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sparrow420
07-10-2004, 05:45 PM
Hello!

I can undestand the supercharger settings, and also setting the mixture at the right (or a decent) setting seems not too complicated.

However: how / why /when should you use a prop pitch less than 100% ???

Thanks!

sparrow420
07-10-2004, 05:45 PM
Hello!

I can undestand the supercharger settings, and also setting the mixture at the right (or a decent) setting seems not too complicated.

However: how / why /when should you use a prop pitch less than 100% ???

Thanks!

Zeus-cat
07-10-2004, 05:59 PM
Think of riding a bicycle. You shift gears so that you can deliver more power to the wheels at a lower RPM. The same is true of airplane propellers and engines.

For a very simple example: Say you get the same thrust out of your plane at the following settings:
1) 100% prop pitch/100% throttle
2) 70% prop pitch/70% throttle

Which is easier on the engine? #2. Lower RPMs and less fuel usage.

Zeus-cat

ZG77_Lignite
07-10-2004, 06:14 PM
Beware the 'gears' analogy (as stated above). It can be very confusing and often incorrect. If you are having trouble with 'prop pitch' (the blue onscreen message is a generic term that can mean a number of different things) it would be most beneficial to narrow your question to one aircraft, or one type of aircraft. FB models 4 (or arguably 5 or 6) 'prop pitch' systems, and they can all operate quite differently. Which aircraft would you like to learn about most?

devill102yu
07-11-2004, 02:08 AM
Hi sparrow,
AFAIK the thing is that in some planes you dont actually change the pitch angle of the propelor blades with "pitch" lever, instead you directly control RPM, that is you set a desired RPM value and a device that maintains constant RPM adjusts prop pitch to match desired setting. Thats why you cant go over 100% because it would just be wasting of engine power since higher RPM wouldnt give you more speed.
As for lower RPM setting Zeus is right, cruise RPM setting (most efficient flight mode) is not max value of RPM.

Nero111
07-11-2004, 02:24 AM
How you manage prop pitch depends entirely on the type of aircraft you are flying at the time and the type of mechanism it has that controls the prop. (eg Variable or constant speed props)
Heres a link that explains some of the differences.
http://www.avweb.com/news/columns/182082-1.html
Do a bit of research on the plane/s of your choice and you will soon figure it out.

http://qwrety.cc/nero.jpg

sparrow420
07-12-2004, 02:30 PM
Thanks for all the replies! I think I understand the basics (thanks for the link: http://www.avweb.com/news/columns/182082-1.html)

From engine (and energy) saving perspectives adjusting the prop pitch is quite important.

But:
What does one do in a combat situation? Just leave the pitch to 100%? Or do you need to change the pitch when you make a looping?
And what in an emergency landing situation? Reduce the pitch to invoke wind milling effects to bleed off energy quickly?


Thanks a lot!

Sparrow