From the P-factor. How do you know where the relative wind is coming from. I dont understand how can the descending blade's relative wind changes when its not levelled
In the slow flight maneuver, you are pitched up but you are not gaining altitude. Thus the relative wind is coming at you from the front and at a horizontal direction because that is the path the aircraft is going (level flight). Because you're pitched up, the blades of the props will have different angle of attacks on the descending and ascending sides of rotation. Relative wind just means the path the aircraft is going. So if the aircraft is not gaining or losing altitude, the relative wind hitting the aircraft at a horizontal level.
Hello, thank you for your comment! A rotating propeller blade experiences a relative wind comprised of two vectors. The primary vector is the rotation of the blade creating its own relative wind, and the other is a result of the forward movement of the aircraft. Together, these two vectors create a resulting relative wind that the propeller experiences. The P-Factor (asymmetrical thrust) is only applicable when the relative wind of the aircraft isn’t perpendicular to the plane of rotation of the propeller. Therefore, the optimal conditions to experience P-Factor are high angle of attack at a high RPM. For example, this may be experienced during a slow flight or when climbing. We hope this helps, and please feel free to reach out with any additional questions! Thank you!
Thank you for all your explanations! I am wondering though, on P-factor, when you show the descending blade angle of attack, the way you put the diagram together, makes it look like that is on the left (of the spinner), when the descending blade is actually on the right. Why do you make the angle of attack of the descending blade on the left in the diagram? If that makes sense.
Hi Hattie, great question! You are actually looking at the aircraft from the left side. Therefore the ascending blade (on the left when viewed from the cockpit) is in front of the descending blade (on the right when viewed from the cockpit). To try and make that more clear, the airplane is flying from right to left on the screen. The image tries to portray left and right by putting the descending blade “behind” the ascending blade. Hopefully that clarifies things for you. Thank you so much for watching!
Assuming we have a standard airplane (prop rotates to clockwise when viewed from inside the cockpit) then if we yawed to the left, it would create a pitch up moment. The other three factors discussed in the video would have no effect.
What I do not believe is the explanation for the P-factor. There are plenty of videos but I think they all make the same mistake. It is right that with more pitch angle of the plane the downwards moving blade on the right side is producing more trust but I think the reaction of this will not be more yaw to the left but it will be more pitch up tendency. The reason for this must also be the gyroscope effect which says that the force reaction will occur 90 degrees later. This means in our example of a right turning propeller that the stronger lift of the blade at the right side will act 90 degrees later at the bottom position which will pull the nose up and not to the left side……..?
While we can imagine that one blade is creating greater thrust than the other, when we apply it to the whole system it is equivalent to shifting the center of thrust away from the centerline axis. In the most common example of a high thrust/high angle of attack scenario, this would be shown as the center of thrust moving to the right of the centerline of the aircraft and therefore creating a moment arm from the CG causing the yaw of the aircraft.
@@flyaeroguard please have a look at a helicopter which is nothing else than a vertical propeller. To let the helicopter move in a forward direction it is not necessary to have the most lift at the rear positioned rotor blade and the lowest lift at the front blade but at a ccw turning rotor (view from the top) the left blade has to have the most lift and the right blade the lowest lift. The gyroscope effect is independently from initiate the force from the propeller itself or from the propeller shaft. The reaction will work 90 degrees later.
@Don Quijote you are mixing 2 different concepts. In order for gyroscopic effect to happen you need 2 different rotations. In that case we don't have that. For the effect you are talking about to happen pilot needs to use left rudder. In which case, propeller is rotating cw, and aircraft yawing left will create a pitch up. But you are claiming that asymmetric trust is result of gyroscopic effect even before it happens. Basically you are saying eggs comes from eggs. Which does not make sense.
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8:38 this is so well explained - well done.
Thank you for the feedback, we're glad you found it helpful!
When I pitch up.....my airplane wants to turn left.....not right.
Good one❤️
Thank you!
From the P-factor. How do you know where the relative wind is coming from. I dont understand how can the descending blade's relative wind changes when its not levelled
In the slow flight maneuver, you are pitched up but you are not gaining altitude. Thus the relative wind is coming at you from the front and at a horizontal direction because that is the path the aircraft is going (level flight). Because you're pitched up, the blades of the props will have different angle of attacks on the descending and ascending sides of rotation. Relative wind just means the path the aircraft is going. So if the aircraft is not gaining or losing altitude, the relative wind hitting the aircraft at a horizontal level.
Hello, thank you for your comment! A rotating propeller blade experiences a relative wind comprised of two vectors. The primary vector is the rotation of the blade creating its own relative wind, and the other is a result of the forward movement of the aircraft. Together, these two vectors create a resulting relative wind that the propeller experiences. The P-Factor (asymmetrical thrust) is only applicable when the relative wind of the aircraft isn’t perpendicular to the plane of rotation of the propeller. Therefore, the optimal conditions to experience P-Factor are high angle of attack at a high RPM. For example, this may be experienced during a slow flight or when climbing. We hope this helps, and please feel free to reach out with any additional questions! Thank you!
Thank you for all your explanations! I am wondering though, on P-factor, when you show the descending blade angle of attack, the way you put the diagram together, makes it look like that is on the left (of the spinner), when the descending blade is actually on the right. Why do you make the angle of attack of the descending blade on the left in the diagram? If that makes sense.
Hi Hattie, great question! You are actually looking at the aircraft from the left side. Therefore the ascending blade (on the left when viewed from the cockpit) is in front of the descending blade (on the right when viewed from the cockpit). To try and make that more clear, the airplane is flying from right to left on the screen. The image tries to portray left and right by putting the descending blade “behind” the ascending blade. Hopefully that clarifies things for you. Thank you so much for watching!
perfect
the best.
Piper fuel time distance
what happens when the single prop
airplane makes a left saw?
Assuming we have a standard airplane (prop rotates to clockwise when viewed from inside the cockpit) then if we yawed to the left, it would create a pitch up moment. The other three factors discussed in the video would have no effect.
What I do not believe is the explanation for the P-factor. There are plenty of videos but I think they all make the same mistake. It is right that with more pitch angle of the plane the downwards moving blade on the right side is producing more trust but I think the reaction of this will not be more yaw to the left but it will be more pitch up tendency. The reason for this must also be the gyroscope effect which says that the force reaction will occur 90 degrees later. This means in our example of a right turning propeller that the stronger lift of the blade at the right side will act 90 degrees later at the bottom position which will pull the nose up and not to the left side……..?
While we can imagine that one blade is creating greater thrust than the other, when we apply it to the whole system it is equivalent to shifting the center of thrust away from the centerline axis. In the most common example of a high thrust/high angle of attack scenario, this would be shown as the center of thrust moving to the right of the centerline of the aircraft and therefore creating a moment arm from the CG causing the yaw of the aircraft.
@@flyaeroguard
please have a look at a helicopter which is nothing else than a vertical propeller.
To let the helicopter move in a forward direction it is not necessary to have the most lift at the rear positioned rotor blade and the lowest lift at the front blade but at a ccw turning rotor (view from the top) the left blade has to have the most lift and the right blade the lowest lift. The gyroscope effect is independently from initiate the force from the propeller itself or from the propeller shaft. The reaction will work 90 degrees later.
@Don Quijote
you are mixing 2 different concepts. In order for gyroscopic effect to happen you need 2 different rotations. In that case we don't have that. For the effect you are talking about to happen pilot needs to use left rudder. In which case, propeller is rotating cw, and aircraft yawing left will create a pitch up. But you are claiming that asymmetric trust is result of gyroscopic effect even before it happens. Basically you are saying eggs comes from eggs. Which does not make sense.
You don't feel it? Nahi bhai..kabhi rudder dabaya hai take off ke time solo? Issa feelsss