R22 Corner
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I'll endorse RotorHorn's comments on Dick Sandford's 1-day safety course. (I seem to remember it being a 2 day thing if you include some flying). Well worth the money! Dick even got me experiencing Rotor-Stall! Yes, we demo'd it, and it was quite sudden & dramatic, even in my '44. OK - don't panic, we were carefully placed in a nice steady 6-inch hover over grass!
...and as for the comments about dumping the lever the second you hear the horn, I'll go for that too.
However, I still remember when I did SFH in a '44 at Cranfield, and the darned thing had a RadAlt, with the threshhold set at 500 feet. So, every time I'm coming on finals, calling on the radio, looking for other a/c, final checks & really busy etc. off goes this horn thingy at 500 ft. Got me every time! Jumped out of my skin & had to override the instinctive desire to dump the lever!
Then again, I suppose I shouldn't complain. I got into this flying thing because it was exciting in the first place! ;-)
Holly_Copter
...and as for the comments about dumping the lever the second you hear the horn, I'll go for that too.
However, I still remember when I did SFH in a '44 at Cranfield, and the darned thing had a RadAlt, with the threshhold set at 500 feet. So, every time I'm coming on finals, calling on the radio, looking for other a/c, final checks & really busy etc. off goes this horn thingy at 500 ft. Got me every time! Jumped out of my skin & had to override the instinctive desire to dump the lever!
Then again, I suppose I shouldn't complain. I got into this flying thing because it was exciting in the first place! ;-)
Holly_Copter
I described the situation on the checkride AR, not to show that I'm a fool or a hero of the skys. One of the advantages of this board is to share experiences and opinions. Sometimes it's normally that we discuss some points from a different view and stand.
I described the checkride AR to show some problems you can encounter on an AR entry. Due to the high pitch climb we had a rapidly decreasing NR and IAS. I have made some hundreds of 206 AR's. There is so much difference between an AR entry on level flight (or on descent) with an IAS >> Vy and the described procedure. Rolling the engine to idle on level with good speed is on a 206 really unimpressive. You can count up to 10 and watch with interest the decreasing NR. Pitch down, a slight flare and everything is under control. NR is good, go for the best speed, control the the glide with speed and NR to reach the best landing site. With enough speed it's easy to recover NR. NR drop depends on flight conditions!!!
Skidbiter is right: "a low-inertia rotor is easier to recover" and this an advantage for the R22, compared to other helicopters. But you need speed to flare! And a low inertia rotor is allways tricky on the AR touch down.
Complete real power failure is definitivly other than on practise. Fuel system decelleration time, rest idle power (17hp c20) helps. Look on the h-v diagramm. Why is 300-500 ft with low speed dangerous? It's no problem on an established AR to glide with zero (or negative) speed to reach the best landing site if you have enough altitude to recover the speed for the touch down flare. (the flare decrease the descending rate and gives som extra MR rounds) Needs not so much time. But on this situation you have an established AR and full a/c control! On the AR entry transition with a decreasing NR and low speed it needs much more time. It takes some seconds to come into the AR airflow with additionally bad a/c control. With a very high descend rate on low speed and no effective flare it's not enough rotor inertia available for a smooth touch down.
OK back to R-22: Due to the very low inertia it's clear to get a big NR drop. But as said, relative easy to recover if enough speed is available. Immediately lower the pitch and flare for NR. If you have not enough speed or / and altitude to recover NR, good luck.
I described the checkride AR to show some problems you can encounter on an AR entry. Due to the high pitch climb we had a rapidly decreasing NR and IAS. I have made some hundreds of 206 AR's. There is so much difference between an AR entry on level flight (or on descent) with an IAS >> Vy and the described procedure. Rolling the engine to idle on level with good speed is on a 206 really unimpressive. You can count up to 10 and watch with interest the decreasing NR. Pitch down, a slight flare and everything is under control. NR is good, go for the best speed, control the the glide with speed and NR to reach the best landing site. With enough speed it's easy to recover NR. NR drop depends on flight conditions!!!
Skidbiter is right: "a low-inertia rotor is easier to recover" and this an advantage for the R22, compared to other helicopters. But you need speed to flare! And a low inertia rotor is allways tricky on the AR touch down.
Complete real power failure is definitivly other than on practise. Fuel system decelleration time, rest idle power (17hp c20) helps. Look on the h-v diagramm. Why is 300-500 ft with low speed dangerous? It's no problem on an established AR to glide with zero (or negative) speed to reach the best landing site if you have enough altitude to recover the speed for the touch down flare. (the flare decrease the descending rate and gives som extra MR rounds) Needs not so much time. But on this situation you have an established AR and full a/c control! On the AR entry transition with a decreasing NR and low speed it needs much more time. It takes some seconds to come into the AR airflow with additionally bad a/c control. With a very high descend rate on low speed and no effective flare it's not enough rotor inertia available for a smooth touch down.
OK back to R-22: Due to the very low inertia it's clear to get a big NR drop. But as said, relative easy to recover if enough speed is available. Immediately lower the pitch and flare for NR. If you have not enough speed or / and altitude to recover NR, good luck.
Last edited by tecpilot; 12th Jul 2002 at 21:32.
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Last edited by Dave Jackson; 12th Jul 2002 at 21:36.
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All very nice to have that (relatively) big 206 blade whopping away with bags of inertia, but the R22's fatal accident rate in the UK between 1992 and 1999 (about one per 115,000 hours) was much better than the 206s (about one per 40,000 hours) and part of the reason was the fact that that big blade often comes whopping in the window in otherwise survivable crashes. (Figures relate to fatal accidents, not persons killed.)
And as yet I've had no replies to the question I asked in my first post on this thread. Does anyone know of an engine failure in an R22 that was not caused by fuel or oil starvation, or carb heat mismanagement? (With the exception of the pilot's coat incident mentioned above).
And as yet I've had no replies to the question I asked in my first post on this thread. Does anyone know of an engine failure in an R22 that was not caused by fuel or oil starvation, or carb heat mismanagement? (With the exception of the pilot's coat incident mentioned above).
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Apples and Oranges
To: T'aint
When you compare the fatalities associated with different helicopter types you should zone in on a specific type of accident. It is suggested that you read the NTSB report contained in Dave Jackson’s’ post above as it deals with loss of rotor control, mast bumping and/or rotor incursion.
Bell has suffered many mast bumping incidents and most of them occurred prior to the US Army discovering the cause. Bells have suffered probably no more than 60 rotor loss incidents since the introduction of the two-blade rotor system. I may be off a bit regarding the total incidents covered in the NTSB reports but I believe it is around 18 or more. Since the report was written and the introduction of AD 95-26-04 at least five more incidents have occurred and several of those were in the UK and Ireland.
Now compare the number of flight hours for both helicopters and divide those hours by the number of rotor loss incidents. The Robinson still comes off with the higher ratio.
Now for something that you may not have been aware of is what is acceptable.
When the Apache was designed the Army indicated that it was acceptable to have a single point failure or some defective procedure among other things that would result in the loss of an aircraft every 34,000 hours of collective flight hours.
If an aircraft is designed in accordance with FAA AC-25-1309-1A the frequency of suffering a catastrophic loss of an aircraft and crew is based on system or component reliability. The acceptable rate of system failure due to a single point failure or induced system failure is 1 10 9 or one time in a billion hours of collective fleet operation. There is no aircraft design at present that has ever met that design requirement and that includes 747s and R-22s.
When you compare the fatalities associated with different helicopter types you should zone in on a specific type of accident. It is suggested that you read the NTSB report contained in Dave Jackson’s’ post above as it deals with loss of rotor control, mast bumping and/or rotor incursion.
Bell has suffered many mast bumping incidents and most of them occurred prior to the US Army discovering the cause. Bells have suffered probably no more than 60 rotor loss incidents since the introduction of the two-blade rotor system. I may be off a bit regarding the total incidents covered in the NTSB reports but I believe it is around 18 or more. Since the report was written and the introduction of AD 95-26-04 at least five more incidents have occurred and several of those were in the UK and Ireland.
Now compare the number of flight hours for both helicopters and divide those hours by the number of rotor loss incidents. The Robinson still comes off with the higher ratio.
Now for something that you may not have been aware of is what is acceptable.
When the Apache was designed the Army indicated that it was acceptable to have a single point failure or some defective procedure among other things that would result in the loss of an aircraft every 34,000 hours of collective flight hours.
If an aircraft is designed in accordance with FAA AC-25-1309-1A the frequency of suffering a catastrophic loss of an aircraft and crew is based on system or component reliability. The acceptable rate of system failure due to a single point failure or induced system failure is 1 10 9 or one time in a billion hours of collective fleet operation. There is no aircraft design at present that has ever met that design requirement and that includes 747s and R-22s.
I must disagree with the 'dump the lever when you hear the horn regardless' argument. Awareness of an engine failure should be from the change in noise of the engine/sudden yaw/Nr sound changing - with the final clue being the Nr horn.
Suppose you inadvertantly let the Nr decay in the hover and the horn goes off - if you are conditioned (as many are) to slam the lever down in a Pavlovian response to the noise then you are going to hit the ground hard and probably roll over. I know because this is exactly what an owner with 150 hours on type did to me - the aircraft went back to California in a box, fortunately we didn't.
Listen to the aircraft and get used to the noises it makes, it might just save your life one day.
Suppose you inadvertantly let the Nr decay in the hover and the horn goes off - if you are conditioned (as many are) to slam the lever down in a Pavlovian response to the noise then you are going to hit the ground hard and probably roll over. I know because this is exactly what an owner with 150 hours on type did to me - the aircraft went back to California in a box, fortunately we didn't.
Listen to the aircraft and get used to the noises it makes, it might just save your life one day.
I like that analogy Crab - the pilot (dog) responding to the horn (bell).
But isn't it important to have second-nature reactions to certain emergency situations? What I mean is that you would hear the horn and immediately react to instinctively lower the lever, BUT this reaction is mitigated by logic based upon the particular situation - i.e. engine failure in the hover, don't dump the lever.
But isn't it important to have second-nature reactions to certain emergency situations? What I mean is that you would hear the horn and immediately react to instinctively lower the lever, BUT this reaction is mitigated by logic based upon the particular situation - i.e. engine failure in the hover, don't dump the lever.
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Lu:
May I refer you to all my previous posts whenever you've jumped on your hobby horse and started playing your one-note tune. May I further suggest that you (a) get a pilot's licence and (b) design something that flies.
May I refer you to all my previous posts whenever you've jumped on your hobby horse and started playing your one-note tune. May I further suggest that you (a) get a pilot's licence and (b) design something that flies.
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I take Crab's point entirely. When I made my post I was thinking about all those 1500ft straight & level hours I've flown in Robbo's. Of course, in the hover the reaction should be somewhat different (pretty much the opposite, as far as the lever's concerned). Squiffy makes the "Consider the situation" point very well.
Did my R44 renewal this week, and the examiner was, co-incidently, the guy who taught me to fly & we've flown together many times around Europe since so we're very tuned in to each other. I think that's why several un-announced (Well, very late announced ;-) throttle-chops were included to sharpen my skills!
Feels different when it's your own aircraft too, I can tell you!
Holly_Copter
Did my R44 renewal this week, and the examiner was, co-incidently, the guy who taught me to fly & we've flown together many times around Europe since so we're very tuned in to each other. I think that's why several un-announced (Well, very late announced ;-) throttle-chops were included to sharpen my skills!
Feels different when it's your own aircraft too, I can tell you!
Holly_Copter
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R22 Accident Analysis 1979-1994
Most of you interested in R22s will probably have run across this at some stage but I'm posting it here for Luoto who expressed an interest in R22 safety in another thread .
http://www.cybercom.net/~copters/mec..._analysis.html
Hope it's useful.
Irlandés
http://www.cybercom.net/~copters/mec..._analysis.html
Hope it's useful.
Irlandés
Iconoclast
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With a grain of salt
To: Irlandes
The crash analysis report you posted should be taken with a grain of salt. It first appeared on the website of a Robinson dealer in Connecticut, USA and is slanted in support of the Robinson design.
If you want to know the true facts log on to http://www.ntsb.gov/publictn/1996/SIR9603.pdf
This is the NTSBs analysis of all of the loss of rotor control accidents up to the date of publication.
The crash analysis report you posted should be taken with a grain of salt. It first appeared on the website of a Robinson dealer in Connecticut, USA and is slanted in support of the Robinson design.
If you want to know the true facts log on to http://www.ntsb.gov/publictn/1996/SIR9603.pdf
This is the NTSBs analysis of all of the loss of rotor control accidents up to the date of publication.
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UK helicopter accident stats for the period 1992 to 1999 were collated by PLH Associates in 2001 from CAA maintenance returns. They showed that while the Robinson R22 now constitutes more than half the UK single-engine fleet, it accounts for far less than half of all accidents - despite the fact that it is used in the most accident-prone pursuits, like ab initio training and low-time self-fly hire. It recorded one fatal accident for every 115,000 hours. Only the single Squirrel performed better.
Despite the monotonous bell-tolling of the monomaniac Zuckerman, or the chauvinism of those too numerous to mention who have never flown Robinsons but who are only too happy to give up the benefit of their experience of the type here on pprune, the R22 remains one of the safest helicopters in the air. Don't take a lend of it and it won't let you down.
There are sound reasons why the R22 outnumbers all the others put together, and why its numbers to continue to rise in proportion to the rest.
Despite the monotonous bell-tolling of the monomaniac Zuckerman, or the chauvinism of those too numerous to mention who have never flown Robinsons but who are only too happy to give up the benefit of their experience of the type here on pprune, the R22 remains one of the safest helicopters in the air. Don't take a lend of it and it won't let you down.
There are sound reasons why the R22 outnumbers all the others put together, and why its numbers to continue to rise in proportion to the rest.
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Back to the fruit stand.
To: t'aint
Quote: the R22 remains one of the safest helicopters in the air. Don't take a lend of it and it won't let you down.
Response: Once again you are comparing apples to oranges. Maybe by your statistics the Robinson is the safest helicopter flying in the UK. However if you consider that there have been at least five rotor incursion, rotor loss, mast bumping incidents on Robinson’s in the UK in the last four years compare that to the number of other helicopters that have suffered loss of rotor control in that same time period. In order to keep this accident rate down the aircraft must be flown with limitations on its’ flight characteristics. There are not many other helicopters that have these draconian limitations placed upon them.
Quote: There are sound reasons why the R22 outnumbers all the others put together, and why its numbers to continue to rise in proportion to the rest.
Response: I can only think of one and that is its’ price. You will please note that in all of the comments I have made relative to the safety of the Robinson design I never attacked its’ reliability. To my knowledge there has only been one accident due to the failure of a part. Discount very early rotor blade failures.
If everything is done correctly in the design of the aircraft then safety is maintained by engineering. In the case of the R-22 R-44 the operator at the controls is the final control of safety and the manufacturer absolves themselves by placing suggested restrictions on the operation of the aircraft.
Quote: the R22 remains one of the safest helicopters in the air. Don't take a lend of it and it won't let you down.
Response: Once again you are comparing apples to oranges. Maybe by your statistics the Robinson is the safest helicopter flying in the UK. However if you consider that there have been at least five rotor incursion, rotor loss, mast bumping incidents on Robinson’s in the UK in the last four years compare that to the number of other helicopters that have suffered loss of rotor control in that same time period. In order to keep this accident rate down the aircraft must be flown with limitations on its’ flight characteristics. There are not many other helicopters that have these draconian limitations placed upon them.
Quote: There are sound reasons why the R22 outnumbers all the others put together, and why its numbers to continue to rise in proportion to the rest.
Response: I can only think of one and that is its’ price. You will please note that in all of the comments I have made relative to the safety of the Robinson design I never attacked its’ reliability. To my knowledge there has only been one accident due to the failure of a part. Discount very early rotor blade failures.
If everything is done correctly in the design of the aircraft then safety is maintained by engineering. In the case of the R-22 R-44 the operator at the controls is the final control of safety and the manufacturer absolves themselves by placing suggested restrictions on the operation of the aircraft.
T'aint natural: Thanks for that, I am sure the recorded stats speak for themselves. However, this does throw up an anomoly:
Read the NTSB report, it is in direct opposition to your sourced findings. R22 use in the States far exceeds UK usage. It is classified as a high risk helo in the US.
I suspect the statement "one of the safest helicopters".... is your personal opinion and not fact.
I also suspect the real reason why the R22 has taken to the air in disproportionately large numbers, is simply because of one fact: COST, and nothing else.
One doesn't have to be an R22 pilot to be aware that there is something strange surrounding the track record of R22's. The R44 doesn't seem to be cursed with the same problems. [You don't have to be a reliant robin driver to have an understanding of its shortfalls].
There is most definitely a problem with the R22 picture, it is either:
1. Badly designed.
2. Very unforgiving.
3. Very dangerous in the wrong hands (inexperienced pilots).
As far as the yanks are concerned, it seems No3 is the culprit.
Read the NTSB report, it is in direct opposition to your sourced findings. R22 use in the States far exceeds UK usage. It is classified as a high risk helo in the US.
I suspect the statement "one of the safest helicopters".... is your personal opinion and not fact.
I also suspect the real reason why the R22 has taken to the air in disproportionately large numbers, is simply because of one fact: COST, and nothing else.
One doesn't have to be an R22 pilot to be aware that there is something strange surrounding the track record of R22's. The R44 doesn't seem to be cursed with the same problems. [You don't have to be a reliant robin driver to have an understanding of its shortfalls].
There is most definitely a problem with the R22 picture, it is either:
1. Badly designed.
2. Very unforgiving.
3. Very dangerous in the wrong hands (inexperienced pilots).
As far as the yanks are concerned, it seems No3 is the culprit.
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Thomas Coupling:
I don't want to go over this in nauseating detail again, but let's put in the bare bones. The NTSB report is not new, and pertains to a time before changes in procedures, mostly driven by Frank Robinson himself with his safety courses, his insurance arrangements, his demands of the FAA and his requirements of pilots.
Back then, the Robinson massively increased the number of civilian helicopter pilots and the number of low-time pilots. As a result, quality of piloting was poor, and the accident rate in the US was high. The situation was exacerbated by the 50-hour rule, which held that any fixed-wing instructor who had 50 hours rotary time could open up the boot of his car and set up shop as a helicopter instructor. Frank Robinson petitioned the FAA time and time again to have that rule rescinded, to ensure that only qualified helicopter instructors could instruct on helicopters. Sounds logical, doesn't it.
Any two-bladed rotor is unforgiving of low-G. The Army taught Vietnam-era pilots how to avoid getting into low-G problems in the UH-1 and others. Robinson didn't invent the two-bladed rotor, and he didn't invent low-G. Knowledge of how to recognise the problem and avoid turning it into an accident is fundamental to good instruction - unless, of course, you're a fixed-wing instructor who just happens to have 50 hours rotary time.
The R22, and later the R44 - which despite your post displays far worse low-G characteristics than the R22 - has always suffered from the attempts of other manufacturers to do it down. I attended the Paris air show some years ago with representatives of a major US helicopter manufacturer who made no bones about the fact that, especially since Robinson was producing the R44 "which aims to eat our lunch" he was a target. In the main they have made a good job of spreading fear and uncertainty about the R22, which by its performance, its reliability and its excellent safety record has nonetheless answered all critics.
As to your assertion that cost is the only reason why the R22 now outnumbers all other singles put together - don't be so bloody stupid. The R22 is bought by pilots who don't give a damn about costs, where their safety is concerned. If your claim were true, the sky would be black with RotorWays. Many cheaper helicopters have come and gone, so don't talk drivel.
Lu Zuckerman's got stuck in a groove that he can't get out of, despite his arguments having been comprehensively destroyed time and time again in this forum by authorities on rotor design and high-time pilots. He has long since blown his credibility on the Robinson, and anything he says about Robinson can safely be disregarded. Look at the facts, and don't just recycle the taproom prattle.
I don't want to go over this in nauseating detail again, but let's put in the bare bones. The NTSB report is not new, and pertains to a time before changes in procedures, mostly driven by Frank Robinson himself with his safety courses, his insurance arrangements, his demands of the FAA and his requirements of pilots.
Back then, the Robinson massively increased the number of civilian helicopter pilots and the number of low-time pilots. As a result, quality of piloting was poor, and the accident rate in the US was high. The situation was exacerbated by the 50-hour rule, which held that any fixed-wing instructor who had 50 hours rotary time could open up the boot of his car and set up shop as a helicopter instructor. Frank Robinson petitioned the FAA time and time again to have that rule rescinded, to ensure that only qualified helicopter instructors could instruct on helicopters. Sounds logical, doesn't it.
Any two-bladed rotor is unforgiving of low-G. The Army taught Vietnam-era pilots how to avoid getting into low-G problems in the UH-1 and others. Robinson didn't invent the two-bladed rotor, and he didn't invent low-G. Knowledge of how to recognise the problem and avoid turning it into an accident is fundamental to good instruction - unless, of course, you're a fixed-wing instructor who just happens to have 50 hours rotary time.
The R22, and later the R44 - which despite your post displays far worse low-G characteristics than the R22 - has always suffered from the attempts of other manufacturers to do it down. I attended the Paris air show some years ago with representatives of a major US helicopter manufacturer who made no bones about the fact that, especially since Robinson was producing the R44 "which aims to eat our lunch" he was a target. In the main they have made a good job of spreading fear and uncertainty about the R22, which by its performance, its reliability and its excellent safety record has nonetheless answered all critics.
As to your assertion that cost is the only reason why the R22 now outnumbers all other singles put together - don't be so bloody stupid. The R22 is bought by pilots who don't give a damn about costs, where their safety is concerned. If your claim were true, the sky would be black with RotorWays. Many cheaper helicopters have come and gone, so don't talk drivel.
Lu Zuckerman's got stuck in a groove that he can't get out of, despite his arguments having been comprehensively destroyed time and time again in this forum by authorities on rotor design and high-time pilots. He has long since blown his credibility on the Robinson, and anything he says about Robinson can safely be disregarded. Look at the facts, and don't just recycle the taproom prattle.
We have heard from certain "one trick ponies" ad-nauseum about the "dangerous" Robbo, and numerous snipes from those who haven't flown it at all. We have also heard from those who currently fly and admire the Robbo.
I would really like to hear from experienced drivers who have flown a few different types as well as logged significant time in the Robbo. I know they are out there!
I would really like to hear from experienced drivers who have flown a few different types as well as logged significant time in the Robbo. I know they are out there!