Technical information

[P-38L]

Hello

Recently I found a document with very interesting information. But I have a question about a type of information presented in it.

http://www.mission4today.com/index.p...etails&id=3265

On page 17, in the Engine Controls table in the column headed "Mixture Setting At." The question is: where and how can I find this information on any plane? The same question applies in the same table, in the column headed "Alt S2-S3".

A few months ago I emailed the author of this document but never got an answer.

Maybe someone could help me with this doubt.

Thanks in advance.

[Marabekm]

I am a bit confused as to what your question is p-38L.

Mixture settings alt is the altitude at which you need to start adjusting your mixture.

s2/s3 is superchargers. The altitude given is when you should shit super charger to stage 2, and stage 3 - second altitude given- if the plane has 3 stages.

[P-38L]

Thank you Marabekm

That is exaclty my question, but how do I get that information from the airplane? How do I know when to hit the key combination to change the superchargers. I guess airplanes have this information as a technical data, not to have to fly the airplane and start doing trial and error to find out.

But thank you for your kind answer.

[majorfailure]

Originally Posted by P-38L

Thank you Marabekm

That is exaclty my question, but how do I get that information from the airplane? How do I know when to hit the key combination to change the superchargers. I guess airplanes have this information as a technical data, not to have to fly the airplane and start doing trial and error to find out.

But thank you for your kind answer.

Trial and error works fine, doesn't it? Okay, that is for me, but if you want charger switch alts, use IL-2Compare, and in case you are not familiar with the max speed vs. alt diagrams, they are usually two triangles combined, peak of each triangle is full throttle height for each stage, and where the two triangles intersect, there is your charger switch alt.
Also engine FTHs can give you a rough estimate, first switch is usually a few hundred meters above first FTH.
And:
http://www.wwiiaircraftperformance.org/
Lots of documents about aircraft, including speed vs. alt test graphs.

And all this is for 100%Power, for less the point to switch is at higher alt.
For mixture setting, as this concerns only a few mostly Russian aircraft, and as you can very easily detect the black smoke from the exhausts and the power drop off I never bothered to get any documentation, I just fly and notice.

[Gel-ler]

Norlmaly after 5000ft you canstart adjusting your mixture, you will see a small increase in rpm(50~75rpm),and wehn it start to drop it is to much.
You should also to pay attention to engine gases temperatur(egt) and cylinder head temperatur(cht) to not pass limits, red line in instrument.
Airplanes like an P-38 should have a chart showing altitude,super charger position, fuel flow (that you control with the mixture) and RPM that you should adjust for that given altitude.
Usualy you will have these settings for max thrust or max endurance!
Martim!

[dimlee]

Originally Posted by majorfailure

...
For mixture setting, as this concerns only a few mostly Russian aircraft, and as you can very easily detect the black smoke from the exhausts and the power drop off I never bothered to get any documentation, I just fly and notice.

One of non-Russian plane which requires a lot of attention to mixture settings is Re.2000. Probably there are more.