RBS, precession & LZ
Joined: Jan 2001
Posts: 3,008
Likes: 62
From: North Queensland, Australia
Well in keeping with the rotary nature of this forum, we're certainly going round and round!
Lu, it's true that in some aircraft the swash plate tilts a different direction to the disc, but as Nick says, it's all the same in the end.
Whatever happens, a blade needs to be getting its 'maximum fly down' pitch input about 90 degrees before the desired lowest point on the disc.
If your swash plate tilts down 30 degrees prior to the forward direction of the longitudinal axis, then the pitch change mechanism that follows that swash plate must lead the blade that it controls by about 60 degrees. In the case of the Bell UH-1, the swash plate tilts in the same direction as the disc because pitch commands go to the stab bar, which leads the blades by 90 degrees.
It seems that your basic conception of the rotor 'disc' is a cause of confusion. All smoke screens aside, a rotor blade is just a wing - lift, drag, stalling, angle of attack, relative airflow - all these things are as per any wing.
So flapback, flapping to equality, retreating blade stall and so on can all be fairly easily described in these terms, and it is a misinterpretation to say that some effects are because the blades make up a 'disc' and some are because they must be treated as individual elements.
If you understand the basic concepts of aerodynamic lift and drag, and how airflow behaves over a wing approaching and during the stall, then you won't have any trouble understanding how they apply to a rotary wing.
Lu, it's true that in some aircraft the swash plate tilts a different direction to the disc, but as Nick says, it's all the same in the end.
Whatever happens, a blade needs to be getting its 'maximum fly down' pitch input about 90 degrees before the desired lowest point on the disc.
If your swash plate tilts down 30 degrees prior to the forward direction of the longitudinal axis, then the pitch change mechanism that follows that swash plate must lead the blade that it controls by about 60 degrees. In the case of the Bell UH-1, the swash plate tilts in the same direction as the disc because pitch commands go to the stab bar, which leads the blades by 90 degrees.
It seems that your basic conception of the rotor 'disc' is a cause of confusion. All smoke screens aside, a rotor blade is just a wing - lift, drag, stalling, angle of attack, relative airflow - all these things are as per any wing.
So flapback, flapping to equality, retreating blade stall and so on can all be fairly easily described in these terms, and it is a misinterpretation to say that some effects are because the blades make up a 'disc' and some are because they must be treated as individual elements.
If you understand the basic concepts of aerodynamic lift and drag, and how airflow behaves over a wing approaching and during the stall, then you won't have any trouble understanding how they apply to a rotary wing.
Joined: May 2001
Posts: 231
Likes: 0
From: perth
Lu Zuckerman,
Here we go again about the Robinson, You know, you are about an inch away from copping a defamation suit, surely you are intelligent enough to realise that this forum is public, Ill say it again Lu, PUBLIC, you may want to know that this forum is not protected from any legal action from any person, you really are a bitter and twisted person when it comes to sound engineering advice and sound test piloting advice. You always post so called advice, as if you are the only person in the world who knows! I GOT A NEWS FLASH FOR YOU LU, there are helicopters all over the world that fly sucessfully everyday, and a lot of them Robinsons. In fact I flew one in NZ In the mountains in shocking turbulence, hey Lu Im still alive. Your life really has to be miserable when you, an unlicensed A&P Mechanic, sit in judgement of Professionals Like Mr Nick Lappos. He doesn't have to do
your research on the Robinson, HE DOES NOT HAVE TO LU, He is an engineer and test pilot, he is very much aware of helicopter rotor head design, YOU ARE NOT!
The subject is closed, the people here do not have to answer to your whinings that keep you up at night, ringing bells, burning insence, or reading Harry Potter books, or whatever it is keeps you awake, mate you gotta get out and breathe some fresh air, it is very obvious to all on this forum that you have no grasp of aerodynamics whatever, and I have no problem with that given your background, but as I said before, you are in no position to question others, or pass yourself off as a helicopter aerodynamics whiz, that you aren't Lu. Your grasp of basic physics and mathmatics is not very good.
All this rubbish about fixing helicopters before Nick was born is nothing but pathetic. You really are scraping the bottom of the river with that crap.
I suppose you invented the internet too Lu.
You really are doing yourself alot of damage to your reputation, I suspect you don't tell the people whose Gulfstream you are working on that you are posting this rubbish.
Concepts of Understanding are different from theories Lu, and you can't even understand that.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, theyre nothing but hearsay,inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
My guess is that Nick Lappos has been training a lot more than you, and I feel you really have not done much training at any serious level at all.
Judging by your previous posts, you should be winning the state lottery every week, you know everything else.
[ 16 August 2001: Message edited by: sling load ]
Here we go again about the Robinson, You know, you are about an inch away from copping a defamation suit, surely you are intelligent enough to realise that this forum is public, Ill say it again Lu, PUBLIC, you may want to know that this forum is not protected from any legal action from any person, you really are a bitter and twisted person when it comes to sound engineering advice and sound test piloting advice. You always post so called advice, as if you are the only person in the world who knows! I GOT A NEWS FLASH FOR YOU LU, there are helicopters all over the world that fly sucessfully everyday, and a lot of them Robinsons. In fact I flew one in NZ In the mountains in shocking turbulence, hey Lu Im still alive. Your life really has to be miserable when you, an unlicensed A&P Mechanic, sit in judgement of Professionals Like Mr Nick Lappos. He doesn't have to do
your research on the Robinson, HE DOES NOT HAVE TO LU, He is an engineer and test pilot, he is very much aware of helicopter rotor head design, YOU ARE NOT!
The subject is closed, the people here do not have to answer to your whinings that keep you up at night, ringing bells, burning insence, or reading Harry Potter books, or whatever it is keeps you awake, mate you gotta get out and breathe some fresh air, it is very obvious to all on this forum that you have no grasp of aerodynamics whatever, and I have no problem with that given your background, but as I said before, you are in no position to question others, or pass yourself off as a helicopter aerodynamics whiz, that you aren't Lu. Your grasp of basic physics and mathmatics is not very good.
All this rubbish about fixing helicopters before Nick was born is nothing but pathetic. You really are scraping the bottom of the river with that crap.
I suppose you invented the internet too Lu.
You really are doing yourself alot of damage to your reputation, I suspect you don't tell the people whose Gulfstream you are working on that you are posting this rubbish.
Concepts of Understanding are different from theories Lu, and you can't even understand that.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, theyre nothing but hearsay,inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
My guess is that Nick Lappos has been training a lot more than you, and I feel you really have not done much training at any serious level at all.
Judging by your previous posts, you should be winning the state lottery every week, you know everything else.
[ 16 August 2001: Message edited by: sling load ]
Joined: Dec 2000
Posts: 31
Likes: 0
From: West Yorkshire, UK
Lu
just an idea... if you can't accept or understand the numerous replies, what about actually attending the Robinson Factory Course? No offence to anyone else that's been replying to the endless challenge to provide the answer you want to hear, but where better to get a audience with Robinson 'experts'. AND you get to fly with one of the factory test pilots as well. When I was there I flew with Doug Thomkins the chief experimental test pilot, started with Robinson in 1982, ask for him or Tim Tucker, I'm sure either could demonstrate "anything" the robbie is capable of. And then there's Pat Cox who takes the maintenance side of things, knows his stuff inside out, and willing to talk about any subject at any level. If he can decipher my explanation of a mag failure and then explain to me what it was in such layman's terms that I knew exactly what he meant then he's a pro. And then whilst you're there Lu, you can personally discuss your opinions with Frank (and Tim Tucker etc.) at the same time... Just an idea ?
just an idea... if you can't accept or understand the numerous replies, what about actually attending the Robinson Factory Course? No offence to anyone else that's been replying to the endless challenge to provide the answer you want to hear, but where better to get a audience with Robinson 'experts'. AND you get to fly with one of the factory test pilots as well. When I was there I flew with Doug Thomkins the chief experimental test pilot, started with Robinson in 1982, ask for him or Tim Tucker, I'm sure either could demonstrate "anything" the robbie is capable of. And then there's Pat Cox who takes the maintenance side of things, knows his stuff inside out, and willing to talk about any subject at any level. If he can decipher my explanation of a mag failure and then explain to me what it was in such layman's terms that I knew exactly what he meant then he's a pro. And then whilst you're there Lu, you can personally discuss your opinions with Frank (and Tim Tucker etc.) at the same time... Just an idea ?
Joined: Nov 2000
Posts: 467
Likes: 0
From: Sunrise, Fl. U.S.A.
Poor poor Lu,
Well since you don't wish to heed what I and Nick have said, let's just keep it to the rest of the planet ...
Heed Sling loads and john's postings above, oh yes, here you could go to the Robbie Factory school, and sleep through the same sections you must have at those supposed 6 Sikorsky schools and the supposed 13 more.
So in essance you have stated you have ZERO flying skills what so ever, notice how you gave a great big "I'm just being attacked" para without directly answering the question of stick time ...
AGAIN: Never in my life has there been a person more in need of an hour of dual actual flight instruction...
You have made large mistakes in recalling a lot of things, but you have NOT corrected them, it goes round and round with you and therein lies the reason this hasn't ended, not for anyone else's part.
No, FR response made sense to anyone who UNDERSTOOD ALL the principles behind it.
YOU DIDN"T, and therefore to you it is crap.
(Heed slings comments again, I don't see why FR doesn't slap a lawsuit on you anyway, that certainly would server to both prove the design AGAIN, and embarrass you both financially and professionaly.)
Arrogant is the person with no experience who asks all to prove him right.
Ignorant is the person who cannot accept that they are wrong, when proven so.
You are both in a huge way.
So I don't have to say it again, just re-read EVERYTHING Sling Load stated, for it rings true. Aww heck, I will say it again:
You are not the professional, your course attendance does not give you any right to say "Well prove me wrong" to the true professionals here, they have explained it, your FAILURE to understand the answer does not make the facts invalid, nor raise your flawed thinking of the topic to a theory level. Period.
Proof: you repeatedly return to the same stupid, proven wrong misunderstanding on FTE and EOL, and you believe you are right based only on what others say to you (which leads to your misunderstandings again) and what you have read.
You have NO practical experience to be making the claims that you do here on the Robbie issue, to be giving aero advice, and certainly as I have stated many many many many many many many many times:
People don't have to prove you wrong, you have to prove you are right. You will not do that on the basis of misdirection, third party comments, what you read somewhere etc. GET IN A HELICOPTER AND GENERATE DATA.
Since you are unable/unwilling to get into a heli to do so, it's done.
You state a differing answer from Ray, well to tell the truth, to all here, it is more likely you didn't understand or again misinterpreted the answer given to you, for to do that leave you room to uselessly argue the matter, whereas if you did, then the answer is the same and Nick's, Mine, Sling's, Arm out the window's, FR's, the rotor gods themselves, and the rest of the planet. Something that would spell "END OF THREAD for LZ."
THE MATTER IS CLOSED.
Now, that said, for all these supposed "Attacks" that have been made on you from I, tell us without excuse why SO many people out there from different parts of the planet;
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his last post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
Hmmm ?
I end this with the best thing that Sling pointed out to you, you do need to study it, for it busts the "Well I got a different theory (you don't) or I heard form another person" line of crap:
[ 16 August 2001: Message edited by: RW-1 ]
Well since you don't wish to heed what I and Nick have said, let's just keep it to the rest of the planet ...
Heed Sling loads and john's postings above, oh yes, here you could go to the Robbie Factory school, and sleep through the same sections you must have at those supposed 6 Sikorsky schools and the supposed 13 more.
So in essance you have stated you have ZERO flying skills what so ever, notice how you gave a great big "I'm just being attacked" para without directly answering the question of stick time ...
AGAIN: Never in my life has there been a person more in need of an hour of dual actual flight instruction...
You have made large mistakes in recalling a lot of things, but you have NOT corrected them, it goes round and round with you and therein lies the reason this hasn't ended, not for anyone else's part.
No, FR response made sense to anyone who UNDERSTOOD ALL the principles behind it.
YOU DIDN"T, and therefore to you it is crap.
(Heed slings comments again, I don't see why FR doesn't slap a lawsuit on you anyway, that certainly would server to both prove the design AGAIN, and embarrass you both financially and professionaly.)
Arrogant is the person with no experience who asks all to prove him right.
Ignorant is the person who cannot accept that they are wrong, when proven so.
You are both in a huge way.
So I don't have to say it again, just re-read EVERYTHING Sling Load stated, for it rings true. Aww heck, I will say it again:
You are not the professional, your course attendance does not give you any right to say "Well prove me wrong" to the true professionals here, they have explained it, your FAILURE to understand the answer does not make the facts invalid, nor raise your flawed thinking of the topic to a theory level. Period.
Proof: you repeatedly return to the same stupid, proven wrong misunderstanding on FTE and EOL, and you believe you are right based only on what others say to you (which leads to your misunderstandings again) and what you have read.
You have NO practical experience to be making the claims that you do here on the Robbie issue, to be giving aero advice, and certainly as I have stated many many many many many many many many times:
People don't have to prove you wrong, you have to prove you are right. You will not do that on the basis of misdirection, third party comments, what you read somewhere etc. GET IN A HELICOPTER AND GENERATE DATA.
Since you are unable/unwilling to get into a heli to do so, it's done.
You state a differing answer from Ray, well to tell the truth, to all here, it is more likely you didn't understand or again misinterpreted the answer given to you, for to do that leave you room to uselessly argue the matter, whereas if you did, then the answer is the same and Nick's, Mine, Sling's, Arm out the window's, FR's, the rotor gods themselves, and the rest of the planet. Something that would spell "END OF THREAD for LZ."
THE MATTER IS CLOSED.
Now, that said, for all these supposed "Attacks" that have been made on you from I, tell us without excuse why SO many people out there from different parts of the planet;
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his last post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
Hmmm ?
I end this with the best thing that Sling pointed out to you, you do need to study it, for it busts the "Well I got a different theory (you don't) or I heard form another person" line of crap:
Concepts of Understanding are different from theories Lu, and you can't even understand that.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, they're nothing but heresay, inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, they're nothing but heresay, inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
Joined: Nov 2000
Posts: 467
Likes: 0
From: Sunrise, Fl. U.S.A.
Ooooh! Nerve hit successful ! 
Oh, oh, oh ... he's making fun of my name ... You really are a child in most respects LZ, and terribly easy to predict, you must overcome this tendancy, maybe by growing up, losing the obsession, arrogance, and ignorance that stems from your brain, to your hands, then into your posts.
That would be like you talking aerodynamics here on the forum .... (See ALL previous comments to you on this fact, and not only by me ... ) 
And based upon your irritating nature here I doubt there is ANY pilot willing to have you in their cockpit for any length of time ...
Don't fret Sparky, you can attack me all you want to defer from the fact that just about everyone else here ALSO thinks you are full of S**t . I'm a man, I can take it, especiually when we all know the source:
An old, obsessed, ignorant, arrogant old man, with no life who is nothing more than a wannabe guru here.
The difference between us is that you try and try and try to present yourself as Mr. Know-it-all, every day.
I have made no such claims to fame, and that certainly means that any one with 1 hour in a heli still seems to know more than you do, with WHATEVER you care to post as a resume to back it up. I also understand the difference between a concept, a theroy, and fact, something that you with ALL your immemense experience have not grasped yet.
(I say yet, for there is always hope, even for you)
THAT has to eat you up, ALL these other TRUE PROFESSIONALS aggreeing with me ...
and not you ...
Not LZ ...
How dare they with all you know?
Well crow hurts when it has to be eaten,'bout time you eat it like a man, and move on.
Resumes are nothing, your actions and statements are what makes for the meat of the thread, and the evidence YOU yourself have contributed says you slept through your classes.
And I didn't even say that until now, gee, how did all the others come to that conclusion? (refer back to attacking me comment, I can take it, go ahead, attack me and not answer the question.)
This is another round of the immature LZ trying to prove he is something he isn't, and the evidence has been given BY YOU to the contrary. Please go back to basics school, go get some dual in something CURRENT, and then come back here and discuss aero.
The issue at hand is that you know not what you speak, and presume that you do. That's sad.
You are not a wannabe. You are THE WANNABE.
However, you still haven't answered the following, Mr. Know-it-all:
For all these supposed "Attacks" that have been made on you from I, tell us, without excuse, why SO many people out there from different parts of the planet:
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
Hmmm ?
You are SAD, just terribly sad .... we're done with you.
You will now continue to make it a LZ vs RW-1 (or insert anyones name here) BECAUSE to do otherwise is to end the thread that has been covered and closed.
So by now going just to me it would seem you have now have ran out of further excuses to make on your end. Plain and simple.
You have a nice day now! I'm going flying this evening, adn I shall enjoy it.
[ 16 August 2001: Message edited by: RW-1 ]
Oh, oh, oh ... he's making fun of my name ... You really are a child in most respects LZ, and terribly easy to predict, you must overcome this tendancy, maybe by growing up, losing the obsession, arrogance, and ignorance that stems from your brain, to your hands, then into your posts.
Once again you have shot your mouth off about something you have no knowledge of.
And based upon your irritating nature here I doubt there is ANY pilot willing to have you in their cockpit for any length of time ...
Don't fret Sparky, you can attack me all you want to defer from the fact that just about everyone else here ALSO thinks you are full of S**t . I'm a man, I can take it, especiually when we all know the source:
An old, obsessed, ignorant, arrogant old man, with no life who is nothing more than a wannabe guru here.
The difference between us is that you try and try and try to present yourself as Mr. Know-it-all, every day.
I have made no such claims to fame, and that certainly means that any one with 1 hour in a heli still seems to know more than you do, with WHATEVER you care to post as a resume to back it up. I also understand the difference between a concept, a theroy, and fact, something that you with ALL your immemense experience have not grasped yet.
(I say yet, for there is always hope, even for you)
THAT has to eat you up, ALL these other TRUE PROFESSIONALS aggreeing with me ...
and not you ...
Not LZ ...
How dare they with all you know?
Well crow hurts when it has to be eaten,'bout time you eat it like a man, and move on.
Resumes are nothing, your actions and statements are what makes for the meat of the thread, and the evidence YOU yourself have contributed says you slept through your classes.
And I didn't even say that until now, gee, how did all the others come to that conclusion? (refer back to attacking me comment, I can take it, go ahead, attack me and not answer the question.)
This is another round of the immature LZ trying to prove he is something he isn't, and the evidence has been given BY YOU to the contrary. Please go back to basics school, go get some dual in something CURRENT, and then come back here and discuss aero.
The issue at hand is that you know not what you speak, and presume that you do. That's sad.
You are not a wannabe. You are THE WANNABE.
However, you still haven't answered the following, Mr. Know-it-all:
For all these supposed "Attacks" that have been made on you from I, tell us, without excuse, why SO many people out there from different parts of the planet:
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
Hmmm ?
You are SAD, just terribly sad .... we're done with you.
You will now continue to make it a LZ vs RW-1 (or insert anyones name here) BECAUSE to do otherwise is to end the thread that has been covered and closed.
So by now going just to me it would seem you have now have ran out of further excuses to make on your end. Plain and simple.
You have a nice day now! I'm going flying this evening, adn I shall enjoy it.
[ 16 August 2001: Message edited by: RW-1 ]
Joined: Nov 2000
Posts: 452
Likes: 0
From: Vancouver, BC, Canada
RW-1
>No, FR response made sense to anyone who UNDERSTOOD ALL the principles behind it.,
I understand very little about helicopters. It is the desire to learn that is a primary reason for participating in this and other related threads.
Thanks to Frank Robinson's posting, and some subsequent reading, things have cleared up a little. For instance, it appears that his use of the word "Wee-wa" probably stands for 'small washout'. Do you agree?
It can be assumed that Frank Robinson does not have the time, or the requirement, to publish a thesis on PPRuNe about helicopter rotorheads. Unfortunately, he addressed delta3, which is relatively common. He did not address the Robinson's unique feature. That being, the reasoning behind the combined use of a teetering hinge plus two flap/cone hinges.
In my limited capacity, I see nothing wrong with the Robinson's rotor. What I do see as wrong is threads that are intended to be technical and informative turning into personalized attacks on individuals or companies.
____________
Lu
You, me and probably most of the world, believe that the association between 'gyroscopic precession' and '90-degrees' is a fact.
Hopefully, the following excerpt on gyroscopic precession should be of interest.
But first, we must agree that a helicopter's rotor does not rotate as fast as a gyroscope and that the rotor's relative mass is not as great as a gyroscope's relative mass.
".............. Otherwise the motion of the gyroscope is much more complicated, as you might observe in an actual experiment where the rotation of the rotor slows down over time. We can see that as the rotor slows, the precessional frequency increases. At some point when the precessional frequency exceeds a critical value, the gyroscope will begin to wobble and eventually tumble in its gimbals." [My change to bold].
[ 16 August 2001: Message edited by: Dave Jackson ]
>No, FR response made sense to anyone who UNDERSTOOD ALL the principles behind it.,
I understand very little about helicopters. It is the desire to learn that is a primary reason for participating in this and other related threads.
Thanks to Frank Robinson's posting, and some subsequent reading, things have cleared up a little. For instance, it appears that his use of the word "Wee-wa" probably stands for 'small washout'. Do you agree?
It can be assumed that Frank Robinson does not have the time, or the requirement, to publish a thesis on PPRuNe about helicopter rotorheads. Unfortunately, he addressed delta3, which is relatively common. He did not address the Robinson's unique feature. That being, the reasoning behind the combined use of a teetering hinge plus two flap/cone hinges.
In my limited capacity, I see nothing wrong with the Robinson's rotor. What I do see as wrong is threads that are intended to be technical and informative turning into personalized attacks on individuals or companies.
____________
Lu
You, me and probably most of the world, believe that the association between 'gyroscopic precession' and '90-degrees' is a fact.
Hopefully, the following excerpt on gyroscopic precession should be of interest.
But first, we must agree that a helicopter's rotor does not rotate as fast as a gyroscope and that the rotor's relative mass is not as great as a gyroscope's relative mass.
".............. Otherwise the motion of the gyroscope is much more complicated, as you might observe in an actual experiment where the rotation of the rotor slows down over time. We can see that as the rotor slows, the precessional frequency increases. At some point when the precessional frequency exceeds a critical value, the gyroscope will begin to wobble and eventually tumble in its gimbals." [My change to bold].
[ 16 August 2001: Message edited by: Dave Jackson ]
Thread Starter
Joined: Jul 2001
Posts: 1,084
Likes: 1
From: the cockpit
Lu,
I will repeat something I said 2 pages ago:
>>Why do you deflect the discussion to irrelevant details such as wether or not you do/don’t teach it that way rather than try and benefit from the explanations offered? You did not acknowledge that any points were even made.
For example, you have avoided any response to my opening posts on RBS, and on which parts of your understanding are flawed. Even in your new explanation of how you “really” teach it you are mixing concepts.<<
You have still not addressed ONE point. You had asked for specific examples/specific explanations to your theories, and I have seen them repeatedly offered to you by various (heedm, Arm out the window, Nick Lappos, sling load, etc) yet you answer only Dave Jackson, as per above. Is it because Dave does not question aspects of your theory?
How about you go back to the subject (RBS), look at the explanations offered to you in this thread, and talk specifics. Otherwise you may never grasp the fundamentals.
Perhaps the detailed gyroscopic discussions could be posted on Dave Jackson's excellent thread?
I will repeat something I said 2 pages ago:
>>Why do you deflect the discussion to irrelevant details such as wether or not you do/don’t teach it that way rather than try and benefit from the explanations offered? You did not acknowledge that any points were even made.
For example, you have avoided any response to my opening posts on RBS, and on which parts of your understanding are flawed. Even in your new explanation of how you “really” teach it you are mixing concepts.<<
You have still not addressed ONE point. You had asked for specific examples/specific explanations to your theories, and I have seen them repeatedly offered to you by various (heedm, Arm out the window, Nick Lappos, sling load, etc) yet you answer only Dave Jackson, as per above. Is it because Dave does not question aspects of your theory?
How about you go back to the subject (RBS), look at the explanations offered to you in this thread, and talk specifics. Otherwise you may never grasp the fundamentals.
Perhaps the detailed gyroscopic discussions could be posted on Dave Jackson's excellent thread?
Joined: Jan 2001
Posts: 3,008
Likes: 62
From: North Queensland, Australia
I have to agree, helmet fire.
I liken a series of posts to a conversation, where a number of people discuss an issue - you have disagreement, interjections and so on, but the basic gist of it goes on, and people either come to some accord, or agree to disagree in the end. Far from what's been happening here!
Lu's posts have been good in that they certainly spark discussion, probably more so than if we all sat around calmly pontificating, but I've had enough of addressing points he raises and then having him spear off on some random tangent.
Compromise ain't on the agenda, by the look of things, so see you all on some other thread!
I liken a series of posts to a conversation, where a number of people discuss an issue - you have disagreement, interjections and so on, but the basic gist of it goes on, and people either come to some accord, or agree to disagree in the end. Far from what's been happening here!
Lu's posts have been good in that they certainly spark discussion, probably more so than if we all sat around calmly pontificating, but I've had enough of addressing points he raises and then having him spear off on some random tangent.
Compromise ain't on the agenda, by the look of things, so see you all on some other thread!
Joined: Nov 2000
Posts: 452
Likes: 0
From: Vancouver, BC, Canada
Lu
>I’m sorry I can’t agree. <
Thanks for the above statement. As I read it, you are not saying that my position is right or wrong. You are saying that you, personally, are not willing to accept it. (At least not accept it yet.
>Even the proverbial bicycle wheel which is considerably lighter than a gyro rotor of the same diameter and rotates at a speed maybe 1 100th of that of a gyro rotor will exhibit rigidity in space and precession. <
Remember that, unlike the helicopter rotor, this bicycle wheel has just about all its mass at the rim (tip). I would suggest that the bicycle wheel is a lot closer to the gyroscope then it is to the helicopter rotor.
>However the stored energy in a helicopter rotor is capable of exerting rigidity in space and precession. <
This may not be a fair analogy but; the spinning gyroscopic toy will maintain orientation for say 1/2 a minute. With the helicopter, you can kiss autorotation goodbye, if you don't do something within a few seconds.
________________
Correct me if I am wrong, but it has been mathematically proven and I think we can agree on the fact that aerodynamic 'precession' can be less then 90-degrees.
My previous posting did not go into the mathematics of gyroscopic precession. Its intent was simply to show that gyroscopic precession can be less than 90-degrees, as well.
In other words; both gyroscopic precession and aerodynamic precession can be, under certain circumstances, less than 90-degrees.
If you agree with this then we can try to determine what these circumstances are.
[ 17 August 2001: Message edited by: Dave Jackson ]
>I’m sorry I can’t agree. <
Thanks for the above statement. As I read it, you are not saying that my position is right or wrong. You are saying that you, personally, are not willing to accept it. (At least not accept it yet.
>Even the proverbial bicycle wheel which is considerably lighter than a gyro rotor of the same diameter and rotates at a speed maybe 1 100th of that of a gyro rotor will exhibit rigidity in space and precession. <
Remember that, unlike the helicopter rotor, this bicycle wheel has just about all its mass at the rim (tip). I would suggest that the bicycle wheel is a lot closer to the gyroscope then it is to the helicopter rotor.
>However the stored energy in a helicopter rotor is capable of exerting rigidity in space and precession. <
This may not be a fair analogy but; the spinning gyroscopic toy will maintain orientation for say 1/2 a minute. With the helicopter, you can kiss autorotation goodbye, if you don't do something within a few seconds.
________________
Correct me if I am wrong, but it has been mathematically proven and I think we can agree on the fact that aerodynamic 'precession' can be less then 90-degrees.
My previous posting did not go into the mathematics of gyroscopic precession. Its intent was simply to show that gyroscopic precession can be less than 90-degrees, as well.
In other words; both gyroscopic precession and aerodynamic precession can be, under certain circumstances, less than 90-degrees.
If you agree with this then we can try to determine what these circumstances are.
[ 17 August 2001: Message edited by: Dave Jackson ]
Joined: Jan 1997
Posts: 7,736
Likes: 1
From: UK
Tempers have been getting very frayed over the last couple of pages.
Many of you have seen what this has done to other sites. We won't have that here.
Attack the argument and not the person.
Rob Lloyd
[ 17 August 2001: Message edited by: PPRuNe Towers ]
Many of you have seen what this has done to other sites. We won't have that here.
Attack the argument and not the person.
Rob Lloyd
[ 17 August 2001: Message edited by: PPRuNe Towers ]
Joined: Nov 2000
Posts: 467
Likes: 0
From: Sunrise, Fl. U.S.A.
Attack the argument
It's the person in question who cannot accept that fact.
Misdirection, inability to remain on topic, various excuses for his misunderstang of basic principles, then returning to the same issues already asked and answered.
It is no longer an arguement, has not been for over a year and a half, but a broken record:
The tune (thread) changes by some degree, but the song itself is ALWAYS the same. The 18 Degree offset concept (not theory, not fact) is dead.
If he cannot accept the answers he gets to the questions he poses to the very people he insults, then you can plainly see where the issue lies.
Helmet and Arm are spot on again.
EVERYTHING I stated in my last posting rings truer than the Liberty Bell (if rung).
[ 17 August 2001: Message edited by: RW-1 ]
Joined: Nov 2000
Posts: 467
Likes: 0
From: Sunrise, Fl. U.S.A.
Lu Sez:
Blah blah blah ....
You mean like that I must have a lot of company in those CORRECT observations that you still HAVEN'T ADDRESSED?
You have made most of the personal attacks here, you have no Alternate Theory at all, just a misguided interpretation that you contnually try to apply to other things going on with the rotor, with flawed results because you started with a bad concept.
THERE IS NO ALTERNATE THEORY. AGAIN THE BROKEN RECORD...
I refer you back to Sling Load:
This is tiresome.
LU Zuckerman, the wannabe, all your posts are nothing more than questions asked so that you can continue to tell people that the answers given are incorrect and you are the one who knows all. They have NOTHING to do with learning, or to instruct, but whether your 18 deg concept is correct or not, so that you may continue to bash robbies. You have always had only this one track on your tiny little mind, you are not kidding anyone here.
The following is not an attack, but a correct observation, made prior to me saying it by many many others:
You are an arrogant, ignorant, wind up.
You really seem to get off thinking you are some kind of guru, that must be it. By continuing to just tell people that you have determined they are off, that they must be off, you could never be further than the truth.
You have never, NEVER given anyone a response that aggrees with them without a if and or but that allows you to continue this totally useless ranting.
Again this is no arguement, no alternate theory crap, nothing more than a continuation of your obsession with the Robinson.
AND FOR THE LAST TIME GET OFF THAT DIFFERENCE IN TRAINING GARBAGE, both sides of the pond have told you you are off, it is just another excuse.
You also take 5 responses in JH and tailor then to suit you, not the way it was said TO you.
(Not to mention the mispelling of gyroscopic in the thread title ...)
So now you presume to tell people what they formulated?
Nope, they formed it by BOTH instruction AND FLYING, something YOU STILL HAVE NOT DONE !
This is WHY pilots do BOTH.
And you still have not answered the following (and when you do lets not make if's and s or but's, nor other excuses):
You cannot answer that one huh ?
You will continue to piss off / annoy others, continue to go round and round, excuse after excuse, and eventually you will have no one to converse with. Maybe then you will realize what everyone has told you is true.
For over a year and a half PPRuNer's have been subjected to your crap concept, you have brought forth NOTHING NEW to your end of the so called "arguement."
You needlessly waste everyone's time with the same sad pattern of excuses, redirection, misinterpretation, tailoring what IS said to you to what you WANT to hear, etc.
After all that time the 18 deg issue is still dead wrong, it will continue to be dead wrong, and remain dead wrong. For as it has been pointed out, you cannot make a mistake a fact by preaching.
Basically this thread has gone in the same direction as ALL your others here. And I didn't even get involved with it until you strayed off track, you stray off track because you don't like the 18 deg concept dead station the train heads into each and every time it's discussed.
Quite frankly you are a bitter old man with an obsession that you will take with you to the grave, and even then it will be unproven. (BTW that is not an attack, it is a fact, submitted by plenty others on this forum prior to my saying so, evidence submitted, look at all the other posts here, anyone ...)
Well, it is the weekend, I shall be out flying.
Say something stupid Lu, make another childish comment towards me while I'm out doing something you seemingly cannot handle, flying a Robinson. Whatever it takes to avoid the issue of your refusal to know when you are done.
Just a bitter old man ... I need not say more on the subject, you do a better job of illustrating what I stated previously about you for the last two years ...
[ 17 August 2001: Message edited by: RW-1 ]
Blah blah blah ....
The Liberty Bell like many of your arguments has a big crack in it.
You have made most of the personal attacks here, you have no Alternate Theory at all, just a misguided interpretation that you contnually try to apply to other things going on with the rotor, with flawed results because you started with a bad concept.
THERE IS NO ALTERNATE THEORY. AGAIN THE BROKEN RECORD...
I refer you back to Sling Load:
Concepts of Understanding are different from theories Lu, and you can't even understand that.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, they're nothing but heresay, inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
Your so called findings are based on "so and so told me this" " another fellow told me that". Findings!, they're nothing but heresay, inconclusive,and the result of an obsession. Get over it Lu. IT WORKS.
LU Zuckerman, the wannabe, all your posts are nothing more than questions asked so that you can continue to tell people that the answers given are incorrect and you are the one who knows all. They have NOTHING to do with learning, or to instruct, but whether your 18 deg concept is correct or not, so that you may continue to bash robbies. You have always had only this one track on your tiny little mind, you are not kidding anyone here.
The following is not an attack, but a correct observation, made prior to me saying it by many many others:
You are an arrogant, ignorant, wind up.
You really seem to get off thinking you are some kind of guru, that must be it. By continuing to just tell people that you have determined they are off, that they must be off, you could never be further than the truth.
You have never, NEVER given anyone a response that aggrees with them without a if and or but that allows you to continue this totally useless ranting.
Again this is no arguement, no alternate theory crap, nothing more than a continuation of your obsession with the Robinson.
AND FOR THE LAST TIME GET OFF THAT DIFFERENCE IN TRAINING GARBAGE, both sides of the pond have told you you are off, it is just another excuse.
You also take 5 responses in JH and tailor then to suit you, not the way it was said TO you.
(Not to mention the mispelling of gyroscopic in the thread title ...)
So now you presume to tell people what they formulated?
Nope, they formed it by BOTH instruction AND FLYING, something YOU STILL HAVE NOT DONE !
This is WHY pilots do BOTH.
And you still have not answered the following (and when you do lets not make if's and s or but's, nor other excuses):
For all these supposed "Attacks" that have been made on you from I, tell us, without excuse, why SO many people out there from different parts of the planet:
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
taught in different manners(according to you)
Flying a vast range of machines (where you fly NONE)
Test pilots (whom you are not)
Designers (where you are not)
Commercial pilots (that you are not)
Would ALL come to the same conclusion that you are full of !!!!!?
And we are not talking about your Robbie bashing, we are talking about the same conclusion that Sling came to in his post, he certainly didn't start out that way, he was a supporter of seeing if you were right, JUST HOW did that happen?
You will continue to piss off / annoy others, continue to go round and round, excuse after excuse, and eventually you will have no one to converse with. Maybe then you will realize what everyone has told you is true.
For over a year and a half PPRuNer's have been subjected to your crap concept, you have brought forth NOTHING NEW to your end of the so called "arguement."
You needlessly waste everyone's time with the same sad pattern of excuses, redirection, misinterpretation, tailoring what IS said to you to what you WANT to hear, etc.
After all that time the 18 deg issue is still dead wrong, it will continue to be dead wrong, and remain dead wrong. For as it has been pointed out, you cannot make a mistake a fact by preaching.
Basically this thread has gone in the same direction as ALL your others here. And I didn't even get involved with it until you strayed off track, you stray off track because you don't like the 18 deg concept dead station the train heads into each and every time it's discussed.
Quite frankly you are a bitter old man with an obsession that you will take with you to the grave, and even then it will be unproven. (BTW that is not an attack, it is a fact, submitted by plenty others on this forum prior to my saying so, evidence submitted, look at all the other posts here, anyone ...)
Well, it is the weekend, I shall be out flying.
Say something stupid Lu, make another childish comment towards me while I'm out doing something you seemingly cannot handle, flying a Robinson. Whatever it takes to avoid the issue of your refusal to know when you are done.
Just a bitter old man ... I need not say more on the subject, you do a better job of illustrating what I stated previously about you for the last two years ...
[ 17 August 2001: Message edited by: RW-1 ]
Joined: Dec 2000
Posts: 31
Likes: 0
From: West Yorkshire, UK
Lu
I know I'm repeating myself but that seems to be an accepted thing in these threads. Cut out all the middle men, go to the source, go to the Robinson factory. Don't call someone/anyone, go there, do one of the factory courses. You have a choice of pilot or maintenance course. I guarantee you'll get a very good explanation as to why things are done as they are.
I know I'm repeating myself but that seems to be an accepted thing in these threads. Cut out all the middle men, go to the source, go to the Robinson factory. Don't call someone/anyone, go there, do one of the factory courses. You have a choice of pilot or maintenance course. I guarantee you'll get a very good explanation as to why things are done as they are.
Joined: Aug 2000
Posts: 219
Likes: 0
From: Asia/Oz
Lu, I read your post on Just Helicopters on 14th August, asking pilots what they were taught in relation to blade movement and gyroscopic precession. With regard to the responses you received you stated that "...although they were differing all were taught that the blades move due to gyroscopic precession." There were only 5, (mostly confused and confusing) responses, and only one actually said that he was taught as you stated. He then went on to say that he now realises that this was wrong. You appear to have interpreted the responses to suit your argument.
Joined: Mar 2000
Posts: 5,197
Likes: 1
From: UK
Well Lu, you certainly keep Rotorheads lively!
We are all entitled to our views even when we are wrong! But, it is quite helpful to know a little of the background, qualifications and experience etc of the person expressing views, especially when they appear to be controversial.
Why not post details of your qualifications and experience in the industry as suggested by a number of contributors?
Most contributors know something of Nick Lappos' position and standing in the industry. For those who don't .......
Nick Lappos is Sikorsky's Assistant Chief Test Pilot. A former U.S. Army Warrant Officer and a combat veteran of Vietnam, he flew Cobra attack helicopters in D Troop, 1st Squadron, 1st Cavalry.
An Aerospace Engineering graduate of Georgia Tech, he came to Sikorsky Aircraft in 1973. Since then, he has flown in the YUH-60 Black Hawk program, flown the first flight and structural shakedown of the S-76, the "Shadow" cockpit research aircraft, the adaptive fuel control experimental aircraft, and the "Fantail" fan-in-fin demonstrator.
He is now assigned to the RAH-66 Comanche project, where he is part of the pilot team flying the shakedown and envelope expansion. In 1988, the Society of Experimental Test Pilots awarded Nick their Tenhoff Award for the most outstanding paper at the Annual Symposium.
The American Helicopter Society awarded Nick their Feinberg award as most outstanding pilot for his contribution to the understanding of maneuverability in 1989 and again in 1998 (as part of the Comanche Team), and in 1994 he was named a Fellow of the Society. He was a member of the American Helicopter Society's Handling Qualities committee and AGARD Working Group #19 (Functional Agility), and is currently a member of the NASA/FAA Air Traffic Management R&D Executive Steering Committee. Nick has written a number of technical papers, and articles for magazines such as "Rotor and Wing," "Interavia," and "Defense Helicopter." He holds 15 U.S. and a number of foreign patents on flight and engine controls and cockpit displays.
Thanks for your contributions, Nick!
We are all entitled to our views even when we are wrong! But, it is quite helpful to know a little of the background, qualifications and experience etc of the person expressing views, especially when they appear to be controversial.
Why not post details of your qualifications and experience in the industry as suggested by a number of contributors?
Most contributors know something of Nick Lappos' position and standing in the industry. For those who don't .......
Nick Lappos is Sikorsky's Assistant Chief Test Pilot. A former U.S. Army Warrant Officer and a combat veteran of Vietnam, he flew Cobra attack helicopters in D Troop, 1st Squadron, 1st Cavalry.
An Aerospace Engineering graduate of Georgia Tech, he came to Sikorsky Aircraft in 1973. Since then, he has flown in the YUH-60 Black Hawk program, flown the first flight and structural shakedown of the S-76, the "Shadow" cockpit research aircraft, the adaptive fuel control experimental aircraft, and the "Fantail" fan-in-fin demonstrator.
He is now assigned to the RAH-66 Comanche project, where he is part of the pilot team flying the shakedown and envelope expansion. In 1988, the Society of Experimental Test Pilots awarded Nick their Tenhoff Award for the most outstanding paper at the Annual Symposium.
The American Helicopter Society awarded Nick their Feinberg award as most outstanding pilot for his contribution to the understanding of maneuverability in 1989 and again in 1998 (as part of the Comanche Team), and in 1994 he was named a Fellow of the Society. He was a member of the American Helicopter Society's Handling Qualities committee and AGARD Working Group #19 (Functional Agility), and is currently a member of the NASA/FAA Air Traffic Management R&D Executive Steering Committee. Nick has written a number of technical papers, and articles for magazines such as "Rotor and Wing," "Interavia," and "Defense Helicopter." He holds 15 U.S. and a number of foreign patents on flight and engine controls and cockpit displays.
Thanks for your contributions, Nick!
