Calling Nick Lappos - Blade Stall

[[email protected]]

AnFi - I have clearly shown that your speed assessment is so full of inaccuracies that it cannot possibly be valid.

[Senior Pilot]

The posts with abusive personal insults have been removed regardless of the rest of the content. The T & Cs that you signed up to will be maintained and it will benefit all if a more reasoned understanding of the very valid contributions made by very experienced aviation professionals is accepted rather than rejected with denigration of the Rotorhead/s involved.

[212man]

......his crusty old QHI called Κάβουρας

:ok::ok: Very good!

[G0ULI]

All Greek to me. A very interesting discussion:ok:

As a fixed wing pilot I feel that all the discussion of coning angles and centrifugal forces is rather missing the point that ultimately each rotor blade is just a wing moving through the air, albeit in a circular path, and the same physics applies with respect to the aerofoil stalling as it does in linear flight. If the airflow through the rotor disk exceeds the maximum angle of attack for that airfoil, it will stall irrespective of any other factors.

Fascinating stuff none the less.

[puntosaurus]

So while I do freely admit the proposed relationship MAY NOT be EXACT, I do say that any difference is just bathwater and not a substantive point. Quantifying the difference might be quite complex and subtle, but at least we can say it is comparatively small.
So I say that my point (whatever it was) still holds ‘in essence’.
AND the onus would be on dc/da to substantiate his objection otherwise.

This passage shows some insight AnFI. Quantifying the difference might indeed be quite complex and subtle. If you care about public acceptance of your UCA hypothesis you are going to have to enlist the services of an independent aerodynamicist. Given that you're probably not offering a fee, you need to ask nicely, pique their intellectual curiosity, and not harangue them every time they offer you some help.

Let's say that for the sake of argument, after some really tricky maths, some heroic assumptions (which because of the spirit of open intellectual curiosity in which you'd embarked on this venture, you would both agree) you jointly conclude that the inflow term drives a 10% sensitivity of CA to Rrpm in the hover and 3% at Vy and 1% at Vne. Now those who care are all a step forward.

At this point you could publish the results, and the aerodynamicists who can follow this can stand back and say, wow that's a good bit of work. Everyone can form their own views as to whether this correction counts as a hair on the egg (what on earth is that ?) or something more significant. And the pilots on this forum can go blissfully about their business knowing that it is totally irrelevant to their work, because the bit that affects them was dealt with a few pages ago.

Or you could conclude, as you hint in the quoted paragraph above, that the point you're making isn't sufficiently important to warrant that level of investment.

[[email protected]]

I did predict the shape AnFi's, 'debating' would take back on page 5 post #88 because I have seen it here many times before.

Now he has been moderated - that has happened before as well.

I do not stalk him or troll him but he has made many threads unreadable and confusing, especially when a simple answer was all that the thread starter had asked for.

Punto - I applaud your position of being prepared to give him chance after chance to turn this thread into something valuable - we will just have to wait and see if there is any humility there.:ok:

And it looks like I need to get a new name badge made up:)

[puntosaurus]

Thank you Crab. You have been a bit of an S.O.B. on this thread, but you're our S.O.B so there you go. The odd thing is I think AnFI is actually the bully. He loves to take someone and twist them onto his own ground so he can torture them. I think if he had the intellectual confidence and humility to take this exercise on he would be a better man for it. Whether he could find anyone to take that journey with him is not clear to me.

Toodles,
Punto

[AnFI]

Punto
You are a diplomat.

i gave the quantification formulaically but it got modded out along with various other answers and of course my opinion of what Crab has added to the debate.
someone else can take the thought forward if they feel like it
It is not possible to continue to illuminate this subject fairly with the deliberate harassment and the support for that from the 'house', sorry to anyone who was interested.

[puntosaurus]

Thank you AnFI. And in the interest of balance, can I ask that you use your restless intellectual energy as a force for good, rather than as a tool to beat other people with.

[Ascend Charlie]

Don't forget to give Senior Pilot some credits here too, this thread was getting unreadable.

[puntosaurus]

Thank you Senior Pilot for putting up with all of us. Good Night Rotorheads.

[Senior Pilot]

Punto
You are a diplomat.

i gave the quantification formulaically but it got modded out along with various other answers and of course my opinion of what Crab has added to the debate.
someone else can take the thought forward if they feel like it
It is not possible to continue to illuminate this subject fairly with the deliberate harassment and the support for that from the 'house', sorry to anyone who was interested.

Despite assertions otherwise from AnFI, the 'house' has no dog in this fight and there is no support for the harassment that has been coming from both sides of the discussion. House rules, however, apply to all contributors here and have been applied to more than one Rotorhead who have crossed the line in posting unacceptable content.

If the lack of overt support for either side of the discussion is seen as taking sides by AnFI, that is an incorrect assumption and continuing to post critical comments about PPRuNe moderating will achieve little in the way of promoting a point of view.

[Black Fly]

The principles of energy management are extremely important to a pilot maneuvering a helicopter close to the ground. The term “energy is life” is often used to emphasize the importance of energy management. Energy management is simply an exchange of potential energy and kinetic energy. Simply described as relates a helicopter return-to-target maneuver; potential energy is the energy of altitude while kinetic energy is airspeed. Energy is critical to survival and the safe execution of the maneuver. Helicopter pilots understand that potential and kinetic energy can be exchanged and that the sum of the aircraft energy must be managed to fly a return-to-target, wing-over, hammerhead, or split-s type of manoeuvre successfully.

The Greek pilot flyng in the video simply mismanaged potential and kinetic energy. The maneuver was performed too low to gain enough airspeed during descent for a low power recovery. The maneuver recovery was attempted too late to use power to prevent impact with the surface of the water. No power loss, control failure, or complex aerodynamic theories are necessary to explain the disastrous outcome of this poorly performed manoeuvre.