I recently got my complex and high-performance endorsements and every video I saw explained how it works but not actually how to use it in flight so thank you! Wish I had this before I got them haha.
The best complex demo out there. It's refreshing to see an illustration of the correlation between coarse/fine pitch and the change in position of the blade as the inputs are made, and also the sequence that power and pitch are used during different phases of flight.
Well Done, I’m a visual learner and I can see how the constant speed propeller works without asking. I’m only a student in a fixed wing but I can reference this aid in future learning, thanks !
You've explained what my instructor couldn't! 350 hrs in my C-182 NOW I fully understand! My instructor would bla bla bla when I asked why? I got the same information from him but in a "just memorized it" format. Thank you👍
@Влад Платон Knowledge and skills are multi-faceted... weak here... strong there. Way oversimplification to say "not a good instructor" he flew 4 engine turbo props with 16,000 hrs for the US airforce. Trust me he knew more than most I've met but likely did not want to waste time with technical explanations. Who knows he's no longer in this world...
@@sonnyburnett8725 Was... it was the company aircraft I had full access to... it was amazing. Now I fly with my buddy in 1950's ish rented C-150-152's When I was flying it I flew many times coast to coast across the US. Beautiful safe aircraft that never let me down... even when I got into IFR and icing conditions. As well it was almost new at the time...I miss it.
This really helped me realise something that's never quite clicked - I knew the 'high/low gear' analogy stuff but had got confused about the prop adjustments in climb and cruise and sort of thought that was the only 'gear change' happening - in fact your video makes it really clear that the prop governor is CONSTANTLY adjusting the 'gear' as airspeed changes, and the pilot's adjustments of the prop lever are more about putting the whole system into more fuel efficient 'modes' for the phase of flight.
This presentation brought back memories from my service in the US Army,that was my job,to overhaul turbo prop hydraulic systems,balance props and inspection of blades under black light in a fluorescent fluid tank,it would reveal possible cracks in the blades.
It was well done and informative. This is how my RC collective pitch helicopters work. Governor keeps the RPM at constant level and you control the lift/torque by changing the angle of attack of blades. Now going back to planes. While this solution has advantages in fuel economy (money always win) it’s much complex mechanically which has more potential to failure compared to a fixed pitch prop so this has to be taken into consideration especially if we talking about commercial aircrafts, right?
In a propeller airplane, the thrust available decreases with an increase of airspeed. A constant or variable-pitch propeller maintains maximum available thrust through out the different speed ranges.
Excuse me, Am I missing something at 5:10 ? As we gain the speed, the DRAG imposed by the relative airflow on the propeller's surfaces will be INCREASED (not decreased, as said in the video, right?). That's the reason we change the pitch to a higher angle (i.e., lower RPM), so propeller airfoils will be more streamlined into upcoming flow of air.
If the manifold pressure continues to drop as you climb, wouldn't that mean that you would have to continue to open the throttle until you reach your cruising altitude? Would there ever be a scenario in which you're cruising at wide-open-throttle in order to maintain the proper manifold pressure (while the prop lever is pulled back a bit in order to reach the desired RPM)? In this case, would the efficiency primarily come from the higher altitude, which calls for a leaner air-fuel mixture (as opposed to the constant-speed prop itself)?
Haha, I get it! I made this video for fun, just like my others; but I'm glad everyone is enjoying it too! Thanks to all your support, there's another one in the works ;)
throttle full forward = throttle flap fully open = engine can breath regular atmospheric pressure (suck on intake stroke) - throttle closed = throttle flap partly closed = engine breathes through a resistor (like your corona mask) thats why the pressure is lower behind the flap (closer to the intake valve - this is also where the pressure gauge is) - 0 on the gauge means full vacuum, 29.92 is atmospheric pressure = this gauge is a absolute pressure gauge - its reference is vacuum - so there can be no negative numbers
I don't understand the name "constant speed". Why is it called that? The propellor rotation speed and the aircraft speed varies. What speed stays constant? On the other hand, you mention the governor which maintains constant torque by adjusting the propellor pitch given the manifold pressure. So why isn't this called a "constant torque" system instead? I'm confused.
Propellers will never be efficient, no matter how modern and how aerodynamic they are, there is a better form of propulsion invented more than 70 years ago.
What he said. When you have set your rpm using the prop lever it stays constant even if you move the throttle (unless you reach the limit of the governed range when it behaves like a fixed pitch).
Pilots transitioning to a plane with a constant speed prop need to know this very important fact. Full throttle is not full power unless the prop is turning at Max rpm. The formula for shaft horsepower is; prop rpm x torque x .00019 = shat horsepower. As can be seen, if the prop is turning at less than Max rpm, shaft horsepower will be less than maximum. Also, the prop is more efficient and makes more thrust at high rpm than at low rpm.
If the engine and prop works forward of the CG its a puller prop, if it works behind the CG it's a pusher prop. So no, the aircraft is being pulled through the air not pushed.
For cruise we want to set propeller to its best angle of attack. Which is around 3° At this setting it has the best thrust to drag ratio. At the same time we want low RPM at high torque, lean fuel mixture and overall aircraft's AoA with the best lift/drag ratio. Everything must be tuned to be able to reach this condition.
If an airplane has oil temperature, EGT, and fuel flow gauges it I suppose it might work at cruise to set the manifold pressure so the oil temperature isn't too high, set the mixture lean or rich enough to lower EGT, and pitch the prop for low fuel consumption.
That's very good explanation but there's something I can't get my head around. In the example at 3:30 there's coarse pitch with 14 pressure 2100rpms and fine pitch with 17 pressure 2500rpms producing the same thrust. So why for takeoff it's recommended max rpms with max pressure that will give fine pitch? Wouldn't be better to find a position with less rpms and higher pitch for takeoff? I guess I'm struggling with the idea of having more rpms with less thrust if you could have the same with less rpm.
information one thing that is not mentioned is, a prop is most efficient at around 2400 rpm. so it is desirable to maintain that rotation rate. as a result of the relatively large radius of a propeller, the engine of a prop-powered plane operates at a mechanical Dis-advantage, at all times. the analogy of gearing is useful, but not perfect. a low gear equals High reduction, which causes the engine rpms to be high. in gearing, reduction converts rpms to Torque. in the case of a propeller, a similar result is achieved with higher engine rpms, and a Reduced prop blade pitch. (i have not tried to answer your questions, directly.)
This is an awesome video and I think this should be the first thing people watch when learning constant speed props. Other resources explained the mechanics and design decently, but being a visual learner like a lot of other people I had a very hard time visualizing and really understanding what’s going on. Thanks for the explanation!
This is the best explanation of constant speed prop operation I have come across! It made things so much clearer for me...Great job!
Agreed. Everything else falls short in my opinion
Agreed. Really brilliant explanation!
indeed
Absolutely, very good!
Indeed, Absolutely Agre!
I recently got my complex and high-performance endorsements and every video I saw explained how it works but not actually how to use it in flight so thank you! Wish I had this before I got them haha.
The best complex demo out there. It's refreshing to see an illustration of the correlation between coarse/fine pitch and the change in position of the blade as the inputs are made, and also the sequence that power and pitch are used during different phases of flight.
Well Done, I’m a visual learner and I can see how the constant speed propeller works without asking. I’m only a student in a fixed wing but I can reference this aid in future learning, thanks !
You've explained what my instructor couldn't! 350 hrs in my C-182 NOW I fully understand! My instructor would bla bla bla when I asked why? I got the same information from him but in a "just memorized it" format. Thank you👍
@Влад Платон Knowledge and skills are multi-faceted... weak here... strong there. Way oversimplification to say "not a good instructor" he flew 4 engine turbo props with 16,000 hrs for the US airforce. Trust me he knew more than most I've met but likely did not want to waste time with technical explanations. Who knows he's no longer in this world...
@Влад Платон
Sorry, yes you're right, I did not intend to disrespect him though... he was excellent albit a man of few words.
Your flying the best airplane around. I envy you.
@@sonnyburnett8725
Was... it was the company aircraft I had full access to... it was amazing. Now I fly with my buddy in 1950's ish rented C-150-152's
When I was flying it I flew many times coast to coast across the US. Beautiful safe aircraft that never let me down... even when I got into IFR and icing conditions. As well it was almost new at the time...I miss it.
By far the best explanation of constant speed prop I have come across on TH-cam.
Thanks man , I have CPL exam coming up next week Tuesday, and these explanations with animations are just clear as crystal.
This really helped me realise something that's never quite clicked - I knew the 'high/low gear' analogy stuff but had got confused about the prop adjustments in climb and cruise and sort of thought that was the only 'gear change' happening - in fact your video makes it really clear that the prop governor is CONSTANTLY adjusting the 'gear' as airspeed changes, and the pilot's adjustments of the prop lever are more about putting the whole system into more fuel efficient 'modes' for the phase of flight.
Great explanation with supporting figures
This presentation brought back memories from my service in the US Army,that was my job,to overhaul turbo prop hydraulic systems,balance props and inspection of blades under black light in a fluorescent fluid tank,it would reveal possible cracks in the blades.
This has been the best explanation I have seen so far! Thanks a lot!
have my exam tomorrow for propeller for my CAT A licence , Video is very helpful. Thanx
Wow, this was well done! Subbed!
Great video, helps me a lot to understand the difference between the constant speed prop and the fixed prop :)! Thanks.
excellent video. I am glad to have found something which explains this concept so well.
WOW ... AWESOME video.
A big THANK YOU from CYQT.👍🇨🇦👍
Great video The best explanation of this that I've seen on TH-cam Good job
Thanks. Definitely the best explanation I’ve seen on the topic. And 1/10th the length of some of the videos that still left me confused.
Best explanation I've heard.
I think that this was beautifully done. Great work!!
It was well done and informative. This is how my RC collective pitch helicopters work. Governor keeps the RPM at constant level and you control the lift/torque by changing the angle of attack of blades. Now going back to planes. While this solution has advantages in fuel economy (money always win) it’s much complex mechanically which has more potential to failure compared to a fixed pitch prop so this has to be taken into consideration especially if we talking about commercial aircrafts, right?
This video really helped me to understand everything!!! Thank you
This was the best explanation for constant speed props I've seen yet, thanks!
Great video thank you
very good explanation and analogy
Best explanation on this topic, amazing!
What amazing video and explanation! Congrats! Thank you very much! 👍👍👍
Incredible explanation!!! Thank you very much!!!
Good job.
This is such a great video! Thank you!
Very well explained 👏👏
Really a good video
In a propeller airplane, the thrust available decreases with an increase of airspeed. A constant or variable-pitch propeller maintains maximum available thrust through out the different speed ranges.
Wow thank you so much!
Can I get my high performance and complex endorsement now?
I believe you can log this time toward a TH-cam Aviation Expert Certification.
well explained man thanks!
Excuse me, Am I missing something at 5:10 ? As we gain the speed, the DRAG imposed by the relative airflow on the propeller's surfaces will be INCREASED (not decreased, as said in the video, right?). That's the reason we change the pitch to a higher angle (i.e., lower RPM), so propeller airfoils will be more streamlined into upcoming flow of air.
Best succinct tutorial on this concept I’ve seen - well done.
i guess I'm quite randomly asking but does anybody know of a good place to stream newly released series online?
@Cade Jose Flixportal xD
@Daxton Lukas Thank you, I signed up and it seems like they got a lot of movies there :) I appreciate it !
@Cade Jose you are welcome xD
Totally agree!
Bro thank you very much to this video.
Why the relative air will change in direction?
This is the best intro tutorial on the subject, without a doubt. Thank you for your work, really great quality.
This has to be the greatest explanation of this topic. Thank you
Thanks for the video! It helped
Great explanation ...great graphics. ...thanks
If the manifold pressure continues to drop as you climb, wouldn't that mean that you would have to continue to open the throttle until you reach your cruising altitude? Would there ever be a scenario in which you're cruising at wide-open-throttle in order to maintain the proper manifold pressure (while the prop lever is pulled back a bit in order to reach the desired RPM)? In this case, would the efficiency primarily come from the higher altitude, which calls for a leaner air-fuel mixture (as opposed to the constant-speed prop itself)?
Hi! How you did this changing pitch blades? In which CAD? Ty
the best, by far
Very good
Such a f!@#ing great video. Thanks!
Top! Liked 30 seconds into the video, maybe I took too long. We'll done! 👍
Throw the power away
Reign the power in
Thank you!
thank bro
Like everyone else is saying, GREAT video. Interesting how the rest of your videos are super random
Haha, I get it! I made this video for fun, just like my others; but I'm glad everyone is enjoying it too! Thanks to all your support, there's another one in the works ;)
I thought manifold pressure us a negative pressure not positive so 29.92 is the lowest pressure not atmospheric pressure.
throttle full forward = throttle flap fully open = engine can breath regular atmospheric pressure (suck on intake stroke) - throttle closed = throttle flap partly closed = engine breathes through a resistor (like your corona mask) thats why the pressure is lower behind the flap (closer to the intake valve - this is also where the pressure gauge is) - 0 on the gauge means full vacuum, 29.92 is atmospheric pressure = this gauge is a absolute pressure gauge - its reference is vacuum - so there can be no negative numbers
@@herzogaero My mistake, I did not take notice of the ABS on the displayed gauge. Thanks for the correction, I'll go sit in the corner quietly.
Pressure is positive, from 0" to atmospheric, 29.92" as you say.
I don't understand the name "constant speed". Why is it called that? The propellor rotation speed and the aircraft speed varies. What speed stays constant? On the other hand, you mention the governor which maintains constant torque by adjusting the propellor pitch given the manifold pressure. So why isn't this called a "constant torque" system instead? I'm confused.
The "constant speed" refers to the constant speed or rpm of the engine
3:21 same fuel, same rpm, more pitch on the left,... means more torque. Efficency may be better but fuel can't be exactly the same,...
Torx ! 1:20 🙂
I’ve been taught that a rule of thumb is to keep manifold pressure 2-3 in less than rpm, but your tutorial is showing the opposite…
its not the induced drag
Act, it isn’t complicated to operate a constant speed prop
Aircraft cvt
So in a dog fight everything goes forward
Vertical helicopter. Go it. Next question
I like the way engine manifold pressure and vacuum are opposite. But remember, that figure will change with altitude and meteorological conditions.
Very good but your manner of speaking and cutting short the ends of your words inhibits the video.
🆒💩‼️🚀😜
Propellers will never be efficient, no matter how modern and how aerodynamic they are, there is a better form of propulsion invented more than 70 years ago.
You call it constant speed but talk about changing RPM. I still don't get it.
The governor will keep the RPM's at what you set them but you can change the setting.
What he said. When you have set your rpm using the prop lever it stays constant even if you move the throttle (unless you reach the limit of the governed range when it behaves like a fixed pitch).
Great video
Well done, good graphics
Pilots transitioning to a plane with a constant speed prop need to know this very important fact. Full throttle is not full power unless the prop is turning at Max rpm. The formula for shaft horsepower is; prop rpm x torque x .00019 = shat horsepower. As can be seen, if the prop is turning at less than Max rpm, shaft horsepower will be less than maximum. Also, the prop is more efficient and makes more thrust at high rpm than at low rpm.
29.92 is standard pressure at sea level. Can't you have greater pressure at SL, for example, on a cold day?
If the engine and prop works forward of the CG its a puller prop, if it works behind the CG it's a pusher prop. So no, the aircraft is being pulled through the air not pushed.
! ! ! OUTSTANDING ! ! !
! ! ! BEST EXPLANATION EVER ! ! !
Many Thanks !👍🏽👍🏽👍🏽
For cruise we want to set propeller to its best angle of attack. Which is around 3° At this setting it has the best thrust to drag ratio. At the same time we want low RPM at high torque, lean fuel mixture and overall aircraft's AoA with the best lift/drag ratio. Everything must be tuned to be able to reach this condition.
If an airplane has oil temperature, EGT, and fuel flow gauges it I suppose it might work at cruise to set the manifold pressure so the oil temperature isn't too high, set the mixture lean or rich enough to lower EGT, and pitch the prop for low fuel consumption.
Great video, spot on. Too bad the world is in such a hurry, and aviation could stay with props.
Thats why we have sport aviation.
I just watched your video....You got the manifold pressure completely backwards.
Its funny because while I assume most pilots don't understand how these work, their mechanic has to even though the mechanic doesn't really care.
Constant propeller speed = constant rpm
Finally i got it. Thanks!
That's very good explanation but there's something I can't get my head around. In the example at 3:30 there's coarse pitch with 14 pressure 2100rpms and fine pitch with 17 pressure 2500rpms producing the same thrust. So why for takeoff it's recommended max rpms with max pressure that will give fine pitch? Wouldn't be better to find a position with less rpms and higher pitch for takeoff? I guess I'm struggling with the idea of having more rpms with less thrust if you could have the same with less rpm.
information one thing that is not mentioned is, a prop is most efficient at around 2400 rpm. so it is desirable to maintain that rotation rate. as a result of the relatively large radius of a propeller, the engine of a prop-powered plane operates at a mechanical Dis-advantage, at all times. the analogy of gearing is useful, but not perfect. a low gear equals High reduction, which causes the engine rpms to be high. in gearing, reduction converts rpms to Torque. in the case of a propeller, a similar result is achieved with higher engine rpms, and a Reduced prop blade pitch. (i have not tried to answer your questions, directly.)
Excellent! 👏🙌
Nicely done!
Cool i have always wondered what the 24x24 meant. I knew it had to do with engine settings. But you explained it very well.
perfect, thanx🙏
Great Video!!! Simple explanation of a very complex topic!!!
great job mannnn tkssssssss
the torque grows with rpm
Thank you.
Wonderful video and great explanation of CSP and how to use it in flight. Good job!!
Great vid
This is an awesome video and I think this should be the first thing people watch when learning constant speed props. Other resources explained the mechanics and design decently, but being a visual learner like a lot of other people I had a very hard time visualizing and really understanding what’s going on. Thanks for the explanation!
Extremely excellent and accurate descriptions and visuals!
awesome breakdown of how and when to use the controls.
It’s pretty simple
Amen to the previous person. What's most important is how to use the levers.
It’s very much like shifting to higher gears if you want to think of it that way.
I wish I saw this video in flying school. Good stuff. Thank you
Wow amazing explaination keep doing more videos😍
This was the easiest to understand video I've found so far.