Gyroscopic Procession

EnRoute

New Member
I'm having a terrible time with understanding the "Force applied" apparently. I understand Gyroscopic procession, however it's apparent that I just don't understand the force.

Scenario- Flying along straight and level. I yank back on the stick. As I see it, the bottom of the propellers rotational path is thrust forward into the relative wind, therefor feeling the greater "force". Hence the applied force should be felt on the left side of the prop rotation 90 degrees ahead of the plane of rotation. If the same force that was originally applied at the bottom of the prop is now felt on the left side of the prop, it seems to me that the airplanes left side would be pushed back resulting in a yaw to the left.

Every thing I'm reading states just the opposite, therefore, again I must not have a firm grasp on the "foce applied"

HELP:dunno:

When you pull back on the stick, the force applied is at the bottom of the prop disk. Since we know the resultant force is felt 90 degrees ahead in the direction of rotation, you can see this force acts forward on the left side of the disk. This force causes the airplane to rotate to the right about the vertical axis.

Imagine standing behind the left propeller blade and pushing forward. It's easy to visualize the airplane rotating to the right.

When you pull back on the stick, the force applied is at the bottom of the prop disk. Since we know the resultant force is felt 90 degrees ahead in the direction of rotation, you can see this force acts forward on the left side of the disk. This force causes the airplane to rotate to the right about the vertical axis.

Imagine standing behind the left propeller blade and pushing forward. It's easy to visualize the airplane rotating to the right.

I'm with you on everything, right up to the time that you said "standing behind the left propeller blade and pushing forward" If the original force was applied to the front side of the prop disc, why is the resultant force felt from behind the prop disk. This must obviously be the case, but why.

I'm with you on everything, right up to the time that you said "standing behind the left propeller blade and pushing forward" If the original force was applied to the front side of the prop disc, why is the resultant force felt from behind the prop disk. This must obviously be the case, but why.
That's exactly what threw me off about gyroscopic precession waaay back then. The force is actually applied from behind the propeller disk and acts forward, just like the force if you stood behind a blade, facing forward, and pushed.

When you look at that drawing, that bottom arrow is the force being applied from behind and acting forward. Forget about the airplane for a second and imagine the spinning disk levitating there perpendicular to the earth. How are you going to tilt the top back, and the bottom forward (climb attitude)? You are going to push forward on the bottom of it. This force is felt 90 degrees ahead in the direction of rotation.

Why is this force said to be applied from behind and acting forward, and not acting rearward from the top of the disk? I have no idea, but I would like to know that myself.

I just started flying a taildragger yesterday, and I can attest that this force is definitely applied -from behind- and acts forward.

No, no, no! You're all talking about "gyroscopic precession."

The OP topic clearly asked about "gyroscopic procession" which is simply a group of gyroscopes marching in unison.

sorry

No, no, no! You're all talking about "gyroscopic precession."

The OP topic clearly asked about "gyroscopic procession" which is simply a group of gyroscopes marching in unison.

sorry

Here, reach out and grab onto the propeller, not actually, but imagine you were doing that. Let us imagine our right hand is on the top of the propeller and our left hand is on the bottom of the propeller. We pitch back by pulling back with our right hand and pushing forward with our left hand (force applied). Now we rotate the propeller to the right 90 degrees with our right hand now on the right side, still pulling back, and our left hand on the left side, still pushing forward. The result would be a yaw to the right from a pitch back, the reverse happens with a pitch forward, a yaw to the left.

Mshunter, thank your buddy Rick for this description.

This yaw to the left is where the idea of gyroscopic precession being a left turning tendency. As it applies to a tail dragger aircraft, the pitch forward to raise the tail causes a very noticeable left yawing tendency. This effect is not experienced in tricycle gear aircraft and furthermore not noticeable from normal pitch forward and back in trainer aircraft. The only reason you should be considering worrying about this is if your flying a high performance aerobatic aircraft.

1) Find an old bicycle wheel
2) Attach a handle as an extension to the axle
3) Hold onto the axle with your arm parallel to the floor, straight out
4) Git 'er spinnin' real good
5) Relax your arm and let the whole spinnin' thing fall
6) You'll notice "something ain't quite right"
7) You will now better understand precession
8) Save the modified bike wheel for future students

-A.S.

Here, reach out and grab onto the propeller, not actually, but imagine you were doing that. Let us imagine our right hand is on the top of the propeller and our left hand is on the bottom of the propeller. We pitch back by pulling back with our right hand and pushing forward with our left hand (force applied). Now we rotate the propeller to the right 90 degrees with our right hand now on the right side, still pulling back, and our left hand on the left side, still pushing forward. The result would be a yaw to the right from a pitch back, the reverse happens with a pitch forward, a yaw to the left.

Mshunter, thank your buddy Rick for this description.

This yaw to the left is where the idea of gyroscopic precession being a left turning tendency. As it applies to a tail dragger aircraft, the pitch forward to raise the tail causes a very noticeable left yawing tendency. This effect is not experienced in tricycle gear aircraft and furthermore not noticeable from normal pitch forward and back in trainer aircraft. The only reason you should be considering worrying about this is if your flying a high performance aerobatic aircraft.

Oh so now you just go and call me out like that?! The gloves are off man!!! The gloves are off.

And it's Rich, not Rick.

I must not be with it because I did not realize it was spelled wrong.

I better lay of the booze.. I think I am losing cells.

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