Complex Engine Management & planes limits

[jf1981]

Hello,

I expect that through time, each single aircraft will start to have very good filght model & engine model.
In numerous airplanes, we have many gauges available, however it is not so easy to know which limits not to exceed to run the engine safely e.g. when to turn compressor on/off and how to set mixture up depending upon altitude, RPM limit, how much time allowable above certain RPM.

In other words, thanks to the packaging, we have a good Sptfire manual available with the game. But for other planes, will we have any documentation ? How do other people do ? Is there some good documentation about that on the web ?

I'd like to have a documentation of quality available with this game for each plane in the technical matter. Would that ever be possible ?

Regards

J.-F.

[Redroach]

http://lmgtfy.com/?q=he+111+pilot+manual

[jf1981]

First of all I'm not sure all of them are available in english, for exmaple the HE-111 you mentionned in your post.

Of course it will be possible to learn through time, I'm posting that to know if the technical documentation will be available through the game. It may not however.

[MadTommy]

There is soooo much documentation lacking for this game. We really should not have to find it from outside sources. Simulators should come with the info needed to master them, or at least explain the basics.

I really hope documentation will arrive in patches soon.

[Redroach]

if you are resistant to learn for yourself (not that I think that anyone would read a 500+ pages manual anyway), why don't you fly with CEM off then?

[Troll2k]

You would need over 200 manuals for IL2 1946.

[jf1981]

Originally Posted by Redroach

if you are resistant to learn for yourself (not that I think that anyone would read a 500+ pages manual anyway), why don't you fly with CEM off then?

I am not, I just keep burning the engines before I figure out what's happening, not a convenient way to learn.

I don't mean a full manual, key figures should be enough. It's like they are implemented but not documented.

I honetsly think it's not too much to ask for such.

Originally Posted by Troll2k

You would need over 200 manuals for IL2 1946.

Of course not realisctic, just engine limits shall be enough.

I just discovered that Bleinheim IV mixture needs to be decreased progressivingly when getting alt but then the engine burnt for an unknown reason (oil & air rads fully open) ?

Just an example.

[Blackdog_kt]

Wall of text incoming...

Engine limits and where to find them:

The PDF manual is in (your games folder)\steam\steamapps\common\il-2 sturmovik cliffs of dover\manual
The section about aircraft operating limits starts with the Spitfire on page 83.

The Spit limits are probably the same as the Hurricane, because they have the same engines. At least i didn't have any problems whatsoever using the same settings on both: 2800 RPM for climb, 2650 for general use including combat, as low as 1800 for fuel economy cruise, the never exceed limit is 3000 RPM and i only use it during take-off.
As for the boost, it's clearly marked on the instruments with a red arc and a white triangle in the middle of it marking level flight power (which is probably max continuous setting).

This also goes for the Ju88 and He-111H, they have Jumo engines so you can use the same settings as in the Ju87, plus the Ju88 also has the limits clearly marked on the RPM and manifold pressure gauges with color-coded lines: green for continuous, yellow for combat/climb (probably a 30-60 minute limit on that one) and red for emergency.

The 110 also has DB601s but they are rated somewhat different than those used on the 109 so you can't use the values from the manual that refer to the 109. Once again though it's not a problem, because the limits for RPM and manifold pressure are marked on the instruments: d means continuous, 30 means "don't use it for more than half an hour" and 1 means "emergency power, don't use for more than 1 minute".
I bet the same settings will work on the He-111P as it has the same engines.


The only aircraft that completely lack any documentation are the radial engined ones: G50, Br20 and Blenheim.
These are a trial and error business with some interesting findings.

G.50 "glider":
For example, i was flying the G50 against some Gladiators in a QMB mission last night. At some point i was getting low on ammo and i had 3 of them swirling around me, so i got hit a couple of times but i didn't suffer any kind of serious damage. I decided to use my higher speed and disengage, so after forcing a sideways head-on merge i rolled level, put the nose down and turned for France, easily escaping them.

They were still following but couldn't catch me, in fact i was increasing the distance constantly. And then i had a "let's see what happens" moment and decided to do a little experiment. There was a cloud in front of me and i decided to see what happens if i fly through it. You see, there are no carb heat controls on the G50, so i assume it doesn't have such a device.
Sure enough, a couple of seconds before exiting the cloud my engine coughed, sputtered and seized

The Blenheim:
The Blenheim is another tricky one, because it seems way sensitive to temp effects and especially having the correct oil temps. If your oil is cold, the oil pressure in the prop governor gets high and you get a governor failure.

Engine run-up:
Make sure to cycle the props between low and high RPM before applying power for take-off, as this will cycle the oil inside the governor and get warmed up oil from the engine into the system. This is called exercising the prop and is done during the engine run-up, prior to take-off.

Just keep the props at fine pitch, step on the brakes, full back stick, apply throttle until you get 1000-1500 RPM or so (arbitrary numbers, just something that won't break the engine from overheating while sitting on the ground and there's no airflow to cool it...in reality all aircraft have a specified RPM for the run-up) and move the pitch controls all the way back and forth a couple of times.

How the props work and how the game interface displays it:
As for the actual props now, it only has two-stage props but to put it in coarse pitch (the low RPM position) you have to pull the pitch slider all the way to the back. Anything higher than that puts it into fine pitch/high RPM. Effectively, this means that it has a prop similar to the one found on the in-game Spit Mk.I, but it doesn't "snap" between the two extreme positions (top and bottom) on its own. The bottom of the slider is the coarse pitch position, the rest of the slider all the way to the top is the fine pitch position.

Carburetor heating:
It does have carb heat but i haven't found any instruments displaying carb temps, so you need to read up a bit more to be able to set it.
You can't just set it to max either as it will reduce power, running too much heating lessens the air density in the carbs, so it's like running with too rich a mixture and choking the engine.

I've had some success setting it by ear, i just increase carb heat until the engines sound like they are losing power (this means i found the critical spot), then i decrease it a notch or two to get it back into the proper operating range and the engines sound healthy again. Had no problems up at 8000ft with this method last time i tried it in the free flight mission.

This is similar to leaning in an aircraft with manual mixture controls, which brings us to...


Setting the mixture:
First of all, there are two correct mixture settings for each altitude. The economy mixture is the leanest you can go without losing engine power, but it won't allow you to run high boost settings because of detonation and overheating. The best power mixture setting is a bit richer, burns a bit more fuel, but lets you run higher boost.

In modern and even not so modern general aviation aircraft, there are easy ways to set this: exhaust gas temperature and/or fuel flow gauges let you judge where is the correct mixture for each altitude.

In the Blenheim however we don't have those toys and we can't see the exhausts either, so we can't lean based on the colour of the exhaust flames.

Fear not, because there is a way. If you have a fixed pitch or two stage prop (which essentially is like having a fixed pitch prop that you can change mid-flight for another one with a different pitch) you can easily judge the changes in power.

This happens because for a given prop angle of attack, the power delivered by the engine has a direct effect on RPM. If your prop pitch remains constant, any change of throttle will change the RPMs too. In a similar fashion, every change of mixture that makes the engine run better or worse will also have an effect on RPMs.

This can be observed in aircraft with fixed props like the Tiger Moth (just lean until you get the highest RPM without touching your throttle), two-stage props and it would also work in aircraft that use the luftwaffe propellers, because they too are manually set to a specific angle by the pilot. It wouldn't work in an aircraft with a constant speed prop, because the resulting RPM change would be mitigated and cancelled out by the propeller governor, giving no useful indication to the pilot.

So, how does that help us with the Blenheim?
First, lean the mixture until you hear the RPMs increase. To know if you can lean further, keep at it until you hear the RPMs drop. This marks the point where further leaning doesn't yield any benefits, in fact leaning too much causes the engine to overheat.

So, as soon as you find that spot you've discovered the bottom of the useful mixture range for your altitude.

Go ahead and bump up the mixture towards rich a notch or two until the RPMs rise again. This is the economy mixture setting we mentioned earlier.

If you add a couple more notches of rich mixture (but not so much that it chokes and starts decreasing the RPM again), you will be at the best power mixture setting. This one is the best power mixture setting and it's the top of the useful mixture range for your current altitude.

In short, the scale looks something like this:
too lean---economy---best power---too rich.

Going too lean or too rich will cause your RPMs to drop, so just move the mixture controls until you find the range of highest RPM: the bottom of the range is economy mixture and the top of the range is best power mixture.

All this is presuming that the Blenheim has a completely manual system.

I don't know how exactly it works (is it semi-automatic between rich and lean like the Spit, or is it completely manual?), but if you try out the above method you can nail it down: if you don't see it working like i described, then it has a different system.

Also, just like in the Hurri, Spit and Tiger Moth, rich is backwards and lean is forward in regards to not only the animated cockpit controls, but also the info window sliders (the interface "HUD") and your actual, physical game controllers: you will need to press your "reduce mixture" key or pull your slider backwards to move towards richer mixture.

I've also found that the engines don't start easily if i set it to full rich, so i set it about halfway (if you look at the throttle quadrant, left-hand side in the cockpit, you will see a line marked as "normal" for the mixture controls, set it there). I guess full rich is only used when setting emergency and/or take-off/climb power to prevent the engines from overheating and cruising is done with mixture between "normal" and "weak".


Damn, you guys got me interested, now i'll have to go and test it all out

[MadTommy]

Blackdog_kt thanks a lot mate.. invaluable information.

[jf1981]

Originally Posted by Blackdog_kt

Wall of text incoming...
[...]

Thanks for your post, in particular Bleinheim, I understand what could have happened, rads open, cold oil => failure