High Altitude Landing and Takeoff

[JasonM]

1st off, I am not with a CFI during anything below. Only someone with experience in the mountains. We were flying a 2004 Turbo 182.

Situation 1

I recently was flying in Colorado with another pilot from that area. I was told to keep the mixture at the same setting it was when in the pattern for my approach and landing. I was told the reason for this is at high altitude the mixture could be too rich and in the event I had to do a go-around I may not have the power needed.

I was not real comfortable doing this as the manual states I should be full rich before landing.

My question for some of you high altitude mountain flyers is this:

What do you do?

At what altitude do you no longer go full rich?




Situation 2

While at the high altitude airport, We are getting ready for takeoff and I was told to adjust the mixture while on my takeoff roll. I do as advised but I find it very hard to focus on the takeoff and the mixture, gph, rpm etc. all at the same time.

My questions:

Would it be ok to just run the engine up to full rpm and adjust the mixture prior to takeoff and then just release the brakes?

Is there a reason for having to do it while on the roll?

At what altitude again would you be concerned about doing this?



In general, I don't want to go against the book, but the book obviously doesn't explain things for high altitude airports.

 

[poadeleted21]

I'm full rich for any density altitude 5,000' or below. When it gets above that I lean "by the seat of my pants" i.e. at 6,000' DA, I'm not going to be leaning a lot only "about that much" I've not taken off in anything much higher than 8,000' DA.

 

[Clark1961]

Turbo 182 is turbo normalized isn't it? If the engine is at 30" then the mixture should be set for 30". The POH will likely say that.

It sounds to me like the other pilot was describing the procedure for a normally aspirated engine which is entirely incorrect for a turbocharged (either normalized or boosted) engine. Bad things (detonation) can happen with the incorrect procedure.

I agree with you that a full power run-up and mixture adjustment for max power is the appropriate technique for a normally aspirated engine rather than attempting to dial-in max power on the take-off roll.

 

[poadeleted20]

Situation 1

I recently was flying in Colorado with another pilot from that area. I was told to keep the mixture at the same setting it was when in the pattern for my approach and landing. I was told the reason for this is at high altitude the mixture could be too rich and in the event I had to do a go-around I may not have the power needed.

Not true in a turbocharged plane like this one unless you're above the critical altitude for the turbocharger, and I'm pretty sure that's higher than any airport in the USA. The reason for leaving that turbocharged engine leaned is so you don't foul the plugs by having full rich at low power.

I was not real comfortable doing this as the manual states I should be full rich before landing.

That's Cessna's lawyers talking -- they're terrified that you'll forget to push the mixture forward on a go-around and cause engine failure or loss of power resulting in injury/death/lawsuit against Cessna.

My question for some of you high altitude mountain flyers is this:

What do you do?

Just what you were told.

At what altitude do you no longer go full rich?

In a turbocharged plane, I never go full rich unless going around.

Situation 2

While at the high altitude airport, We are getting ready for takeoff and I was told to adjust the mixture while on my takeoff roll. I do as advised but I find it very hard to focus on the takeoff and the mixture, gph, rpm etc. all at the same time.

My questions:

Would it be ok to just run the engine up to full rpm and adjust the mixture prior to takeoff and then just release the brakes?

Probably, although you might still need a small adjustment after brake release as the prop unloads due to forward velocity.

Is there a reason for having to do it while on the roll?

The prop will unload as you start moving forward. That may cause a small change in fuel flow, and if that takes you over 24 gph, you want to fix it (see below).

At what altitude again would you be concerned about doing this?

With a Turbo 182, elevation/DA doesn't change the takeoff power setting procedure, which from the T182T POH is:

On any takeoff, the

manifold pressure should be monitored and the throttle set to provide​

32 in.hg.; then, for maximum engine power, the mixture should be​

adjusted as required, during the initial takeoff roll to 24 GPH fuel flow.

 

[poadeleted20]

I'm full rich for any density altitude 5,000' or below. When it gets above that I lean "by the seat of my pants" i.e. at 6,000' DA, I'm not going to be leaning a lot only "about that much" I've not taken off in anything much higher than 8,000' DA.

Good for non-turbo, but not for this Turbo 182, in which you need full rich (or something close to it) for full power even up high.

 

[poadeleted20]

Turbo 182 is turbo normalized isn't it?

No -- pulls 32 inches MP for full rated power...

If the engine is at 30" then the mixture should be set for 30". The POH will likely say that.

...but the POH does say go full throttle, then adjust to 32 if it starts to overboost, and set mixture for 24 gph.

 

[JasonM]

In a turbocharged plane, I never go full rich unless going around.

Should I take this to mean that I should stay leaned on approach, but if a go-around is required, go full rich regardless of the altitude?

Reason I ask is even on climb through altitude we are adjusting the mixture to retain the recommended settings. If I was to land at an airport at say 8000' MSL, I would have already been adjusted closer to that altitude than sea level or whatever full rich would give me.

In the old 172's I was always told to go full rich on climb. In the 182 I was told to keep making adjustments on the climb.

If I am full rich at said 8000' MSL runway and needed to go around, would I have a substantial power loss? Is it a safer bet to go full rich than to stay leaned for altitude?

 

[Clark1961]

No -- pulls 32 inches MP for full rated power...

...but the POH does say go full throttle, then adjust to 32 if it starts to overboost, and set mixture for 24 gph.

32 inches is normalized to sea level when flow loses and exhaust back pressure are considered. One needs to be very careful with mixture in normalized engines since they typically have higher mechanical compression ratios than boosted engines. For example the boosted 'kota is a low compression engine (7.5 to 1) so at 30 inches and lower I really can't hurt it with mixture no matter what I do. Not so with a normalized engine since it will be set up to need full fuel flow at 30 to 32 inches.

Go full rich on short final and lean on the roll out - safest way to operate on a turbocharged or normalized aircraft.

The fuel trim should be set to deliver the specified fuel flow rate at full power. If the engine doesn't do that then the fuel trim needs to be reset. It's not rocket surgery but it does need to be done.

 

[Clark1961]

If I am full rich at said 8000' MSL runway and needed to go around, would I have a substantial power loss? Is it a safer bet to go full rich than to stay leaned for altitude?

What is your manifold pressure on the go around? If it is 32 inches then you need to be full rich.

It's bad advise to suggest not going to full rich for landing with a normalized or boosted engine. It can be leaned on roll out. Screw up the mixture on the go around and you're looking at engine heating if not damage from detonation. Someone else posted this in the forum: plan for the go around, take the landing if it is available.

 

[JasonM]

Maybe I am confused, but just to see if i'm on the right track...

If this were a naturally aspirated motor, staying lean for a go-around would be normal? I ask because the other pilot giving me insight normally flies a non-turbo.

Since this is a turbocharged motor, I should go full rich on final? There is no risk of the engine cutting off on me or sputtering on a go-around at high altitude correct?

 

[Clark1961]

Maybe I am confused, but just to see if i'm on the right track...

If this were a naturally aspirated motor, staying lean for a go-around would be normal? I ask because the other pilot giving me insight normally flies a non-turbo.

Since this is a turbocharged motor, I should go full rich on final? There is no risk of the engine cutting off on me or sputtering on a go-around at high altitude correct?

Normally aspirated motor - leaned for altitude is correct. This should be leaned for max power at that density altitude - a brief full power check on downwind is fine to check leaning.

Turbocharged go full rich on short final. If the engine has a problem with that then get the fuel trim checked.

Yes, the engine can be flooded if there is something wrong with the fuel system or setup - be prepared to pull mixture back if it dies and it will start firing again. I flooded the 'kota one day inadvertently (turned boost pump on) when landing at Leadville, engine died on rollout but restart was simple and it would have had full power if I had simply opened the throttle.

 

[chartbundle]

If this were a naturally aspirated motor, staying lean for a go-around would be normal? I ask because the other pilot giving me insight normally flies a non-turbo.

An appropriate mixture setting for full power at the density altitude you're at is always appropriate to be prepared for a go-around, if turbo or normally aspirated. Trying a go-around at full rich normally aspirated at a 5000' DA day is going to be bad. Similarly heavily leaned on a 0' DA day would also be bad.

 

[poadeleted20]

Should I take this to mean that I should stay leaned on approach, but if a go-around is required, go full rich regardless of the altitude?

That's how I'd fly it a Turbo 182.

In the old 172's I was always told to go full rich on climb.

Following that advice will cost you power and spark plug cleaning.

In the 182 I was told to keep making adjustments on the climb.

For a NON-Turbo 182, that's good advice.

If I am full rich at said 8000' MSL runway and needed to go around, would I have a substantial power loss?

In a non-turbo 182, yes, you would have a significant power loss, so you would not want to go full rich. In the Turbo 182 about which the OP asked, the engine is still essentially at sea level all the way up to its critical altitude (the altitude at which the turbocharger can no longer compress the air enough to maintain the sea level rated 32 inches MP), and that altitude is well above any runway in the USA. So in that Turbo 182, you want to have the mixture set to give you 24 gph at 32 inches MP, which will be pretty close to full rich.

Is it a safer bet to go full rich than to stay leaned for altitude?

Again, that depends on whether your 182's engine has a turbocharger on it or not.

 

[poadeleted20]

32 inches is normalized to sea level when flow loses and exhaust back pressure are considered. One needs to be very careful with mixture in normalized engines since they typically have higher mechanical compression ratios than boosted engines. For example the boosted 'kota is a low compression engine (7.5 to 1) so at 30 inches and lower I really can't hurt it with mixture no matter what I do. Not so with a normalized engine since it will be set up to need full fuel flow at 30 to 32 inches.

Go full rich on short final and lean on the roll out - safest way to operate on a turbocharged or normalized aircraft.

The fuel trim should be set to deliver the specified fuel flow rate at full power. If the engine doesn't do that then the fuel trim needs to be reset. It's not rocket surgery but it does need to be done.

My advice was intended for the Lycoming TIO-540-AK1A. engine in a Turbo 182 and based on the T182 POH. The Continental TSIO-360-FB engine in a Turbo Dakota is very different, and so should be operated differently IAW the PA28-201T POH which I don't have available.

This is an example of "negative training transfer" -- what happens when someone tries to apply procedures for one airplane to another, different plane. Please remember that whatever plane you are flying should be flown according to its POH, not something you learned somewhere for another type unless you know they are similar enough for the other procedures to apply -- and this is not one of those cases.

 

[Clark1961]

My advice was intended for the Lycoming TIO-540-AK1A. engine in a Turbo 182 and based on the T182 POH. The Continental TSIO-360-FB engine in a Turbo Dakota is very different, and so should be operated differently IAW the PA28-201T POH which I don't have available.

This is an example of "negative training transfer" -- what happens when someone tries to apply procedures for one airplane to another, different plane. Please remember that whatever plane you are flying should be flown according to its POH, not something you learned somewhere for another type unless you know they are similar enough for the other procedures to apply -- and this is not one of those cases.

I understand that you cannot admit that you gave bad advise with respect to not going full rich on mixture prior to landing. That action is called for in the Turbo 182 POH as noted by the OP.

You can apologize to me for making the false claim above. What I did was tell the OP to go full rich prior to landing and I noted the likely and possible consequences of failing to be full rich in that engine. What I typed was based on the OPs own note of what the POH called for and from my knowledge of turbocharged engines.

 

[murphey]

Maybe I am confused, but just to see if i'm on the right track...

If this were a naturally aspirated motor, staying lean for a go-around would be normal? I ask because the other pilot giving me insight normally flies a non-turbo.

Since this is a turbocharged motor, I should go full rich on final? There is no risk of the engine cutting off on me or sputtering on a go-around at high altitude correct?

Find a mountain flying instructor (we can provide 2-3 names of excellent local CFIs) with Turbo 182 experience in Colorado. They will take you to Leadville and you will learn when/how/where to lean or not to lean, and isn't that the question?

 

[Henning]

There's two factors involved when figuring mixture on a turbo normalized engine such as in the T-182, first is critical altitude on the turbo, second is load on the prop. If you can make redline MP you are below critical altitude, so running full rich will not cost you power, if you can't make full MP, then leaning is called for to make power. Prop load though will be reduced at altitude so mixture rich isn't necessary, wastes fuel, and can foul your plugs eventually. Anything above 6000' I'll go ahead and lean to 200-250° ROP on a full power run up. I'll be richer than when I landed because I will have landed 20° LOP.

 

[JasonM]

Sounds to me that I need to get another checkout by someone with more experience in a turbo 182 and not listen to advise from guys that don't fly a turbo. I feel like my gut was telling me something the whole time. Sounds like my gut was right and that following the POH exactly as written was what I should have been doing rather than something that works in non-turbo cessna's or just what some guy was used to doing in his airplane.

 

[JasonM]

Find a mountain flying instructor (we can provide 2-3 names of excellent local CFIs) with Turbo 182 experience in Colorado. They will take you to Leadville and you will learn when/how/where to lean or not to lean, and isn't that the question?

I'd love to do that. May have to look into that for this summer. Please message me some names/numbers if you don't mind.

 

[JasonM]

There's two factors involved when figuring mixture on a turbo normalized engine such as in the T-182, first is critical altitude on the turbo, second is load on the prop. If you can make redline MP you are below critical altitude, so running full rich will not cost you power, if you can't make full MP, then leaning is called for to make power. Prop load though will be reduced at altitude so mixture rich isn't necessary, wastes fuel, and can foul your plugs eventually. Anything above 6000' I'll go ahead and lean to 200-250° ROP on a full power run up. I'll be richer than when I landed because I will have landed 20° LOP.

That makes a lot of sense. I will have to go up and pay more attention to what happens with the mixture full rich at altitude and the correlation to the MP.

 

[Henning]

Sounds to me that I need to get another checkout by someone with more experience in a turbo 182 and not listen to advise from guys that don't fly a turbo. I feel like my gut was telling me something the whole time. Sounds like my gut was right and that following the POH exactly as written was what I should have been doing rather than something that works in non-turbo cessna's or just what some guy was used to doing in his airplane.

Why would you not follow the POH if you were in question? Running 200°-250° ROP will always produce you maximum power with a safety margin over detonation though. It's a turbo normalized engine so you aren't running any extreme cylinder pressures and altitude reduces load.

 

[Jthamilton]

Where in Colorado are you? I just sold my 2002 T182T and am upgrading to turbo Saratoga.

Before bringing it up here to Steamboat from Oklahoma I researched and read everything I could regarding fuel management. After that I took a mountain flying course where it was mentioned about going full rich while in the pattern. This was contrary to what I had read. I learned if you apply full mixture you have a good chance of stalling your engine if at a higher altitude.

Well the comments in the class just confused me until we asked the nicest OLD man, literally been flying for 60 plus years and still flies his T210. If he wasn't the founding member of the Colorado Pilots Association I don't know who it would be. The question was posed to him and his response was "if I set my mixture to full rich before landing then I'm planning on landing dead stick". This was good enough for me. I never touched my mixture during the pattern and applied full rich only when I was doing a go around. I believe the POH said run 50 degree ROP TIT per POH or 1650 if it redlined before peaking which mine would redline first.

The mountain flying course is a great day with good people and really good info, I strongly recommend it.

Crap just saw turbonormalized, well I tried

 

[Scott@KTYR]

Colorado pilots association has a mountain flying course.
http://coloradopilots.org/

 

[poadeleted20]

I understand that you cannot admit that you gave bad advise with respect to not going full rich on mixture prior to landing. That action is called for in the Turbo 182 POH as noted by the OP.

And it's not the only bad advice in a Cessna POH. I'll stick with mine.

 

[poadeleted20]

Sounds to me that I need to get another checkout by someone with more experience in a turbo 182 and not listen to advise from guys that don't fly a turbo.

Good idea.

 

[murphey]

Colorado pilots association has a mountain flying course.
http://coloradopilots.org/

First class is June 7, all day ground. Flying next day or when you choose to schedule it. Generally, the flying part starts KAPA or nearby, over Corona/Rollins Pass, Granby, Steamboat, Vail, Glenwood Springs, Aspen (but not landing unless you want to pay the landing fee), backtrack around to Leadville then back to the Front Range. Takes about 4-5 hours of flying. Lunch stop somewhere, forgot where.

Doing it again in early September. Check the website for details and registration.

The 30 min online course on AOPA website is marginal, almost funny. Even the schools around here believe that the ground portion should be at least 2-3 hours. Civil Air Patrol uses a version of the CPA course, written by the people who wrote the CPA course and again, an all-day ground program.

 

[JasonM]

Why would you not follow the POH if you were in question?

Because I was flying with someone with a lot more experience than me whom insisted I did it his way and that most everything I did was incorrect.

Where in Colorado are you?

The question was posed to him and his response was "if I set my mixture to full rich before landing then I'm planning on landing dead stick". This was good enough for me. I never touched my mixture during the pattern and applied full rich only when I was doing a go around.

I'm in WV.

Reading what you say definitly goes in line with what I was told to do and contradicts the POH again. Now this thread is going in different directions.

Colorado pilots association has a mountain flying course.
http://coloradopilots.org/

Thank you!

First class is June 7, all day ground.

I'm going to see if I can make it out there for one of those classes. Unfortunately I wont be able to make the June 7th.

 

[denverpilot]

Because I was flying with someone with a lot more experience than me whom insisted I did it his way and that most everything I did was incorrect.

Let me ask you a question and then offer some advice on this one...

Who is PIC?

Advice: Unless you know some ninny in your right seat is right about YOUR airplane, fly the damn thing your way and by the book and tell them politely the first time that you'll talk about it on the ground. The second time tell them to STFU and that you are PIC. The third time, flip the Isolate switch on the intercom, land at the nearest airport, and offer to pay for their rental car.

Ha. Okay maybe a bit dramatic. Modify as you wish, but remain PIC at all times. Your delivery of said news that you shall remain PIC for this flight can be as friendly or unfriendly as the circumstances require.

I'm not opposed to bodily injury if you reach for my controls, especially my engine controls, unless asked to do so or we have positively exchanged aircraft control duties.

 

[Clark1961]

Well the comments in the class just confused me until we asked the nicest OLD man, literally been flying for 60 plus years and still flies his T210. If he wasn't the founding member of the Colorado Pilots Association I don't know who it would be. The question was posed to him and his response was "if I set my mixture to full rich before landing then I'm planning on landing dead stick".

If it will idle full rich on the ground then it will idle full rich on short final. Engine idle is always (supposed to be) checked after the run-up. If it won't idle take it to the A&P and get the fuel trim set - in this case it's the idle fuel jet or injector. Of course other repairs may be necessary and ignition system problems are always worse at high altitude.

I'm more than just a little picky about engine performance and have an A&P that is willing to take the time (and charge me) to set things up according to the book. Now if you're at sea level the A&P may tend to set things rich just the "protect" the owner - watch that like a hawk and make sure it is set correctly and that the fuel controller is functioning correctly. Anything else puts one into test pilot territory with the engine.

 

[N801BH]

Why would you not follow the POH if you were in question? Running 200°-250° ROP will always produce you maximum power with a safety margin over detonation though. It's a turbo normalized engine so you aren't running any extreme cylinder pressures and altitude reduces load.

Great point.........

32 inches of MP is not really boosted at all.. It equates to 1 PSI of boost at sea level....

For instance,, take a naturally aspirited motor into Furnace Creek, which is several hundred feet BELOW sea level on a 20f day with a high pressure weather system giving you 30.60 on the altimeter setting and your naturally aspirated motor will be damn close to 32".......

Nothing in the POH about that overboost is there.....

 

[gismo]

Great point.........

32 inches of MP is not really boosted at all.. It equates to 1 PSI of boost at sea level...

It's not even that. Because the air is heated during compression by the turbo the DA in the intake manifold(which is what really matters to the engine) is almost exactly the same as a NA engine at sea level.

 

[N801BH]

It's not even that. Because the air is heated during compression by the turbo the DA in the intake manifold(which is what really matters to the engine) is almost exactly the same as a NA engine at sea level.

agreed

 

[skidoo]

I'm no expert, but I do fly a 2004 T182T. If I intend to use full throttle, I always use full mixture as per the POH. If you don't, the TIT will likely exceed the red line TIT. Are you paying attention to that? It is a lot easier to just go full rich and trim the fuel flow back slightly to 24 GPH as needed. You can climb at that setting up to 20Kft if desired. But, I usually dial it back to 25" and 16 GPH as per the POH for a "Normal" climb. Doesn't matter much what altitude I am at. Just set it and it stays pretty close all the way up.

Often times, I may take it slow and set a cruise for 20" and about 9.6 GPH or 1585 TIT. Then, I can adjust power from 15 to 20" at will without re-tweeking the mixture. If I need to go above 20", then mixture needs to be increased and then re-set for that MP.

When descending, I just leave the mixture as is, as long as I don't intend to apply more MP than where it was last adjusted. If more MP is needed such as a go around, mixture is increased. I never lean for takeoff, except inadvertently. Once I took off with it leaned on the ground. Power was noticeably different and less. I quickly noticed and pushed the mixture in, power came back and climbed normally.


Whose airplane is it, yours or his? If it is yours, learn everything you can about it. I find the POH numbers are very accurate. If it is his, well, I suspect something will break before too long.

This is kind of funny because the first time I flew a NA 182 for mountain search pilot training, I asked about leaning it, and the owner/instructor said to just leave it full rich for the whole flight.... Well, ok, it was his plane....

 

[JasonM]

I'm no expert, but I do fly a 2004 T182T. If I intend to use full throttle, I always use full mixture as per the POH. If you don't, the TIT will likely exceed the red line TIT. Are you paying attention to that? It is a lot easier to just go full rich and trim the fuel flow back slightly to 24 GPH as needed. You can climb at that setting up to 20Kft if desired. But, I usually dial it back to 25" and 16 GPH as per the POH for a "Normal" climb. Doesn't matter much what altitude I am at. Just set it and it stays pretty close all the way up.

Often times, I may take it slow and set a cruise for 20" and about 9.6 GPH or 1585 TIT. Then, I can adjust power from 15 to 20" at will without re-tweeking the mixture. If I need to go above 20", then mixture needs to be increased and then re-set for that MP.

When descending, I just leave the mixture as is, as long as I don't intend to apply more MP than where it was last adjusted. If more MP is needed such as a go around, mixture is increased. I never lean for takeoff, except inadvertently. Once I took off with it leaned on the ground. Power was noticeably different and less. I quickly noticed and pushed the mixture in, power came back and climbed normally.


Whose airplane is it, yours or his? If it is yours, learn everything you can about it. I find the POH numbers are very accurate. If it is his, well, I suspect something will break before too long.

This is kind of funny because the first time I flew a NA 182 for mountain search pilot training, I asked about leaning it, and the owner/instructor said to just leave it full rich for the whole flight.... Well, ok, it was his plane....

Thanks for chiming in here. It is my airplane. So you don't go full rich on final at high altitude airports? I see your from Montana and I would assume you have landed at some high Alt fields.

 

[SkyHog]

This is the problem when we make such a big deal about how "different" everything is at high altitude airports, and high DA situations. Everything is exactly the same.

EXACTLY!

CFIs should be teaching their students to manage mixture on takeoff, approach, cruise, climb, descent, etc. the same way regardless of the altitude or DA: "Set it for best power." Then, when the Kansas based pilot flies in Cheyenne, they're not doing anything differently than they were trained.

Same with flying passes. There's nothing "special" or "different" about flying in mountain passes - you navigate the same way, you deal with wind and shear the same way, and you deal with power the same way.

We build our own problems here.

 

[Apelsin Elise]

It's not even that. Because the air is heated during compression by the turbo the DA in the intake manifold(which is what really matters to the engine) is almost exactly the same as a NA engine at sea level.

Not always. The engine might have an intercooler. Then this logic does not apply.

 

[Apelsin Elise]

IMHO, asking questions about engine management on an Internet forum is a very bad idea unless the whole purpose is pure entertainment.

Lots of bad advise in this thread already.

 

[N801BH]

Not always. The engine might have an intercooler. Then this logic does not apply.

I disagree....

In a plane, the BEST intercooler gets about 50% efficiency since it is a air to air cooler... Intake temp rise of 250f only can get cooled to 125f or so.. That is for 15 lbs = 30" of boost or 60" MP..... This is a rough discription so take it with a grain of salt..

In a marine application where you can use lake/ocean water for the cooling medium then you can get close to 80% efficiency....

My point is an intercooler can NOT reduce boosted intake temps down to turbo inlet temps.......

 

[Apelsin Elise]

I disagree....

In a plane, the BEST intercooler gets about 50% efficiency since it is a air to air cooler... Intake temp rise of 250f only can get cooled to 125f or so.. That is for 15 lbs = 30" of boost or 60" MP..... This is a rough discription so take it with a grain of salt..

In a marine application where you can use lake/ocean water for the cooling medium then you can get close to 80% efficiency....

My point is an intercooler can NOT reduce boosted intake temps down to turbo inlet temps.......

And this is a problem with this thread in a nutshell.

Do you know how these numbers apply to the airplane OP was flying? I don't.

Is it possible to give a meaningful advise on mixture management without knowing the specifics of the particular engine besides "turbo + when in doubt = full rich"?

Is it turbo-charged or turbo-normalized? Automatic or fixed waste gate? Is the engine flat rated? Is it possible to overboost? Is intake intercooled?

BTW, these pesky intercoolers do come with power calibration charts and temp reduction rates. For example, American Aviation intercoolers for Continental TSIO-360 claim cooling efficiency way in excess of 50% under some conditions).

I strongly support the suggestion to take Colorado pilots association mountain flying course. Until then... compared to the alternatives... POH usually gives a good advise.

 

[skidoo]

Thanks for chiming in here. It is my airplane. So you don't go full rich on final at high altitude airports? I see your from Montana and I would assume you have landed at some high Alt fields.

Your airplane, then study the POH and know it well. I think they did a good job on the numbers there. It seems that the book numbers for cruise will keep the TIT about 1585. So, I try to keep it there or less. I don't do anything different (engine management wise) from a sea level field vs a high altitude airport other than pay attention to take-off distances per DA and the POH. I have not been to fields above 6K, but still would not change engine management. I do, however, notice differences in ground speed.

I go full rich at the GRUMPS check or short final or if there is some reason to delay such, when I would add power for a go around or climb. I do the same at sea level or any higher field.