R44 crashed Alps

[Flying Bull]

https://www.heli-archive.ch/en/helicopters/helicopter-accidents/25102020-robinson-r-44-raven-ii-i-olli/?fbclid=IwAR0QMOqVMX_HtYvtufeOs5D0aSuc3pkZSgT7dtr6L_kZHAPK12 uRztFDaGc

one died, one survived.
Rescuers had problems finding the ELT (Reflections from the mountains?)

Other fixed wing pilots reported strong gusty winds between 25 and 35 knots in the area

[nomorehelosforme]

From WIKI with some links

https://aviation-safety.net/wikibase/244398

Owner/operator: Private Registration: I-OLLI C/n / msn: 11439 Fatalities: Fatalities: 1 / Occupants: 2 Other fatalities: 0 Aircraft damage: Written off (damaged beyond repair) Location: Cervinia (AO) - https://aviation-safety.net/database/country/flags_15/I.gif Italy (https://aviation-safety.net/wikibase/dblist.php?Country=I) Phase: Unknown Nature: Private Departure airport:
Destination airport:
Narrative:
The helicopter crashed at an elevation of about 3000 m in the Alps. Both occupants had going skiing and were flying back at 16:00 hours local time. The helicopter did not arrive at the destination and an ELT signal was detected.
Sources:
https://aostasera.it/notizie/cronaca/e-precipitato-al-colle-di-cime-bianche-lelicottero-disperso-un-morto-ed-un-ferito/
https://ansv.it/incidente-nella-valle-daosta-2/
https://www.bresciatoday.it/cronaca/alfredo-buda-giorgio-oliva.html

[ApolloHeli]

For anyone unfamiliar with the area, here's a topographical map. There's a helicopter mountain landing site just on the Swiss side of the border (where "Rifugio" is marked) near the 3444m elevation mark, so it could be speculated that they landed there as it is provides access to a ski resort.
https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/2000x926/screenshot_2020_10_27_at_12_32_38_bae3f640b145a9c5f1132b565b 9925ad69ea999e.jpg
Topographical map of the area. The Swiss-Italian border is the violet line on the top right. Based off the news reports, the approximate crash area is highlighted in red.

[A681001]

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1500x2000/122977825_3354580894578788_2227283863739890454_o_474bf183112 05ad776c0b4d7b9f789c5dbc6dc2b.jpg
A very sad sight

[atakacs]

I believe they found one survivor who spent many hours in sub zero temperatures. Did he not make it ?

[[email protected]]

With all that is known about the Robinson susceptibility to mast bumping in turbulence - why would you go flying in the mountains in 25 - 30 Kt winds???

[Hughes500]

Crab because they are invincible !

[casper64]

With all that is known about the Robinson susceptibility to mast bumping in turbulence - why would you go flying in the mountains in 25 - 30 Kt winds???

why would you go and fly a Robinson at all... 😥

[Robbiee]

why would you go and fly a Robinson at all... 😥

Congratulations! You've just won the "Butthurt over Robinsons" comment of the week!
:D :D :D

Click the following link to claim your prize!

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[nomorehelosforme]

Congratulations! You've just won the "Butthurt over Robinsons" comment of the week!
:D :D :D

Click the following link to claim your prize!

https://alexnld.com/product/inflatable-vinyl-ring-round-seat-cushion-hemorrhoid-pillow-donut/

And once again your paranoia has showed itself, and off we go again with your same old ****e! ...

[malabo]

I'm accustomed to more astute observations from the usual posters. First the fuel cel red herring, lots of other helicopters didn't have them and they'd burn when crashed as did some that did, at any rate it didn't burn so nothing interesting there. Then the mast bumping based on what, wind? If there is some evidence the mast sheared I've been unable to find it. I'm more interested in weather and daylight and pilot. They departed at 16:00, sunset was at what, 17:20? Maybe dark sooner depending on cloud cover? 3000m is pretty high for an R44, but they weren't landing or taking off, and they were light. Just 'cause it was a Robbie isn't a reason to crash in itself. They are favoured by private owner/operators for cost though, similar to the Norway R44. Do we know any more about the pilot or the weather?

[Robbiee]

And once again your paranoia has showed itself, and off we go again with your same old ****e! ...

I don't think paranoia means what you think it means.

[Arnie Madsen]

With all that is known about the Robinson susceptibility to mast bumping in turbulence - why would you go flying in the mountains in 25 - 30 Kt winds???
I am not anti-Robinson but we must acknowledge that very light blades are more sensitive to turbulence & mast bumping.
Heavy blades retain their plane of rotation long enough to handle sudden strong gusts.
But they require extra strength (heavy) laminations & spar at the root end to handle bending loads at the root (blade coning)

Frank came up with a good solution to save ounces and pounds in the rotor system
By incorporating coning hinges at the root which relieved any coning stress
Thus he could build very light blades .... which had the additional benefits of lower centrifugal force on the hub and feather bearings which meant he could build a lighter head.

Early blade de-laminations were the first red flag , but were attributed to outsourced blade manufacturing errors
Then came the numerous unexplained rotor incursions into the cabin or boom. A big red flag ... not to mention further de-laminations through the years

Easy for me to say ... but if he (stubborn frank) had halted production , built a blade similar to the H269 , strengthened the hub to take the extra loads , the problem would have been solved.

Of course those several pounds of weight would have reduced payload .... but extra pitch along with extra power from the de-rated engine should solve that ..... working the Lycoming a bit harder would likely reduce TBO from 2200 hrs to 1800 hrs which is still excellent for piston helicopters.

I am also suspicious of having 3 hinge points on a 2 blade rotor .... if a split second disturbance caused one blade to pivot on a coning hinge it would immediately put everything out of phase and would self-destruct.

[HeliMannUK]

I personally wouldn't fly a Robbie in mountains, time and time again we see this accident. It is obvious to me that when a Robbie is flown in mountainous terrain and it lands where it intended then the pilot got away with it and they didnt know how close to the edge they were. So they will do it again.

Its the wrong tool for the job, use a heli not susceptible to mast bumping if you want to fly over high hills or mountains.

No disrespect to people involved.

[Torquetalk]

Its the wrong tool for the job, use a heli not susceptible to mast bumping if you want to fly over high hills or mountains.

So no 205s, 212s, 214s, UH-1s in the hills either?

Think being aware of rotors and having wind limits makes sense, but avoiding mast bumping is about training and awareness.

And that is why there are a lot of Robbie accidents, esp R44: Low cost helicopter meets low experience pilot flying in a low discipline environment.

TT

[Hot and Hi]

I think this is the right way of putting it.

[Hot and Hi]

why would you go and fly a Robinson at all... 😥
If you don’t, and if you fly a helicopter that is four or ten times more expensive, and if you bought your helicopter with your own money, then you would know why.

[Nubian]

So no 205s, 212s, 214s, UH-1s in the hills either?

Think being aware of rotors and having wind limits makes sense, but avoiding mast bumping is about training and awareness.

And that is why there are a lot of Robbie accidents, esp R44: Low cost helicopter meets low experience pilot flying in a low discipline environment.

TT

No, these models don't have the coning hinges in the head as Arnie Madsen describes above.

[Torquetalk]

No, these models don't have the coning hinges in the head as Arnie Madsen describes above.

It may be that by design that Robbies are less tolerant to turbulence thaN the other 2-blade helicopters mentioned, but all can experience mast bumping. I think singling out the helicopter and not the more relevant factors in these accidents is the wrong focus. People just need to be more aware of the limitations of the aircraft. And particularly of their own.

[Bell_ringer]

How many other teetering head machines have speed warnings for turbulence in the manual?

[aa777888]

Congratulations! You've just won the "Butthurt over Robinsons" comment of the week!Hahahahahaha! That literally made me laugh out loud! :)

On a more serious note, Robinsons are fine machines and clearly capable of being operated in mountainous terrain safely. And, yes, you do that in part by paying attention your speed in accordance with the POH and applicable Robinson Safety Notices, BR. My personal minimums tend more towards gust 25 for mountainous terrain, and I do try to respect the terrain in appropriate ways. But don't take my word for it. There are plenty of schools who teach mountain and high altitude operations in Robinsons. Youtube is full of those videos. You don't see Robinsons dropping from the sky like flies.

TT hit the nail squarely on the head: "Low cost helicopter meets low experience pilot flying in a low discipline environment." That statement could probably preface 90% of all Robinson accident reports.

@Torquetalk please confirm that by "low cost" your meant "more easily accessible and affordable" as opposed to "poorly designed or incapable"?

eta: this topic and this (https://www.pprune.org/rotorheads/618547-r44-down-norway-2-dead.html)one are so similar you could probably combine them.

[TTSN]

I am not anti-Robinson but we must acknowledge that very light blades are more sensitive to turbulence & mast bumping.
Heavy blades retain their plane of rotation long enough to handle sudden strong gusts.
But they require extra strength (heavy) laminations & spar at the root end to handle bending loads at the root (blade coning)

Frank came up with a good solution to save ounces and pounds in the rotor system
By incorporating coning hinges at the root which relieved any coning stress
Thus he could build very light blades .... which had the additional benefits of lower centrifugal force on the hub and feather bearings which meant he could build a lighter head.

Early blade de-laminations were the first red flag , but were attributed to outsourced blade manufacturing errors
Then came the numerous unexplained rotor incursions into the cabin or boom. A big red flag ... not to mention further de-laminations through the years

Easy for me to say ... but if he (stubborn frank) had halted production , built a blade similar to the H269 , strengthened the hub to take the extra loads , the problem would have been solved.

Of course those several pounds of weight would have reduced payload .... but extra pitch along with extra power from the de-rated engine should solve that ..... working the Lycoming a bit harder would likely reduce TBO from 2200 hrs to 1800 hrs which is still excellent for piston helicopters.

I am also suspicious of having 3 hinge points on a 2 blade rotor .... if a split second disturbance caused one blade to pivot on a coning hinge it would immediately put everything out of phase and would self-destruct.

There ... you just hit the nail firmly on the head. In 25 years plus of following Robinson rotor issues this seems to be the view of a number of the worlds experts. The numerous unexplained Robinson rotor divergence issues are unique but so is the rotor head design with a teeter and 2 coning hinges. I’m sure this particular accident was due to being out in the wrong kind of weather and the result would have been the same regardless of what type of light helicopter was being flown. More frequent checks on the condition of the coning bolts and closely monitoring preload (resistance to movement) should be introduced. A Robinson operator told a story on here (PPrune) a couple of years ago of finding the broken off end of his coning bolt during a pre flight check in the hangar (a little alarming I know). I’m not a Robinson hater in any shape or form and would be willing to assist in any way I could reducing or solving this issue.


I am also suspicious of having 3 hinge points on a 2 blade rotor .... if a split second disturbance caused one blade to pivot on a coning hinge it would immediately put everything out of phase and would self-destruct.

[Robbiee]

You know, there used to be some cars whose engine would overheat when you drove them uphill with the air conditioning on. Some would whine that this was a design flaw and swear to never drive one of those cars,...others would just turn off the air conditioning, drive over the hill, then turn it back on.

I guess everyone just handles limitations in different ways.

[HeliMannUK]

Torquetalk The Bells have stronger components which may help in turbulent situations but you cannot tell me that using a Robbo in the Alps is not the wrong tool for the job. Also I dont think low experience of the pilot has anything to do with it, look at the accidents that have occurred in New Zealand over the years.

[ApolloHeli]

R44's are flown daily around the Alps without issue, because the pilots and companies that operate them do so safely by knowing the limitations of both the aircraft and the pilots. I think many of the posters trying to suggest that they are unsuitable for the environment simply haven't been here and don't have a clear idea of the helicopter operations in & around the Alps.

Although we have no idea what the cause of this incident was (and my personal hunch is that must bumping is unlikely to have been involved), the crash of G-RAMY on the Isle of Man in 2015 (https://www.gov.uk/aaib-reports/aaib-investigation-to-bell-206b-jet-ranger-ii-g-ramy) is a clear example that any semi-rigid/teetering rotor system is susceptible to mast bumping so we can all agree 3+ blades are best :).

Despite the satisfaction of pointing out the numerous shortcomings of the Robinson design, I think posts on this thread would be more constructive and worth everyone's while if they were related to the incident at hand and on the possible causes. Maybe this was whiteout/loss of references? Could icing have brought them down? Maybe the wind did cause the crash with a sudden downdraft when they were close to obstacles/ground? Hopefully there will be some lessons learned out of this one, and it's not just another repeat of last episode on 'R44 wreckage found in challenging terrain.'

[rottenjohn]

Exactly. Another question might be how those bloody things were ever certified in the first place. Any other mass produced aircraft that doesn’t seen to be able to handle 35 knots?

[Robbiee]

Exactly. Another question might be how those bloody things were ever certified in the first place. Any other mass produced aircraft that doesn’t seen to be able to handle 35 knots?

I have flown an R22 in 35kts.

,...they can handle it just fine.

[Torquetalk]

@Torquetalk please confirm that by "low cost" your meant "more easily accessible and affordable" as opposed to "poorly designed or incapable"

aa777888, I was simply talking about cost. The Robinsons are what they are and perfectly capable aircraft if flown properly.

The R22 is very light and there is very little energy in the main rotor and little authority margin in the tail rotor. It‘s a bit like a metal gnat. But gnats bounce of things harmlessly when they hit them, R22s don‘t.

The R44 is as different as it is similar. There is much more energy in the main rotor. R44s accidents are often performance related, with pilots clearly flying into situations which are just accidents waiting to happen. Many will have done a lot of autorotation training, but generally neglected the skills and knowledge needed to fly in performance limited situations. Exactly the kind of situations they are likely to find themselves in because it is a four seat helicopter, whilst training is generally done with 2 on board...

I have also flown an R22 in high winds, but I think you need to be very careful about when and where and why you would do this. Also had LTE through sheer niavety in an R22. Might have happened in other light types, but I reached and passed a limit very quickly in that case.

One of our fellow ppruners was killed ferrying an R22 back from Spain some years ago, encoutering CAT on the lee side of the Pyrenees in high winds causing the aircraft to break up mid-air. They clearly didn’t see that coming.

But Robinsons are not reasponsible for bad decsions to fly. At least one of the pilots involved was quite experienced in that case, but clearly failed to anticipate the danger. A counter example would be the Gazelle accident in NE England on a high wind day some years ago. In that case, it also involved a pilot flying in the lee of hills on a high wind day and completely lacking the skills and experience to be in or cope with the situation he put himself in. Nothing to do with the aircraft, he was just too cocky. Sadly not around to learn the lesson.

[rottenjohn]

Good for you, so have I. However this is about the R44.

[Torquetalk]

Not entirely John, the discussion has also encompassed criticism of Robinsons in general as being unsuitable for mountain flying by design and citing design as the main problem with Robinsons, as opposed to how they are sometimes flown. This discussion applies to all Robbies insofar as it‘s about people either flying an inappropriate design or poor airmanship being involved in many Robbie accidents.

I‘m in the poor airmanship camp.

[aa777888]

R44's are flown daily around the Alps without issue, because the pilots and companies that operate them do so safely by knowing the limitations of both the aircraft and the pilots. I think many of the posters trying to suggest that they are unsuitable for the environment simply haven't been here and don't have a clear idea of the helicopter operations in & around the Alps.

Although we have no idea what the cause of this incident was (and my personal hunch is that must bumping is unlikely to have been involved), the crash of G-RAMY on the Isle of Man in 2015 (https://www.gov.uk/aaib-reports/aaib-investigation-to-bell-206b-jet-ranger-ii-g-ramy) is a clear example that any semi-rigid/teetering rotor system is susceptible to mast bumping so we can all agree 3+ blades are best :).

Despite the satisfaction of pointing out the numerous shortcomings of the Robinson design, I think posts on this thread would be more constructive and worth everyone's while if they were related to the incident at hand and on the possible causes. Maybe this was whiteout/loss of references? Could icing have brought them down? Maybe the wind did cause the crash with a sudden downdraft when they were close to obstacles/ground? Hopefully there will be some lessons learned out of this one, and it's not just another repeat of last episode on 'R44 wreckage found in challenging terrain.'Outstanding post, well said!

[aa777888]

aa777888, I was simply talking about cost. The Robinsons are what they are and perfectly capable aircraft if flown properly.Thank you.

The R22 is very light and there is very little energy in the main rotor and little authority margin in the tail rotor.I disagree with the latter half of that statement. There is plenty of tail rotor authority in the 22, and the same for the 44 and 66. They all will work fine in a 30KN breeze. I'm told by other pilots they work fine in a 40KN breeze but that much wind is beyond my personal limits right now. Obviously one must fly carefully in such conditions.

The R44 is as different as it is similar. There is much more energy in the main rotor. R44s accidents are often performance related, with pilots clearly flying into situations which are just accidents waiting to happen. Many will have done a lot of autorotation training, but generally neglected the skills and knowledge needed to fly in performance limited situations. Exactly the kind of situations they are likely to find themselves in because it is a four seat helicopter, whilst training is generally done with 2 on board...A very good point. Similar to that being discussed (https://www.pprune.org/showthread.php?p=10915803)in the other R44 crash thread. All that performance margin helps you survive training. Helps you right up until that very first flight with your newly minted pilot certificate and all the seats filled. I am very happy that the school I used intentionally included lessons at max. gross weight. The extra pressure and cat calls from the other students in the rear are also good training. Made another student airsick once as when it was my turn in the front the instructor had me performing "enhanced training in autorotation procedures", as SFAR 73 puts it. That was pretty funny!

I have also flown an R22 in high winds, but I think you need to be very careful about when and where and why you would do this. Also had LTE through sheer niavety in an R22. Might have happened in other light types, but I reached and passed a limit very quickly in that case.What were the conditions when you had your "LTE" experience? Not to create a major thread drift, but a paper presented at the EASA Rotorcraft & VTOL Symposium 2019 entitled "The Myth of Losing Tail Rotor Effectiveness" makes some compelling arguments that there is no such thing as LTE and it is hard to refute the research. I have attached it to this post.

One of our fellow ppruners was killed ferrying an R22 back from Spain some years ago, encoutering CAT on the lee side of the Pyrenees in high winds causing the aircraft to break up mid-air. They clearly didn’t see that coming.

But Robinsons are not reasponsible for bad decsions to fly. At least one of the pilots involved was quite experienced in that case, but clearly failed to anticipate the danger. A counter example would be the Gazelle accident in NE England on a high wind day some years ago. In that case, it also involved a pilot flying in the lee of hills on a high wind day and completely lacking the skills and experience to be in or cope with the situation he put himself in. Nothing to do with the aircraft, he was just too cocky. Sadly not around to learn the lesson.Thanks for another excellent post!

[Robbiee]

A very good point. Similar to that being discussed (https://www.pprune.org/showthread.php?p=10915803)in the other R44 crash thread. All that performance margin helps you survive training. Helps you right up until that very first flight with your newly minted pilot certificate and all the seats filled. I am very happy that the school I used intentionally included lessons at max. gross weight. The extra pressure and cat calls from the other students in the rear are also good training. Made another student airsick once as when it was my turn in the front the instructor had me performing "enhanced training in autorotation procedures", as SFAR 73 puts it. That was pretty funny!


This seems to be more of an issue with schools who use the R44 exclusively. If you did your training in an R22 you'd be intimately familiar with flying at max gross weight and not being able to HOGE without busting power limits. An R44 with four on board is just an R22 with two. :8

[[email protected]]

That is a very good paper aa777888 :ok:

[Arnie Madsen]

Everyone knows all 2 blade systems can experience mast bumping. Nothing new there.
But the R series has more than double the amount of others.
This was determined by an exhaustive study by NTSB and a high level aviation university
It was a true apple to apple comparison , nothing to do with number of machines sold or pilot experience.

NTSB nomenclature call it "loss of rotor control" or "blade incursion into cabin or boom"
And of course all of them also show mast bumping and broken droop tusks.

But my question has always been ..... what caused the initial loss of rotor control which caused all the other bumping-incursion damage ???

We all know about Zero-G ..... strong gusts ... updrafts ..... downdrafts ... equally applicable to all 2 blade systems .... with some advantage to heavy blades .... but can we blame the R failures on light blades alone ??? .... personally I dont think so.

I have always been suspicious of the 3 hinge points in the R system . It works as advertised and is a clever way to eliminate stress and bending at the blade roots. And at overhaul time mechanics will see wear at the main teeter pin and bushings (normal) and no wear at the coning hinge pins (good)

This indicates the coning hinges will only compensate for coning and pretty well remain fixed (no continuous movement-flapping in flight.) .... just as it was designed to do.

But what is to say that a rare aerodynamic situation could not occur that causes one blade to flap up on its coning hinge .... it would put the rotor system out of balance , plus without a lead-lag hinge a lot of stress on the (un-reinforced) blade root.

Other 2 blade rotor systems have a rigid head and are stiff and reinforced at the first few feet of each blade , thus the disturbance would be dampened and partly transferred to the other blade.

The R system is like a limp noodle by comparison with those 3 hinge points. And yes .... I realize centrifugal force tries to keep the coning hinges "stiff" but maybe a split second disturbance could alter that

I could be creating a monster that does not exist .... just trying to reason out why the R rotor experiences almost double the rotor incursions of other 2-bladers when all other circumstances are equal. (apples to apples )

[Arnie Madsen]

There ... you just hit the nail firmly on the head. In 25 years plus of following Robinson rotor issues this seems to be the view of a number of the worlds experts. The numerous unexplained Robinson rotor divergence issues are unique but so is the rotor head design with a teeter and 2 coning hinges. I’m sure this particular accident was due to being out in the wrong kind of weather and the result would have been the same regardless of what type of light helicopter was being flown. More frequent checks on the condition of the coning bolts and closely monitoring preload (resistance to movement) should be introduced. A Robinson operator told a story on here (PPrune) a couple of years ago of finding the broken off end of his coning bolt during a pre flight check in the hangar (a little alarming I know). I’m not a Robinson hater in any shape or form and would be willing to assist in any way I could reducing or solving this issue.


I am also suspicious of having 3 hinge points on a 2 blade rotor .... if a split second disturbance caused one blade to pivot on a coning hinge it would immediately put everything out of phase and would self-destruct.

Too add to that there is another unusual thing about the R rotor head.

ALL OTHER 2-blade systems connect the swash plate linkage to the blade pitch arm exactly at the teeter hinge position.

That way pitch is never altered when the rotor teeters, Pretty much an industry standard .

HOWEVER in the R system the pitch link is offset of main teeter point.

I could never wrap my head around how they get that to work



https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/788x588/robinson_rotor_offset_pitch_link_6d7898ed5e053041611d2dddcf3 08a9a450ca4fd.jpg

[aa777888]

That is a very good paper aa777888 :ok:
@crab thanks! There's also a Youtube video, but I found it superfluous after reading the paper. I just hope if the day ever comes when I let the **** get all spinny that I have the presence of mind to put the boot in and keep it there properly!

https://youtu.be/MGC0jeDUD9Q

[172510]

And that is why there are a lot of Robbie accidents, esp R44: Low cost helicopter meets low experience pilot flying in a low discipline environment.
Every pilot has started to fly without experience. I think that it's not about experience, I think it's about discipline. I do know my limits, they depend on my experience on type, my recency, my overall experience, fatigue, stress etc.
If you know your limits and only fly missions within your personal flying envelope, you're professional
If you want to fly out of your personal flying envelope you are taking chances.
Experience doesn't change that. Experience expands your personal flying envelope but does not immunise you against accidents.

[chopjock]

Too add to that there is another unusual thing about the R rotor head.

ALL OTHER 2-blade systems connect the swash plate linkage to the blade pitch arm exactly at the teeter hinge position.

That way pitch is never altered when the rotor teeters, Pretty much an industry standard .

HOWEVER in the R system the pitch link is offset of main teeter point.

I could never wrap my head around how they get that to work



https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/788x588/robinson_rotor_offset_pitch_link_6d7898ed5e053041611d2dddcf3 08a9a450ca4fd.jpg

Arnie,
We use the offset pitch link system on model helicopters. It adds in negative feedback to the blade during gusty conditions. Imagine advancing blade flaps up but the pushrod from the swash plate holds the grip where it is, the result is the blade introduces momentary less pitch during the flapping (up) event and automatically twists the blade back down again at the same time. This happens for both teetering and flapping events when the pitch link is offset in this manner.

[Robbiee]

@crab thanks! There's also a Youtube video, but I found it superfluous after reading the paper. I just hope if the day ever comes when I let the **** get all spinny that I have the presence of mind to put the boot in and keep it there properly!

https://youtu.be/MGC0jeDUD9Q

That video seemed less about disproving the existence of LTE and more about the pilots just not putting in enough left pedal to stop it. I think?,..I was having trouble following him.

Anyway, I remember once during my commercial training back in '06, while in a hover the instructor jammed in the right pedal and I was to react by chopping the throttle. I did, the yaw stopped and we set down.

I don't recall this guy mentioning that as an option?

[Arnie Madsen]

Arnie,
We use the offset pitch link system on model helicopters. It adds in negative feedback to the blade during gusty conditions. Imagine advancing blade flaps up but the pushrod from the swash plate holds the grip where it is, the result is the blade introduces momentary less pitch during the flapping (up) event and automatically twists the blade back down again at the same time. This happens for both teetering and flapping events when the pitch link is offset in this manner.
.

Thank you

Frank also incorporates some Delta-3 angle in the main rotor.
Now I wonder if that offset pitch location is how he accomplishes it

Of course 2 blade tail rotors have Delta-3 to retain the plane of rotation and prevent flapping into the boom
but as far as I know he is the only one who does it on the main rotor as well.

Through the years my suspicious mind has pondered whether his unique Delta-3 combined with his unique coning hinges can create an unknown gremlin in certain conditions

I have often wished some researcher would mount the R system on a test stand and put it through every conceivable
motion to see if the blades would divert from their proper plane of rotation (not including Zero-G of course)

It would not require a lot of funding and if they used measuring instruments on all 3 hinge points could determine
if the coning hinges sometimes pivot beyond the design intentions.

[rottenjohn]

I have flown an R22 in 35kts.

,...they can handle it just fine.

the discussion is about R44s.

[[email protected]]

Anyway, I remember once during my commercial training back in '06, while in a hover the instructor jammed in the right pedal and I was to react by chopping the throttle. I did, the yaw stopped and we set down. Robbiee, that will have been a poor attempt to simulate a TR failure not unintentional yaw - this is only safely and realistically done in a simulator.

[aa777888]

That video seemed less about disproving the existence of LTE and more about the pilots just not putting in enough left pedal to stop it. I think?,..I was having trouble following him.That's not correct. The video is quite hard to follow given the English-as-second-language challenges. The paper suffers less from that. You are encouraged to read the paper at the link posted earlier in the thread.

Anyway, I remember once during my commercial training back in '06, while in a hover the instructor jammed in the right pedal and I was to react by chopping the throttle. I did, the yaw stopped and we set down.

I don't recall this guy mentioning that as an option?The intent of his research was to show that LTE as many pilots currently understand it is, if not a myth, substantially misunderstood, and that under all conditions associated with certified designs sufficient tail rotor thrust can be developed to stop the rotation. While reducing torque is one way to assist the resolution of unanticipated yaw, it is not always an option available depending upon phase of flight, nor necessarily the best option. Also, one should not confuse responses to a stuck pedal or tail rotor failure with that suitable for unanticipated yaw.

[aa777888]

.

Thank you

Frank also incorporates some Delta-3 angle in the main rotor.
Now I wonder if that offset pitch location is how he accomplishes it

Of course 2 blade tail rotors have Delta-3 to retain the plane of rotation and prevent flapping into the boom
but as far as I know he is the only one who does it on the main rotor as well.

Through the years my suspicious mind has pondered whether his unique Delta-3 combined with his unique coning hinges can create an unknown gremlin in certain conditions

I have often wished some researcher would mount the R system on a test stand and put it through every conceivable
motion to see if the blades would divert from their proper plane of rotation (not including Zero-G of course)

It would not require a lot of funding and if they used measuring instruments on all 3 hinge points could determine
if the coning hinges sometimes pivot beyond the design intentions.
Modeling and simulation of the design have been performed. The original GTRI modelling effort is documented here:

https://smartech.gatech.edu/handle/1853/52548

It's quite a large document. Chapter 5 is where the meat is, starting on PDF page 118 (not document page number).

There is also this, however I have not paid the $30 to download it and see if it is any good. It is quite recent:

https://vtol.org/store/product/mast-bumping-simulation-and-mitigation-analysis-for-teetering-rotor-systems-12593.cfm

[Arnie Madsen]

Modeling and simulation of the design have been performed. The original GTRI modelling effort is documented here:

https://smartech.gatech.edu/handle/1853/52548

It's quite a large document. Chapter 5 is where the meat is, starting on PDF page 118 (not document page number).

There is also this, however I have not paid the $30 to download it and see if it is any good. It is quite recent:

https://vtol.org/store/product/mast-bumping-simulation-and-mitigation-analysis-for-teetering-rotor-systems-12593.cfm

Thank you very much ..... this is exactly what I was looking for (wishing for) .... lots of reading so off I go to do it .... I may even pay the $30 and download the second one ...... will report back if I do.

[Robbiee]

That's not correct. The video is quite hard to follow given the English-as-second-language challenges. The paper suffers less from that. You are encouraged to read the paper at the link posted earlier in the thread.

The intent of his research was to show that LTE as many pilots currently understand it is, if not a myth, substantially misunderstood, and that under all conditions associated with certified designs sufficient tail rotor thrust can be developed to stop the rotation. While reducing torque is one way to assist the resolution of unanticipated yaw, it is not always an option available depending upon phase of flight, nor necessarily the best option. Also, one should not confuse responses to a stuck pedal or tail rotor failure with that suitable for unanticipated yaw.

Ok then, what is LTE?

[Bell_ringer]

Ok then, what is LTE?

It’s a phenomenon where an aircraft tries to punish the pilot for demonstrating his superior skills and inferior footwork.

[Robbiee]

It’s a phenomenon where an aircraft tries to punish the pilot for demonstrating his superior skills and inferior footwork.

Hmm, already knew that.

,...but thanks for saving me from that excruciatingly long paper!

[ShyTorque]

Anyway, I remember once during my commercial training back in '06, while in a hover the instructor jammed in the right pedal and I was to react by chopping the throttle. I did, the yaw stopped and we set down.

But what would you have done for full left pedal?

[aa777888]

It’s a phenomenon where an aircraft tries to punish the pilot for demonstrating his superior skills and inferior footwork.Ha ha, that's awesome, love it! :ok:

To answer your quesiton, Robbiee, per the paper, what everyone likes to call LTE is instead "unanticipated yaw", because at no point does the tail rotor demonstrate any ineffectiveness. It could be called "loss of pilot foot control" ;) Per the paper, if the pilot lets significant yaw rates develop it can take quite a bit of time to get it stopped, but assuming full pedal deflection it will stop. If the pilot does everything else necessary, such as maintaining altitude and position, it should stop without the helicopter doing anything else untoward. You really should read the paper.

Edited to add: unanticipated yaw (incorrectly termed "LTE") is not the same as stuck pedal is not the same as tail rotor failure.

[[email protected]]

There is also LTA - loss of tail rotor authority where you reach the pedal stop and still the unintended yaw continues. It is why some aircraft have a reducing crosswind limit with increasing density altitude.

As an example, the Wessex MAUM was 13,600Lbs but in Cyprus at the top of Troodos, the PA was 6,500 and the OAT often in excess of 20 deg C which could leave the DA in excess of 9000'.

The yaw envelope of the venerable old girl narrowed markedly up there and we were limited to 12,500 lbs for landing at the top and coming to a hover wasn't an option.

I took a visiting (Ex-84 Sqn) pilot up there and let him fly the approach as he had done it before when he had been in theatre but I reminded him about the yaw problem we might encounter.

We lost too much speed on short finals and reached the left pedal stop and started to yaw right - the only solution was to turn right, lower the collective slightly and try to get airspeed on. I succeeded but it taught me a lot about yaw control!

[Robbiee]

Ha ha, that's awesome, love it! :ok:

To answer your quesiton, Robbiee, per the paper, what everyone likes to call LTE is instead "unanticipated yaw", because at no point does the tail rotor demonstrate any ineffectiveness. It could be called "loss of pilot foot control" ;) Per the paper, if the pilot lets significant yaw rates develop it can take quite a bit of time to get it stopped, but assuming full pedal deflection it will stop. If the pilot does everything else necessary, such as maintaining altitude and position, it should stop without the helicopter doing anything else untoward. You really should read the paper.

Edited to add: unanticipated yaw (incorrectly termed "LTE") is not the same as stuck pedal is not the same as tail rotor failure.

Hmm, this sounds like the whole SWP thing all over again. You guys just don't like how the FAA names things.


By the way, if you understand what causes LTE, then you should be anticipating it. Therefore, the only "unanticipated" yaw should be from stuck pedal, loss of tailrotor thrust, or engine failure.

[Robbiee]

But what would you have done for full left pedal?

Had that happen in training once too. It was at the end of the flight and we had just gotten back to our home airport. Assuming the training was over I was nice and relaxed (guard down) as I brought it to the pad. Just as I got the nose straight and was about to set it down, BAMN! the nose snapped left! I jammed in the right pedal, the yaw stopped (about 90° later) I raised the collective, we hit the ground, and had a good laugh.

Ah, how I miss surprise throttle chops..

,...'course if you're referring to stuck pedal, than well, I've only had about five minutes of stuck pedal training (none of it in a hover) so I'd probably crash before figuring out the correct course of action. :(

[Two's in]

Operating at 3,000 metres over mountainous terrain immediately puts you into a corner of the operating envelope where you had better have some options up your sleeve. Power margins, turbulence, down draught velocity, escape routes, visibility and control issues are all great things to cover on the pre-flight briefing. It's a very unforgiving environment when things don't go to plan, and a great place to have experience on your side.

[aa777888]

Operating at 3,000 metres over mountainous terrain immediately puts you into a corner of the operating envelope where you had better have some options up your sleeve. Power margins, turbulence, down draught velocity, escape routes, visibility and control issues are all great things to cover on the pre-flight briefing. It's a very unforgiving environment when things don't go to plan, and a great place to have experience on your side.
No joke. The highest I've flown my trusty 44 is not quite 2000M, and I treated her like a delicate flower up there. Not at all like the tough old bird she is nearer to sea level. 3000M op's has got to be something else entirely.

[[email protected]]

Hmm, this sounds like the whole SWP thing all over again. You guys just don't like how the FAA names things.


By the way, if you understand what causes LTE, then you should be anticipating it. Therefore, the only "unanticipated" yaw should be from stuck pedal, loss of tailrotor thrust, or engine failure. I think you should learn a little bit more about helicopters before you make sweeping statements like that.

You could start by reading that 'excruciatingly long paper' !

[Robbiee]

I think you should learn a little bit more about helicopters before you make sweeping statements like that.

You could start by reading that 'excruciatingly long paper' !

If its anything like that video, its just going to put me to sleep.

[[email protected]]

If its anything like that video, its just going to put me to sleep. well it sort of depends if you want to learn about something that might save your life or not!

[Robbiee]

well it sort of depends if you want to learn about something that might save your life or not!

Well (as with SWP) what the FAA taught me about LTE has kept me alive for almost twenty years.

,...but if you think you've discovered something new in that article, please, feel free to share with the group.

[[email protected]]

A summary would be - LTE doesn't really exist and most encounters were caused by pilots being reluctant to put in sufficient pedal to stop the rotation. There are yaw disturbances caused by the interaction of the MR downwash and other turbulent flows.

There, saved you hours of excruciating reading.....

Well (as with SWP) what the FAA taught me about LTE has kept me alive for almost twenty years. perhaps because the type of flying you are doing isn't very demanding.......

[[email protected]]

As a check of understanding Robbiee - imagine you are operating at MAUM at high density altitude into a landing site where you can't approach into wind, only crosswind - which way do you take the crosswind, from the left or the right?

[Robbiee]

As a check of understanding Robbiee - imagine you are operating at MAUM at high density altitude into a landing site where you can't approach into wind, only crosswind - which way do you take the crosswind, from the left or the right?

Well, I don't know who MAUM is, but having done crosswind approaches from both sides, I guess I'd just pick the side that has the best view of the chicks on the beach.

[Robbiee]

A summary would be - LTE doesn't really exist and most encounters were caused by pilots being reluctant to put in sufficient pedal to stop the rotation. There are yaw disturbances caused by the interaction of the MR downwash and other turbulent flows.

There, saved you hours of excruciating reading.....

perhaps because the type of flying you are doing isn't very demanding.......


Hmm, so again, no new information, just a desire to no longer call it LTE. Yep, that sounds like its worth fifteen pages.

[aa777888]

Hate to say it, Robbiee, you and I are usually on the side of goodness and light, but in this case I'm in total agreement with crab!

Open your mind, read the damn article, and get with the program. You have already passed your oral exam, no need to parrot the FAA textbooks. And do a damn Google search for "MAUM" as it relates to flying. Certainly those on the wrong side of the pond ;) have some differences in jargon, but you are an intelligent guy (seriously, you are, you can't fool us), you really don't need to be spoon-fed this stuff, come on!

[[email protected]]

Robbiee - Maximum All Up Mass FFS...perhaps you prefer MTOW?

The flippancy of your answer leads me to believe you really don't understand the importance of the question in regard to TR performance and yaw control.

aa777888 - :ok:

[Robbiee]

Robbiee - Maximum All Up Mass FFS...perhaps you prefer MTOW?

The flippancy of your answer leads me to believe you really don't understand the importance of the question in regard to TR performance and yaw control.

aa777888 - :ok:

I suppose not. Guess I'm just doomed to spin endlessly. :(

[[email protected]]

I suppose not. Guess I'm just doomed to spin endlessly. https://www.pprune.org/images/smilies/sowee.gif and if you bothered to read the paper, you would know that doesn't happen either.

It would be quite nice once in a while if the seasoned professional pilots (of which there are a large number on here) were actually listened to by the less experienced when knowledge is being imparted. It's for your good not ours as we have 'mostly' learned from our mistakes and close calls.

[Robbiee]

and if you bothered to read the paper, you would know that doesn't happen either.

It would be quite nice once in a while if the seasoned professional pilots (of which there are a large number on here) were actually listened to by the less experienced when knowledge is being imparted. It's for your good not ours as we have 'mostly' learned from our mistakes and close calls.

Sorry, oh wise one, your great secret will just have to remain hidden amongst those fifteen sacred pages.

[Bell_ringer]

Sorry, oh wise one, your great secret will just have to remain hidden amongst those fifteen sacred pages.

Hopefully you are less flippant with the owners of those 22's you have to haggle down to hire. At least there is only 1 other seat if ego runs out.

[Robbiee]

Hopefully you are less flippant with the owners of those 22's you have to haggle down to hire. At least there is only 1 other seat if ego runs out.

Well, those 22 owners never tried to convince me that the textbook was wrong while keeping their great truth buried in a book so dull that it makes my VCR owners manual seem like a Penthouse Forum.

,...but please, more melodramatic responses, I really need the distraction from the insanity that is playing out in my neck of the woods these days. :bored:

[ApolloHeli]

...but please, more melodramatic responses, I really need the distraction from the insanity that is playing out in my neck of the woods these days. :bored:

Perhaps that paper could be a timely distraction. You don't have to agree with or believe in the findings, but at least the exposure to the perspective that the paper takes on the 'phenomenon' of LTE will broaden your knowledge and approach to flying challenges in the future. It won't do you any harm, but there's a good chance some thought-provoking will entertain the aviator in you.

[nomorehelosforme]

Robbie,

You have dug yourself a rather large hole and worse than that have fallen head first in it. Maybe it’s time to get off your high horse and actually take on board some of the proven advice that has been offered to you in recent posts... as a pilot show some form of responsibility!

[Robbiee]

Robbie,

You have dug yourself a rather large hole and worse than that have fallen head first in it. Maybe it’s time to get off your high horse and actually take on board some of the proven advice that has been offered to you in recent posts... as a pilot show some form of responsibility!

"Proven advice"? What?,...you mean, "read our awesome fifteen page dissertation on the great LTE secret",...?

Nah, I think I'll just stay on my high horse,...I can check out a lot of cleavage from up here! :ok:

[[email protected]]

Nice attitude, perhaps you should consider another forum since there is nothing professional about your approach to flying it seems.

[Robbiee]

Nice attitude, perhaps you should consider another forum since there is nothing professional about your approach to flying it seems.

Such melodrama and smugness,...you must be a delight at the pub. :rolleyes:

[[email protected]]

Such melodrama and smugness,...you must be a delight at the pub. but my smugness and melodrama has kept me alive and flying safely for 38 years where as your gash attitude is far more likely to lead you into problems:)

I'm sure they love you at the flying club.................

[Robbiee]

but my smugness and melodrama has kept me alive and flying safely for 38 years where as your gash attitude is far more likely to lead you into problems:)

I'm sure they love you at the flying club.................

Hmm, preferring knowledge I gained from a textbook (knowledge which has kept me from crashing for almost twenty years) over some great secret hidden in some abstract paper I found on the internet, is considered "gash",...?

Know what?,...next beer is on me. :}

[Torquetalk]

There is plenty of tail rotor authority in the 22

What were the conditions when you had your "LTE" experience?

Great reference paper aa77788.

I think my LTE/unanticipated yaw experience can firmly be placed in the poor aircraft management category as opposed to lack of inherent tail rotor authority. In strong laminar wind I made a lazy clearing turn with right pedal turn and presented the tail rotor directly into wind, with entirely predictable results. Whether there would have been enough authority to reverse the problem is moot, as the first 90 degrees were through so fast, it was clear that a continued turn back into wind was the easiest solution.

The moral of the story was be aware of aircraft limitations and don’t fly daft. I say aircraft limitations because many larger aircraft would have tolerated the same winds without the sudden snap. TR authority is, necessarily related to the aircraft‘s mass and the R22 is a light helicopter.

[Torquetalk]

There is a very good video of an R44 down under that gets into all sorts of trouble due to poor management which was attributed to LTE, but isn't really. From a dozy lack of awareness that the aircraft was running out of power, to pretty much losing control took less than 10 seconds. And under stress, the pilot fought the aircraft almost into the sea, before it flew itself out of what had become vortex ring state. The one thing the pilot didn't do was lower the collective, roll on and get airspeed. Lucky. Very, very lucky.

I can't upload my versions of it. But maybe someone has another format (I have non-accepted MPEG & FLV).

[[email protected]]

over some great secret hidden in some abstract paper I found on the internet, is considered "gash",...? I think aa777888 found it and it is hardly abstract but you are too clever and knowledgeable to learn anything new....

The answer to my question was - take the crosswind from the left (or the same side as your power pedal is). Why? Because weathercock effect (the desire for the aircraft to point into wind) will require non-power pedal to overcome, meaning a lower Tq demand and a reduction in power required (important at high AUM and high DA). If you take the wind from the non-power pedal side, you need more power pedal to stop the weathercock and therefore more Tq overall.

There, that wasn't too abstract was it?

Gash is an attitude of mind - it's the opposite of professional. A bit like a closed mind not willing to embrace new knowledge compared to one striving to learn and improve.

[Robbiee]

I think aa777888 found it and it is hardly abstract but you are too clever and knowledgeable to learn anything new....

The answer to my question was - take the crosswind from the left (or the same side as your power pedal is). Why? Because weathercock effect (the desire for the aircraft to point into wind) will require non-power pedal to overcome, meaning a lower Tq demand and a reduction in power required (important at high AUM and high DA). If you take the wind from the non-power pedal side, you need more power pedal to stop the weathercock and therefore more Tq overall.

There, that wasn't too abstract was it?

Gash is an attitude of mind - it's the opposite of professional. A bit like a closed mind not willing to embrace new knowledge compared to one striving to learn and improve.

Left crosswind, hmm? I didn't make it very far into that article when I first found it (yes aa posted it here, but I still found it on his post) before my eyes got heavy and I started losing focus, but I thought that dude said that the trade-off of the left crosswind approach wasn't really as beneficial as those of you who prefer it think it is?

Anyway, weathercocking is not a new phenomenon, nor is making decisions based on power limitations when hot, heavy, and high.

,..but thanks for the refresher.

[nomorehelosforme]

I think aa777888 found it and it is hardly abstract but you are too clever and knowledgeable to learn anything new....

The answer to my question was - take the crosswind from the left (or the same side as your power pedal is). Why? Because weathercock effect (the desire for the aircraft to point into wind) will require non-power pedal to overcome, meaning a lower Tq demand and a reduction in power required (important at high AUM and high DA). If you take the wind from the non-power pedal side, you need more power pedal to stop the weathercock and therefore more Tq overall.

There, that wasn't too abstract was it?

Gash is an attitude of mind - it's the opposite of professional. A bit like a closed mind not willing to embrace new knowledge compared to one striving to learn and improve.

Crab, the poor guy will take weeks to get his head around that, and after he figures out what “abstract “ really means he might want to contend with
“The answer to my question was” paragraph .... at which point who knows what the 20 year experienced 5 minute tour flying pilot might respond with, we live in hope of something sensible....

[Robbiee]

Crab, the poor guy will take weeks to get his head around that, and after he figures out what “abstract “ really means he might want to contend with
“The answer to my question was” paragraph .... at which point who knows what the 20 year experienced 5 minute tour flying pilot might respond with, we live in hope of something sensible....

Be honest, you love smelling your own farts,...don't you. :D

[rottenjohn]

Not entirely John, the discussion has also encompassed criticism of Robinsons in general as being unsuitable for mountain flying by design and citing design as the main problem with Robinsons, as opposed to how they are sometimes flown. This discussion applies to all Robbies insofar as it‘s about people either flying an inappropriate design or poor airmanship being involved in many Robbie accidents.

I‘m in the poor airmanship camp.

possibly, but if that’s the case they should not be used as a training aircraft or an aircraft for entry level pilots to build experience.
I’d get in a 22 if I knew it’s history. Wouldn’t get me in another 44, I personally know 4 people who have lost their lives in those things,

[[email protected]]

but I thought that dude said that the trade-off of the left crosswind approach wasn't really as beneficial as those of you who prefer it think it is? I don't think that is what he says at all. There are some relative wind directions from the left where the MR vortex can be ingested by the TR and make heading control more difficult but otherwise left crosswind uses less pedal and less power than a right crosswind (US rotor rotation) as all their pedal curve graphs show.

You can get caught out with a wind from the left if it is past the 9 o'clock position as the weathercock effect can push the nose round towards a downwind position - depends on the aircraft and its distribution of lateral surfaces fore and aft of the rotor mast.

The highest percentage of accidents are spinning right (US rotation) but not because of a left crosswind.

[Torquetalk]

possibly, but if that’s the case they should not be used as a training aircraft or an aircraft for entry level pilots to build experience.
I’d get in a 22 if I knew it’s history. Wouldn’t get me in another 44, I personally know 4 people who have lost their lives in those things,

I would agree that there are light helicopters better suited to training: the 269; Enstrom and G2, for example. But Robbies are inexpensive and ubiquitous, so they are going to be both used for training and bought for private use. That is the reality to be dealt with.

Robinson in fairness has the factory safety course, offered at a discount. And the SFAR73 regs require more time to qualify on the aircraft than equivalent types.There is nevertheless clearly a training deficit, as the kinds of accidents which befall R44s have a wearisome familiarity. As per previous posts, I believe more focus on performance and the flight envelope, together with targeted CRM could help.

For the record, I would prefer the R44 over an R22. It is a very capable aircraft and has much more energy in the rotor than the R22. Just be aware than when you fly at a higher TOM, the performance margins start to evaporate rapidly requiring good situational awareness.

[aa777888]

There is nevertheless clearly a training deficit, as the kinds of accidents which befall R44s have a wearisome familiarity. As per previous posts, I believe more focus on performance and the flight envelope, together with targeted CRM could help.It's worth pointing out that there appear to be clear systemic failures associated with training, operations and maintenance in certain geographical areas. New Zealand and Brazil appear to have suffered the most, with Australia also noteworthy. You simply don't see the same level of Robinson carnage in the US and UK.

For the record, I would prefer the R44 over an R22. It is a very capable aircraft and has much more energy in the rotor than the R22.Agreed. I enjoy flying the 44 much more than the 22 and feel much safer in it. However, it seems people can get much more casual about W&B with the 44, too casual. When you walk up to the 22 you intuitively know weight is going to be an issue, and with only two folks on board the calculations are half that of the 44 (not that they are anywhere near complex, of course). With the 44 it's all too easy to think "Half tanks, I'm good!" and be wrong. This is particularly true in the US where people super-size themselves with a depressing amount of normalcy.

[Robbiee]

I don't think that is what he says at all. There are some relative wind directions from the left where the MR vortex can be ingested by the TR and make heading control more difficult but otherwise left crosswind uses less pedal and less power than a right crosswind (US rotor rotation) as all their pedal curve graphs show.

You can get caught out with a wind from the left if it is past the 9 o'clock position as the weathercock effect can push the nose round towards a downwind position - depends on the aircraft and its distribution of lateral surfaces fore and aft of the rotor mast.

The highest percentage of accidents are spinning right (US rotation) but not because of a left crosswind.

I'm not sure what he was getting at with that example, but the way he brought it up just made it seem like he was trying to dispell a myth?

Either way, the left crosswind preference seems more like a high altitude technique (which like lowering the carb heat on short final) just isn't necessary down here at sea level,...but then there are plenty of techniques which are best suited just for specific conditions.

[Robbiee]

I would agree that there are light helicopters better suited to training: the 269; Enstrom and G2, for example. But Robbies are inexpensive and ubiquitous, so they are going to be both used for training and bought for private use. That is the reality to be dealt with.

Robinson in fairness has the factory safety course, offered at a discount. And the SFAR73 regs require more time to qualify on the aircraft than equivalent types.There is nevertheless clearly a training deficit, as the kinds of accidents which befall R44s have a wearisome familiarity. As per previous posts, I believe more focus on performance and the flight envelope, together with targeted CRM could help.

For the record, I would prefer the R44 over an R22. It is a very capable aircraft and has much more energy in the rotor than the R22. Just be aware than when you fly at a higher TOM, the performance margins start to evaporate rapidly requiring good situational awareness.

I have never regretted learning how to fly in an R22,..but I learned after SFAR 73 was initiated, had I started before, maybe I'd feel differently?

Having flown the Schweizer and Enstrom I can definitely agree that they are better suited for training (especially considering the R22 was not designed as a trainer). However, as a renter I am glad that I was able to rent an R22 all those years as it is far more fun to fly than any other small piston I have flown (including the R44).

I cannot speak of the Cabri as I cannot find justification in paying more for just another two seat piston Perhaps if it had air conditioning I'd pick it over the R22 (in the Summer) but come cooler weather I'd be right back in that cheaper (and tons of fun to fly solo) R22!

As for the R44, until another piston comes out with a back seat, it will remain the champion of the private market. That's just simple supply and demand.

[Hughes500]

R22 is more fun to fly than a 269 really ? Love to know why you think that is considering one has a fully articulated head and one doesn't !

[Robbiee]

R22 is more fun to fly than a 269 really ? Love to know why you think that is considering one has a fully articulated head and one doesn't !


I found the Schweizer to be rather sluggish in its control reponses,...not to mention its slow. I was only able to get them up to just over 70kts before hitting full throttle. These were CB and CBi models, so maybe the C is faster, but I doubt it would be any quicker.

The R22's instability (a fart can make it turn) may make training more difficult and hazardous, but when the training is over, that same instability makes it very responsive, quick, and agile.

In short, the Schweizer was like a paddleboat, the R22,..a jetski!

,...unless your idea of fun is mearly cruising at 70kts then diving the nose?

[aa777888]

Got to back Robbie on this. My perspective is admittedly somewhat limited, I only have Cabri time to compare it to, but the Cabri is also relatively sluggish compared to the R22. The friction in the controls (Teflon sliders and all that), and the inertia in the main rotor disk, conspire to make the Cabri feel somewhat plodding. On the other hand, that's probably a good thing from a training perspective. I do very much enjoy having a sandwich during auto's in the G2 ;) With a very tiny bit of time in an EC130, it is easy to imagine that they wanted the G2 to feel a bit like that, also. So while pushovers in the G2 are fun, the R22 still feels much more sporty, flingable, faster, and motorcycle-like. Just keep those G's positive, and I would not recommend emulating any mustering pilot antics, either!

[Torquetalk]

The R22 may be faster and agile, and it also comes into balance easily. But the 269 needs more finesse to get properly in balance and fly nicely. Then it really is a joy to fly. The 269 also has a much broader safe envelope for flight exercises. There are many fundamental things that can be taught more effectively on it than on the Robbies making it a better trainer by a mile.

[[email protected]]

Either way, the left crosswind preference seems more like a high altitude technique not specifically - it is a technique for any time you are limited on power - that can be any where from sea level to the top of Everest.

And it is just a choice to make your life easier rather than harder.

[Robbiee]

The R22 may be faster and agile, and it also comes into balance easily. But the 269 needs more finesse to get properly in balance and fly nicely. Then it really is a joy to fly. The 269 also has a much broader safe envelope for flight exercises. There are many fundamental things that can be taught more effectively on it than on the Robbies making it a better trainer by a mile.

That's the key factor. The safer you make it, the less fun it is.

,...and eventually you want to kick off the training wheels, and just have some fun! Which brings us back to the R22. :E

[Bell_ringer]

That's the key factor. The safer you make it, the less fun it is.


say what?
you need to spend more time in rigid head aircraft.

the muster guys also think its fun, but they’d prefer something safe AND fun, if the cost model permitted.

Hot and High the 22 is anything but fun. We never went much above 70kts, the vibration got a bit unpleasant from there onwards.
Still, we could at least get airborne, the Cabri could only manage one, light pilot and low fuel, that’s why they are limited to the coastal areas in these parts.

[Torquetalk]

That's the key factor. The safer you make it, the less fun it is.

,...and eventually you want to kick off the training wheels, and just have some fun! Which brings us back to the R22. :E

For point-to-point flights and some light aerial work, the R22 is by some measure the better helicopter.

But the point I was making is that you can train in more depth on the 269 because the safe envelope is bigger. It is also much more fun to train on than an R22. I have quite a lot of instructional hours on both and there is simply no contest.

Robbies are easy to fly. And, of course, very easy to fly badly.

[Robbiee]

For point-to-point flights and some light aerial work, the R22 is by some measure the better helicopter.

But the point I was making is that you can train in more depth on the 269 because the safe envelope is bigger. It is also much more fun to train on than an R22. I have quite a lot of instructional hours on both and there is simply no contest.

Robbies are easy to fly. And, of course, very easy to fly badly.

Train in more depth? How so?

[[email protected]]

Train in more depth? How so? Engine off landings for a start I would think - there isn't a huge margin for error in a 22 and it all happens pretty quickly.

[Robbiee]

Engine off landings for a start I would think - there isn't a huge margin for error in a 22 and it all happens pretty quickly.

In my experience doing 180° autos in both, it seemed like they both fell at the same pace, but with the 22 I had more room to glide, whereas the 300 felt like sliding down a flag pole. As for rpm loss and gain, they're both low inertia and I couldn't tell any difference in controlling it.

The only aspect with an engine off landing I could see was a lesser likelihood of rolling over in the 300, but I have done full downs in the 22 and I never felt like that was an issue. I've even had a 22 hop 90° after lowering the collective too fast on a running landing, with no hint of rollover, so,...?

[Torquetalk]

As Hughes500 hinted, it has a fully articulated rotor head, so the manoeuvre tolerances are greater for a start. That is a world of difference.

The governor/correlation relationship in the Robbies only offers limited exposure to the relationship between ERPM and RRPM. This can really be drilled to intuition in the 269

The power range used in the 269 is greater (it is not D-rated) and you can more easily simulate power-limited situations.

Bringing the aircraft into balance and trimming the cyclic are good fundamentals for other larger types. The Robbies come into balance pretty much on their own and there is no cyclic trim.

It is more robust and has more energy in the rotor. The margin of safety is greater during autorotation meaning there can can be more tolerance of error. This margin can be translated into more exercises getting done which don’t always have an eye on the thin RRPM margin and the risk of mast bumping.

It is easier and safer to demonstrate t/r problems..

[Robbiee]

As Hughes500 hinted, it has a fully articulated rotor head, so the manoeuvre tolerances are greater for a start. That is a world of difference.

The governor/correlation relationship in the Robbies only offers limited exposure to the relationship between ERPM and RRPM. This can really be drilled to intuition in the 269

The power range used in the 269 is greater (it is not D-rated) and you can more easily simulate power-limited situations.

Bringing the aircraft into balance and trimming the cyclic are good fundamentals for other larger types. The Robbies come into balance pretty much on their own and there is no cyclic trim.

It is more robust and has more energy in the rotor. The margin of safety is greater during autorotation meaning there can can be more tolerance of error. This margin can be translated into more exercises getting done which don’t always have an eye on the thin RRPM margin and the risk of mast bumping.

It is easier and safer to demonstrate t/r problems..

"Its easier to demonstrate tail rotor problems" lmao,...I'll definitely give you that one.

Anyway, it may be a better trainer, but from what instructors have told me (not to mention my own experience) its easier to transition from a 22 to a 300 than the other way around.


A couple more things I might be misunderstanding. If the Schweizer has a greater power margin, why was I hitting full throttle at just over 70kts at sea level? Whereas, not only can I go faster, but I've never hit full throttle in a 22.

Then theirs the stability thing. In the Schweizer I could let go of the cyclic and if it was out of trim it would just lean to one side, then I'd move the hat and it would stabilize,...easy peazy. In the 22, I wouldn't dare let go of the cyclic, as its just not stable enough for that.

Anyway, maybe I'm just missing something?

[Torquetalk]

"Its easier to demonstrate tail rotor problems" lmao,...I'll definitely give you that one.

Anyway, it may be a better trainer, but from what instructors have told me (not to mention my own experience) its easier to transition from a 22 to a 300 than the other way around.


A couple more things I might be misunderstanding. If the Schweizer has a greater power margin, why was I hitting full throttle at just over 70kts at sea level? Whereas, not only can I go faster, but I've never hit full throttle in a 22.

Then theirs the stability thing. In the Schweizer I could let go of the cyclic and if it was out of trim it would just lean to one side, then I'd move the hat and it would stabilize,...easy peazy. In the 22, I wouldn't dare let go of the cyclic, as its just not stable enough for that.

Anyway, maybe I'm just missing something?

I didn’t say power margin Robbie, I said power range. As you know, the same engine is in both aircraft, but is D-rated in the R22. There is, in fact quite a bit more power margin in the R22. But parts like the MGB won’t thank you for using it. Using the full range of power in the 269 means you are not constantly making small inputs within a limited range (which are further fine tuned by the governor). The inputs in a 269 encompass a bigger range and require more compensation. That trains the relationships between pilot input and associated corrections better.

The R22 is arguably “less stable”. Flighty you might say. But we are talking at cross purposes. I am talking about balance: The R22 comes easily into balance; the 269 needs more help. A poorly flown 269 feels clumsy. The fact that you can trim out the 269 cyclic is also very important in terms of workload management and safety. There are no prizes for making things unnecessarily hard.

[[email protected]]

Robbiee - the training for EOL s is where there is little margin for error in a 22 - you can't let an error develop to make a training point because it is difficult to recover from with that low inertia head.

[Robbiee]

I didn’t say power margin Robbie, I said power range. As you know, the same engine is in both aircraft, but is D-rated in the R22. There is, in fact quite a bit more power margin in the R22. But parts like the MGB won’t thank you for using it. Using the full range of power in the 269 means you are not constantly making small inputs within a limited range (which are further fine tuned by the governor). The inputs in a 269 encompass a bigger range and require more compensation. That trains the relationships between pilot input and associated corrections better.

The R22 is arguably “less stable”. Flighty you might say. But we are talking at cross purposes. I am talking about balance: The R22 comes easily into balance; the 269 needs more help. A poorly flown 269 feels clumsy. The fact that you can trim out the 269 cyclic is also very important in terms of workload management and safety. There are no prizes for making things unnecessarily hard.

Well, I guess I just don't have enough time in them to really get what you're driving at,...plus I'm not an instructor, so its almost like we're speaking different languages.

I'm kinda like Tom Cruise in Days of Thunder. I just know that the 300 was easy to fly, and I didn't enjoy it. Same impression of the Enstrom by the way.

The Sikorsky S-55,...now that I did enjoy flying. :E