Constant Speed Propeller - How it really works

against the throttle plate, that's why it happens, so when you pull back on the blue stick, the blue lever or the knob, whatever you're flying, then what you're doing is you're decelerating the engine correctly because you're decelerating the RPM, that is, you take a bigger bite of the air, which makes it harder to turn exactly right, which then makes the engine spin more slowly, which makes the pistons want to spin. it sucks rather and then you will have uh oh to uh to do it, so what will happen if the motor is not sucking enough? It's not sucking as much so the manifold pressure goes up, that's it, you got it, yeah, almost.

I almost did a full PW there, but you caught me. I almost put it backwards, and I was like, wait, like when, when you said yesterday was about, uh, what was some topic where you said, oh, that's not true? right I almost went there so we might have to cut that so we're G we've cut that right so let's talk about why then when you reduce the RPM why the manifold pressure goes up why that's why I said because the Well, they're not sucking in as much air as before, they're not trying to suck in as much air as they could because the RPM's are low and worst case scenario, if you think about if we could slow down the

propeller

completely. to nothing, there is no suction at all, so yes, that is the reason, yes, that is the reason, so I think that clears everything up, in terms of how a

constant

speed

propeller

works

, how the governor system

works

and what the manifold pressure is like. an indication of power, as long as everything is working correctly, you know that if the engine goes out in flight, you will be at whatever pressure the outside air has and that will no longer be a reflection of power, right, so it's just a reflection of power.

If everything is working correctly in the system, related question, then, on downhill, is it good practice to reduce the RPM to help reduce

speed

? Does the plane actually talk, could it accelerate, is a good question. Yes, would it make it quieter? Although, mhm, yeah, that's it. better what you get, then, yeah, it's not

really

. I mean, you could reduce it a lot, but the case we want to avoid is high manifold pressures versus low RPM because then you're causing the pistons to take the load from the engine properly. That's right, when you apply power, you want to make sure the RPM is high before you push it, and if you reduce power, you can do it from the reverse, from the throttle to the propeller lever.

Not now D, which one is yours? The question was about a beta, maybe you need to finish what you're good at, yeah, so the other topic was "don't let that fool you" and say "uh", because of the old wives' tale about "never pass a plane above the square." So on takeoff we do it like Tradition at 2500 rpm versus 25, that's just to be nice and smooth for the engine, but if we increase the manifold pressure nothing will happen, it takes a huge amount more than what we have to do. any damage if you don't believe it look at your plane's loming manual and look at it at 75% power and note there are two ways to get it one is at 2400 or 2500 rpm with say 22 inches of manifold pressure and the other way is at 2100 RPM with much more pressure in the manifold and they say to run it like that, they say it's easier on the engine because it spins less.

Okay, it's harder on the cylinders compression-wise, but not by much, so it's an old wives' tale. but it's true in big horsepower and a lot of manifold pressure, so we're talking about a completely different ball game, but in our airplanes we're not too worried about that, but what are we doing? We are training people to fly almost. Anyone, to the best of our ability, we can do almost anything, so we have to give you some rules of thumb, hey, you know, don't avoid having or well, no, no, but avoid having high manifold pressures versus low RPM, but you must know that. our low power, which is certainly normal enough to be able to run the engine at 21 2200 RPM with a lot of manifold pressure, most people here don't do it, but it's just because of that fear, but if you look in the manual , it's certainly there, it's certainly there, uh, if you get this angle of attack too high, what can happen is it can produce lift in the other direction and that's called beta, right, it's the turboprops that stall when you slide.

Yes, we have to put the plane plan into beta. the terrain, that's what I do with the TPM, right, is when it lands you're just going to push it into beta mode, so it's like air brakes, basically what it is and it's very good to use when you have uh contaminated. beyond flat, yes, it actually starts, okay, yes, that's the reverse, it's not like the other girl or boy who asked me thought, no, the motor doesn't stop, it changes direction, right, it doesn't do that , but it's okay. for a contaminated track, yeah, fine, so if there's a little bit of sleet or maybe a little bit of ice on the track or something, you use the brakes, it doesn't matter if they have abs, it won't stop, but if you have reverse It is very effective, why do they call it beta?

Because it is the beta angle. Alpha is the angle of attack. Alpha is a positive angle attack and beta is a negative angle attack. Just for aerodynamics, that's all, so we call it beta mode, it's not and. By the way, we are not a beta tester when we do it right, which is very important, there you go, if you do it, I can imagine an altitude, yes, some planes you can make, yes, but many, most of them. Can't you can't you can't do it in TBM Al and you can't do it in the King era uh but uh oh well, I don't know if you can I can't recommend it, I shouldn't uh, you know, there's a lot of them. things that don't, yes, there are good things to know, but those airplanes use high RPM, so, uh, you can get a lot of reverse very well from that, so TBM, what is that?

Or similarly, it has multiple pressure. It's a turboprop, it has torque, okay, it does, no. This measure of power output is torque, okay, yes, horsepower is 850, T-shaft, 700 normally correct, but you can get 850 if you push a little bit and you can go a little higher. but that's it, but you measure the output and the torque because you

really

want to know how much torque you have because that's the shaft turning clockwise, the blade okay, so the percentage T, do you have pressure in the manifold? No, so you just look at the T axis. power torque, okay, that's it, torque, yeah, and you get it on takeoff, you can go to 100, you can go a little more, but in general, and then on cruise flight, you'll set it up for a fuel flow, um and then, that gives you the speed so it's pretty easy to fly and just knowing a few things, Iran is a lot harder and there's also a propeller control on the TPM and there's one for boom or output, you know, on the back you say that a turbo is easier. to F really interesting, it's harder to start, but it's easier to fly because you can be at altitude like here we come back to us.

I wanted to come here to Paloalto for a short time to give you a quick idea of ​​the TBM and so he's tall but you can just hit the throttle to the idle point and hold it there, it'll slide, yes it'll slide, but it won't. it's going to do nothing to the engine, you know, basically, you have to, you don't have to do it. Worry about that, yeah, no, you can't do that in a no, you can't, so, you can't do that. There are very few moving parts. You know he uses a generous jet. You can fly it anywhere, so there are many and it can.

He also uses 100. You can also put it there sometimes so he can use both. How does it work? They allow you a certain number. Well, it's essentially a jet engine, so a jet engine can have a diesel or a jet engine. You can take diesel or you can take now normally, you have to change the gauge, the fuel metering system to change it, it's like a tank, yes usually you may have to change the gauge, but the TVM will do it automatically, but There are only a certain number of times you can do that per number of fill-ups.

I forget what it is but there is something there so this is really convenient yeah is anyone clear how the

constant

speed propeller works? how the manifold gauge works and the float plate and all that, okay we have a few more questions just about the pre-flight, when to look and then maybe things that could happen in the flight, cool so let's talk about that , if we have a loss of oil pressure, what happens to the blade? It's going to be fine, you're going to hit your best PCH and you can over rev, so if you rev ​​too hard, if this regulator breaks down and allows all the oil to come out of the shaft at high speed, it's going to run. at high power it is going to reach excessive speed, so what do we do about it?

We can take the propeller lever and try to bring it back and see if we can get something to happen and if that doesn't work, we'll have to do it. reduce the power because the blade can go supersonic, which is not good, so we have partial power on the plane and we have to plan for that, we are not going to have full power, maybe it will not be enough to take, yes or maybe. not enough to maintain level flight, was something I was thinking about, but that's one thing, and the other thing that can happen is that the propeller like on our arrow is a little bit set back, so it lags, which which means at that point you really want to turn around, you know, it takes a while before the governor speeds up again, so we have to adjust to that kind of thing, we know that's another thing, um, what happens the most.

It's just that they had never released one on me before. they are pretty reliable if the engine goes out the governor no longer works but that is the least of your worries before the flight you should check the seals where the propeller connects to the hub because it is under pressure and if there are uh you can see leaks in the spring, it's equivalent to a spring that's pushing back and these things are spinning on that, so if there's a leak there, it can cause the steering to fail. Also just a regular check of accessories, make sure there are no nicks or big indentations in the thing