THE INFAMOUS TEST, LATEST VERSION
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THE INFAMOUS TEST, LATEST VERSION
I caught so much flack on other threads when I suggested that the Robbie drivers perform a test to see if the rotor system responded in the same sense as the cyclic movement. Well here is a test that you can all do on the helicopter you fly and it does not require you to leave the ground.
With your helicopter running up, move your cyclic forward or sideward from the rigged neutral position and see if the disc tilts in the direction you moved the cyclic.
I don’t know how much movement would be required to tip you over if you fly a rigid rotor helicopter so be careful.
If you have no objections to performing the test please report your findings on this thread said he as he ducks for cover awaiting another flack attack.
AFTER READING THE FIRST TWO RESPONSES I REALIZED THAT THE TYPE OF HELICOPTERS SHOULD BE IDENTIFIED IN THE RESPONSE. THE MAIN PURPOSE OF THIS POST IS TO DETERMINE THE RESPONSE OF ROBINSON OPERATORS AS OPPOSED TO ALL OTHER HELICOPTER OPERATORS.
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The Cat
[This message has been edited by Lu Zuckerman (edited 16 March 2001).]
[This message has been edited by Lu Zuckerman (edited 17 March 2001).]
With your helicopter running up, move your cyclic forward or sideward from the rigged neutral position and see if the disc tilts in the direction you moved the cyclic.
I don’t know how much movement would be required to tip you over if you fly a rigid rotor helicopter so be careful.
If you have no objections to performing the test please report your findings on this thread said he as he ducks for cover awaiting another flack attack.
AFTER READING THE FIRST TWO RESPONSES I REALIZED THAT THE TYPE OF HELICOPTERS SHOULD BE IDENTIFIED IN THE RESPONSE. THE MAIN PURPOSE OF THIS POST IS TO DETERMINE THE RESPONSE OF ROBINSON OPERATORS AS OPPOSED TO ALL OTHER HELICOPTER OPERATORS.
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The Cat
[This message has been edited by Lu Zuckerman (edited 16 March 2001).]
[This message has been edited by Lu Zuckerman (edited 17 March 2001).]
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To: IHL and Jed A1
I modified my post to have the respondent identify the type of helicopter upon which the test was performed. The main point of the test is to prove or disprove that the Robinson rotor will tip down left of the nose when the cyclic is moved forward from the rigged neutral position. The operative word is “rigged neutral”. If the cyclic is not in this position when the test is performed the results will be different.
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The Cat
I modified my post to have the respondent identify the type of helicopter upon which the test was performed. The main point of the test is to prove or disprove that the Robinson rotor will tip down left of the nose when the cyclic is moved forward from the rigged neutral position. The operative word is “rigged neutral”. If the cyclic is not in this position when the test is performed the results will be different.
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The Cat
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To: IHL
Having an incomprehensible mixing unit will have no effect on the test. The mixing unit allows the coupling of vectors in flight control movement while at the same time allowing for collective (up / down) movement. All things being equal when you perform the test with low collective you will only be utilizing the fore and aft (longitudinal) movement of the mixing unit. On some Sikorsky helicopters there is a built in left bias to counter the tail rotor (propeller) effect when the collective is raised. With low collective this does not come into effect
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The Cat
Having an incomprehensible mixing unit will have no effect on the test. The mixing unit allows the coupling of vectors in flight control movement while at the same time allowing for collective (up / down) movement. All things being equal when you perform the test with low collective you will only be utilizing the fore and aft (longitudinal) movement of the mixing unit. On some Sikorsky helicopters there is a built in left bias to counter the tail rotor (propeller) effect when the collective is raised. With low collective this does not come into effect
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The Cat
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Oh, yet not again, another teat that everyone else need do EXCEPT LZ .....
Geez ...... Give it a reat. You are the only one who needs to perform this, it's amazing you have waited this long to start this yet again. I had private bets that I can now collect on, thank you very much.
So tell the above people what they missed, or how they must have missed something, because it doesn't do what you predicted.
'Cause so far, the only thing I see here is:
It don't do it !
Not on the 22, Not on the 44, not on the 206,
not on the MD500, Not on the 430 ....
INFAMOUS ANSWER, SAME VERSION:
Perform thy test yourself, so you can move past this obsession ... and PPRuner's won't have to listen to this anymore.
To new Ppruner's, some history: LZ would like everyone to do this test except him, because if he did it and got the same results as we do every time we fly, end of theory.
I say that LZ do his test and formulate why it DOESN'T do what he predicts. But I've got as much chance of that happening as the next pope being Jewish.
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Marc
[This message has been edited by RW-1 (edited 18 March 2001).]
Geez ...... Give it a reat. You are the only one who needs to perform this, it's amazing you have waited this long to start this yet again. I had private bets that I can now collect on, thank you very much.
So tell the above people what they missed, or how they must have missed something, because it doesn't do what you predicted.
'Cause so far, the only thing I see here is:
It don't do it !
Not on the 22, Not on the 44, not on the 206,
not on the MD500, Not on the 430 ....
INFAMOUS ANSWER, SAME VERSION:
Perform thy test yourself, so you can move past this obsession ... and PPRuner's won't have to listen to this anymore.
To new Ppruner's, some history: LZ would like everyone to do this test except him, because if he did it and got the same results as we do every time we fly, end of theory.
I say that LZ do his test and formulate why it DOESN'T do what he predicts. But I've got as much chance of that happening as the next pope being Jewish.
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Marc
[This message has been edited by RW-1 (edited 18 March 2001).]
Guest
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Hey Lu, have a look at page 73 (Acrobat page 81) of the following 1996 NTSB report on the Robbies. That page has a copy of a certification document from Robinson HC showing the various positions of the flight controls and the teeter angle of the rotorhead, recorded at various airspeeds at 97% and 104% rotor rpm.
I think you'll be cheered up when you look at the lateral position of the cyclic as it was expressed in percentage of total travel. I'm assuming the flight conditions being tested were straight ahead level flight (title of the page is "Table V - Summary of level flight conditions").
http://www.ntsb.gov/Publictn/1996/SIR9603.pdf
You'll like it.
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Safe flying to you...
I think you'll be cheered up when you look at the lateral position of the cyclic as it was expressed in percentage of total travel. I'm assuming the flight conditions being tested were straight ahead level flight (title of the page is "Table V - Summary of level flight conditions").
http://www.ntsb.gov/Publictn/1996/SIR9603.pdf
You'll like it.
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Safe flying to you...
Guest
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To: RW-1
If you will note, those that have responded to the test request have not posted any objections or saying “that” here we go again. The original test request response from most of the respondents stated that it would be against sound flight principles or would impact flight safety or, it would require a test pilot to perform the test. None of them if I remember correctly took your point of view in that I should perform the test myself. This new test is something that every helicopter pilot would do just prior to lift off in that he is checking control response to control input. The only deviation from that normal test is that I put a restriction in that the movement must take place from the rigged neutral position and that it be done on the ground.
I would expect that most helicopters would have the desired response in that with the cyclic moved forward from the rigged neutral position the disc would tip down over the nose. The same would be true for other helicopters that the disc responds in the same sense of cyclic movement with the cyclic displaced left or right. I also don’t appreciate your stating that if the test was performed correctly and the feedback was contrary to my theory that I wouldn’t believe what I was told. The final arbiter in this matter is the NTSB and based on what I was told they may not perform the test for reasons that may be explained in another post.
I proposed that this control input / response test is performed from the rigged neutral position. If you don’t know where that is, ask your mechanic or, check the maintenance manual as it tells you the exact position the cyclic must be placed when rigging the helicopter.
To: SPS
In performing the test in the hover you have displaced the cyclic to compensate for lateral CG and tail rotor propeller effect. Do the same test on the ground with low pitch. The reason for this is to keep the blades in the pure radial (centrifugal loading with no coning) position. This will minimize pitch coupling and the disc will only teeter and the blades will not flap.
To: The Nr Fairy
Sounds good, but was the stick in the rigged neutral position when you performed the test?
To: Flight Safety
I have the report. Assuming that the test was demonstrated in forward flight the results show that the cyclic was always to the right of its neutral travel (Fore and aft). You will note that the test began at thirty knots most likely when they had passed through transverse flow effect (inflow roll) which would have required left cyclic input..
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The Cat
[This message has been edited by Lu Zuckerman (edited 18 March 2001).]
If you will note, those that have responded to the test request have not posted any objections or saying “that” here we go again. The original test request response from most of the respondents stated that it would be against sound flight principles or would impact flight safety or, it would require a test pilot to perform the test. None of them if I remember correctly took your point of view in that I should perform the test myself. This new test is something that every helicopter pilot would do just prior to lift off in that he is checking control response to control input. The only deviation from that normal test is that I put a restriction in that the movement must take place from the rigged neutral position and that it be done on the ground.
I would expect that most helicopters would have the desired response in that with the cyclic moved forward from the rigged neutral position the disc would tip down over the nose. The same would be true for other helicopters that the disc responds in the same sense of cyclic movement with the cyclic displaced left or right. I also don’t appreciate your stating that if the test was performed correctly and the feedback was contrary to my theory that I wouldn’t believe what I was told. The final arbiter in this matter is the NTSB and based on what I was told they may not perform the test for reasons that may be explained in another post.
I proposed that this control input / response test is performed from the rigged neutral position. If you don’t know where that is, ask your mechanic or, check the maintenance manual as it tells you the exact position the cyclic must be placed when rigging the helicopter.
To: SPS
In performing the test in the hover you have displaced the cyclic to compensate for lateral CG and tail rotor propeller effect. Do the same test on the ground with low pitch. The reason for this is to keep the blades in the pure radial (centrifugal loading with no coning) position. This will minimize pitch coupling and the disc will only teeter and the blades will not flap.
To: The Nr Fairy
Sounds good, but was the stick in the rigged neutral position when you performed the test?
To: Flight Safety
I have the report. Assuming that the test was demonstrated in forward flight the results show that the cyclic was always to the right of its neutral travel (Fore and aft). You will note that the test began at thirty knots most likely when they had passed through transverse flow effect (inflow roll) which would have required left cyclic input..
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The Cat
[This message has been edited by Lu Zuckerman (edited 18 March 2001).]
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You still fail to understand anything but what you generate. Perhaps the others were just thinking if they tell you it doesn't, which they did, that would be the end of it. However I know better, and will always head this thread off before the pass.
Flight controls free and correct. check 'em on ground, and do a slight cyclic wipe before bringing coll up for liftoff. No coupling.
>>I also don’t appreciate your stating that if the test was performed correctly and the feedback was contrary to my theory that I wouldn’t believe what I was told. <<
I don't CARE that you don't appreciate it.
You don't appreciate it because it is a true statement of fact.
If you go out and perform your test as you want it, test pilot or not, rigged or not, then you will eliminate ANY recorse available to you if you don't like the desired outcome of said test.
So it's easier for you to sit there and ask everyone else to do it, then you can defend the weak position until everyone is tires of hearing it.
Gee, what are you going to say to Nr Fairy and SPS when they report they did it as advertised, without the lateral movements you predict? Hmm ? My bet: you won't accept it, you will bring in another factor, or something they "Failed" to check, measure, or have blessed before doing it. (oh, sorry ... seems you are already off to that prediction already ...)
Quit telling others how to do it, and do it yourself.
IN SHORT: You like to leave an out for yourself, and you will never do the test yourself, because then you would not have that out. Game over.
This isn't about the results, this isn't about the Robbie, this is about you maintaining a useless compulsion, to which if you did it yourself, leaving no "outs" to continue the arguement, would leave you dead in the water. And you just couldn't stand for that ....
Oh and thank you, I'm getting in 2 hours of 206 time later this week (the bets were for $500 each and my friends lost)
'nuff said, it's in print for all to read and form their own behavioural conclusions based upon what you say and do next with your respondants, but let's be clear about it ... And I have where the topic is concerned. All I have done here is place the burden on you, you seem not ot be able to accept it. Unfortunately, that only serves to weaken your position and standing, no matter how you choose to reply, either with a personal attack, or some other taunt designed to keep me in this arguement.
[This message has been edited by RW-1 (edited 18 March 2001).]
Flight controls free and correct. check 'em on ground, and do a slight cyclic wipe before bringing coll up for liftoff. No coupling.
>>I also don’t appreciate your stating that if the test was performed correctly and the feedback was contrary to my theory that I wouldn’t believe what I was told. <<
I don't CARE that you don't appreciate it.
You don't appreciate it because it is a true statement of fact.
If you go out and perform your test as you want it, test pilot or not, rigged or not, then you will eliminate ANY recorse available to you if you don't like the desired outcome of said test.
So it's easier for you to sit there and ask everyone else to do it, then you can defend the weak position until everyone is tires of hearing it.
Gee, what are you going to say to Nr Fairy and SPS when they report they did it as advertised, without the lateral movements you predict? Hmm ? My bet: you won't accept it, you will bring in another factor, or something they "Failed" to check, measure, or have blessed before doing it. (oh, sorry ... seems you are already off to that prediction already ...)
Quit telling others how to do it, and do it yourself.
IN SHORT: You like to leave an out for yourself, and you will never do the test yourself, because then you would not have that out. Game over.
This isn't about the results, this isn't about the Robbie, this is about you maintaining a useless compulsion, to which if you did it yourself, leaving no "outs" to continue the arguement, would leave you dead in the water. And you just couldn't stand for that ....
Oh and thank you, I'm getting in 2 hours of 206 time later this week (the bets were for $500 each and my friends lost)
'nuff said, it's in print for all to read and form their own behavioural conclusions based upon what you say and do next with your respondants, but let's be clear about it ... And I have where the topic is concerned. All I have done here is place the burden on you, you seem not ot be able to accept it. Unfortunately, that only serves to weaken your position and standing, no matter how you choose to reply, either with a personal attack, or some other taunt designed to keep me in this arguement.
[This message has been edited by RW-1 (edited 18 March 2001).]
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Lu,
Although I haven't put much into this subject it has been simmering away on my 'back burner' for a good while.
I read all of your posts on the matter thouroughly and gave it careful consideration over the last two months at least.
The development of your theory on the 18 deg. offset and the possible consequences when in a negative G situation appeared well founded and was well put over, logically explained.
The problem is that unless you can demonstrate it, prove it, it remains just that, a theory.
I have very carefully watched my cyclic grip whilst others are flying the a/c in all sorts of flight configurations and conditions
and did so with an open mind.
I have to say that I cannot find a shred of evidence to support your theory.
If I had, I'd have been 100% with you on it because I would dearly like to find a way to reduce the numbers of rotor separation occurrences with Robinson helicopters (and all others).
Your experience in Helicopter design is vast, invaluable to all in helicopter avaition and carries much weight. Don't mar it by continuing to worship a false idol now.
You don't even have to throw the theory away, but I think you'd be well advised to rest it a while until such time as you can prove otherwise.
With respect for your experience,
SPS
Although I haven't put much into this subject it has been simmering away on my 'back burner' for a good while.
I read all of your posts on the matter thouroughly and gave it careful consideration over the last two months at least.
The development of your theory on the 18 deg. offset and the possible consequences when in a negative G situation appeared well founded and was well put over, logically explained.
The problem is that unless you can demonstrate it, prove it, it remains just that, a theory.
I have very carefully watched my cyclic grip whilst others are flying the a/c in all sorts of flight configurations and conditions
and did so with an open mind.
I have to say that I cannot find a shred of evidence to support your theory.
If I had, I'd have been 100% with you on it because I would dearly like to find a way to reduce the numbers of rotor separation occurrences with Robinson helicopters (and all others).
Your experience in Helicopter design is vast, invaluable to all in helicopter avaition and carries much weight. Don't mar it by continuing to worship a false idol now.
You don't even have to throw the theory away, but I think you'd be well advised to rest it a while until such time as you can prove otherwise.
With respect for your experience,
SPS
Guest
Posts: n/a
Interesting NTSB report, particularly the statement from the FAA Flight Standards Division that "the R22 had no unusual flight characteristics when flown within the operating limitations" and the statement that "the R22 could pass a certification to MIL-H-8501A" (used by most western armed forces for flight test handling assessments).
I would also suggest that no test pilot would certify a helo that does not have acceptable handling qualities, which does include going in the direction of cyclic movement! (Don't argue that point as I know of one type that TPs refused to fly until modifications were made.)
If you disagree so much with the NTSB and the FAA Certification Test pilots, why not join them, or at least get some hours in to find out what constitutes normal flight characteristics in various types.
PS Lynx - Cyclic moves, disk follows, strangely enough.
I would also suggest that no test pilot would certify a helo that does not have acceptable handling qualities, which does include going in the direction of cyclic movement! (Don't argue that point as I know of one type that TPs refused to fly until modifications were made.)
If you disagree so much with the NTSB and the FAA Certification Test pilots, why not join them, or at least get some hours in to find out what constitutes normal flight characteristics in various types.
PS Lynx - Cyclic moves, disk follows, strangely enough.
Guest
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Lest this deteriorates into a repeat performance, I feel compelled tostick my neck out by indulging in my dictatorial powers.
Cheers
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Cheers
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You are welcome to visit HELIDRVR here
