Prop Pitch question...
 

I've never used the propeller pitch. What does it do, when do you change it, how to best programme it on Xf52? Thanks in advance.

It's something like the transmission on your car in effect, but not really. The pitch on the propeller is the angle at which the blades meet the air, the greater the angle (or pitch) the more air the prop "grabs". Most of the aircraft in IL2 that have adjustable pitch have a constant speed prop, where you set the engine speed you want and the propeller automatically turns the blades to keep the engine at that RPM, the theory is that you are applying the power directly to the air at the RPM you set rather than reving the engine higher. More like traction control than a transmission in that respect.

So when you set the "prop pitch" in game, you are setting the engine RPM. If max RPM on a given plane is 3000, then 66% will be 2000, etc.

That said, the aircraft in the game are all quite different, and like different settings for different purposes.

In general, 95-100% will be for max power, eg. takeoff, climbing, fighting. (experiment, most planes make best power at 100%, some, esp japanese planes run better at slightly less RPM, and many planes overheat less at lower RPM)

60-80% will be for cruising, diving, limping home, etc. lower rpm settings will keep the engine cooler,use less fuel and ease wear and tear on the engine. Many planes dive much better at lower rpm settings, dont forget to throttle back! you can over-rev your engine.

One big thing, always land at 100%, if you need power for an abort, you need it fast!

Oh, BTW some planes like the 109, 190 and many spitties are fully auto, controlling even the rpm automatically.

Have fun.

I never really understood the proppitch behaviour in IL2.

Of course 95-100% PP will achieve the most power .... but not speed. It's much like you push the pedal to the metal in first gear in a car. You will accelerate very fast with very high RPM's, but if you want to accelerate further, you have to swith to second/third ... gear.

In other sims - like BoB:WoV for example - you have to adjust the proppitch according to your speed, like the transmission in a car.
You DON'T achieve the highest speeds with 100% PP. If you cruise in the 109 for example with 300 kph and decrease PP accordingly, you can actually see the speed increase dramatically. (Which seems logical, because the prop blades grip more air). In IL2 you actually loose speed when decreasing PP in level flight - which I find kinda strange.

thank you for your details, I am no mechanic (ie; dont even know how a transmission works) and I am finding the concept a little ambiguous...
This is how I see it...can you please correct my thinking where need be...
If I set the prop pitch to 66% (in a plane with a constant speed prop) this will:
adjust the pitch of the blades to have less of an angle therefore making the prop spin easier and faster...increasing the RPM of the engine??
Another thing , you say "when diving use 60-80% prop pitch, and also to throttle back".
Does this mean that the increasing air speed (which your plane encounters during a dive) can and will increase the speed of your planes prop, which is what causes over revving?
Therefore as a precaution you should throttle off and change blade pitch?

Thats wrong. Your comparison with a manual transmission in a car is only valid when having a manual pitch control, but not for constant speed. A csp is a car with automatic transmission where 100% rpm is for "sporty" driving and everything below 100% rpm is for economical driving.

Top Speed is at maximum rpm and maximum boost, just look at historic performance tests, for top speed they always were at maximum rpm and maximum boost. Why would they do this when there was more speed at lower rpm ;)

Tip: don`t use manual pp on German planes.

Have read here: http://people.ee.ethz.ch/~chapman/il.../proppitch.htm

Be patient with it, read it over a few times if you have to...you'll get it eventually.

need a bit of help on this
 

I think I understand a little of the prop pitch article, but I'm not all that clear on it as I think I should be. Someone check me out, please. I'm thinking of altitude, and speed situations where I need to adjust prop pitch to either achieve, or maintain performance. For instance:
* I think I need more pitch at higher altitude for biting into the thinner air, and less drag on the airfoils (wings, and propeller blades), especially if speed has fallen off like during a long climb.
* I think I need to decrease prop pitch when I dive from high altitude, as speed builds up, and engine rpm rises ( I'd have to watch, and adjust pitch to keep rpms from over-reving the engine).
* I think I don't need as much "bite", in general, from the prop at lower altitudes where the air is more dense.
* I think all of the above are dependant on tactical power requiremens. That is, whatever it takes to keep the engine in the desired performance regime: Max aircraft speed at low altitude versus max aircraft speed at high altitude: increasing diving speed: takeoff: landing: cruising.
I guess it all depends on the individual aircraft, and knowing your plane, or watching the engine revs. Anyway, that's my thinking. Am I on the right track anywhere here?
thanks!
Flyby out

I really don't understand why so many people have problems with that topic. In fact you can reduce it to some basic rules:

If you have a CSP you don't need to care about the angle of the blades or something, all this is done by the CS governor. The only thing you need to think about is the engine RPM. And there the rule is simple:
High RPM = high acceleration, high speed, high temperature, high fuel consumption
Low RPM = low acceleration, low speed, low temperature, low fuel consumption

When diving you can make a "power dive" which is with high RPM and high Boost, or you can do a "low drag dive" with low RPM and low Boost, or you can do a "high drag dive" with high RPM and low Boost.

Thats all ... Same rules for a manual propeller, only that you need to maintain the RPM yourself at the high or low level.

hmmmm.....
 

I wonder how many planes in IL2 have a cps? At least Banks is honest when he says he doesn't understand why so many people have a problem understanding with this topic. Now I wonder how many people actually DO have a problem understanding the topic. I think I'm at least one who is/was not perfectly clear on it.
Flyby

CEM is so messed up in this game, I mean, he never really had it modeled.

I believe you got things mixed up a bit. Manual pitch control and constant speed propellers are the same thing. When you set a RPM with your prop lever you are doing two things, changing the angle of the blade AND setting a particular RPM. Neither change with power (manifold pressure) inputs.

If you're confused in game about how to use these things, its understandable since it isn't modeled correctly. Each aircraft has a chart in the pilot operating handbook that shows manifold pressure and prop settings for different phases of flight ie; takeoff, climb, cruise climb, cruise, decent, approach and landing. For full power and speed its always full MP and full Prop. Again, this game doesn't model it correctly and the little tricks learned to do different things in here (concerning CEM) would not work in a real plane, it would destroy the engine.

I fly aircraft with constant speed propellers daily for work, turbines included. My boss would kill me if I pulled my pp back to 50% (as it is in game) and had full power. lol

Here's an example that explains a bit of what you shouldn't do, generally. It puts it into words better than I can.

"For any given RPM, there is a
manifold pressure that should not be exceeded. Manifold
pressure is excessive for a given RPM when the cylinder
design pressure is exceeded, placing undue stress on them.
If repeated or extended, the stress would weaken the
cylinder components and eventually cause engine failure."

http://www.coryat.com/faa-pp-written/index11.html

Read the Q & A there. It should help explain things a bit. The short answer to someone about pulling your PP back for more speed isn't correct. Again, before you even begin to pull your prop back you have to pull your throttle back or you will damage your engine, just not in game because it isn't modeled.

One last thing, that info is for real world aircraft/flying. In game you can do whatever and have different results, none of which are correct in the real world.

Sorry, but you're wrong.
With CSP, inside the CS governor limits, the blade angle WILL change with speed and attitude variations.
Since Speed and attitude will change il you change power (manifold pressure), then blade angle WILL change.... and same if you use elevator input to climb or dive.

Manual pitch control is different: The pitch angle is directly controlled by the pitch lever.

With IL2, almost all planes are CSP equiped when they don't have fixed pitch.
Only Bf109 (and maybe Bf110... don't remenber...) use manual prop pitch when automatized control is off.
Even FW190 never use manual controlled pitch, but CSP when Kommandogerät is off.

I think you misunderstood me or vice versa. The RPM's remain the same after you set them with the prop lever is what I was trying to convey. Either way, this sim does not model anything even close to what should happen other than the RPM you see on the gauge.

I see you were refering to an old system "manual pitch" otherwise known as controllable pitch. Most aircraft are CSP if they have a prop lever today. That threw me off.

In any of the convention constant speed aircraft, for example the P51 or F6F Hellcat. If you have run low rpm settings with a high manifold pressure, you will/can damage the engine. The way you explained it makes it sound as if the blade angle will adjust for the MP change and it will not. In the 190's and 109's, its automatic.

The blade angle will adjust for the MP change, until the the CS governor limit is reached, then blade angle will stay fixed and MP will change. (when low stop limit or high stop limit is reached)
This is actually modelled in the game, and with most of the planes, if you set RPM very low and Boost at max, engine will heat, then breake (so you can overtorque)
Overrev is modelled only for some planes, so with most off them you can dive with high RPM without risking overreving (which isn't realistic)

So I agree the game is much more tolerant to overreving and overtorque than reality..

For Bf109, the automatic control can be switched off, and then you get manual prop pitch (not CSP, but pitch direct input). This is correct in real and correctly modelized.
For FW190, when automatic control (Kommandogerät) is switched off, then you get the standard CSP for pitch control.

I believe you're just reading stuff on the internet without practical experience. You had me second guessing myself and doing that because of this sim could get me killed in RL. lol I even called my father who is a 30+ thousand hour professional pilot. He started on DC3's, Elektra's, DC4's and 727's. He basically said the same as I have. Please don't take this as flaming, it is not. Yes on CSP aircraft, the pitch will change if you change the MP, but only a minute amount. It will NOT make up for large changes in MP. A good example is at idle. Although I have my prop lever at full, I will still idle at about 700 rpm. The same goes if I am at a lower RPM and shove my throttle up to max MP, it will damage the engine because the prop governor will try to keep the RPM's constant, but the MP pushing the engine to its limits or past.

I have tested over and over for extended periods in game. I will take, for example, a P51 run it at full throttle and drop my PP to 50% and run all day without damage. That is what I'm talking about.

Again, I am only referring to standard US aircraft. I have very little knowledge of German, Russian and British planes.

Most of the American ones do... and as far as a CSP prop goes.... think throttle = Manifold pressure prop pitch = RPM.. If you do not let your RPM redline you will get more out of the engine.

Well... you're wrong... don't try to guess... just stick on what you know.
I have my pilot license (I'm only a sunday pilot) and I'm an engineer with quite good knowings in fly mechanics

You didn't read or understood what I said.... well... it's not a big problem.

I totally agree with that. It doesn't contradict what I said.
Like I said, in this case you will overtorque the engine.

Now try at full throttle and 0% PP... you will see (I'm not 100% sure for the P51, but for other planes I experienced in game engine heating and breakdown after a few minutes)

So In game overtorque IS modelled, but not reastically, the game is too tolerant (and even more for overreving)
... as I said in previous post.

Respectfully, you being an engineer has zero bearing on your weekend knowledge of being an amature pilot. For the sake of simplicity, the pitch angle does not change with throttle changes. I'll see if I can get some other professional pilots in here. My dad just shakes his head at this. He recalls the worst pilots he ever flew with were the ones that were too "book smart". There's more to flying than by the book, you gotta feel it and live it. If you can't get past all the technical/books you'll be confined in a box.

The game is exceptionally tolerant to anything concerning CEM to the point of being arcadish.

Despite you saying "respectfully", you don't show much respect... no problems... if you feel superior, that's your problem.
It's just making a difference with all the pro pilots I know... all very nice guys.
... and you obviously you have a problem with understanding CSP mecahnical fonctionning and CS governor...
CS governor controls pitch angle and adjust it to keep RPM constant. that's why when you adjust throttle pitch do change (adjusted by CSP to keep RPM constant).
not much knowing is needed to understand that... look there for example: http://www.pilotfriend.com/training/...wing/props.htm

Maybe this will clear things up. Let's keep it simple.

Throttle Levers control power and RPM from idol up to Flight power settings.
Prop Levers control and refine RPM and Prop Pitch.
Mixture Leverscontrol fuel flow.

*NOTE: Throttle does NOT have any input to prop pitch settings what-so-ever.

The reason for Constant Speed/Variable Pitch propellors is to Optimize the pitch of the propellor in conjuction with power -i.e.throttle- settings at various stages of flight.

High RPM/Low pitch with Hi power setting for take-offs.
Med-Hi RPM/Low Pitch with Medium Power setting for climb-outs.
Medium RPM/Medium Pitch with Medium Power setting for Cruise flight.
High RPM/Low pitch with Low power setting for final stage -i.e. last few hundred feet- before landing. WHY you ask?

1. The flat-low pitch helps slow the plane down.
2. The Low pitch/Hi RPM is readily available without danger of overspeeding via manifold presure inputs from the throttle for Go-Arounds proceedures.

Keep in mind...
Medium - Hi Power settings may only be a difference of 2" of Manifold Pressure, and Medium to Hi RPM may only range 200-300 RPM from max power back down to Cruise flight.

Depending on the power plant, there are specific limits to manifold pressure to specific RPM settings. You never want to put manifold pressure past the specified RPM setting.

Everything Mr Sniper has said is completley correct.



V

I can sorta see what your getting at there Rama, but I too would have to agree with Vidar and Sniper on this too. My question is will it be different when BoB comes out.

S!

Comswim

Rama, I apologize. I just tend to get excited when I know I'm right about something, especially if someone blatantly says I'm wrong about something that is my profession. I doubt you tell your professional pilot friends "You are wrong" when they correct you on something. No harm intended though. Vidar stated things more clear than I was able to.

I did talk to our company A&P. (airframe and powerplant mechanic) The one time the pitch changes without input of the prop levers is if you go into a dive. The change is, however, so brief that it is not something noticed and only a technical note. It would have to be something extreme so that the relative wind is driving the prop and not the engine. The RPM's will speed up a bit and only VERY briefly. That will change the prop pitch, but the governor will bring them back to what the pilot set them at. It's just a brief second or two of change, nothing that would be noticed normally by the pilot.

So in the end, the throttle (Manifold Pressure) will not change Prop Pitch.

We can only hope and pray.

Actually... nothing Vidar said actually contradict what I said, except the last sentence.

He even sais in another form what I said:
CSP do control pitch and do it constantly to adjust for RPM... I said nothing different.
So for a fixed position of the RPM Lever, then, inside the CS Propellor limits:
- if you increase boost (admission pressure): CSP will adjust pitch and blade angle will increase to keep RPM constant.
- if you decrease boost (admission pressure): CSP will adjust pitch and blade angle will decrease to keep RPM constant.
- If you pull the stick, speed will go down: CSP will adjust pitch and blade angle will increase to keep RPM constant (up you reach the limit of the CSP, then RPM will decrease, and you will risk overtorque if you did set RPM too low)
- If you push the stick, speed will increase: CSP will adjust pitch and blade angle will decrease to keep RPM constant (until you reach the limit of the CSP, then RPM will increase and you'll risk overreving if you did set the RPM lever too high)

I did try to stay as simple as possible to be sure to be understood (since I begin to think my English is so bad that Sniper and Vidar don't understand it.... then I should go to take some English lessons...)

Correct me if I'm wrong, but I believe you are saying that if you increase boost (manifold pressure) the prop governor will adjust the prop pitch to keep a particular RPM. Is that correct?
If so, I have to disagree still. lol

as far as IL2's engine management goes
 

This is an interesting topic, and I'm trying to learn something about about real life prop pitch control. But I see that since IL2's complex engine management is not the most accurate representation for a few planes (P51 as an example?) this topic has turned a bit arcane for me. In other words I've missed how I can use this discussion to improve my engine managment in the game itself. I'll go back and re-read this thread, and maybe I'll get the gist of it. Getting a bit dim in my old age, I guess.
Flyby out

Absolutly correct, and that's what CSP is designed for.
In order to absorb the increased torque (power is equal to torque times RPM) the CSP will adjust the propellor pitch.

As you want.... but better then get some documentation about CSP... (The link I provided could be a first step...)
Just a simple question: How do you think the CSP maintains constant RPM?
Once you will have answered this one, there will be no more missunderstanding between you and me.

Take a look at what Vidar said. He also stated that input from the throttle does NOT change prop pitch. I also spoke with our company A&P mechanic as I stated earlier, he said the samething. The prop lever sets the prop pitch AND RPM. Each RPM has a specific prop pitch setting. Thats why in the case of a dive, when the reletive wind drives the prop to a faster RPM, the pitch changes until the prop governor brings it back to the pilot's setting. What I'm trying to convey is that the throttle does not change the pitch of the prop.

You may be saying that introducing more throttle (power) will cause the governor change the prop pitch to take a bigger bite of air to hold the RPM's the pilot set. Am I getting close to what you mean?

http://www.faa.gov/pilots/training/handbook/

ADJUSTABLE-PITCH PROPELLER
Although some older adjustable-pitch propellers could
only be adjusted on the ground, most modern
adjustable-pitch propellers are designed so that you can
change the propeller pitch in flight. The first
adjustable-pitch propeller systems provided only two
pitch settingsa low-pitch setting and a high-pitch
setting. Today, however, nearly all adjustable-pitch
propeller systems are capable of a range of
pitch settings.
Aconstant-speed propeller is the most common type of
adjustable-pitch propeller. The main advantage of a
constant-speed propeller is that it converts a high
percentage of brake horsepower (BHP) into thrust
horsepower (THP) over a wide range of r.p.m. and
airspeed combinations. A constant-speed propeller is
more efficient than other propellers because it allows
selection of the most efficient engine r.p.m. for the
given conditions.
An airplane with a constant-speed propeller has two
controls—the throttle and the propeller control. The
throttle controls power output, and the propeller
control regulates engine r.p.m. and, in turn, propeller
r.p.m., which is registered on the tachometer.
Once a specific r.p.m. is selected, a governor
automatically adjusts the propeller blade angle as
necessary to maintain the selected r.p.m. For example,
after setting the desired r.p.m. during cruising flight, an
increase in airspeed or decrease in propeller load will
cause the propeller blade angle to increase as necessary
to maintain the selected r.p.m. A reduction in airspeed
or increase in propeller load will cause the propeller
blade angle to decrease.
The range of possible blade angles for a constant-speed
propeller is the propeller’s constant-speed range and is
defined by the high and low pitch stops. As long as the
propeller blade angle is within the constant-speed range
and not against either pitch stop, a constant engine
r.p.m. will be maintained. However, once the propeller
blades contact a pitch stop, the engine r.p.m. will
increase or decrease as appropriate, with changes in
airspeed and propeller load. For example, once a
specific r.p.m. has been selected, if aircraft speed
decreases enough to rotate the propeller blades until
they contact the low pitch stop, any further decrease in
airspeed will cause engine r.p.m. to decrease the same
way as if a fixed-pitch propeller were installed. The
same holds true when an airplane equipped with a
constant-speed propeller accelerates to a faster
airspeed. As the aircraft accelerates, the propeller blade
angle increases to maintain the selected r.p.m. until the
high pitch stop is reached. Once this occurs, the blade
angle cannot increase any further and engine
r.p.m. increases.
On airplanes that are equipped with a constant-speed
propeller, power output is controlled by the throttle and
indicated by a manifold pressure gauge. The gauge
measures the absolute pressure of the fuel/air mixture
inside the intake manifold and is more correctly a
measure of manifold absolute pressure (MAP). At a
constant r.p.m. and altitude, the amount of power
produced is directly related to the fuel/air flow being
delivered to the combustion chamber. As you increase
the throttle setting, more fuel and air is flowing to the
engine; therefore, MAP increases. When the engine is
not running, the manifold pressure gauge indicates
ambient air pressure (i.e., 29.92 in. Hg). When the
engine is started, the manifold pressure indication will
decrease to a value less than ambient pressure (i.e., idle
at 12 in. Hg). Correspondingly, engine failure or power
loss is indicated on the manifold gauge as an increase
in manifold pressure to a value corresponding to the
ambient air pressure at the altitude where the failure
occurred. [Figure 5-6]
The manifold pressure gauge is color-coded to indicate
the engine’s operating range. The face of the manifold
pressure gauge contains a green arc to show the normal
operating range, and a red radial line to indicate the
upper limit of manifold pressure.
For any given r.p.m., there is a manifold pressure that
should not be exceeded. If manifold pressure is
excessive for a given r.p.m., the pressure within the
cylinders could be exceeded, thus placing undue stress
on the cylinders. If repeated too frequently, this stress
could weaken the cylinder components, and eventually
cause engine failure.
Manifold Absolute Pressure (MAP)—The absolute pressure of the
fuel/air mixture within the intake manifold, usually indicated in inches
of mercury.
ch 05.qxd 10/24/03 6:50 AM Page 5-4
You can avoid conditions that could overstress the
cylinders by being constantly aware of the r.p.m.,
especially when increasing the manifold pressure.
Conform to the manufacturer’s recommendations for
power settings of a particular engine so as to maintain
the proper relationship between manifold pressure
and r.p.m.
When both manifold pressure and r.p.m. need to be
changed, avoid engine overstress by making power
adjustments in the proper order:
• When power settings are being decreased, reduce
manifold pressure before reducing r.p.m. If r.p.m. is
reduced before manifold pressure, manifold
pressure will automatically increase and possibly
exceed the manufacturer’s tolerances.
• When power settings are being increased,
reverse the order—increase r.p.m. first, then
manifold pressure.
• To prevent damage to radial engines, operating time
at maximum r.p.m. and manifold pressure must be
held to a minimum, and operation at maximum
r.p.m. and low manifold pressure must be avoided.
Under normal operating conditions, the most severe
wear, fatigue, and damage to high performance
reciprocating engines occurs at high r.p.m. and low
manifold pressure.

Could of done without the huge copy and paste, thanks all the same though. lol I've got the books and the FAA certificate. :)

I'm just trying to clarify what Rama is saying so we can get on the same page.

Im with you Flyby...I cant read anymore theory on the pp (though what I have read is interesting). Can somebody now tell me how and when they use pp in IL2?

The later is correct (and what I allways said).

You can see the contradiction with the first sentence?

You can also look at the text quoted by Loco-S.... especially this part:

Which is also what I allways said.

ok guyz, to help you all with PP settings as they relate TO THIS GAME, is this:

Automatic props ( german, british ) don't worry about them.

CSP equipped planes ( USA, USSR, Japan ): Take off: Full throttle 110%/ PP= 100%

Ballz-to-the-wall full on speed run: Full throttle/ PP=95-90%
why 95 to 90? try this: take a p38L late and go full throttle and fly as fast as you can on the deck....the plane hits a brickwall at about 470kph IAS and refuses to go any faster. Now keeping full throttle, adjust your prop pitch to 95-90% and watch your speed jump to about 570kph IAS.

Dogfight: Full throttle 110%/ PP=100% Since dogfighting takes place at slower speeds ~300kph and lower....you'll need max power and ur prop blades grabbing the most air as possible to keep you from stalling at high angles of attack.

Cruise: throttle 50-60%, PP=60% . A good rule of thumb that I go by when cruising is if I throttle back power to say...50%...I also pull my pp lever to nearly 50%. Keep ur throttle and pp levers on same % and you'll be doing good.

Dives: Throttle back and pp back to nearly 50%. The game's aircraft dive rate is incredible and they all pick up speed very fast...no need to overwork ur motor by keeping it at 100 throttle and pitch..this actually hinders ur initial dive rate. Pull ur prop pitch back during a dive and you'll dive like the devil @!!@

AND THAT'S ALL YOU NEED TO KNOW ABOUT PROP PITCH IN THIS GAME.

Agree with all Ironman.

I could also add (also strictly for IL2):
- if your engine is damaged, reduce PP, it will last longer
- if you're low fuel, reduce PP to 0%-5%, your engine will heat, but you will save maybe enough fuel to reach base (against, it's IL2.. real thing is different)

In fact, all planes in IL2 are equiped with CSP, except a few with fixed pitch (TB3, Gladiator, CR42, maybe a few others...)
There are also those with fully atomatized CEM, like:
- Bf109/Bf110 (if auto is off, then pitch is fully manual... don't use it without strong experience)
- FW190 (if auto is off, then pitch is CSP controlled)

This is always a source of confusion for many reasons. First, there is many types of prop pitch setups in IL-2, as there were in the real planes. Second, people have a misconception about the idea of changing the pitch of a prop.

After reading the first page and a half, I just have to post and hopefully clear the air.

First, adjustable pitch props are just like transmissions in a car. BUT, this is in the sense of ALLOWING the driver or pilot to set the engine RPM. In a race car, the transmission is geared to put the RPMs at or close to where the engine produces maximum power.

In a sedan, the transmission is not geared the same way, and a balance between power and efficiency is made.

When an engine is producing power, it doesn't do so linearly across the RPM and power output doesn't just keep going up with RPM. There is a curve where at low RPMs its producing a low amount of power, at higher RPM the engine will be producing more power; BUT at max RPM the engine MAY NOT be producing max power. However, power output is directly related to RPM. There is a POWER CURVE related to RPM.

Since the above paragraph is true, you want some tool to allow the pilot to set the RPM of the engine. In combat situations, he would want to set the RPMs where ever the engine produces most power, at the peak of the power curve. In cross country situations, the pilot would favor efficiency over power output so he may set the engine RPMs lower than peak so to save on fuel and engine life.

There are a handful of types of adjustable props in the game. The best is a CONSTANT SPEED PROP. This term is misleading as it really dictates the speed of the engine, not the speed of the prop. This type is found mostly on the US birds such as the P51. What happens is the pilot finds the RPM he wants to use (ie 2500) and sets the pitch to keep the engine @ 2500 rpms. The neat part now is, no matter what throttle settings he uses the governor will dynamically adjust the pitch of the prop so the engine maintains a constant speed of 2500 RPM. Now, at really power settings, the engine just can't produce enough power and the governor is set to NOT go to a 0° propeller AoA, so the RPMs will drop at low settings. The big payoff with this system, is the RPMs will be constant at all airspeeds, without intervention from the pilot.

The next type of adjustable pitch propeller is just that; The Adjustable Pitch Propeller or Variable Pitch Propeller. The german fighters are built like this, IN GENERAL! (I say in general because 190 & 109 prop systems are similar they are really different) In this system, the pilot has direct control over the pitch of the prop. But again, the pilot would want to set the pitch to dictate the engine RPM's for he given situation. BUT... BUT... BUT... He must constantly change the pitch as his airspeed changes. In a climb, he has to apply a finer setting (closer to 100%), in a dive he has to apply a coarser setting (closer to 0%). Else in the former case he'll stall out or in the latter burn his engine up due to the high RPMs. Even straight and level flight needs attention as generally the airspeed increases so therefore you must use a coarser setting to maintain the same RPMs. In this system the RPMs will change also with throttle setting. Its a relationship between throttle, pitch setting and air speed; if any of these change, so does the RPMs. Therefore the pilot must constantly manually change the pitch setting.

NOTE: 100% PITCH DOES NOT EQUAL 100% POWER AT ANY THROTTLE SETTING! More RPMs does not mean go faster. It's all about setting the engine to the RPM at which it produces the maximum power for any throttle setting*.

*Even if the throttle isn't @ 100% or above, the engine still has a power curve, it's peak is the same RPM at max power, but it's just not putting out max power.

Note: 190 is NOT a Constant Speed Propeller.
Petition to get power curves published!

It is IN GAME, when kommandogerät is OFF (once you set the automatism off).
When automatism is on, then of course the kommandogerät drives the pitch along with mixture, turbo, etc....

kommandogerät is not a CSP, CSP will maintain a constant engine rpm regardless of throttle.(within reason)

This is not true with kommandogerät. Reduce your throttle, your RPMs will also reduce.

kommandogerät is really just an automatic VPP system tying pitch and throttle to rpms.

-Raven

You're absolutly right.... but it doesn't contradict what I said
Read what I said.... I never said Kommandogerät is CSP.

When Kommandogerät is ON, then it manage the whole stuff (including pitch)
BUT.... when Kommandogerät is OFF (one you turned it OFF), THEN (and only then) Pitch is CSP controlled.
Try it in game, first turn the kommandogerät OFF, then you will see RPM will be fixed for a given position of the PP lever.

On or off, the 190 is never a CSP. CSP maintains a constant engine rpm regardless of throttle setting (within reason). That is why it's called constant speed propeller.

Again, reduce your throttle (Kommandogerät OFF) and your RPMs reduce. That is NOT CSP that is VPP.

You obviously haven't tried with Kommandogerät off..... try and you'll see I'm right (reduce or increase throttle, and RPM wont move).
I'm of course talking in game, not real.

Thanks Rama for the clarification. BTW, what type aircraft to you fly in real life?

Ironman has given great advise for Prop Pitch Managment for gaming IL2. IRL you would burn out an engine in no-time-at-all with these techiques.

Roma also had terrific advise for saving a bad engine. Again, useless IRL, however; Throttlinge back to 70% and bringing my prop pitch back to about 80% gives me more flight time with a crippled engine... My training as a pilot and a flight instructor has ingrained into my brain bucket to never exceed Manifold Pressure over Prop Pitch, so I follow that rule in-game too. It saves me from transfering bad engine management techiques into RL. :cool:

Example how Prop pitch should work in-game - HIGH SPEED DIVES:

Prop Pitch should be full forward to prevent over-speeding the airframe. Sounds confusing to some, I know, but here's why.

Dispite the High RPM pitch, this setting flattens the blade angle. The Govenor will prevent over-speeding the engine. The flat plane of the spinning prop now acts as a huge spinning speed-brake.

Great thread gents!

S!

\/

Robin DR-400 (fixed pitch) and Aquila AT01 (CSP)

not on my PC..............
i easily hit 570km/h TAS at SL with 100% pitch , not sign of any "wall" at 470.
than when reducing the pitch to ~90%, i get slower.


i'm am using that summary when flying IL2 concerning the pitch:

for all piston engined planes except:
Ki-27
J8A
TB-3s
Fw190 in auto mode
Ta152H in auto mode
Spitfire IX and VIII in auto mode
Bf109, Bf110,Do335,Ta152C in manual and auto mode:
the prop pitch in game is controlling the engine revolutions - so 100% pitch here means you allow the egnine to run at max rpm if enough throttle/power is available.
in combat you shoud fly always with 100%.
to lower your pitch is actually only necesarry if you want realy fly slow (that your comrades or the AI can close formation or you want safe fuel) , than you have to reduce the pitch like the throttle. same % rate or pitch 10% more than the throttle % is a good solution.

also using full throttle and useing only 90-95% pitch can reduce the overheat chance - usefull in some planes like the Tempest or the Corsair and Hellcat. that doesnt harm your speed/climb much, if at all !

very few planes in game are overrev in a power dive (full power, 100% pitch) - IIRC that are the Cr.42, G.50, Mc.200, Fw190A/F in manual mode, Fw190D/Ta152H in manual mode, the Brewsters(not sure about that , may have changed in a patch)


Fw190 in auto mode
Spitfire IX and VIII in auto mode
Bf109, Bf110,Do335,Ta152C in auto mode:
have a one lever system, if you control the throttle, the pitch is automaticly also controled


Bf109, Bf110,Do335,Ta152C in manual mode:
thats totaly different, here you control the propeller blade angle direclty ! no automatic will keep the rpm in a "good" condition. it brings you no benefit to use this manual settings anymore (there was a time ). so, dont bother it

the
Ki-27
J8A
TB-3s:
have fixed propellers, so nothing to control there




sure, others may have other experiences - but it fits for me.

Same here. With preducing pitch you may gain a little more speed for short time but it will fall below topspeed quickly.

that any plane (with a CSP) in game reaches its max level speed, at least at Sealevel, with less than 100% Propellerpitch setting is a myth for me (beside using any exploit !)..........

I do so exclusively, here are two tracks one with a CSP (P51) and one without (190A9). You will see changes in throttle do not change RPMs in the 51 (auto OFF) while changes to throttle in the FW produces engine RPM differences of 300 RPM or more between 2300 and 2600 RPM.

http://www.fly-eaglesnest.com/downloads/FW190A9.ntrk
http://www.fly-eaglesnest.com/downloads/P5120DNA.ntrk
http://www.fly-eaglesnest.com/downloads/CSPvVPP.zip

The zip file is just both files zipped up and all are provided in case of file corruption of the zip.

While there are minor fluxuations in the RPM of the P51, that's to be expected: Reasoning the engine is producing more power faster than the hydraulic system can adjust for, but it does definitely settle and maintain engine RPM, 2650 I believe: Even down to about 50% power.

On the other hand, the FW setting of 40% pitch (Auto = OFF) is turning about 2600 RPM @ 100% throttle. Reducing throttle in this case reduces engine RPM; @ about 70% throttle ~2300 RPMs. Definitely NOT a Constant Speed Propeller since by definition a CSP maintains a constant engine rpm.

-Raven

Okay, I would very much appreciate if someone can clear up some of my questions:

If I'm in an American plane (p47, p51) and I want good level acceleration, should I be at about 80% pitch or so or should I do 100%?

If I'm in the same plane and in a hurry to get somewhere, or to get away from someone, should I be at 100% pitch, 110% throttle? Or should I be at lower pitch?

Does the same thing apply for Russian planes and FW190's (in manual mode)? (I'm aware the 109 has a different manual pitch system)

Thanks

true, there is too much rpm loss while reducing power in the Fw190 on manual mode compared to other CSP planes in game . so we "have" to say the Fw190 in manual mode has a very bad CSP moddeled in game ;)
or however you want call that thing in front of the engine.

anyway, in combat the manual mode is the choice over the auto mode in the BMW driven Fw190s.

@Krupinsky
The rpm stay relativelly constant for small change of throttle. it's a kind of CSP, With some limits (like all CSP). The limits being tighter than on other planes does'nt change this for the in-game comportment (this is also the case for some russian planes).
In any case, the lever control rpm, not pitch, which is typical of a CSP...(good or not, it isn't the question)

@Frankyboy
Yes, "manual" mode is better in combat for FW190. Since you can set RPM much higher than with kommandogerät. With rpm at 100% you get better acceleration and better climb rate (like you would do with using highest rpm with a CSP).

What about in Stormy Weather?

I was playing a campaign last week (Wings over Waves) and it was blowing so much that just sitting on the runway the aircraft was turning sidewasy without the tailwheel locked.

With the PP and Throttle at 100/110% the aircraft shook like mad. The only way to stop the shaking was to reduce the PP to about 70-80% at all times. I was flying a P40 I think.

If you want good response and acceleration use 100% prop pitch. Anything else is just for cruise, cooling the engine or diving faster and holding your E a bit longer when you level off.

Just how realistic is using 100% prop pitch? I think a lot of people just hoon along at 100 % pp and 110 % throttle online in il2.
I imagine in real life the power and speeds were a lot lower.

Well, you can check for many planes handbook (notes for pilots).... it gives you the rpm and boost you have to use for usual flight phase (take off, sustained climb, cruise flight, combat power, emergency power, etc....)
These advices were not given for no purposes... they were given in order to assure that a plane engine will remain reliable during some times (and at least some flights)

If every pilots was using rpm 100% and boost 100% all the time, then there will be a high probability of engine failure at each mission.

The problem is that engine stress is hard to simulate, even during one flight session... and impossible for a plane life (since basically a plane flown by a simmer has no "memory" of previous flights and of the stress accumulated during its life.

Distances are longer too.

For best acceleration in game and top speed also top climb values it is required to use 100% prop pitch.
As Franky said everything else is a myth to me, I've yet to see the track where one can get greater speed on less prop pitch than 100.
However, in dive you can have a luxury of using less than 100, say 80-90%... and maintain the similar speed you'd have with 100% prop pitch.
That works good in P-47/51.

Russian planes are bound to same rules, top performance = 100% prop pitch. Less = less performance.

German planes are better to just leave alone in this case. They have automatic system that works good.:)
Anyhow, if you mess around with Bf-109 prop pitch you will gain nothing; at best you will just get crappy performance, at worst you get a ruined engine. It wasn't always like that, but due to prop pitch exploit (109 always climbed like a rocket, but even more so with prop pitch exploit, from Auto to 100%) OM team made manual prop pitch unusable for performance gains in 109's some time ago in some patch (can't recall exactly).

The strange thing is that German really used that exploit during the BoB (Manual Pitch for a faster compression of the air and Auto Pitch for the release of a better boost).

Infact English people could recognize a 109 from a Merlin engined airplane simply hearing the sound emetted fomr the engine: the 109's sound wasn't linear, but was a highrev sound followed by a lowrev sound, while the spitfire sound was quite constant.

With most of the aircraft in IL2 being fitted with Constant Speed props, we need our friendly mod community to change the "prop pitch" message to a "Engine RPM" (or something similar) and it would clear up most of the problems in understanding.

The only ones that would be upset would be the LW pilots that use the manual pitch settings, which we are told lead to a can of worms anyway! ( That would lead to a bigger whine than 109 at full throttle ;) )

I of the question you have to ask your self in regards to CSP and that is why and how they used them.

In the Battle britan the hurricane and spitfire could only use Max house power for 2 mins and the merlin engine if over revs by 150 RPM they would have to replace it.
Every 200 hour of operation they have to over haul the motor.
The way the game is model to the real thing is a big difference and the fact that i can run a spitfire mkIXC 25bls and full power till i run out of fuel was and is impossible to do in real life.

the only time i lower the RPM is if i get engine damage out side of that there is no needed to do it because i can fly constantly at the higher RPM means that i can cruise faster, climb fast and respond fast if i needed to. And as for over heating most engine will not over at 90% throttle even with the rads closed.

You also have to remember that to get a motor to produce 1400 HP is hard to do and even today it is hard to find (if not impossible) a piston engine that has the same weight and HP as the merlin they did it in 1945.

What's your source for this information ?

Don't confuse the drone of the bombers which was different for Axis and Allieds, the German bombers would sound like they were pitching up and down due to unsynchronized engines.
My house was on the WW2 German bombing flight path and the flak enplacement at the end of my road (London) was active at night and the listening stations along with radar would identify the enemy, locally by sound then confirmed to fire barrage flak.
Some of my neighbours have lived here since the war and are useful for local history etc.

IIRC it was in "Spitfire on my tail" by Ulrich Steinhilper. :)

This happens a lot in the game, the thing is i don't how pronounced it is in comparison to real life. For example, i fly 190s a lot and i use manual pitch on everything except Doras and the 190A3 which is a custom-built mod that more closely resembles real life kommandogerat operation, so i don't have to mess with it.

As a rule of thumb, i use the following pitch settings:

100% for take-off/landing, braking in a dive and hanging it on the prop in a climb

80% in level flight/acceleration when i'm doing more than 320kmh and the start of a dive

90% when climbing or when i'm level but slower than 300kmh

60-70% when i exceed 500-600kmh and want to keep diving faster

50% when i exceed 700kmh and still want to go faster

The general rule of thumb for dives is to start at 80% and reduce 10% for every 100kmh, but in a combat situation it might become a pain to monitor closely so i go with the above settings.

I would really love it if BoB:SoW has more accurate engine modeling and management as this made a huge difference in real life. Your P47 may be way faster at 8km but it should also be much more complex and require more attention to supercharger RPMs, intercooler settings and so on when you take it into a series of dives and climbs in combat. A 109/190 on the other hand will be slower but you shouldn't have to touch anything apart from the throttle.

Things like that can probably decide the outcome of a fight due to differences in pilot workload, so it would be important to get it right.

Another thing that's missing is the constant adjustment of throttle during a climb to maintain optimal manifold pressure. I was at a friend's place and had some stick time on that Spitfire add-on for FSX. All i can say is "Wow!". It can reach rated take off power at probably 60% throttle because ambient air pressure is higher on the runway. As you go higher, the drop in ambient pressure results in a drop in manifold pressure too, so you need to advance your throttle a bit to offset this effect.

This means that maximum power is not simply a case of shoving the throttle forward against the stops, but it's more a question of maintaining the rated power settings. So, what happens when you do shove the throttle to the forward-most position in low level? Well, you can do it but you have a minute or so until it overheats and seizes. That's another thing that's missing right now, all planes can go full throttle at low altitudes and exceed the real power settings. In reality, the travel of the throttle lever is calibrated to give you the rated power settings for the top part of your flight envelope, ie your effective service ceiling and not for flight on the deck.

Using that Spitfire add-on as an example, it shouldn't make much of a difference if you are flying a regular Spit IX or a 25lbs version if the recommended settings for maximum continuous operation is +8lbs of manifold pressure. Think about it guys, being unable to go over +8lbs for most of the dogfight unless you do it briefly, like for example in a zoom climb, and then you have to let it cool off too. Now compare this to what we have in IL2, where every plane can go full throttle on the deck without penalties at all. It would make all kinds of difference in how we fight.

I wish i could link you the free PDF manual for that Spitfire add on, but the realairsimulations website isn't loading for me at the moment for some reason.

Great thread by the way.

Edit: Ok, it works now. According to the manual these are the settings for the MKXIV (the MkIX is more or less similar):
+18lbs for 5 minutes
+12lbs for takeoff
+9lbs for one hour
+7lbs max continuous power

Have a look here if you're interested: http://www.realairsimulations.com/li...it08_downloads