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wipeout01

How may I correctly apply the mixture to the default A36 Bonanza from Carenado?

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Hi there, I'm trying to fly this beautiful plane, the A36 Bonanza from Carenado, which is inside Prepar3D.

However, when I am gaining altitud a get a disturbing message saying my mixture is not leaned correctly.

 

"Your engine is loosing power because the mixture is not leaned correctly".

 

So my question is how may I correct this adjusting properly the mixture?

 

I know you can disable this notification, which is a flying tip, but I'd prefer to learn how to correct the mixture settings.

 

I have the handles, the black one, power, the blue one, RPM, the red one, MIXTURE.

 

I get this message when I am gaining altitude... so what should I do when I gain altitude? reducing the mixture or having it full rich?

 

How much I should reduce the mixture for the A36 Bonanza to do the things properly and not as a guess...

 

I would appreciate some advices about this.

Cheers

 

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Typically you should pull the mixture lever rearward (lean as opposed to rich) every couple thousand feet in the ascent, normally you monitor the exhaust gas temperature (EGT) guage while you're leaning and 25° C rich of peak EGT should be your target. You'll hear the engine's sound change as you lean so it's possible you can also lean by the sound. Likewise in the descent you would do the opposite.

Ctrl+Shift+F2 also leans the mixture, Ctrl+Shift+F3 enrichens it, Ctrl+Shift+F4 is full rich, and Ctrl+Shift+F1 is full lean (idle cutoff, the engine dies, which is the proper way to shut down an aircraft engine incidentally).

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Jim! thanks a lot, it works fantastic :D In three lines you helped me a lot.

 

When taking off I must be Full Rich, while ascending I must Lean, when descending I must Enrich

Every couple thousand feet 2000 ft, 4000 ft, 6000 ft... I must apply changes, enriching (descending) or leaning (ascending)...

 

However, I would like to understand a bit better the mechanism.

I don't get any more that message of "Your engine is loosing power because the mixture is not leaned correctly" so what you told me works fantastic !

However I have some doubts.

I've seen the EGT gauge in the cockpit... it start in 20ºC...

Why that temperature in particular? why 20ºC?

When I am at SEA LEVEL (SL) I have the EGT gauge in 25ºC

Okay...

You told me to put the lever rearward to lean the mixture (which is opposed to rich) every couple thousand feet.

But how much rearward? Half rearward? Full rearward? I do that as a guess? or should I follow a rule?

I took several screenshots

 

The gauge start at 20ºC.

At the SEA LEVEL (SL) I start with 25ºC EGT (right needle)

 

bonanzamixture1_zpsdjsc2uq0.jpg

 

I monitor the EGT gauge while I am leaning when ascending, and I get optimal results when the mixture lever is at the 50% or 40%

These are my instruments at 7900 ft with the mixture properly leaned.

 

mixture2_zpshcdgv0sn.jpg

 

 

As you may see I have the EGT in 38º C ? I don't understand very well that gauge seems to be it start in 20ºC and every line goes in increments of 20?

So I think at 7900 ft, I have the EGT in 38 ºC and the mixture lever is at its 50%... in that configuration I have the mixture leaned correctly and I don't get that message...

 

mixture3_zps922wn81g.jpg

 

 

So what I don't understand very well here is how much I have to move rearward or forward the mixture lever to lean correctly the mixture, instead doing it as a guess...

 

Cheers

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If you lean the mixture you will see the EGT needle rising. What you are aiming for is the peak temperature - where the needle is at it's highest. If you lean more than that you will see the needle start to fall again. When that happens enrich the mixture to it's peak EGT again. You could leave it there but it is generally recommended to have it slightly rich of peak so enrich it some more until the needle is 25 degrees rich of peak.

 

Alternatively you could ignore the EGT gauge and do it by ear - not as accurate of course but it will probably be good enough while you are learning.

 

Good luck with it!

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Hi...

 

I don't think the EGT gauge starts at 20C - it's just indicating 20C increments - we don't really care what the temp is - just that we can find the "peak EGT" - from that we can lean accordingly...

 

As for how much in a climb to move the mixture nob is determined by watching your EGT gauge - you want to keep finding max EGT periodically and then making it a bit richer as Jim stated so you are making best power... If you pull too much - you'll be running "lean of peak" and you'll start feeling the power dropping off pretty quickly... In normally aspirated engines you don't want to run "lean of peak" - although it is common practice in fuel injected engines (to save fuel)...

 

Also keep in mind at high altitude airports starting at 4000 to 5000 feet - you may be required to lean before takeoff - as you want the engine making the rated power to insure a successful launch... Many GA POH's have a high altitude procedure where you lean for "Max RPM" prior to takeoff - which should also equate to 20 degrees or so "rich of peak" on the EGT gauge... Not all planes have an EGT gauge...

 

If you truly want to emulate real world procedures - when at low altitudes - we need to lean aggressively for ground operations as the engines are set to run really rich at sea level - because the fuel air mixture is so rich - carbon quickly builds up on your spark plugs (typically 2 per cylinder) - which foul your plugs degrading performance...

 

It might sound a bit confusing but you get used to it pretty quick...

 

Regards,
Scott

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Hi...

 

Also - we can discuss the blue nob when you're ready as well...

:wink:

 

Regards,

Scott

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You can also use Your RPM needle to Lean - as You Pull back on the Mixture - You will get a slight rise in RPM - then a sharp drop off as the Engine leans out - push Your mixture back in to just the rich side of the RPM rise - GOOD to GO !! Johnman B)

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Not with a constant speed prop though as the prop governor will always hold the same RPM :smile:

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Good Point Jim - Most of the Puddle Jumpers I fly - Don't have such Advanced Technology as "Controllable Pitch Props" or "EGT" Gauges - Suck Bugs in One end - Blow Smoke Out the the Other - Cram'er  to the Wall - and away You Go - like a Herd of Turtles - Hundreds of Aircraft Quality Parts Flying in Close Formation - Johnman :smile:  :smile:  B) 

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Not with a constant speed prop though as the prop governor will always hold the same RPM :smile:

 

In certain range yes. However, if you pull throttle to idle RPM will drop as well. Flight weight prop governor can manage only certain ranges of crankshaft revolutions

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Good Point Jim - Most of the Puddle Jumpers I fly - Don't have such Advanced Technology as "Controllable Pitch Props" or "EGT" Gauges - Suck Bugs in One end - Blow Smoke Out the the Other - Cram'er  to the Wall - and away You Go - like a Herd of Turtles - Hundreds of Aircraft Quality Parts Flying in Close Formation - Johnman :smile:  :smile:  B)

Heck, in some of the a/c I used to fly, if the termites ever let go the wings would fall off. (PT-19)

 

Vic

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Wow, my God, I am overwhelmed with the technical level of the people here, amazing, what quantity of information. Thanks to everyone.

As Scott said, this could be confusing sometimes, so I still having some doubts.

Please, have patience with me, I am not a real pilot, but I like to fly close to real procedures, so I like to fly "seriously" (or as seriously as possible).

What I've learnt until now:

As Jim said, when we ascend we much lean the mixture, when we descend we must enrich the mixture. When we take off I assume we must be always full-rich.

We apply changes to the mixture lever every 2000 ft. ascending or descending.

Now the question is how much should I push back or forward the mixture lever?

A bit, a lot?

 

1) First thing is I don't understand the EGT gauge... Those white lines are increments of 5? 10? The EGT gauge start at zero? or 20? and why that 20ºC quantity in the EGT gauge? That confuse me...

 

Well... I was doing some practical experiments, so I just took off and began to ascend.

I did not lean the mixture, I wanted to see the behaviour of the EGT needle.

While ascending and getting the message to lean the mixture, the EGT needle was in a high position... I reached 7000 ft which was my programmed altitude in the autopilot, I did not lean the mixture intentionally to see the EGT needle behaviour and it had no changes, it was in a high position. The needle did not gave me any information about when should I push back the mixture lever...

 

What I did is what Stufer said... listening the engines and learning how to lean or enrich using the ears...

 

"Alternatively you could ignore the EGT gauge and do it by ear - not as accurate of course but it will probably be good enough while you are learning."

 

This method seems to work fine in me :P So I did this...

 

  • I was at 7000 ft... I got that message that my mixture was not leaned correctly, then I moved rearward the mixture lever and whilst I was doing that I listened the sound of the engine was more "happy", like more power... (but the EGT needle continued without changes, also in a high position)

Ups... then I knew I was leaning the mixture properly right away...

  • Then I did other experiment, with the mixture lever at the 50%.... I pushed it forward to enrich it intentionally (I knew this was wrong, I just wanted to listen the engine)... I knew the engine's sound changed a bit, less happy, like less power, I was still having power... but the sound was not the same... of course, I got again the message that my mixture was not leaned correctly... (but the EGT needle continued without changes, also in a high position)
  • So I was able to know the right settings just listening the engines... but I did not observe any changes in the EGT needle, I was able to realize this just by the engine's sound

 

Then I decided to do other experiment... that was... moving all the way rearward the mixture lever... and of course, the engine stopped... but I was able to listen how the engine's performance was reducing considerably whilst I was moving the lever... (when I did this, yes, the EGT needle went down close to the 20ºC number)

 

Again, I pushed the lever forward and the engine started... (then the EGT needle was again in a high position)

 

With this experiments what I have learnt is...

 

When I am at a certain altitude, 2500 ft, 3000ft and more..., the best performance I get when leaning the mixture, and the proper setting seems to be a 50% or 40% more or less, so basically the mixture lever must be in the middle possition...

When I am descending, I must push it forward to enrich gradually the mixture and it must be almost full rich when descending to land...

I guess this would change according the field elevation also, but listening with the ears, I can feel more or less how is the engine's behaviour and then applying the proper settings...

Am I doing this well? or is this a total disaster?

 

I am calculating the settings just listening the engines... taking a look to the gauge I was not able to see any information?

 

As Scott said, THE BLUE LEVER, yes, I would like to talk about that.

 

I don't know very well why should I reduce the RPM or increase them... what function perform this lever and what are the practical uses? but also I'd like to learn well how to lean the engines, right now I am doing this fine with the ears, but I don't know if this method is valid or should I do other stuff to be more accurate?

 

Cheers

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In any of Your Experiments - did You Check to see what Your RPM was Doing ?? - Believe Me it will Drop off when You Lean too far - along with Great Belching and Backfiring - Enrich-en till it runs Smooth - and You should be OK - Smeeuthe LIke a Pussy Cat - Johnman B)  


You will Also get a rise in CHT (Cylinder Head Temp) as You reach Optimum Mixture - All them Dials and Clocks ?? - Johmman B)


Vic - I still Remember My First Scarf Joint Spar Patch - Sigh - !! Johnman :Doh:

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I still Remember My First Scarf Joint Spar Patch...

 

 

15:1 :smile:

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