Wow, some of you guys have some long winded posts....LOL, mine will be too and probably more info than you're looking for. Ahh....hitech's post regarding which lever to move first brings back many a memory from A&P school......Oh those were the days.....tearing down and rebuilding R-2800's, puttin the Ham-standard props on....runnin em up......aaahhhhhh....that was the life. Real oil, not this synthetic stuff I work with now....yuk!
Now, given a, let's say, round engine....the 2800 for example. there are 4 controls. 1. Throttle 2. Prop control 3. mixture control. 4. Supercharger control. All four are important and to avoid a jug leaving home, ya gotta do what hitech said in his earlier post. Now for grins let me say this: (hope this helps a bit to straighten out the confusion)
1. Throttle: Primarily controls manifold pressure (with a couple exceptions)
2. Prop Control: Primarily controls the prop position through a governer of some kind. Since we're talking constant speed here, the prop control has three positions full low pitch (increase rpm), full high pitch (decrease rpm) and everywhere inbetween, which is the constant speed range.
3. Mixture Control (don't have in AH) controls the fuel/air mixture for best performance/economy. Also shuts down the engine...No, you don't use the magneto switch to shut the engine off.
4. Supercharger control (not in AH): Controls the amount of boost given to the cylinders.
Everything sinking in alright? I think most will agree on those. Now, when we say increase/decrease RPM we're referring to the engine, not the prop. I think you're straight on that. Now on to the next thing....building blocks of information....gotta love it! LOL
When you start a high powered recip. engine, like the 2800, you'll start it with the mixture control in idle cutoff, both mags on. You've primed it with the primer and as soon as the engine fires and starts to run, you move the mixture to "full rich"....this is how the engine is run before takeoff. It keeps the engine cooler using full rich. Now, the engine is running....rumble, burp, rumble, rumble, burp......(valve overlap) R2800 doesn't like to idle.....it's a runner! Now, the prop control should be at the "full increase rpm" (low pitch) stop. If you look at your manifold gauge, you should see a pressure which is way under atmospheric.... (no boost) Next we set the engine rpm to 2200 with the throttle (one of the exceptions mentioned above) and do our magneto checks.....75-150 rpm drop per mag.....not more than a 50 rpm split between em. Ok, thats' normal...now we check the constant speed range...drop the throttle to around 1400-1800 rpm and let it stable out. move the prop control out of the "full increase rpm" position. The further aft you move it, the higher the prop pitch will become and the engine will start to "load" dropping rpm.... Now if you leave the prop control in that position (other than the two stops)...moving the throttle will change the prop pitch to either a higher or lower blade angle depending on which way you move the throttle.....increase throttle=increase prop pitch (constant speed remember?) decrease throttle=decrease prop pitch. During this time, if you look at the engine RPM gauge, it'll be constant (it'll move slightly with abrupt changes in throttle setting, but return to it's selected rpm) BUT, if you look at the manifold gauge you'll see it move up and downas you move the throttle. Forward, increase prop pitch, your manifold pressure will rise accordingly. (don't worry, there's a red arc where you're not supposed to exceed). As you move the throttle back toward idle, prop pitch decrease, the manifold pressure will decrease. Now if you grab the prop control and jerk it back toward you to the "full decrease rpm" stop, you've just blown the jugs off your engine and oil's going all over the damn place! The engine is making all kinds of bad noises which it shouldn't. The mechanics are PISSED! However, if you do it slowly and watch the manifold pressure, you may be able to get it to the full high pitch stop without overboosting the engine. If not, you'll have to lower the throttle before going any further. Any clearer? I hope it is....
That's how a constant speed prop works...
There are three basic kinds (excluding the exotic models like the one bladed prop) of propellers in this world. They are:
Fixed pitch
Ground Adjustable
Variable Pitch
In the variable pitch category you have the constant speed prop, and the two position prop. The only difference between the two is what makes them work. the constant speed uses a prop goverener and the two position prop has what's called a three-way valve.
We won't get into the mixture control or the supercharger control as hitech didn't model them in the game. Suffice to say that throttling back in the game has the same effect as moving the mixture control to "auto-lean". and presing the E key after landing has the same effect as moving the mixture into "idle-cutoff". In AH we have some really super performng engines...They run at full power all day long and produce sea level peformance at 30k! I like it
FWIW
EDO;)
