixture knob.   

I agree and fly out west too, so similar techniques, but he’s in Florida, so maybe cruise at 3,500’msl and he needs to be careful with his mixture?  If you use a target egt lean in the climb, you’ll be somewhere around 150-200 or more rich of peak though, so I agree that you can just start leaning from there to find peak.

[Utah20Gflyer]

1 minute ago, Ragsf15e said:

I agree and fly out west too, so similar techniques, but he’s in Florida, so maybe cruise at 3,500’msl and he needs to be careful with his mixture?  If you use a target egt lean in the climb, you’ll be somewhere around 150-200 or more rich of peak though, so I agree that you can just start leaning from there to find peak.

I agree when at sea level full rich is prudent and almost certainly doesn’t come with the power penalty you get when flying in Utah in the summer.   

[EricJ]

28 minutes ago, Ragsf15e said:

One thing I have learned from MS is that your governor shouldn’t be affecting your rpm during the takeoff roll.  At full power and zero kts, the prop is on the low pitch stop.  At some point ~60-90kts the governor Will start to increase pitch to hold it at 2700.  Point is, full power and initial part of the roll you should see 2600+ regardless of your governor (i see about 2675 initially).  If you don’t, your engine isn’t making full rated hp or the low pitch stop is set poorly which i heard was less likely.  Maybe one of the A&Ps will clear up or correct my rudimentary knowledge of this…

That's about right.   There's also a high-rpm stop on the governor, which stops the control arm moved by the control cable, that sets the high rpm limit of the governor.   This effectively sets the high rpm limit.   The low pitch stop of the prop should rarely come into play, but it is an available adjustment.

[ArtVandelay]

I live close to Sea Level.   On takeoff, full power with full rich EGT on my IO-360 is about 1250F with a fuel flow of about 19 gph.    I climb full throttle, full rpm (2700) to cruising alt.   Once I get to 5000 ft, I'll lean until the EGT rises to about 1250F.   I'll lean every 1000 ft or so to keep it at 1250.
I fly out west quite a bit.   In fact, I learned to fly there.   At density altitudes greater than 4000 ft I was taught to take off with the mixture pulled to an extent that kind of comes with experience.  My instructor during my pp training had me pull it about an inch in a C152.  
Last summer I took off from a field with a D.A. over 9000 ft.   I had the mixture pulled about 2 inches on takeoff, and used that 1250 EGT to adjust it once the engine got up to full power.   It took forever to get off the ground and I was on a 6000 ft runway so I had time to watch it.
I agree with [mention=15539]EricJ[/mention], your redline should be 2700, and that red arc should be a yellow arc.  If your engine is not making 2700 on takeoff, you should have your governor adjusted so that it does.
If you don't have one, a great first upgrade for an older Mooney is an engine monitor.

Same FF, my EGTs run under 1200, I start leaning by the time I get to 3000’, sometimes sooner, and lean a little more aggressively to 1300. At cruise it’s LOP.
I use a general rule of thumb to set fuel flow on takeoff; 19 - altitude in 1000s. So at 5000’, I set FF to 14 gph.

[Echo]

11 hours ago, Ragsf15e said:

I question where your red lines are and why the range is red?  The continuous operation one is yellow on mine and the max is 2700.  Are you talking about the markings on the tach or the note under it limiting your climb?  I don’t think either of them do?

The plane had an experimental class turbo (for testing) installed prior to my ownership.  Perhaps this tach was put on during that period?  Regardless, I need to address that issue.  Just didn't occur that the markings would be wrong so focused on the placard.  Now I need to confirm that engine is getting to rated redline.

[Shadrach]

10 hours ago, Ragsf15e said:

One thing I have learned from MS is that your governor shouldn’t be affecting your rpm during the takeoff roll.  At full power and zero kts, the prop is on the low pitch stop.  At some point ~60-90kts the governor Will start to increase pitch to hold it at 2700.  Point is, full power and initial part of the roll you should see 2600+ regardless of your governor (i see about 2675 initially).  If you don’t, your engine isn’t making full rated hp or the low pitch stop is set poorly which i heard was less likely.  Maybe one of the A&Ps will clear up or correct my rudimentary knowledge of this…

 

10 hours ago, EricJ said:

That's about right.   There's also a high-rpm stop on the governor, which stops the control arm moved by the control cable, that sets the high rpm limit of the governor.   This effectively sets the high rpm limit.   The low pitch stop of the prop should rarely come into play, but it is an available adjustment.

Interesting discussion for me as I just reclocked my PCU5000 per the installation guide. I was maxing at 2640rpm in climb as measured by an optical tach. After reclocking (that's a whole "nother" thread) We are now at a constant 2700 but it does push to 2730 for a split second if you advance too aggressively. So it seems that the governor is what is holding it at 2700 rather than the pitch stop.  I am sure that the pitch stop is close. I am glad I got it right the first time. The Lycoming governor location combined with the proximity of the accessory to the firewall is terrible in terms of accessibility.

[Ragsf15e]

33 minutes ago, Shadrach said:

 

Interesting discussion for me as I just reclocked my PCU5000 per the installation guide. I was maxing at 2640rpm in climb as measured by an optical tach. After reclocking (that's a whole "nother" thread) We are now at a constant 2700 but it does push to 2730 for a split second if you advance too aggressively. So it seems that the governor is what is holding it at 2700 rather than the pitch stop.  I am sure that the pitch stop is close. I am glad I got it right the first time. The Lycoming governor location combined with the proximity of the accessory to the firewall is terrible in terms of accessibility.

I think that matches with how I think it should work.  What rpm do you have at full power during the first say 0-50kts of takeoff?  Mines around 2650 or so.  That’s where it’s on the low pitch stop.  Once you’re at flying airspeed, the airflow makes it a little easier for the engine and it will rely on the governor to keep it at 2700.  At that point, without the gov, you would start to exceed 2700.

[Shadrach]

20 hours ago, pagirard said:

Hi everyone,

I have a question for the Mooney experts here: do you lean in climb ?

I fly in Florida, low density altitude most of the time and MSL is almost AGL. I typically lean for taxi (by ear), take off full rich. Climb 25inMP/2500RPM and I start leaning "a bit" every thousand feet starting at 4000ft. I choose my IAS to keep the CHT below 405F, it's usually 105-107kts, when the sky is clear, I also engage the RAM boost air to help with cooling and the additional inch of MP.

When I reach my cruise altitude and the plane is configured for cruise: 24inMP/2400 and trimmed. I then go back to full rich and then do a big lean pull to find the peak EGT and try to lean around -10F/-20F LOP while carefully observing the CHTs.

My climb performance isn't great so my question is: is it better to leave the mixture full rich in climb and only lean when reaching cruise or leaning as you climb ?

Bonus question: how about in places with much higher density altitude, do you ever take off with mixture not full forward? How about the climb ?

Thanks in advance for your help.

 

Pierre

As others have said, climb full throttle, max RPM, there is no benefit to throttling an IO360 in the climb. At wide open throttle, internal cylinder pressure and therefor CHTs will likely be lower at 2700 than they will at 2500.  Don't lean just for the sake of leaning. At max power, you want to be a minimum of 250° ROP (peak EGT "readings" for an IO360 are typically 1450°-1525°).  That means EGTs should be in the low to mid 1200s at the highest (mid to high 1100s are fine too).  Verify that takeoff EGTs are in range (I do this on every flight) and then use the EGT on the richest cylinder (likely but not necessarily #3 for your engine) to maintain take off EGT (+/- 50°).  

[A64Pilot]

20 hours ago, pagirard said:

Hi everyone,

I have a question for the Mooney experts here: do you lean in climb ?

I fly in Florida, low density altitude most of the time and MSL is almost AGL. I typically lean for taxi (by ear), take off full rich. Climb 25inMP/2500RPM and I start leaning "a bit" every thousand feet starting at 4000ft. I choose my IAS to keep the CHT below 405F, it's usually 105-107kts, when the sky is clear, I also engage the RAM boost air to help with cooling and the additional inch of MP.

When I reach my cruise altitude and the plane is configured for cruise: 24inMP/2400 and trimmed. I then go back to full rich and then do a big lean pull to find the peak EGT and try to lean around -10F/-20F LOP while carefully observing the CHTs.

 

My climb performance isn't great so my question is: is it better to leave the mixture full rich in climb and only lean when reaching cruise or leaning as you climb ?

 

Bonus question: how about in places with much higher density altitude, do you ever take off with mixture not full forward? How about the climb ?

 

Thanks in advance for your help.

 

Pierre

Your doing fine, But maybe do use full throttle and full RPM, 200 RPM isn’t negligible.

Our little motor Mooney’s just aren’t great climbers, climb is of course a function of excess horsepower, and we just don’t have all that much excess HP, most aircraft with our cruise speeds have much higher HP the power is where the speed comes from, a 4 cyl Mooney gets its speed from a lack of drag not high power

With constant speed props you can’t lean for highest RPM at a high altitude airport like you can a fixed prop. You have to go by EGT if the airport is high enough, I think 5,000 DA is the break point, DA not MSL, but anyway in my opinion you likely know about what your temp at peak is, lean to 100F or a little more than that, I’d say a little more. 100F ROP is max power but a little extra gives you cooling and the power loss is very small.

DA can be tricky, you can be at a 2,000 MSL airport on a hot Summer day and be above 5,000 DA, the engine only “knows” DA of course as the engines power is related to air density not actual altitude.

[Ragsf15e]

1 hour ago, Echo said:

The plane had an experimental class turbo (for testing) installed prior to my ownership.  Perhaps this tach was put on during that period?  Regardless, I need to address that issue.  Just didn't occur that the markings would be wrong so focused on the placard.  Now I need to confirm that engine is getting to rated redline.

If the engine has been modified, then yes, do some research because maybe you have different limits.  There should be STC paperwork describing those limits if they were installed on a certified aircraft.  Additionally, if you have an aftermarket prop , gov, etc, check that paperwork because you may have limits there.  I have a 3 blade Mcauley prop which changes my non-continuous zone.

[Shadrach]

1 minute ago, Ragsf15e said:

I think that matches with how I think it should work.  What rpm do you have at full power during the first say 0-50kts of takeoff?  Mines around 2650 or so.  That’s where it’s on the low pitch stop.  Once you’re at flying airspeed, the airflow makes it a little easier for the engine and it will rely on the governor to keep it at 2700.  At that point, without the gov, you would start to exceed 2700.

I don't know yet. My Mechanic has not done the final inspection yet.  Our schedules keep conflicting for the final inspection and many of those "while I'm in here" situations.  A lot of of little detailed jobs and messy jobs. 

[Ragsf15e]

13 minutes ago, Shadrach said:

I don't know yet. My Mechanic has not done the final inspection yet.  Our schedules keep conflicting for the final inspection and many of those "while I'm in here" situations.  A lot of of little detailed jobs and messy jobs. 

I wish Clarence was still here, but I think I remember him describing the “full power runup” to check engine output and trying to ensure the rpm was 2600+. This would rely only on the engine and low pitch stop, not the gov.  Maybe there were even limits.  I don’t even know where to look for a reference for this…

Here a short piece of a hartzell manual describing checking the stop and gov… 

Edited February 13, 2024 by Ragsf15e

[Shadrach]

17 minutes ago, A64Pilot said:

Our little motor Mooney’s just aren’t great climbers,

Must be a Florida DA thing. Could be a weight thing too.  At solo weight this time of year I see initial rates of 1300-1500ft and hold greater than 1000 through 5K.  Me +4hrs of fuel puts my bird at 2150lbs. A while back I did a time to climb from takeoff to a pressure alt of 10,500 and I believe I averaged over 800FPM from breaking ground to altitude intercept.  I'll have to find the date so I can check the ADSB data.

 

[Shadrach]

14 minutes ago, Ragsf15e said:

I wish Clarence was still here, but I think I remember him describing the “full power runup” to check engine output and trying to ensure the rpm was 2600+. This would rely only on the engine and low pitch stop, not the gov.  Maybe there were even limits.  I don’t even know where to look for a reference for this…

Here a short piece of a hartzell manual describing checking the stop and gov… 

Well wherever we end up is hopefully close enough. I do not want to get back into that governor.  I will report back after post mx shake out.