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Saw the play of autorotation

I always thought the angle of attack on the advancing blade was pulled down by the mecanical link on the main rotor mast. As the blade is allowed to move up thanks to an hinge. This movement also forces its angle to reduce, thus achieving equality ? Is it a wrong explanation ? I must admit I didn't really get the induced airflow shown in the video. I must watch again

Why does driven section move inboard when we raise the collective level ?

Thanks, I think explaning it as a continuous action and a rate of flapping makes it easier to grasp, compared to many other explanations just giving states/snapshots.

The drag vector component always seems arbitrary not only in this video but in every drawing including the FAA materials. How is the drag vector component length determined and how can its accuracy be determined? Can it be calculated? Is it irrelevant as long as a drag vector is shown/included?

Beautiful explanation 😊

Great job, thanks

Traffic!! Perfect analogy

A marvelous job!

Do your drawings bigger and before video makes videos shorter .

So when a helicopter pilot flies without knowing this, actually his mind has made these calculations unconsciously along with other things like moments, dissymmetry of lift, adverse pressure gradient, all kinds of powers like required, available, profile, induced, parasite, and all those forces like centrifugal twist, inertia etc?

Love all your videos. Perhaps worth mentioning the centre of pressure on your first diagram and how it fits (or doesn’t) on your main diagram?

The best explanation I have seen on this topic. Thank you very much and keep going

add the transverse flow roll or inflow roll to this shit and make things more clearcut lol..

then they say why are helicopter pilots so complicated!!

Why and how does the inter blade move slower than the outer blade??? It is one solid attachment from one end to the other. Does not make physical sense.

Great explanation. Thank you for doing these videos!

A dumb question from a non-helicopter guy - is the rotor blade airfoil symmetric or does it have some camber?

As a helicopter pilot for 35+ years as well as an instructor for 25 years, your videos on PoF have given me immense joy to watch and reminded me so much of my good time in Bristow Redhill. Well done.

To simple thanks❤

ealaa majhudatik The best people are those who learn knowledge and teach it. Thank you for your efforts

Great explanation

Eyeopener. I understood that on side would Flap up and the other would flap down. But I always thought that (flapping up, for example) would explicitly decrease the angle of attack due to the linkage staying "stationary" and forcing the angle of attacht to decrease. But now I understand it actually initiates a vertical airflow.

A little confused...why looking at points A, B, C, D do we assume that the lift vector has the same magnitude at each? Using the lift proportional to 0.5*p*V^2, V is increasing going toward the tip yielding (all things being equal like lift coefficient at each station), higher lift. What am I missing?

Brilliant 👍

Good afternoom my frien...first of all I would llike to thank you for your videos. It is beeing very enlighting. I am from Brazil and noticed that you didnt make anymore...what happened? I am looking foward to watch more of them. I wish you all the best.

Legend 💪🏻

can you describe the speed where the translational lift occurs in the graph?

Hello there, First of ALL o would like to thank tou for your vídeos, everything is Very enlightening... Why did you stop? I am looking forward for more vídeos... my best regards

allow me to download all your videos and share to others sir, thanks in advance.

Sorry, your vector diagrams are wrong. You correctly showed the changes in Induced Flow due to flapping up and flapping down, but you left off the more important vector - the change in airflow. The RHS diagram needs an extra length added to the horizontal line (the rotational flow) for the extra airflow on the advancing side, and a negative length on the retreating side. On the RHS, if the IF stayed the same, the extra horizontal line will give a resultant vector coming in at a shallower angle, adding to the angle of attack, and on the retreating side, the shorter airflow line brings the IF arrow closer, elevating the resultant vector and reducing the AoA. But the flapping changes the IF line, adding to the RHS and subtracting from the LHS, so the AoA remains essentially the same. BUT the shorter horizontal vector means that there is more lift on the advancing side. Along comes Phase Lag - the rate of upward acceleration is at the max at 3 o'clock, but the mass of the blade means that the blade takes time to move, and the resultant high point is correctly shown at 12 o'clock. Remember that this is not gyroscopic precession, because the rotor system is not a gyroscope. The phase lag is usually around 90 degrees, but for light blades, like the R22, it is only 72 degrees.

Hi More video please. I am doing my instructor rating and would like some more of your excellent video to use inconjunction with the AP3456 notes. They are excellent. thanks for your time and effort.

Tqvm!!!

Finally! Someone proficiently explains why flapping up reduces the aoa and vice versa. Thanks.

You're the best (detailed, complete, concise, clear) when it comes to aviation vector diagram! Can't believe this channel doesnt have millions of subscribers! Keep it up you're so helpful.

Love the videos, any chance of you doing one on recirculation. Thanks

Amazing analysis

You are such a great explanations about the theory. Thanks a lots

Sorry, but I think this is rubbish. Forget all your diagrams, take a model airplane propeller, hold it against an airflow, it will spin with a negative incidence. Try spinning it the opposite way round, it will slow down and spin the opposite direction. Rotors of gyrocopters have a negative 1.5deg incidence. Think of the rotors as glider wings, instead of going forward they spin in a circle. And as we know gliders wings point downwards, otherwise they would stall. Basically your diagrams are incorrect. Firstly it would be more clear if you show the centre of forces going through the centre of the spar. The force on the foil should be shown at right angles to the plane of the foil. You will then see that in all the cases the drag is always backwards

Very clear and concise explanations, even for a newbie like me. Congrats

Excellent video!

Why transition on forward flight to hover

that is the best explanation I have ever had. thank you so much for this tutorial.

Good explanation thanks Please what do you mean by TR ( Thrust Reduction )and TQ.

Great explanation,does the highest and lowest points have something to do with the gyroscopic precession?

some videos regarding phase lag and advance angle also.

you videos are highly appreciated

please add videos about zero speed auto rotation, loss of tail rotor effectiveness, functioning of tail rotor. thanks

Great explanation, thanks.

Brilliant video, thanks! Do you have an email I could contact you on with some questions? Thanks!