Vuichard technique for settling with power?

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Rotorbee - I believe the diagram simply refers to rates of airflow up through the disc all the way from hover to autorotation but does not cover the aggravating and deepening of the stalled section and the enlivened tip vortices caused by raising the lever in the middle of the IVRS and turning it into FDVRS.

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Rotorbee - the reason that the diagram has a dotted line marked autorotative state and windmill brake state is that in a vertical descent (in auto) the rotor is slowing down the air passing through it and extracting the energy to keep the rotor turning. As such there is a limit to the RoD in auto because of the size of the rotor disc - although some of the inboard section is causing rotor drag, the outer areas are producing rotor thrust (with the tips creating drag again.

The point is that essentially none of the disc is stalled (apart from the absolute root) and it is all providing a useful function in slowing the RoD.

Now in VRS, when the root end of the blades are stalled due to high AoA (collective raised) and the outboard section is enveloped in a very high drag vortex, only a small part of the disc (a ring between the root and the tips) is producing lift and/or slowing the airflow down.

The more the lever is raised, the worse it gets so the size of your rotor disc (or that part that can slow your RoD) is greatly reduced, leading to much higher rates of descent than can be experienced in auto.

This is why in FDVRS there are the stories of 3 - 5000'/min RoD and why it is so deadly - and why the VT just won't cut it in FDVRS.

[Rotorbee]

Crab, I agree.
But:
With adding power I pump more energy into the vortex, how much does the vi change? Can you achieve a vi of 2000ft/min to keep the rotor in the shaded area? Or is the added power used, just to overcome the added drag of the stalled area?
One can assume, that the vortex will always be there, even at the highest RoD, because otherwise the rotor would completely stall and that would be the end of it. That does not happen as we know. But how big is it and where is it.
A bigger stalled area or a bigger vortex would be hard to tell apart, with all the turbulence produced from the fuselage and stalled area.
I am not absolutely convinced, that at high RoD, where Vd/vi is higher than 1.5 (there is a limit to vi) the vortex is still the problem, because it should by now be blow above the disk, as wind tunnel test show, where it's influence would be greatly diminished, because the following blade would not hit it smack on to pump energy into it, but I would still have all the ingredients of the controls not responding and so on, due to the stalled area. Which would not go away, but would get bigger.
In that case the VT would not work as advertised, it would just add a bit TR-trust to help speed up the ship to get the stalled area flying again, because that is still the whole point, to stop the descend. But since we are talking about a disk, it does not care about left, back or front. I suspect that moving the ship sideways (crab) is just faster with the help of the tail rotor than nosing over.

Instead in the darker area, I have the perfect situation to pump the most energy into the vortex with each blade, because the ship sinks too fast for the vortex to sink away and not fast enough to get the vortex blown above. That's why in that area you get the worst turbulence and control problems (the biggest and meanest vortex). If you move the vortex off the tip inside, it will be blown away pretty fast. How much control I would have left there, is not something I can find out. Reports of flight test show, that it is extremely difficult to stay inside and a very disturbing experience.
As it happens, in an early NACA paper, the dark grey area was a half circle starting at zero forward air speed. Flight and wind tunnel tests have shown, that this isn't the case and now it is between 70° and 40°. That's a problem I still have to get my head around.
Anyway, I still think the VT solves a artificially blown up problem. It is a trick of last resort.

[n5296s]

One thing I should have mentioned: the reason why my (relatively low time) instructor was interested in VT was because he said they'd found quicker recovery - iirc 400 feet to recover with conventional technique, versus less than 100 with VT.

So we went out and flew both. We flew them as identically as we could, and they both recovered in less than 100 feet. Obviously this was from just-barely-I VRS, as I said we waited one second from starting to feel the shaking and see the altimeter start to drop, to recovering.

So the VT works, but from IVRS it doesn't really make much difference, unless you have a cliff face directly in front of you.

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N5296s - So not really in any form of VRS then, just slow speed with a RoD that you had enough power to overcome.

Rotorbee - the problem with assuming the TR thrust will help is that in FDVRS and to some extent IVRS you will experience random pitch roll AND yaw so you might not have that as an immediate option.

According to Nick Lappos, if you have enough power you can muscle yourself out of VRS - it is just a question of overcoming the massive amounts of rotor drag - not many aircraft have that capability.

I know that those who used to do the VRS demo on the Sea King sometimes struggled to get the aircraft into it (at 10,000') and sometimes it pretty much flew itself out again. I think you have to work hard (or be very unlucky) to keep in the very high RoD area - but it clearly can be done.

[FICH]

Claude Vuichard has just launched his new website, on which his demo video is integrated:

https://vimeo.com/156886502

[Rotorbee]

Oh boy, he is really trying to get himself into the history books.

@N529s: Was to be expected and you point out, why the whole VRS recovery discussion is lame. I think your test has merits, because the best thing is to avoid VSR altogether, the second best is getting out of it as early as possible, the worst is to let build up a huge descend rate and probably crashing before you wake up.

Crab, I could not agree more. I only have my doubts about the common FDVRS definition. Every research, every aerodynamics paper, Prouty, Antonio Fillipone, all of them show, that at the claimed high descent rates, there is no real VRS anymore. While you can't get rid of vortices completely, the rotorblades do not sustain a huge vortex ring, because the air molecules just will not follow a ship down at that speed. Stubborn little bastards.
Therefore Vuichard has an easy game getting out of it. He isn't even in there. All he does is getting rid of the stalled area. The tail rotor is perfectly working in that state. It might even be faster than pushing the stick forward, because there is additional help going sideways from the tail rotor and going sideways will not loose that much altitude compared to shoving the stick forward to the stops and literally diving out of it. In that case I still loose altitude when the VR is long gone. Speeding up the ship from lets say 10 to 15 knots in any direction is done in a blink of the eye and your out of it. If N529s is willing to do another test, he could measure stick displacement. But that is rather difficult. Isn't there an app for this?
(Just an idea. Two pencils, a ruler, two rubber bands and a knee pad. Make an H with the ruler and the pencils. Hold one pencil like Shawn Coyle does it with the new students and place the other pencil on the knee pad - with a paper. Crude but might work).
Will the Vulcan Technique save any lives? I am sure the claims will come, but since nobody is crazy enough to repeat the same mistake willingly just to prove anybody's point, we will never know for sure.
And I go with Nick Lappos again:

Like Typhoid Mary, VRS has been blamed for crimes where it wasn't even in the neighborhood

Surprise, surprise, it was SWP.

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Strange that the last few 'demonstrations' don't show any of the instruments and are just pretty pictures of the Eiger.

Not even remotely convincing - note that the ones with the instruments don't show anything like the 4000'/min RoD claimed for the last clip after 3 secs in VRS.

Smoke and mirrors and don't try it at home

[Rotorbee]

4000ft/min after 3 seconds needs about 3/4 of a g (6.8m/s^2). That would be almost free fall of a sky diver. Oh, the doubts.
To get out there in a second you need 20.3m/s^2. That's more than 2g.
And since I am pretty sure that there isn't a upwind part of the vortex - because the vortex isn't there at 4000ft/min, I wonder what really happens there. Oh, and the VSI only goes up to 3000ft/min.

... and whatever he means with full VRS.

[Vertical Freedom]

Watched the Vulcan tech vid.......Bullocks I say, smoke & no sense nothing proven - a few easy recoveries at 1,000 fpm rod,, what a crock, he's just swp no vr at all

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And also worth highlighting that the use of 'max power' in a 350 might achieve something but in a R22 (which has just enough excess power to pull the skin off a warm rice pudding) you might just put yourself in SWP using the VT.

[Hughes500]

Just watched the video what a load of rollocks. The N face of the Eiger is 5000 ft ( you can only really see on the video from death bivoac to the white spider and to the summit, less than half the full wall ( looked at climbing it when i was young dumb and full of ... but it looked too terrifying ! )I would love to see how he gets into FVRS so quickly. I have been in FVRS as stated in a previous post and i can assure those who have not been there that the North wall would be going up a dam site quicker than is shown. There is no pitching / rolling massive vibration that I encountered so i seriously doubt that he is in FVRS probably just a high rate of descent that most helicopters can power out of . In the case of a Hu300 800ft a min and she will climb back up, Hu 369 about 1000 ft a min those are all from a high hover dumping the lever and at 800 ft a min pulling power back in !
Oh well i suppose i could be wrong

[ShyTorque]

That looked very much like how I recall my QHI's very lame demo of "vortex ring" in a Whirlwind almost forty years ago, up around 10,000 feet.

"There, vortex ring!" he said, "Did you see that?"

"Er, no".. said I, honestly.

"Well that's all you're seeing", he said. and that was it, end of demo.

Nothing like what FDVRS really looked like when I saw it some years later!

The demos remind me of "stall recovery at the incipient stage" in a fixed wing. Just lower the nose slightly and fly away, easy and rapid recovery because it's not a fully developed stall.

Sorry, not convinced at all by that video but in fairness, just like a fixed wing stall, the incipient stage is the best time to recover (if you can do so).

[Rotorbee]

You guys missed something.

Vuichard Recovery Aviation Safety Foundation


And please, donate, it's for a good cause.

[[email protected]]

Good grief!!

[Thomas coupling]

So that is confirmed then, the man himself confirms by describing and also by videoing that his technique is a way of exiting quite early onset of INCIPIENT VORTEX RING once and for all. he didnt last more than 3 seconds inside IVRS nor did he exceed 900 feet per minute (which is another indication he didnt enter FDVRS).
We all now know where this technique comes from and why it is so damn convincing - don't we?

My question is therefore:

Why in the name of JC is he asking for a donation towards his web site that is describing absolutely NOTHING special whatsoever?

Can you please donate to my project:

Changing direction in a helicopter without using pedals?

FFS what a massive disappointment after all this hype

[Rotorbee]

What the FAA has to say...

When recovering from a settling with power condition,
the pilot tends first to try to stop the descent by increasing
collective pitch. However, this only results in increasing
the stalled area of the rotor, thereby increasing the rate of
descent. Since inboard portions of the blades are stalled,
cyclic control may be limited. Recovery is accomplished
by increasing airspeed, and/or partially lowering collective
pitch. In many helicopters, lateral cyclic combined with
lateral tailrotor thrust will produce the quickest exit from the
hazard assuming that there are no barriers in that direction.
In a fully developed vortex ring state, the only recovery may
be to enter autorotation to break the vortex ring state.
Tandem rotor helicopters should maneuver laterally to
achieve clean air in both rotors at the same time.

faa-h-8083-21 Helicopter Flying Handbook 11-9

And before you get all excited because about the SWP, the definition of VRS/SWP given by the FAA:

VORTEX RING STATE (SETTLING WITH
POWER)
Vortex ring state describes an aerodynamic condition
where a helicopter may be in a vertical descent with up
to maximum power applied, and little or no cyclic
authority. The term “settling with power” comes from
the fact that helicopter keeps settling even though full
engine power is applied.

That's fine with me, since the FAA has to be careful not to puzzle to many old CFI's who have taught SWP for their whole life.

That book is from 2012. Since the FAA isn't the fastest agency in the world, we can assume, that it took them a few years to get to that point.
In the acknowledgements the FAA has the guts not to mention Vuichard for his contribution, neither Robinson nor Tim Tucker. Didn't they know, that Vuichard owns the rights? Or have the authors just known that stuff for years and did not bother. According to the FAA you don't even have to use more power.

Man, must be a shock to the Swiss, that the FAA, that terrible agency that certifies people after cheap training, was actually faster ... again.

And if somebody is really interested in VRS, I found this from NASA.

And for heavens sake yes, I will call it from now on FVRS with a descent rate way beyond the lightly shaded area. You win.

[Devil 49]

It's been decades since I thought about fixed wing stuff, but doesn't the 'school' solution to VRS seem very similar to an airplane departure stall book answer?

[Rotorbee]

From my Inbox

You will not believe what found the way on my desk.
There is a long interview with Vuichard in the Freiburger Nachrichten from the third of march. A local newspaper , but since it is in black and white, it must be true ... with a picture of the recent crash in Hawaii (which had nothing to do with VRS, but that's journalism).

Apparently many have died in VRS with billions of dollars (I do not exaggerate, it‘s written there) in damage.
"They" must have covered up thousands of VRS accidents and told us for years lies about the cause, like engine failures, cables, CFIT or other almost impossible ways to crash a helicopter. Bad that, very bad.
The FAA has become aware of him and has allowed him to speak at HAI Expo 2016.

Therefore my friends of bad faith, you must now bow your head in remorse, for you will never again question the Great One. Because it is written in the Holy News that his own words were: „Das kommt ins Fliegermuseum in Washington“. In plain English: „This will be in the aviators museum in Washington“ (probably the A&S Museum or they open one for him alone).

Probably his portrait will hang above the other not so great stick jockeys. Da Vinci himself will paint it. Resurrected by the Pope just for this unique occasion. The new millennium has its hero.

Apparently he found his technique 28 years ago. That is still after some of our colleagues here have known it, but hey, what's a few decades between prophets.

I will now ritually burn my helmet, license, bush pilot belt buckle, log books, Prouty, Coyle and all the other heretic books and hope that the great one will one day choose me to be his humble disciple.

And that one: "Never has a operational procedure been named after a person". No kidding. Who would call a procedure after himself?

But let's give the man a break. He will be 60 this year and his flying days are more or less over. He will now embark on a crusade around the world to save us all from doom (Coming soon in a hangar near you).

Hail Cross Control Recovery, for VRS is the mortal sin.

[Vertical Freedom]

Thanks 4 der gude larff Rotorbee...I almost had to change nappies I laughed so damn hard. 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