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-   -   Vuichard technique for settling with power? (https://www.pprune.org/rotorheads/557861-vuichard-technique-settling-power.html)

Rotorbee 11th Mar 2016 14:16

Oh VF, I am so disappointed that you don't see the light. :=

Admit your sins. Your meagre hills are nothing compared to the mighty Alps where the Great One had his revelation. You will from now on preach cross control or the Yeti will be lurking in the shadow one day and barf on your shoes. :=

Now let us pray ...

Lonewolf_50 14th Mar 2016 14:54

As requested, Rotorbee ...

Our Vouchard
who art in hover
Settling be thy bane
Thy cyclic come
Thy flight undone
Striking earth
Plunging down from the heavens
Give us this day a pedal slide
And forgive us our descent rates
As we forgive the CFI's who smote our pates
And lead us not unto the hillside
But deliver us from the vortex

Jimmy. 9th Sep 2017 13:23

Demonstration Video
 

Ascend Charlie 9th Sep 2017 22:36

Excellent bit of filming there, shows the flows beautifully.

aa777888 10th Sep 2017 00:29

Wow. Best video I've seen in a long time. Brilliant use of the spray system. Bravo!

newfieboy 10th Sep 2017 02:43

Awesome,
I'm flying an AS350 at the moment on forestry spray. Can really relate on what's going on. We're going max gross off the deck sometimes every ten minutes. Like tonight's session wind is calm but enough to be a tad downwind in the turns. Only way to spray the block due environmental. Can really feel the bump as you go through your vortices at the start of the line.
Another tool in the survival kit, especially tree tops heavy. The lack of height lost is very appealing.

jellycopter 10th Sep 2017 06:46

Great images, rousing music, proves nothing. Where are the corresponding images of a regular IVR recovery for scientific comparison? Still not convinced.

Vertical Freedom 10th Sep 2017 07:14

The Vulcans retirement kitty....please give generously
 
Nice video :ok:

Undoubtedly the Grand Mashter Flash Vulcan technique will all save us one day from an early grave (NOT) as the far greater One; once said...'if it ain't broke don't fix it'

Moral of the story....if You find Yourself in VRS or IVRS then; leave power on or apply more to the red line, at the same time give a big pole forward & maintain some heading of sorts, until You fly out of it works every-time every bleedin' time
Happy Yappy stay Happy :cool:

[email protected] 10th Sep 2017 07:44

jellycopter - 100% agree - at best that was a quick recovery from IVRS, nowhere near full VRS.

yellowbird135 10th Sep 2017 09:00

...but the thing is....in day to day ops how often do you encounter fully developed VRS?
In my experience, in the day to day ops, you notice immediately something is not right and you act.....this is mostly in the initial phase of VRS.
Now, the reaction on brain stem level is to dump collective, drop the nose and fly away.
I think it requires a lot of effort and training to make this technique your 'brain stem' response.....
I do think however that this might be a better approach to recover from it..
Let's see how the company training dept. feels about it...not in the sim but in the real thing..

[email protected] 10th Sep 2017 11:30


...but the thing is....in day to day ops how often do you encounter fully developed VRS?
Mr Vuichard seems to imply it is a regular occurence, hence his crusade to prevent loss of life from VRS accidents.

However, we don't actually see many VRS accidents, there are far more CFIT or power-settling accidents.

Whilst I agree that recovering from IVRS early is a good thing, it is far better to avoid it in the first place by planning and calculating performance before flight and avoiding the conditions where IVRS might occur - it's not difficult to do.

Non-PC Plod 10th Sep 2017 13:11

Situational awareness is the key, and that usually comes with experience (as well as planning/briefing). I had a great example last week - I selected the AHRS to "DG" instead of "Mag" before startup to see how long it would take the student to see that something was not quite right.
45 mins later....(and with a big yellow HDG box on the PFD all this time), we were going for a hover OGE 1000' AGL as previously briefed. The wind indication on the PFD was now well and truly corrupted, showing about 180 deg out. But any check of groundspeed versus airspeed would show that we were 10-12 kts downwind (as per the weather forecast discussed at the brief).
Of course I could see all this unfolding, and I was ready to shove the nose forward (sorry M.Vuichard!) as soon as the vertical speed started to get out of the comfort zone. But, you would expect any competent and aware pilot to have noticed one of the many clues that were there all along, and we would never have got into the situation.

ShyTorque 10th Sep 2017 14:28

I'd say the demo is more like what I'd call "settling with power" (i.e. running out of enough power to arrest a vertical descent) and flying out of it by putting the main rotor laterally into clean air to the side, rather than by a transition straight ahead.

It certainly doesn't look anywhere near as exciting as the fully developed VRS that I experienced, which involved quite rapid pitching, rolling and yawing.

[email protected] 10th Sep 2017 16:43


It certainly doesn't look anywhere near as exciting as the fully developed VRS that I experienced, which involved quite rapid pitching, rolling and yawing.
and that is the danger of this 'technique' - people might think this is a magic bullet to save them from real VRS which it most certainly isn't.

Hughes500 10th Sep 2017 16:53

I am perhaps not the most experienced pilot on this forum but that video DOES not show VRS. As for pulling full power yes that will possibley get you out of IVRS but not fully developed. I know I have said this before but as a junior instructor one of my students had made 5 normal recoveries from IVRS using the normal stick the cylic forward technique. For someone unknown reason on the 6th go with a ROD of around 800ft a min with the cabin shaking, pitching and rolling the student pulled full power. Well fu.k me the result was what felt like an 80 degree nose up with the ac falling on its tail. ( so Mr Vulchard please explain that ) the vsi hit the stop at 3k a min. As for recovery I had the cylic on the forward stop, nothing happening, lever fully down and still falling on its tail. last resort was full pedal, then again wtf now facing 80 degrees pitch down and looking at the ground hurtling up. Slowly pulling power and rear cynic. I guess we missed the ground by about 200 ft. Not really sure how the rotor head stayed on the heli. So I was undoubtedly very close to full VRS when student pulled full power. This caused instantaneous fill VRS so I do not see how pulling full power and lateral cylic with pedals would work. But always happy to hear from those with more experience. Sorry that video shows nothing !

[email protected] 10th Sep 2017 17:32

Hughes500 - and your story correlates exactly with Shy's and many others who have experience full VRS.

Mr 'magic-technique' Vuichard is clearly not the aviation God he professes to be - perhaps he is just someone looking to make a name for himself by selling snake-oil to the unsuspecting.

Bell_ringer 10th Sep 2017 17:58


Originally Posted by Hughes500 (Post 9887860)
...on the 6th go with a ROD of around 800ft a min with the cabin shaking, pitching and rolling the student pulled full power. Well fu.k me the result was what felt like an 80 degree nose up with the ac falling on its tail. ( so Mr Vulchard please explain that )!

Well, the technique isn't about purely pulling power which on it's own would make the situation worse, the key is pulling power and simultaneously pushing the power pedal and rolling to the opposite side (ie left peddle and right roll in a yank machine and the opposite in a flying bus).
It's the roll assisted by the the tail rotor drift that helps you get into clean air.

Washeduprotorgypsy 10th Sep 2017 20:54

Well first off I salute the entrepreneurial spirit of the whole technique and its"commercial" application.

Secondly, making the analogy with blowing smoke rings with stage of vortex development. I think VT can blow smoke but I'm not sure the ring part makes it past the end of his nose. Whereas everyone else on the forum who has submitted a more visceral response has experienced being entrained in the smoke rings of Gandalf himself blown clear across the room or to the base of the mountain as it may actually be.

Not sure the technique is new at all within the vertical reference community, but understand the outcry at trivializing VRS for the less experienced who might be tempted to disobey tried and true descent rates, in favour of faster productivity (i.e "ego posturing") because the VRS dragon has been slayed by the "VT two step" into the 300 foot hole/gully.

I don't think the technique is without merit just that it is a last line of defence in steep and slow(big trees,confined gullies, downwind, longline) situations versus a healthy respect for traditional descent rates around 300 fpm.

Hughes500 10th Sep 2017 21:11

Washed
300fpm ? thats not even close to IVRS. can demonstrate 600 fpm vertical descent in a Hughes 300, pull power and she climbs back out of it
In the video I doubt the Lama has much more than 600 to 800 ft ROD
Anyone on the forum a test pilot at Boscombe Down with an ac with the kit on it to prove or disprove the theory. I don't see how you can get an ac in VRS ( say 1200 ft a min ROD plus ) can suddenly be stopped within 20 to 50 ft

Washeduprotorgypsy 10th Sep 2017 22:37


Originally Posted by Hughes500 (Post 9888020)
Washed
300fpm ? thats not even close to IVRS

Yes, precisely, there could be some wiggle room in there for a sleepy brain ,flabby biceps and a big pitch pull at the bottom depending on all the factors. However the time and distance verticalled is so short why rush it?

nigelh 10th Sep 2017 22:47

Well it certainly looks like this guy has ruffled some feathers !!!! No surprise that it is the usual crew of old school pprune resident experts ( you know who you are !!) who are the most dismissive . It looked clear to me by the accelerated RoD combined with the reversal of spray pattern that the helicopter was indeed just into VRS and the neat " side step" certainly looked to bring it to an abrupt end ..... Far quicker than forward cyclic I thought and with less height loss . So wouldn't it be better to actually learn more about this idea and see if it really is as good as they say ?!! It would be relatively easy to pitch the two recoveries head to head .....that way we may make things safer and maybe even prick some inflated egos at the same time 👍👍. ( or God forbid prove them right and never hear the last of it !!!)

Vertical Freedom 11th Sep 2017 03:41

All opinions are welcome here.............as for the (magic self labeled) Vuichard technique; my Mountain colleagues & I have tried many, many times, sure it works OK (just) during the onset of a pussy footed SWP or IVRS , but once Your in a full blown skid mark serious VRS; then the Vuichard technique is as useful as licking Your microphone wind sock for a recovery. Be warned the Vuichard technique is Bollocks, it won't do diddly squat for you in full blown VRS.

Moral of the story................stick to what works & you'll live longer; :ok:

'If it ain't broke? Don't fix it'

When Your in VRS:
1. immediately & abruptly Pole forward (a good hand full of forward Cyclic)
2. leave Power (Collective) applied &/or add some more to the red-line
3. keep her straightish with pedals

.........works like a charm, every time! Tried, tested, proven; too many times to count :D

[email protected] 11th Sep 2017 08:32

Nice try at stirring it Nigel - please carry on.....those that want to believe Mr Vuichard's fantasy can continue in ignorance of real VRS if they like.

Jabberwocky82 11th Sep 2017 11:26

What is the reasoning for it to be a better technique? Surely the rotor disc cares not which direction it flies to find clean air? Is it the added thrust of the tail rotor which is meant to help compared to the normal poling forward?
What's the physics behind it?

[email protected] 11th Sep 2017 12:12


What's the physics behind it?
there isn't any.

All the pretty videos and flow patterns show that this is not a recovery from VRS, it is simply using power to fly away from the incipient and very early stage, long before full VRS has developed. And you are right, the disc doesn't care which way the clean air is coming from - in fact if you have any forward speed then moving forward is the quickest way to reach undisturbed air.

Thomas coupling 11th Sep 2017 13:20

Firstly,
I'd like to congratulate Mr Vuichard on the making of a very professional film about crop sprayers.
The colours, backdrop, photoshop and music (especially) make for a very convincing story line................

until you realise this is one seriously FUC*ED UP commercial.

Either there is some meaning lost in translation between Mr Vuichard's interpretations and technical languaage or Mr Vuichard is one helluva'n ignorant pilot.
Nothing wrong in being an ignorant pilot - (one just posted on the 10th)....but it's best if they fly quietly out of harm's way somewhere in the boon docks chasing wart hogs.

We have been round the buoy with this particular Mr Vuichard before and as long as he continues to promote a very very dangerous message to those in the helicopter community that this is the gospel when it comes to VRS - I will continue to correct him.

Let me list facts and plead with the 'converted' that this message is WRONG, so very WRONG.

1. VRS is a fully developed aerodynamic state where the controls of a helicopter do not respond normally. Therefore adjustments/ corrections to these controls are sporadic.

2. VRS by definition includes a RoD in excess of 75% OF THE DOWNWASH SPEED OF THE MAIN ROTORS. this means RoD's in excess of 300,400,500 feet per minute - to start with and can reach thousands of feet per minute.

3. VRS is exacerbated by PULLING POWER. It accelerates stall.

4. Incipient VRS [IVRS], is not VRS.

5. Alternatively, flying controls react normally during IVRS.

6. Departure from the airstream beneath the tip path plane will diminish IVRS. This is normally achieved using the cyclic in either a sideways or forward direction. Departure to the side, rear or front of the vortices removes the cause.

7. IVRS rarely if ever exceeds 300 fpm.


Inaccuracies in the video:

(a) There is an "N" in Robinson.
(b) The subject matter he refers to has an "I" missing from the mnemonic: "VRS". The video would then make sense.
(c) A minimum height loss of "20-50 feet" cannot be achieved during VRS as the a/c is descending hundreds if not thousands of fpm.
(d) the audio suggests pulling power initially. This will of course accelerate loss of lift developing at the root, further aggravating the RoD.
(e) None of the controls would respond to the pilot's inputs if the demo actually showed VRS.

For those out there who wish to accept this video in its entirety - as gospel. You are living on borrowed time. It is essential you grasp the fundamentals of IVRS and then VRS before you even think about attempting to emmulate these manouevres for yourself.

Vertical Freedom lives and breathes the perfect environment for VRS in that rarefied atmosphere up there in the mountains - his comments require serious thought and consideration - because he is of course: correct.
As for Crab and myself who taught this for a living...................

Rotorbee 11th Sep 2017 15:31

Well, it does not stop and it never will. For the Swiss and Robinson he is a hero.
I find it rather funny to call that thing in the video a VRS. As we have seen in his other videos in front of the Eiger, Mr Vuichard isn't to open with a view on the instruments. Not even in free fall he would have reached the RoD he claims in that time. The same with this Lama. Nice pictures, but never a VRS, one needs a few more feet to get into VRS.
I don't want to be in a helicopter that had a stop of a RoD from in excess of 3000 ft/min to zero in 20 feet. That is better than any quickstop I ever did.
It is strange, that Vuichard is so fixated on this problem. I can recall just one accident in Switzerland where VRS was the cause. In that case (the one with the REGA Agusta) the pilot did not realise what happened until he reached more than 900 ft/min RoD and > 20 kts and the IVRS started. Pulling power aggravated the situation, therefore he was quite close to a pretty good VRS.
I wonder if Vuichard bent a few ships in his lifetime with VRS. Otherwise I can not explain, why he is making up terrifying numbers of accidents that just are not true.
What is this man trying to do?

One thing in the Agusta accident final report I find interesting. They wrote, that some light helicopter manufacturers are evaluating a alternative method = Vuichard + Robinson.
The optimal recovery technique is set by the manufacturer. No Vuichard for Agusta, ups, sorry, Leonardo.
The recommendations do not include the Vuichard technique but a warning of some audible form from dangerous combinations of airspeed and RoD. Something I think is a very good idea and would probably completely eliminate VRS accidents. Much better idea than listening to a self-proclaimed prophet on a crusade against imaginary windmills. But why haven't they done that. With modern electronics this would not be a problem. Probably because it isn't the number one killer of helicopters. More number 347.

nigelh 11th Sep 2017 15:53

You guys may well be right and i agree ( and bow to his professionalism in this field ) with Verticals " if it aint broke dont fix it " !!
I would still however like to see a proper comparison of the two techniques, as it may be that the pilot doesnt have the room infront and below to pole forwards and dive due to obstacles . Either way it seems that there are two groups of highly experienced pilots who disagree which can only confuse the rest of us mere mortals !! If he is wrong then his theory should be disproved and he should stop touting it around !!!

Thanks Crab ....a decent cast always gets a rise from the old TC Trout !!

Paul Cantrell 11th Sep 2017 18:30


Originally Posted by nigelh (Post 9888632)
I would still however like to see a proper comparison of the two techniques, as it may be that the pilot doesnt have the room infront and below to pole forwards and dive due to obstacles .

I regularly teach both techniques in R44s, and less frequently in B206 and R66. My typical recovery is from sink rates of 1000-1700 feet per minute. I have been in VRS in an R22 that pegged the VSI, but I guess I'm not good enough to nail the downwash as well as that pilot could; I've never been able to peg the VSI myself - I tend to fly out of it before I can get those kinds of sink rates.

I'll also mention that a while back Nick mentioned that sink rate to achieve VRS varies with disk loading (which affects downwash velocity) thus a light disk loaded machine like most pistons will be in VRS at a lower sink rate - he had calculated that the R44 was in VRS @ 800 ft/min. So we have the issue that the least experienced pilots are flying the machines that are the easiest to get into VRS.

In any case, I do indeed see quicker recovery using Vuichard than traditional... typically 40-50 feet vs 150 feet. It is quite abrupt - it's like hitting a speed bump as it shoves you out of the downwash. It's also slightly less comfortable for student pilots because you then have to recover from sideways flight which can be disorienting for a low time student pilot.

The traditional method also has a problem for low time pilots in Robinsons - we spend a lot of time teaching them not to do aggressive cyclic pushes in order to avoid low gee, so it feels weird for them to do an aggressive cyclic push in that situation. This can cause very slow recoveries from VRS..

My suspicion all along is that the faster recovery I see with Vuichard is because I'm not lowering the collective, the way I am with the traditional technique. It would be interesting to understand what Vuichard would do with a deeply stalled rotor system, however in 30 years of teaching probably tens of thousands of recoveries from VRS, I've never felt any indication that the cyclic was losing effectiveness. So it might be that if I did the forward recovery without lowering collective I would see the same 40 feet (but I'm somewhat skeptical that I would).

Of course, we shouldn't be recovering from fully developed VRS anyway, because what the heck were you doing all that time the sink rate was increasing??? My general advice to new pilots is that if they are on approach and they feel that sinking feeling down around ETL speeds, they should simply go around - chances are fair that they had a tailwind or otherwise screwed up the approach. If you detect it while you're right around ETL speed, you don't have to gain very many knots of airspeed to be flying again.

If it's an OGE hover it's a little different, but in that case you're presumably trying to hold a specific altitude, so it's pretty obvious when you start to sink... long before you hit VRS you should have fixed the sink rate...

Reely340 11th Sep 2017 19:15


Originally Posted by Vertical Freedom (Post 9888151)

When Your in VRS:
1. immediately & abruptly Pole forward (a good hand full of forward Cyclic)
2. leave Power (Collective) applied &/or add some more to the red-line
3. keep her straightish with pedals

.........works like a charm, every time! Tried, tested, proven; too many times to count :D

Being the newbie that I am I don't get it: The only difference I see is that the Anti-Vuichard faction advocates forward stick, whereas Vichard likes sideward stick better.

Both recommend to "leave power applied" (at least VF did in post #226) and keep her straight with pedals.
I don't see any difference, besides maybe rolling a heavy airframe might need less energy that pitching it.

What am I missing, why is it so extremely important which direction I ram the stick to, to end full VRS?




Paul Cantrell 11th Sep 2017 19:29


Originally Posted by Reely340 (Post 9888799)
Being the newbie that I am I don't get it: The only difference I see is that the Anti-Vuichard faction advocates forward stick, whereas Vichard likes sideward stick better.

Both recommend to "leave power applied" (at least VF did in post #226) and keep her straight with pedals.
I don't see any difference, besides maybe rolling a heavy airframe might need less energy that pitching it.

What am I missing, why is it so extremely important which direction I ram the stick to, to end full VRS?

For Vuichard, I was taught that if I'm at a low power setting to increase to a moderate climb power and use power pedal to maintain heading - the idea being to make sure tail rotor is producing enough thrust to shove me sideways out of the downwash. Also, you want to tilt the rotor in the direction of tail rotor thrust, i.e. in an American helicopter bank right, in a French helicopter, bank left... so that main rotor thrust and tail rotor thrust are working together.

Thomas coupling 11th Sep 2017 21:28

Reely 340.
The big big difference is that Vuichard is calling his technique: recovery from VRS.
The lesson to learn here reely is that he is never in VRS. He is only ever demonstrating (in all his shots) how to recover from IVRS.

There is a HUGE difference.
Quite a few helicopter pilots have experienced IVRS, they probably aren't 100% sure what is happening but they manage to scramble out of it - somehow. And they live to fight another day.

BUT when you enter FULLY DEVELOPED VRS, your helicopter takes on its own persona and you may well become an unwilling passenger.

We used to teach FDVRS in the mil - many moons ago. Entry heights were greater than 8000 feet due to the height lost. Some a/c were lost before the mil put an end to it all.

But I will never forget the characteristics of FDVRS:
yawing, pitching, rolling - uncontrolled (yawing was dependent on the vortices blowing thru the tail rotor area).
RoD: extreme figures - 2,3,4000+ feet per minute. As some say- the gauge was off the clock - pegged!

Recovery must be forceful and sustained - fwd cyclic (20 degrees plus and lower the collective, maintain pedals central.
[If you bottom the collective - autorotation is a recognised way of coming out of VRS]. You cannot get VRS in an auto state - aerodynamically impossible.

So - all these pretty videos are bull****, UNLESS there is a loss in translation and Vuichard means IVRS and not VRS.

One simply cannot recover from FDVRS within tens of feet - absolute complete and utter bollock*.

How does one sift thru this minefield of cross purpose advice and guidance:

Simple, remember this:

If you are experiencing a gradual and increasing RoD.
A/c starts to vibrate.
Controls gradually feel less responsive.
Speed is low (<20kts ish - no fixed figure).
You are almost certainly entering IVRS.

Response - gentle nose fwd atleast 20 degrees and HOLD, gently lower the collective (IF height permits). Sorted.

If height doesn't permit: nose fwd 20 degrees and apply collective to a sturdy RoC setting - this is called the "minimum ht loss technique".

IVRS will always allow the pilot to respond without much of a rush.




YOU HAVE TO ALLOW IVRS TO CONTINUE if you want to experience the true VRS.
And believe me when I say - you will never forget what that feels like (if you live to tell the tale), because you'll need hundreds possibly 1000' to recover.

Here the recovery technique is the same but because you are running out of height - the minimum ht loss technique is advised, in this order:

Nose down atleast 20 degrees and HOLD (to regain ample fwd speed).

THEN

Raise collective to max RoC setting to get away from terra firma!

Look back over this very long thread to learn more. And spread the word that Vuichard is talking bollox. [Unless of course he actually is talking about IVRS and not FDVRS].

FlimsyFan 11th Sep 2017 21:31

It is indeed quite mind boggling to the lowly 250hr private pilot. As alluded to, Robinson are now promoting the Vuichard as their recommended recovery.

During the Robinson Safety course, having gone through the theory we went and flew the recovery with Tim Tucker from RHC in an R66.

With 4 POB, I have video recorded from the back seat showing ROD at 1900 ft per min, and the thing was shaking and rolling all over the place. The recovery certainly seemed massively swifter than the 'traditional' technique as demonstrated, but I'm very reluctant to dismiss the views of the highly experienced guys here.

It seems to me with the numbers we saw, this must have been way past incipient; however as a low time pilot, my conclusion is to work very hard to avoid the basic ingredients for VRS in the first place - after all, it's fine saying that you can recover in 100ft from fully developed VRS when you start at 3500 ft, something else entirely when you f**k up a downwind approach into a confined area and the job goes tits up at 150 ft.

As someone else commented, I will probably stay with the Vuichard, just because rapid forward cyclic + R66 has been known to lead to much worse than VRS...

Very interesting discussion tho.

nigelh 11th Sep 2017 21:56

Well maybe I am wrong but I wouldn't call 1900 ft sec incipient. There is far too much evidence here to just call it " Bollox " TC . Have you had this recovery demonstrated to you or done it yourself ?? If it didn't work ... Well tell us !
Everyone here just wants to learn ..if this really is a better technique then we should investigate it surely ??? I personally have no idea having never been in VR in 35 years and have no intention of doing so training or otherwise !!

Washeduprotorgypsy 12th Sep 2017 04:43

A Classic semantic, pedantic internet vortex ring
 
Robinson could be supporting the technique because they are making the tacit assumption that most of their pilots have a uncanny knack for making downwind approaches. In which case, the sidestick makes sense.

Upon further review of that well done and beautiful video It is interesting to note that in the first "main showpiece" clip explaining the "visualization of the airflow" at 50% slow mo. It seems to be that the RoD is high enough that the recovery takes place in the turbulent wake state , punching right through the vortex ringstate, he falls right through the donut centered on the tip path. The lama is getting clean air and able to reverse the flow with pure grunt, escaping a redeveloped vortex with lateral cyclic. It would be interesting to see the scene reshot slowing the initiated descent so that the pitch pull could tease the strength of the building vortex ring , just right, without falling through it. .....like we are ever going to see that clip. The rest of the clips show IVRS nicely.

Maybe it's just me , but with the charts depicting modern day disc loadings as making 500 - 1000 fpm vertical descents acceptable. I' m not sure they really factor in the rate of vertical deceleration and power application or the recovery profile, so as not to stir a dragon. At the extremes we have the V22 which according to its induced velocities should be immune to vortex ring in moderately aggressive conventional helicopter flight. Somehow I don't think they baby it around on short final because it's 'spensive.

Hughesy 12th Sep 2017 05:26

Isn't it more important to recognize the onset of settling and recovery immediately rather then allowing full blown vrs to develop?
Regardless of what recovery technique used?
Personally I would be using the normal forward cyclic way.
But recovering before if gets more interesting.

FlimsyFan 12th Sep 2017 06:09

Correction
 
Had a quick look through videos from training the VT, and max ROD you can just make out on the panel is 2400ft/min.

But then I accept that all the high time guys here have the tacit understanding that I am a **** pilot in a **** helicopter and therefore don't much care what I have to say.

Heliringer 12th Sep 2017 06:28


Originally Posted by FlimsyFan (Post 9889161)
Had a quick look through videos from training the VT, and max ROD you can just make out on the panel is 2400ft/min.

But then I accept that all the high time guys here have the tacit understanding that I am a **** pilot in a **** helicopter and therefore don't much care what I have to say.

Hi mate, is there any chance you can post the video here or youtube?

Slack day at work here and we are looking Robinson VRS stuff up. The highest ROD I've seen so far is about 500fpm, although it is hard to see the dials sometimes. It would be interesting to see this at 2400fpm.

[email protected] 12th Sep 2017 08:24

I have a suspicion that the demonstrations don't give a real world perspective - in the classic VRS scenario, you are already pulling a lot of power because you are either approaching or trying to establish an OGE hover.

The demonstrations seem to involve lowering the lever to initiate the descent, leaving you a fair surplus of power to recover.

Nick Lappos has always said that with a powerful enough helo, you can muscle your way out of VRS because you are able to overcome the massive increase in rotor drag.

So the difference between going from a low/medium power setting to max power (as prescribed by Vuichard) is going to be greater than going from almost max power to max power - this might help explain why these artificial setups seem to work well.

When we see a video of full blown VRS - with a high power setting to fully aggravate the situation - being recovered in tens of feet, then I might start to believe but not until then.

For those who have done the Robinson course, do they only show this in the R66 or do they do it in R22/44 as well? I only ask this because of the extra power available in the 66 over the 22/44.

aytoo 12th Sep 2017 09:20

Hi Crab! Long time no speak...

What an interesting thread! M Vuichard, FWIW, is an examiner with the Swiss CAA, with a long history of long lining and mountain flying. Not directly defending his technique - I have insufficient data for that. However, I do think it is one of the more interesting concepts that I have seen in my limited flying career (1983 - 2011).

Like others on here, I have always had a healthy respect for VRS, and used to teach my students to listen for/feel the aircraft growling at you as a warning - as they all will on a poorly flown, low-speed, and steep approach.

I also recall seeing an explanation of the origins of the terms VRS and SWP, but cannot now locate it. IIRC it has the US Army calling it one thing, and the USN the other - and no agreement on a common way forward. Imagine! (Quickstop v fast stop springs readily to mind).

All I will say on Vuichard is to keep an open mind. Until we see quality data from an unimpeachable (and not-for-profit) source, shall we consider that he might - just might - be on to something?


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