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View Full Version : IL-2 Noob with a question .... prop pitch ??????????



Cicada--LS--
06-02-2004, 04:11 PM
what the heck is the purpose and how is it used ? No props on the fighter jets i normally "fly" http://ubbxforums.ubi.com/images/smiley/blink.gif

Cicada--LS--
06-02-2004, 04:11 PM
what the heck is the purpose and how is it used ? No props on the fighter jets i normally "fly" http://ubbxforums.ubi.com/images/smiley/blink.gif

El Turo
06-02-2004, 04:23 PM
Don't have the required 5-10 minutes to sit and type it all out this second.. try the "find" button at the top of the forum and type in "Prop Pitch".

Should get you what you need.

In short:

For Allied aircraft, controls your RPM.. max "pitch" gets you max power.

For Axis aircraft (manual mode), you are controlling pitch rather than RPM so you'll have to keep an eagle eye on your RPM as you adjust pitch.

More RPM, more power. Too much RPM, blown motor.

Good luck!

Best,

~T.

Callsign "Turo" in IL2:FB & WWIIOL
______________________
This place
was once
a place
of worship
I thought,
reloading my rifle.

~V.

Flightvector
06-02-2004, 05:41 PM
Prop Pitch control is nearly synonymous to RPM control. In complex WWII aircraft, props are constant speed, meaning that a RPM is maintained by modifying pitch and prop control modifies this selected RPM. Aircraft engines normally run at an RPM that is fully limited by the drag upon the propeller. Unlike a car's gears in which RPM is limited to redline in the lower gears, an aircraft engine runs at what would be equivalent to 6th gear in a Corvette (where RPM/speed is limited by drag).

So...changing pitch/RPM does not change power levels and certainly not proportionally! We can however say it has an effect on torque...in full fine pitch (100% in IL2), the engine does the most work per unit distance.

But remember that aircraft engines produce more power and torque at certain RPM bands depending on the engine, so thats why the prop control is not proportional. Making pitch finer theoretically increases torque, but if it brings RPM out of the optimal torque band, lower performance may result.

So prop pitch is a combination of a torque/cruise performance optimizer to increase climb performance or cruise speed efficiency, and a way to make the best use of the optimal RPM bands if high speed is needed rather than climb (i.e. MAX Hp vs. MAX Torque).


Generally, do not use anything less than 100% (most auto pitch aircraft will overstress at 100% so it doesn't apply to everything) pitch for takeoff and climb, which is procedure in simple GA aircraft. You can start playing with 60% or 70% if long range cruise is needed or to maintain higher speed. Lower % pitch also reduces prop frontal area or drag only in dives where the prop is overdriven.

This a very simplified description (even for IL2!) by the way, many pilots have better pitch modulation, but these fully depend on the aircraft. You need to test for optimal RPM bands and aircraft characteristics for a while to learn. But you get the general idea.

[This message was edited by Flightvector on Wed June 02 2004 at 04:59 PM.]

VMF-214_HaVoK
06-02-2004, 05:49 PM
You can find a indepth description here http://magnum-pc.netfirms.com/mudmovers/Sims/FB/fb_cem.htm

=S=

http://www.flightjournal.com/fj/images/hellcat_head_short.jpg

www.vmf-214.net (http://www.vmf-214.net)
(The Original BlackSheep Squadron of IL-2/FB/AEP/PF)

Cicada--LS--
06-02-2004, 10:51 PM
Thanks Fellas