R22 Corner
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Every now and then I follow the checklist in the flight manual, even though that seems like an odd habit..... It is based on the belief that the maker of the machine had some thoughts on the matter at hand.
Ever seen a flight manual that called for a mag cut shutdown?? I have not.
Ever seen a flight manual that called for a mag cut shutdown?? I have not.
Joined: Feb 2001
Posts: 103
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From: the other America
Thanks for the input & yeah Nick it's a bit of a funny habit to follow those pesky checklist (damn where did I leave it).
Also gotten the impression the Manufacturers have a clue as to how best operate the plant to best effect.
Hey by the way Nick I've just read the S92 checkflight (for about the 4th time) again recently. Love the bit where the chase van gets pushed into the ditch. Are you really that slender and sleek or was it the camera angle??????. .lol
Cheers & fly Safe. .Hone
Also gotten the impression the Manufacturers have a clue as to how best operate the plant to best effect.
Hey by the way Nick I've just read the S92 checkflight (for about the 4th time) again recently. Love the bit where the chase van gets pushed into the ditch. Are you really that slender and sleek or was it the camera angle??????. .lol
Cheers & fly Safe. .Hone
Joined: Dec 2000
Posts: 171
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From: midcoast US
I decided, why not ask those who know, so I emailed engineering at RHC. Gas_producer was spot on. Here's the note I received back:
"Hate to disappoint you but the answer is a lot simpler than your theories.. .The reason the pre-takeoff check was reduced to 75% was purely to reduce. .noise levels and be neighborly.. .Regards,. .Kurt Robinson"
Guess that means that if there aren't any nearby people to offend, Vorticey could keep doing mag checks at 104% afterall. <img src="smile.gif" border="0">
"Hate to disappoint you but the answer is a lot simpler than your theories.. .The reason the pre-takeoff check was reduced to 75% was purely to reduce. .noise levels and be neighborly.. .Regards,. .Kurt Robinson"
Guess that means that if there aren't any nearby people to offend, Vorticey could keep doing mag checks at 104% afterall. <img src="smile.gif" border="0">
Iconoclast
Joined: Sep 2000
Posts: 2,132
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From: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
At the risk of antagonizing everyone on this forum I add the following although I thought it might be better to add another thread. This won out so here goes.
In many of my posts I referenced under high flapping loads the blade tusk would contact the down stop and the kinetic energy would displace the blade much like a first class lever. With this displacement the rotorhead would most likely bump the mast or the blade would hit the fuselage.
Well, I was wrong. (pause for everyone to say we told you so)
Yes I was wrong because I only got it half right. What I thought about the tusk hitting the down stop and levering the blade was correct but what I did not consider was that if the tusk hit the stop one or two times it would fracture and then the blade is completely unrestrained relative to flapping limits. This information was provided offline by an engineering consultant who has participated in several court cases involving Robinson Helicopters.
So, now let’s consider the blade being unrestrained and the damage that can be done to the fuselage, mast bumping and the destruction of the blade itself. My source indicated that there are many conditions that would initiate flapping excursions over and above those covered in section 4 of the POH
In many of my posts I referenced under high flapping loads the blade tusk would contact the down stop and the kinetic energy would displace the blade much like a first class lever. With this displacement the rotorhead would most likely bump the mast or the blade would hit the fuselage.
Well, I was wrong. (pause for everyone to say we told you so)
Yes I was wrong because I only got it half right. What I thought about the tusk hitting the down stop and levering the blade was correct but what I did not consider was that if the tusk hit the stop one or two times it would fracture and then the blade is completely unrestrained relative to flapping limits. This information was provided offline by an engineering consultant who has participated in several court cases involving Robinson Helicopters.
So, now let’s consider the blade being unrestrained and the damage that can be done to the fuselage, mast bumping and the destruction of the blade itself. My source indicated that there are many conditions that would initiate flapping excursions over and above those covered in section 4 of the POH
Joined: Nov 2000
Posts: 452
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From: Vancouver, BC, Canada
Lu
From a couple of line drawings in the Robinson maintenance manual, it appears that the tusk on the inside end of the spindle will immediately fall off, if it fractures and if the metal is of a sufficient hardness. Have there been many accidents where the tusk was never found at the site of the copter?
. .Grey Area
I do not understand "an articulated head with no eccentricity". Would you be please elaborate, a little?
From a couple of line drawings in the Robinson maintenance manual, it appears that the tusk on the inside end of the spindle will immediately fall off, if it fractures and if the metal is of a sufficient hardness. Have there been many accidents where the tusk was never found at the site of the copter?
. .Grey Area
I do not understand "an articulated head with no eccentricity". Would you be please elaborate, a little?
Iconoclast
Joined: Sep 2000
Posts: 2,132
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From: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
To: Dave Jackson
Good question. I will ask my source but it will take a while as he told me he is going on a business trip. When he gets back I’ll ask him.
Good question. I will ask my source but it will take a while as he told me he is going on a business trip. When he gets back I’ll ask him.
Iconoclast
Joined: Sep 2000
Posts: 2,132
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From: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
A must read for Robie drivers
This should be required reading for all Robinson drivers and students.
<a href="http://www.ntsb.gov/Publictn/1996/SIR9603.pdf" target="_blank">http://www.ntsb.gov/Publictn/1996/SIR9603.pdf</a>
[ 06 February 2002: Message edited by: Lu Zuckerman ]</p>
<a href="http://www.ntsb.gov/Publictn/1996/SIR9603.pdf" target="_blank">http://www.ntsb.gov/Publictn/1996/SIR9603.pdf</a>
[ 06 February 2002: Message edited by: Lu Zuckerman ]</p>
Joined: Jun 2001
Posts: 251
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From: Australia
these accidents sound like pushover low"g" accidents to me. only one was done in a comercial op, other than instruction. its hard to learn to fly one, but i'd definately fly a 22 before a 47.. .i find a 47 harder to hover than a robbie, the power assistance and throttle are the trouble i think.
Joined: May 2001
Posts: 528
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From: London
That report has been around for seven years. Do you have a particular motivation in posting it now?. .It states quite clearly that efforts by RHC and the FAA to increase pilot awareness had had the desired effect, and that no design fault was apparent in the helicopter.. .It also, incidentally, pours a good deal of cold water on the Georgia Tech mathematical model that you keep wittering on about.. .Face it, Lu, you're on a loser.
Iconoclast
Joined: Sep 2000
Posts: 2,132
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From: The home of Dudley Dooright-Where the lead dog is the only one that gets a change of scenery.
To: T'aint Natural
What you say about the report being around for a long time and the actions taken by the FAA and Robinson is true. However, since that report was generated there have been at least seven rotor loss incidents and at least five of them in the last two years with two occurring in the UK. The FAA and Robinson still do not know what caused it so by inference, it was pilot error. I am trying to get an acquaintance to come on this forum and if he does, he can lay it all out so that everyone can understand exactly what happens and why it happens.
What you say about the report being around for a long time and the actions taken by the FAA and Robinson is true. However, since that report was generated there have been at least seven rotor loss incidents and at least five of them in the last two years with two occurring in the UK. The FAA and Robinson still do not know what caused it so by inference, it was pilot error. I am trying to get an acquaintance to come on this forum and if he does, he can lay it all out so that everyone can understand exactly what happens and why it happens.
Joined: Jan 2002
Posts: 25
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From: northampton
T'AINT NATURAL
The report might have been around for seven years, but how many people have started flying during the last seven years that havn't seen this report?? Surely if any of these more recent pilots have ready access to this information and can learn just one fact it might one day save their lives!!!. .Any way do you have a reason to keep it coverd up?
The report might have been around for seven years, but how many people have started flying during the last seven years that havn't seen this report?? Surely if any of these more recent pilots have ready access to this information and can learn just one fact it might one day save their lives!!!. .Any way do you have a reason to keep it coverd up?
Joined: Jun 1999
Posts: 216
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From: by the seaside
HALF A PILOT
Maybe you do not realize that Lu does not bring this to your attention to help you learn and enjoy but rather to boost his cause that the Robinson aircraft is a dangerous aircraft and should not be flying.
I don't think that t'aint natural has anything against the information being published only that Lu didn't trumpet it as new information against the Robinson.
Information contained within this document is covered within your helicopter training and if you ask your instructor he should be only too happy to discuss this with you.
[ 09 February 2002: Message edited by: Rotorbike ]</p>
Maybe you do not realize that Lu does not bring this to your attention to help you learn and enjoy but rather to boost his cause that the Robinson aircraft is a dangerous aircraft and should not be flying.
I don't think that t'aint natural has anything against the information being published only that Lu didn't trumpet it as new information against the Robinson.
Information contained within this document is covered within your helicopter training and if you ask your instructor he should be only too happy to discuss this with you.
[ 09 February 2002: Message edited by: Rotorbike ]</p>
Joined: May 2001
Posts: 528
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From: London
The report is not secret, never has been, and if you read it in full you'll find that it casts no aspersions on the Robinson at all. A deft misrepresentation of it, however, larded with selective and out-of-context phrases, can be used to fuel the obsessions of those to whose bait I should not rise.. .Robinsons now comprise half the fleet and do more than half the hours. They have fewer than half the accidents and far fewer than half the fatalities, despite the uses to which they are put and the lack of experience of the majority of their pilots.. .Damn, I promised myself I wouldn't get involved in this...
Joined: Nov 2000
Posts: 452
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From: Vancouver, BC, Canada
Dynamics ~ The opposite of Robinson
It has been said that the Robinson has an additional pair of hinges in the rotor hub so that the rotor assembly will weigh less. This has caused some to question the amount of control that is available.. .. .As an idea for consideration, what about the opposite. Give the teetering rotor an amount of rigidity?. .. .What about a teetering rotor hub that is conventional Bell, except that it has a 'spring' device at the teetering hinge. This device attempts to return the rotor disk to its mean position (normal to the mast) when the disk is tipped. This centering device can only impart a small amount of force, but it may result in;. .. .Pros: </font><ol type="1">[*]<font size="2" face="Verdana, Arial, Helvetica"> Faster responses by the helicopter to cyclic inputs. </font></li>[*]<font size="2" face="Verdana, Arial, Helvetica"> A reduced tendency for blade incursion into the tail boom, when the rotor-disk is unloaded. </font></li>[*]<font size="2" face="Verdana, Arial, Helvetica"> No need for droop stops. . .</font></li>[/list=a]<font size="2" face="Verdana, Arial, Helvetica">Cons: </font><ol type="1">[*]<font size="2" face="Verdana, Arial, Helvetica"> The blades, hub, feathering bearings and mast must be slightly stronger and heavier.. .</font></li>[/list=a]<font size="2" face="Verdana, Arial, Helvetica"><img border="0" title="" alt="[Eek!]" src="eek.gif" /> Posted to RAR as well, to see where the 'technicos' reside. <img border="0" title="" alt="[Wink]" src="wink.gif" />
