Cairns Helicopter Crash
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I read Brian Abraham's post with great interest. I have not read Nick Lappos's article on LTE but I get the drift that LTE is a design problem and not pilot error. Where can I find this article ?
I have done a lot of research on LTE and the literature seems to be divided into two camps: some say the tail rotor stalls in an LTE but others say it doesn't. Which is correct ?
If Brain cannot help, can Mr Lappos or anyone else enlighten me ? Thanks in advance.
I have done a lot of research on LTE and the literature seems to be divided into two camps: some say the tail rotor stalls in an LTE but others say it doesn't. Which is correct ?
If Brain cannot help, can Mr Lappos or anyone else enlighten me ? Thanks in advance.
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ATSB Report Released
AO-2008-043
Di 
(Abstract)At 1026 Eastern Standard Time on 18 June 2008, a Robinson Helicopter Company R44 Clipper II helicopter, registered VH-RYW, departed Cairns Airport, Qld, to film a residential development site that was located in the vicinity of False Cape, about 10 km east of the airport. On board the helicopter were the pilot and three passengers.
The occupants of the helicopter reported that while conducting the second period of filming, there was a sudden and violent movement of the nose of the helicopter to the right, which continued into a rapid rotation of the helicopter. The pilot's reported attempt to reduce the rate of right yaw was unsuccessful, and he entered autorotation and attempted to reach a clear area. The helicopter subsequently collided with trees before impacting the ground, seriously injuring the pilot and front seat passenger.
This accident highlighted the risk of loss of tail rotor effectiveness associated with the conduct of aerial filming/photography and other similar flights involving high power, low forward airspeed and the action of adverse airflow on a helicopter.
The investigation also identified that the lack of the nomination of a search and rescue or scheduled reporting time for the flight, decreased the likelihood of a timely response in the case of an emergency.
In response to this accident, the helicopter manufacturer advised that it was considering a revision to the aerial survey and photography flights safety notice that was contained in the R44 Pilot's Operating Handbook. That revision would, if adopted, include a discussion of the risk of unanticipated right yaw associated with the conduct of those flights.
The occupants of the helicopter reported that while conducting the second period of filming, there was a sudden and violent movement of the nose of the helicopter to the right, which continued into a rapid rotation of the helicopter. The pilot's reported attempt to reduce the rate of right yaw was unsuccessful, and he entered autorotation and attempted to reach a clear area. The helicopter subsequently collided with trees before impacting the ground, seriously injuring the pilot and front seat passenger.
This accident highlighted the risk of loss of tail rotor effectiveness associated with the conduct of aerial filming/photography and other similar flights involving high power, low forward airspeed and the action of adverse airflow on a helicopter.
The investigation also identified that the lack of the nomination of a search and rescue or scheduled reporting time for the flight, decreased the likelihood of a timely response in the case of an emergency.
In response to this accident, the helicopter manufacturer advised that it was considering a revision to the aerial survey and photography flights safety notice that was contained in the R44 Pilot's Operating Handbook. That revision would, if adopted, include a discussion of the risk of unanticipated right yaw associated with the conduct of those flights.
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Diatryma, thanks for the belated but nonetheless interesting response to my post over a year ago. I note the date of the report is Dec 2009 while the date of the last revision to the POH was Apr 2009. Is there going to be yet another revision to the last amendment before another R44 pilot bites the dust ?
http://www.robinsonheli.com/srvclib/rchsn34.pdf
http://www.robinsonheli.com/srvclib/rchsn34.pdf
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RF, forgive me for I missed your long past request. A google of "loss tail rotor effectiveness" will throw up any number of hits. This may be of use
Helicopter Safety | Loss of Tail Rotor Effectiveness [LTE]
Helicopter Safety | Loss of Tail Rotor Effectiveness [LTE]
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RF, forgive me for I missed your long past request. A google of "loss tail rotor effectiveness" will throw up any number of hits. This may be of use
Helicopter Safety | Loss of Tail Rotor Effectiveness [LTE]
Helicopter Safety | Loss of Tail Rotor Effectiveness [LTE]
But there seems to be a certain smugness about the outcome as reported.
Even though I have a fairly strong feeling that it was statements on this thread which injected a certain amount of enthusiasm to ATSB to get off their butt and go look, so to speak.
Now, for the sake of newbies, and many others who do not usually delve into low level maneuvres reading these columns, it may be best if it was quantified.
There is no doubt that the hapless driver may have invoked the wrath of the VRS on his T/R given the data as presented. BUT, that is no reason to crash a perfectly serviceable helicopter, even from as low as fifty feet above the terrain when it is induced.
One also needs to be careful in examining the stated wind flow ( which from experience I can say is the usual doctor around those parts) but with the surface interference of yon great hill may have been somewhat changed?
I certainly challenged the author of the OZ Paper many years ago to demonstrate to me this massive nightmare inducing phobia - LTE - as reported in his paper, just after he had published it. Result, no show.
For his benefit I have been able to induce such circumstance a bare handful of times of many years trying, so it can be done, by god. That's for sure, but I never crashed a machine doing it, Eh.
However before I go further into the analysis which I will not tonight, let me just portray one fact from the investigation. "there was a sudden yaw to the right"
For everyone's sake and opportunity to contradict it, I will say that a "sudden yaw" can only emanate from one of two causes.
1) T/R drive from the engine has gone AWOL
2) VRS of the T/R.
Overpitching, will initially only produce a slowly increasing yaw. Agreed?
Cheers tet
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There seems to be a bit of a Cool Kat ambience on this thread saying that - of course it was LTE
LTE;
Lack of Technical Education,
Lack of Training for the Environment,
or simply
Lackadasial Transient Enzyme.
Lack of Technical Education,
Lack of Training for the Environment,
or simply
Lackadasial Transient Enzyme.
that is no reason to crash a perfectly serviceable helicopter, even from as low as fifty feet above the terrain when it is induced
Overpitching, will initially only produce a slowly increasing yaw. Agreed?
Last edited by Brian Abraham; 12th Dec 2009 at 23:28.
The following is pulled from another thread fixated on LTE: B206 You tube crash
I have trawled the previous threads on the LTE issue and have posted the following summary for future reference. It is made up from the previous work of three authors, Nick Lappos, Arm out the Window and myself. Thanks/apologies to Nick and AOTW!
If you see the sections on recovery techniques and the contrasting symptoms, you might understand why the distinction is very important and why mis-labelling the issue is dangerous.
Here goes:
Loss of tail rotor control: You are not able to control the tail rotor pitch mechanism - it is a true emergency. This could be a stuck control (left pedal, right pedal, or centre) or it can be a total loss of thrust (broken drive shaft or gear box). It can occur on any helo, but is relatively rare. Part of the training on every helo.
Loss of tail rotor effectiveness (LTE): "Newly" discovered and named in the 80's after many accidents - in particular OH-58/B206 model, and is the cause of a significant percentage of those model's accidents. Although somewhat awkwardly named (as the tail rotor is still effectively working and must be providing thrust) LTE refers to what is thought to be an ingestion of main or tail rotor vorticey through the tail rotor which causes a rapid onset of yaw in the direction induced by torque that cannot be overcome by the application of full "power pedal". The yaw rotation is typically high and can build up quickly enough to fool most pilots into believing they have experienced a loss of tail rotor thrust.! It forces a loss of directional control while inside the normal envelope.
It is prevented by using very conservative flying techniques, and preparing recovery escape manoeuvres, or by re-designing the tail rotor to assure adequate thrust. The typical LTE involves an approach to a spot with moderate cross wind, and a loss of yaw control when the approach is terminated near the hover. Once entered, recovery is very difficult without descending, often ground contact is unavoidable.
Loss of Tail Rotor Authority (LTA): In this situation, the tail rotor does not produce enough thrust to counteract the torque/crosswind combination you require, your power pedal hits the stop, and around you go - though gently when compared to LTE or total loss of thrust. LTA can occur on almost any helicopter when operated outside its normal envelope, typically when the rotor rpm is abused, or when very high torque is demanded. It is a symptom of mishandling the RRPM or Torque, not a separate cause.
It is prevented by pre planning weight/DA/power demands and carefully managing RRPM. Typical LTA events involve a takeoff or landing when the helicopter hits its engine topping, and the rotor rpm droops below the green arc, and subsequent Torque reaction overcoming the reduced tail rotor thrust even at max (maximum power pedal applied) causing a loss of yaw control. Recovery often can be made by lowering collective to recover rpm without significant descent, so that ground contact is often avoidable.
I have trawled the previous threads on the LTE issue and have posted the following summary for future reference. It is made up from the previous work of three authors, Nick Lappos, Arm out the Window and myself. Thanks/apologies to Nick and AOTW!
If you see the sections on recovery techniques and the contrasting symptoms, you might understand why the distinction is very important and why mis-labelling the issue is dangerous.
Here goes:
Loss of tail rotor control: You are not able to control the tail rotor pitch mechanism - it is a true emergency. This could be a stuck control (left pedal, right pedal, or centre) or it can be a total loss of thrust (broken drive shaft or gear box). It can occur on any helo, but is relatively rare. Part of the training on every helo.
Loss of tail rotor effectiveness (LTE): "Newly" discovered and named in the 80's after many accidents - in particular OH-58/B206 model, and is the cause of a significant percentage of those model's accidents. Although somewhat awkwardly named (as the tail rotor is still effectively working and must be providing thrust) LTE refers to what is thought to be an ingestion of main or tail rotor vorticey through the tail rotor which causes a rapid onset of yaw in the direction induced by torque that cannot be overcome by the application of full "power pedal". The yaw rotation is typically high and can build up quickly enough to fool most pilots into believing they have experienced a loss of tail rotor thrust.! It forces a loss of directional control while inside the normal envelope.
It is prevented by using very conservative flying techniques, and preparing recovery escape manoeuvres, or by re-designing the tail rotor to assure adequate thrust. The typical LTE involves an approach to a spot with moderate cross wind, and a loss of yaw control when the approach is terminated near the hover. Once entered, recovery is very difficult without descending, often ground contact is unavoidable.
Loss of Tail Rotor Authority (LTA): In this situation, the tail rotor does not produce enough thrust to counteract the torque/crosswind combination you require, your power pedal hits the stop, and around you go - though gently when compared to LTE or total loss of thrust. LTA can occur on almost any helicopter when operated outside its normal envelope, typically when the rotor rpm is abused, or when very high torque is demanded. It is a symptom of mishandling the RRPM or Torque, not a separate cause.
It is prevented by pre planning weight/DA/power demands and carefully managing RRPM. Typical LTA events involve a takeoff or landing when the helicopter hits its engine topping, and the rotor rpm droops below the green arc, and subsequent Torque reaction overcoming the reduced tail rotor thrust even at max (maximum power pedal applied) causing a loss of yaw control. Recovery often can be made by lowering collective to recover rpm without significant descent, so that ground contact is often avoidable.
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Loss of tail rotor control: You are not able to control the tail rotor pitch mechanism - it is a true emergency. This could be a stuck control (left pedal, right pedal, or centre) or it can be a total loss of thrust (broken drive shaft or gear box). It can occur on any helo, but is relatively rare. Part of the training on every helo.
A tail rotor driveshaft is more straightforward to deal with; usually this requires the engines to be shut down for landing.
If you did that when the tail rotor has run away to high or full positive pitch, it could be a fatal mistake.
ummmm...
I was not detailing the recovery actions and insinuating they were the same. At least that is what I think you are getting at...was it??
The purpose was to distinguish LTA and LTE which are now so often mis-labelled that "LTE" has crept into our vernacular as the sole cause of all ills. It has now even crept into the accident reports - see the skycrane thread as another example. I am concerned about this ever increasing mistake as it also increases the chance of an incorrect diagnosis and thus reduces the possiblity of a successful selection of the appropriate recovery.
See the thread I linked above: and the video. Then read the amount of "It was LTE" comments that indicate exactly what I am talking about.
Reminds me of the VRS versus insufficient power issue as well....
I was not detailing the recovery actions and insinuating they were the same. At least that is what I think you are getting at...was it??
The purpose was to distinguish LTA and LTE which are now so often mis-labelled that "LTE" has crept into our vernacular as the sole cause of all ills. It has now even crept into the accident reports - see the skycrane thread as another example. I am concerned about this ever increasing mistake as it also increases the chance of an incorrect diagnosis and thus reduces the possiblity of a successful selection of the appropriate recovery.
See the thread I linked above: and the video. Then read the amount of "It was LTE" comments that indicate exactly what I am talking about.
Reminds me of the VRS versus insufficient power issue as well....
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HF, I hate to argue but my concern is in your wording. The sentence that I re-quoted states that a tail rotor drive shaft failure involves a loss of tail rotor pitch control, obviously it doesn't.
I'm unhappy to see these two types of emergency incorrectly grouped together because it can cause confusion and the pilot's actions, as you agree, may need to be very different.
From experience gained in teaching tail rotor failures of all types and how pilots react to them, I have see many get it wrong at first attempt. I ran the RAF's Puma simulator programme for a while. Our unit (240 Puma OCU, later 27(R) Sqn) was tasked with using the simulator to investigate all types of tail rotor emergencies, to expand the advice given in the FRCs and to increase the knowledge of all Puma pilots through additional training. Not long afterwards a 33 Sqn Puma had a tail rotor pitch control spider failure over the sea. As it was he was able to reduce power and carry out a gradual spiral descent. Although the aircraft had no floats they all got out without injury and the airframe was recovered from the sea more or less intact. The experienced pilot stated afterwards that without the new simulator training he would almost certainly have incorrectly shut down the engines and tried to autorotate. The outcome might then have been very different because it's likely it would have resulted in a total loss of control.
I do think it's vitally important for all helicopter pilots to understand from the outset that there is a basic and important difference between drive shaft failure and tail rotor control failure. Obviously, the required actions may also differ markedly between aircraft types.
Here's a very useful document:
http://www.caa.co.uk/docs/33/CAPAP2003_01.PDF
I'm unhappy to see these two types of emergency incorrectly grouped together because it can cause confusion and the pilot's actions, as you agree, may need to be very different.
From experience gained in teaching tail rotor failures of all types and how pilots react to them, I have see many get it wrong at first attempt. I ran the RAF's Puma simulator programme for a while. Our unit (240 Puma OCU, later 27(R) Sqn) was tasked with using the simulator to investigate all types of tail rotor emergencies, to expand the advice given in the FRCs and to increase the knowledge of all Puma pilots through additional training. Not long afterwards a 33 Sqn Puma had a tail rotor pitch control spider failure over the sea. As it was he was able to reduce power and carry out a gradual spiral descent. Although the aircraft had no floats they all got out without injury and the airframe was recovered from the sea more or less intact. The experienced pilot stated afterwards that without the new simulator training he would almost certainly have incorrectly shut down the engines and tried to autorotate. The outcome might then have been very different because it's likely it would have resulted in a total loss of control.
I do think it's vitally important for all helicopter pilots to understand from the outset that there is a basic and important difference between drive shaft failure and tail rotor control failure. Obviously, the required actions may also differ markedly between aircraft types.
Here's a very useful document:
http://www.caa.co.uk/docs/33/CAPAP2003_01.PDF
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Simulator training can be of outstanding value, but the usual computer garbage in, garbage out needs to be kept in mind. A major simulator trainer providing training to the industry on a widely used Cat A aircraft was of the view that with the loss of tail rotor drive in the hover you could pull collective, spiral up to 1,000 feet or so, nose over and gain airspeed, and continue in side slipping flight to a suitable runway for an engine off auto. And you were able to do it in the sim. In real life? Not from what I saw of a Huey losing tail rotor drive in the hover, executed a 270° turn in a nanosecond before a rapid wind off of throttle and landing with no damage.
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Brian, I am aware of the limitations of simulators in that respect; indeed it's a whole separate topic in itself.
Obviously, no-one goes out flying and fails tail rotors deliberately to gain absolute data to put in a simulator programme! What is programmed into a simulator when insufficient data is available is a best guess by the programmer and is known as "off-model" simulation.
Despite this limitation, what simulator training can do is to make the pilot more aware of the different scenarios he might one day be faced with in the air. Before the RAF began using helicopter simulators (Puma was first, using the Helikopter Service facility in Stavanger), the information given was insufficient and incorrect. Certainly during my initial training, we only practiced the stuck pedal situation and engine offs, as per the t/r drive failure scenario. MOD thankfully realised this was inadequate because there are so many different variations on the tail rotor failure theme and made provision to expand the relevant training. There is some reference to this in the CAA document I have linked to; albeit the main mention is about the Army Lynx.
Obviously, no-one goes out flying and fails tail rotors deliberately to gain absolute data to put in a simulator programme! What is programmed into a simulator when insufficient data is available is a best guess by the programmer and is known as "off-model" simulation.
Despite this limitation, what simulator training can do is to make the pilot more aware of the different scenarios he might one day be faced with in the air. Before the RAF began using helicopter simulators (Puma was first, using the Helikopter Service facility in Stavanger), the information given was insufficient and incorrect. Certainly during my initial training, we only practiced the stuck pedal situation and engine offs, as per the t/r drive failure scenario. MOD thankfully realised this was inadequate because there are so many different variations on the tail rotor failure theme and made provision to expand the relevant training. There is some reference to this in the CAA document I have linked to; albeit the main mention is about the Army Lynx.
HF, I hate to argue but my concern is in your wording. The sentence that I re-quoted states that a tail rotor drive shaft failure involves a loss of tail rotor pitch control, obviously it doesn't.
Loss of tail rotor control: You are not able to affect yaw control using the yaw control pedals - it is a true emergency. This could be a stuck control (left pedal, right pedal, or centre) OR it can be a total loss of thrust (broken drive shaft or gear box) in which case the pedals move but the aircraft does not react in yaw to the input. It can occur on any conventional helo, but is relatively rare. Part of the training on every helo.
The Puma incident may need a little more info to explain it to us non Puma types. What is the consequence of the "tail rotor pitch control spider failure" and why did they ditch?
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HF, I'm not descending into semantics; there are three different types of tailrotor system failure, each with it's own issues. You have grouped them into just two types.
Re. the Puma ditching: The Puma has five tail rotor blades. Running through the length of the hollow tail rotor drive shaft, is a push/pull rod. At the opposite end of the rod from the servo is a five armed "spider" (although everyone knows most spiders really have eight "legs", French ones perhaps have only five). At the end of each leg is a pitch control link, attached to control horns, one for each blade. As the servo moves the rod, the spider moves with it (it's bolted on), push/pulling on the pitch control links.
In this incident, IIRC, something between the servo and the links broke, giving fixed pitch, somewhat less than that required to balance yaw in the cruise. The aircraft began to yaw away from the MRG torque, giving very similar symptoms to a tail rotor drive shaft failure.
An unwitting pilot might have mistaken the situation for a driveshaft failure, in which case he would probably have auto-rotated and shut down both engines. In previous years there had been little in the Puma FRCs or Pilots' Manual to suggest otherwise.
This would be incorrect because the tail rotor was still producing some positive (anti-torque) thrust. Devoid of main rotor thrust, the aircraft would then have begun yawing in the opposite direction, possibly meaning the pilot would have lost control.
The only correct action, as taken by this pilot, was to reduce collective sufficiently to control the yaw. He kept the aircraft under control but unfortunately he had insufficient torque to mantain level flight. He was able to fly in a descending turn to the surface, whereupon they did a relatively gentle ditching and escaped unhurt.
Re. the Puma ditching: The Puma has five tail rotor blades. Running through the length of the hollow tail rotor drive shaft, is a push/pull rod. At the opposite end of the rod from the servo is a five armed "spider" (although everyone knows most spiders really have eight "legs", French ones perhaps have only five). At the end of each leg is a pitch control link, attached to control horns, one for each blade. As the servo moves the rod, the spider moves with it (it's bolted on), push/pulling on the pitch control links.
In this incident, IIRC, something between the servo and the links broke, giving fixed pitch, somewhat less than that required to balance yaw in the cruise. The aircraft began to yaw away from the MRG torque, giving very similar symptoms to a tail rotor drive shaft failure.
An unwitting pilot might have mistaken the situation for a driveshaft failure, in which case he would probably have auto-rotated and shut down both engines. In previous years there had been little in the Puma FRCs or Pilots' Manual to suggest otherwise.
This would be incorrect because the tail rotor was still producing some positive (anti-torque) thrust. Devoid of main rotor thrust, the aircraft would then have begun yawing in the opposite direction, possibly meaning the pilot would have lost control.
The only correct action, as taken by this pilot, was to reduce collective sufficiently to control the yaw. He kept the aircraft under control but unfortunately he had insufficient torque to mantain level flight. He was able to fly in a descending turn to the surface, whereupon they did a relatively gentle ditching and escaped unhurt.
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bin away a bit and have had a good look at the full ATSB report, which appears quite sound.
Very interesting photo of the T/R assy I must say when you blow it up. no rotation damage at all it seems just a major sideways swipe on one blade, as it was departing the rear end, by something hard and fast.
when I talked about fast rotation, I was slightly wrong in my description.
Having experienced T/R drive shaft failure in a zero airspeed very high power-on profile, I can say that the rotation is slow from the start but increasing in intensity very quickly, to the point where at the second rotation, one said to myself, "self, you'se agotta wind that there throttle off and you'se a gotta do it now, eh" things were becoming very blurred out from I can say.
I did chop the gas, I landed, from about sixty feet in a '47 3B1 with just a slight bend in the rear cross tube, and luckily the t/r gaurd tube had contacted a light bush which helped slow the spinning down. Holding off until the thing fell onto the ground was also a major player.
shy Torque I hear what you are saying with the training, i had not done any of it prior to my event as described, it had merely been told to me. I was lucky. The Cairns pilot, it appears, had also never done any training, not so lucky.
The drive shaft failure scenario did not fit this accident though. especially the bit about blurred vision from fast spinning which was not at all mentioned.
I have never experienced over pitching of the T/R but can only imagine that the commencement and accelaration of rotation would be very similar to the Drive failure.(without it being checked that is)
Which of course does not fit this scene either.
However i have tried countless times to get myself into T/R vortex ring state, and only succeeded on four or five times but have also inadvertantly picked up the condition a few other times whilst mustering in areas of extreme surface interference, where one can never really predict the exact wind direction and intensity.
I can say that on each occasion that the onset severity is entirely different. To descibe it, May i say that if one was fitted out with false teeth, and that if one was silly enough to leave one's mouth open then one may expect to leave one's false teeth - over there - where one was a milli second ago.
On each occasion I had the full left pedal in within a heart beat, but prior to that in nearly all occasions the rotation had stopped with the same snapping severity.
There is a simple reason for that, have a look at the conditions for VRS and where it ceases, also of course never forget that the speed of rotation will be such that no vortices will be able to keep up with it and will simply wash off.
The other times it stopped very quickly even before i had commenced flying away with collective down and cyclic forward simultaneously.
To sum up, what is shrieking from this accident, and it is fortunatethat the ATSB were convinced to investigate, is the Lack of standards. As it shrieks at us from elsewhere in these threads.
shy, what you did and what happens now are two different things, and in response the dispensation of the frivilous I will submit another explantion of LTE. Lack of Training for Emergencies.
No matter whatever this manufacturer or others, writes nothing will change until "standards" are applied by those resposible to do so.
cheers tet
Very interesting photo of the T/R assy I must say when you blow it up. no rotation damage at all it seems just a major sideways swipe on one blade, as it was departing the rear end, by something hard and fast.
when I talked about fast rotation, I was slightly wrong in my description.
Having experienced T/R drive shaft failure in a zero airspeed very high power-on profile, I can say that the rotation is slow from the start but increasing in intensity very quickly, to the point where at the second rotation, one said to myself, "self, you'se agotta wind that there throttle off and you'se a gotta do it now, eh" things were becoming very blurred out from I can say.
I did chop the gas, I landed, from about sixty feet in a '47 3B1 with just a slight bend in the rear cross tube, and luckily the t/r gaurd tube had contacted a light bush which helped slow the spinning down. Holding off until the thing fell onto the ground was also a major player.
shy Torque I hear what you are saying with the training, i had not done any of it prior to my event as described, it had merely been told to me. I was lucky. The Cairns pilot, it appears, had also never done any training, not so lucky.
The drive shaft failure scenario did not fit this accident though. especially the bit about blurred vision from fast spinning which was not at all mentioned.
I have never experienced over pitching of the T/R but can only imagine that the commencement and accelaration of rotation would be very similar to the Drive failure.(without it being checked that is)
Which of course does not fit this scene either.
However i have tried countless times to get myself into T/R vortex ring state, and only succeeded on four or five times but have also inadvertantly picked up the condition a few other times whilst mustering in areas of extreme surface interference, where one can never really predict the exact wind direction and intensity.
I can say that on each occasion that the onset severity is entirely different. To descibe it, May i say that if one was fitted out with false teeth, and that if one was silly enough to leave one's mouth open then one may expect to leave one's false teeth - over there - where one was a milli second ago.
On each occasion I had the full left pedal in within a heart beat, but prior to that in nearly all occasions the rotation had stopped with the same snapping severity.
There is a simple reason for that, have a look at the conditions for VRS and where it ceases, also of course never forget that the speed of rotation will be such that no vortices will be able to keep up with it and will simply wash off.
The other times it stopped very quickly even before i had commenced flying away with collective down and cyclic forward simultaneously.
To sum up, what is shrieking from this accident, and it is fortunatethat the ATSB were convinced to investigate, is the Lack of standards. As it shrieks at us from elsewhere in these threads.
shy, what you did and what happens now are two different things, and in response the dispensation of the frivilous I will submit another explantion of LTE. Lack of Training for Emergencies.
No matter whatever this manufacturer or others, writes nothing will change until "standards" are applied by those resposible to do so.
cheers tet
Last edited by topendtorque; 16th Dec 2009 at 21:35.
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If you are doing research on LTE then the paper must be blank because according to a chap named Lappos, it doesn't exist. Sorry to break it to you old man. cheers anyhow
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Well it's certainly not me that's doing research on LTE for sure. I've always been quite critical of the usage of the term and particularly worried that it has done nothing for the confidence of young punters more than erode their confidence as some sort of bogeyman that is going to smite them from the sky.
I'd lay even odds that some of the accidents due to the scare factor of this bogey man are nothing more than a lack of training and understanding of the various maladies as described by shy torque, a hundred years ago.
Would you agree?
Those maladies are all that I demonstrate and teach recovery of. If some damm helicopter comany was so dim as to design a machine that didn't have a big enough T/R to counter torque at full throttle, when pulling a big hook load say, and those drivers there-of are also so dimm as to not be aware of it and be careful of it, well that's their problem.
but to pontificate on a litany of figure drawings of vortices that are supposedly attacking the T/R from various disastrous regions and confuse those issues with the above design problem is sheer lunacy.
I'll tell you one thing again, when you hit VRS state with the T/R, it's violent, It remains for a fraction of a second, and then the ceasing of it is just as violent. Been there done that. But to be the font of all wisdom on it without one hour of mustering or by just flying around in straight lines holding your mouth right is dead wrong.
LTE is purely and simply a lack of training for emergencies, proven again in Cairns.
ATSB should step up to the plate and make some recommendations to the CASA standards people to sort it.
tet
I'd lay even odds that some of the accidents due to the scare factor of this bogey man are nothing more than a lack of training and understanding of the various maladies as described by shy torque, a hundred years ago.
Would you agree?
Those maladies are all that I demonstrate and teach recovery of. If some damm helicopter comany was so dim as to design a machine that didn't have a big enough T/R to counter torque at full throttle, when pulling a big hook load say, and those drivers there-of are also so dimm as to not be aware of it and be careful of it, well that's their problem.
but to pontificate on a litany of figure drawings of vortices that are supposedly attacking the T/R from various disastrous regions and confuse those issues with the above design problem is sheer lunacy.
I'll tell you one thing again, when you hit VRS state with the T/R, it's violent, It remains for a fraction of a second, and then the ceasing of it is just as violent. Been there done that. But to be the font of all wisdom on it without one hour of mustering or by just flying around in straight lines holding your mouth right is dead wrong.
LTE is purely and simply a lack of training for emergencies, proven again in Cairns.
ATSB should step up to the plate and make some recommendations to the CASA standards people to sort it.
tet
