Vuichard technique for settling with power?

[Flying Binghi]

...Poling sideways to obain the sort of recovery speed one is after would require signifiacnt nose left/right and maintaining it - not very comfotable at all. Better to nose down which the a/c is designed for from a slipstream perspective.
But technically as long as you exit the turbulence beneath the rotor disc - left/right/back front - you will recover.

(A comment from a VRS novice) Going off the comments of those who have been in a fully developed VRS the helicopter is bib-bobbing all over the place. So the idea of being uncomfortable with the direction of cyclic input may be moot. I'd imagine by the time the world stops tumbling and the sideways movement becomes the next item of pilot attention then the machine is out of VRS state and can be recovered to forward flight - likely already straightened up before the VRS-novice pilot starts to think about it.

Note - my only exposure to what were called VRS were during initial training where the instructor demonstrated it to me in a 300. It were such a pleasant experience compared to what is described here that in hindsite I'd say we wern't anywhere near a developed VRS. I have though whilst mustering had what i thought were some bumpy settling with power incidents. And the difference is...






.

[Reely340]

I would wager a large bet that you are far more proficient and comfortable with 30 degrees nose down than 30 degrees sideways slip for a prolonged period.
Absolutely! I've never ever done these things.
My "(I)VRS training" was one single demonstration by the FI at 1500ft AGL were I faintly remember a ROD of maybe 800fpm when he got excited & pointed out some "shaking/trembling of the frame" however unnoticed by me and did the normal pitch low nose forward maneuver. Then it was my turn, I was urged to "recover from VRS" at an even lower ROD, got a thumbs up, noted it as piece of cake and carried on with the training.

I'm pretty sure that should I personnaly ever get into "true VRS" ((c)pprune) I'll dump the pitch and autorotate away.

TC you'll most probably win your inital bet,
but I think that one has to practice either FDVRS escape, neither is comfortable,
especially for low height situations the ones with pitch raised.

[Reely340]

Note - my only exposure to what were called VRS were during initial training where the instructor demonstrated it to me in a 300. It were such a pleasant experience compared to what is described here that in hindsite I'd say we wern't anywhere near a developed VRS.
.Exactly the same here. One never gets introduced to pprune VRS during training, it just doesn't happen. Or maybe our 300s are VRS proof :p

[Hughes500]

As both instructor and examiner I find it very depressing that lip service is paid to VRS by instructors from what people are saying here
Reely a 300 will start to vibrate through its controls as it loses translational lift. At about 600 ft a min < 20 kts the airframe will start to shudder. At this point you can add power and she will climb ! Leave it to about 800 ft a min ROD and the ac is telling you she doesn't want to fly by shaking the arse off you. At this point any of the techniques work including Mr V's but I can't say I have noticed any difference between the techniques, certainly not a recovery in 20 to 50 ft ( not sure my altimeter is accurate enough to determine that )
As has been said the most important lesson is being shown what flying situations you would get this !

[Reely340]

Reely a 300 will start to vibrate through its controls as it loses translational lift.
Hmm. I'll try to notice that the next time I take her for a spin. :hmm:
At about 600 ft a min < 20 kts the airframe will start to shudder. At this point you can add power and she will climb ! Colud be that I've been there during instruction. Wasn't particularly impressive, though. :cool:
Leave it to about 800 ft a min ROD and the ac is telling you she doesn't want to fly by shaking the arse off you.:eek: Definitely never been there.
Maybe our ROD was lower or we still had some forward speed.
Anyhow, my recollection of "ROD 800 fpm" must be wrong then, nerver ever did we do anything that shaky.

The only thing that actually made me hold my breath was when the examiner, one our way home from the check flight announced that "we'll do an auto together". As I've no idea how that shoudl work, I obediently nodded and simply "felt" te controls. He ripped her back, I'd only see blue sky in any direction (hence we mut have been verticall on her tail) , and did a nice autorotation to a soso power recovery.

[FlimsyFan]

Crab, thanks for your pragmatic and entirely logical post. It makes a lot of sense that in order to kick off the VRS, there is a massive lowering of power OGE in the simulation, and even though power is applied liberally to achieve the sink rate we saw, the condition is still very artificial. What we are doing is nothing like any real approach profile, no matter how poorly executed.

Trouble with being a low hour pilot is that there's no shortcut to having 10000 hrs, so some of us do attend courses and read these forums in order to try to become better pilots. Posts like yours greatly help with understanding the issues, and come across as far more professional and constructive than many of the others here.

I will try to tidy up my videos of the VT demo, which were taken with an iPhone. As we have glass we get a 'scan' effect, and the ROD descent bug can only be seen when zoomed in.

I'll post a link when I've got it sorted.

In answer to another question, whilst I've only done the RHC safety course in a 66, VT demos were most definitely being done in 44s too. Don't know about the R22 tho.

FF

[TeeS]

Am I the only one here who is getting a little worried that lots of keen/brave aviators, equipped with a variety of experience and skill, are being tempted to go off and investigate the boundaries of the VRS flight envelope?

Please, before you do, remind yourself about how the pitot-static system works and what sort of flight regime it is designed to work in. Then ask yourself whether a 600'/minute indicated rate of descent at an indicated airspeed of 10kt is likely to anywhere near accurate. I suspect that is why you often see qualified test pilots flying aircraft with all sorts of probes sticking out of them?

Cheers TeeS

[FlimsyFan]

http://i63.tinypic.com/2rqok0l.png

http://i67.tinypic.com/2yzfo6g.png

Not sure if this will successfully upload photo. If not, link should be self explanatory...

It's the best I could do with the poor video for now. Zero airspeed, 40% torque and ROD (lower right bug on PFD).

I'll try to upload video later - doesn't show a great deal more other than the machine bucking around a fair bit. I take Crab's point that pulling takeoff power from developed VRS at 40% torque is not equivalent to a slow, steep downwind approach with big power pulled through loss of ETL. Illustrates a decent rate of descent though.

EDIT - ROD descent displayed is showing 2100fpm. In video rises to 2400 but couldn't capture a decent still

FF

[n5296s]

Wow, what a thread! To think I started it in all innocence...

I guess my big question is why you would EVER end up in fully developed VRS, other than for demonstration purposes. Same as a spin in fixed-wing.

I've had exactly one case of unintended IVRS (HOGE in an R44 close to gross). I was out of it in a heartbeat - unintended but not unexpected!. Seems to me that whenever you're HOGE you're spring-loaded for IVRS. It's hard to imagine a situation where you'd get IVRS and not recover LONG before it turns into the real thing (though I did see the post about the ham-handed student).

Sideways recovery would make a lot of sense if you were say nose-in to the scenery, like the tour pilots in Hawaii showing the waterfalls. But even that isn't Vuichard, just moving the disk out its own shadow in a different direction. If I understand correctly, a key part of Vuichard is pulling MORE power.

So to all you experienced heli pilots... why would ever be in developed VRS in the first place?

[Hughes500]

Flimsey

I assume the altimeter is on QNH in which case your instructor is not a wise man demonstrating VRS with less than 1500 ft underneath him.
In fact presumably not in VRS but IVRS:ugh:

[albatross]

Minor rant and then I will grab my hat and coat and head for the door.
"Settling with Power" and "Vortex Ring State" are two totaly separate events.
Both can require a change of underwear if not dealt with but I am so tired of folks lumping them into the same bag of bad things you can experience.
No replys required.

[FlimsyFan]

View My Video (http://tinypic.com/r/j0900w/9)

[FlimsyFan]

Flimsey

I assume the altimeter is on QNH in which case your instructor is not a wise man demonstrating VRS with less than 1500 ft underneath him.
In fact presumably not in VRS but IVRS:ugh:

Hello Hughes. It's over a year ago, when I was probably at about 120hrs TT, so the whole thing was quite daunting to be honest.

Screenshot would suggest QNH on steam gauge and QFE on PFD. As to competence of the instructor, I'm led to believe he's got a pretty solid reputation here and in the States, but maybe that's the RHC viewpoint and not that of the wider industry.

If you're able to view the video I posted, you'll see the VT nips the 2200fpm rate of descent in the bud almost immediately.

I'm obviously a simpleton, but do you suggest that this is not developed VRS, even at that rate of descent and what seemed like serious vibration and instability?

I'm not being facetious, just trying to draw my own conclusions presented with a differing set of 'facts' to deal with.

EDIT - I guess whether 2200fpm qualifies as IVRS or VRS or FDVRS, it's still a bad do if it happens at 100ft...

[Reely340]

Seems to me that whenever you're HOGE you're spring-loaded for IVRS. That's among the most scary parts I've learned from PPRune. There was that guy doing geometer-work where he had to hover HOGE so that some vertical laser pointer would be hitting the helo's belly inside a 10" x 10" sensor section, hence effectifely staying pinned at some 1000 ft AGL, ROD being 0. He claimed that during this prolonged HOGE he would get inevitably and demonstrably into IVRS.
That somehow doesn't add up to them vids showing the live powerline cleaning stunts which presumable never have such VRS issues, but one truly gets the impression that HOGE has one "springloaded" for VRS.

[[email protected]]

Flimsyfan - thanks for the video - what it does show clearly is that while he is talking about high RoD, he has over 10 degrees nose down.

Now that to me looks like a fudge - 10 degrees nose down will give you a high RoD in any helicopter and it would also mean that by the time you pulled power to try and recover, you already have enough forward speed not to be in VRS anyway.

He then pulls the nose up and, strangely enough, the RoD reduces rapidly with aft cyclic and power applied.

Definitely not convinced by that demo.

[FlimsyFan]

As I say, it's quite a while back, but my recollection is that the nose drop was a function of the VRS rather than a deliberate input.

If the nose down was what instigated the ROD, would the airspeed not increase as a consequence? Would 10 degrees really equate to 2200fpm in a matter of seconds with 40% torque?

It seemed to me at the time that the acceleration in rate of descent was quite breathtaking - more so than an aggressive entry into autorotation.

The good thing to come out of all this for me is to keep the main contributing factors to VRS firmly in mind and avoid any iteration of VRS in the first place.

I promise, I am trying to understand...

[[email protected]]

Flimsy - at all seems to be over far too quickly for a proper entry into an aggravated full VRS - initially he pulls the nose up to wash off the speed with, from what I can see, 40% Tq applied.

Then he falls behind ETL and describes the 'drop' and an almost instant 2000'/min RoD and by then the nose is 10+ degrees down - then he pulls in power.

So what he has done is enter a slow speed, almost autorotative descent - I expect the Min Pitch on Ground Tq is between 15 and 20% - at least with a very low power.

We can't see from the video what happens to the IAS at this point but with that nose down it will be increasing to take you out of VRS conditions so applying full power will inevitably recover the situation.

To be convincing, he needs to get the descent going, maintain the low IAS and then pull pitch in that configuration - that would induce full VRS.

I don't think he would fly out of that in a few seconds.

As I said earlier, VRS accidents/incidents usually occur with an already high pitch/Tq setting - often in trying to come to an OGE hover or controlling a steep/downwind approach.

The use of roll rather than pitch would be better in the event of a downwind approach since it is a quicker route to clean air but that's the only place I can see it being of value (unless there is a mountain in the way).

If anyone has more convincing video footage of this 'technique' then it would be good to see it.

[nigelh]

You are slowly coming around to it Crab .....even just a little bit !! So you say that in a downwind approach a roll may be quicker ( which makes sense as pitch forward is going with the air ) . On the basis that full VRS is unlikely ...or MORE likely to happen in a downwind approach then this technique could by definition quite regularly be the best action ??!!
So not withstanding that we all agree the old method works ......maybe this technique should be taught as another tool in the tool box that all pilots need for a long life ! That is a massive change in the old guards stance i would say ....is TC in with you or are you going it alone ??
Lets not lose sight that we are all , joking aside, interested in making our profession or hobby safer . However i believe like many others that for 90% of pilots there should be no reason to ever get near full VRS even if you are stupid !

[[email protected]]

Not quite Nige - although there may be merit in roll rather than pitch in limited circumstances the 'technique' hasn't been demonstrated in full VRS which is the condition it has been touted to be so special and new in.

Neither the Vuichard video nor the one from the Robinson course come close to being convincing.

So, no change from me really:ok:

[Jelico]

Flimsey

I assume the altimeter is on QNH in which case your instructor is not a wise man demonstrating VRS with less than 1500 ft underneath him.
In fact presumably not in VRS but IVRS:ugh:

When Tim Tucker demonstrated this technique to me as part of a Robinson course, we only had a 1000'-1100' cloud base. He was happy putting the machine in an 800FPM descent VRS before using the Vuichard technique to pop out at around 600'. I managed to slot it into more like 1000 FPM accidentally when it was my turn, pulling about 23" MAP. Popped out as per the Vuichard video in around 100' once the recovery was initiated. I was impressed.

Whether or not I could pull it out of the bag at the gravy stroke is another thing altogether...

[cattletruck]

...and I thought the Vuichard technique was designing nice web sites.

Vuichard Recovery Aviation Safety Foundation (http://vrasf.org)

Popped out as per the Vuichard video in around 100' once the recovery was initiated.

Bzzzzzz: Incorrect. The web site says 20-50 ft.

Ya'now, VRS is next to impossible on a windy gusty day. Therein lies the answer.

[Thomas coupling]

Having read and re-read the link you sent about Vuichard's web page, and having looked at the testimonies regarding departure from the VRS, I am genuinely beginning to wonder if there is a difference in translation here between european definitions and ours.
For the same reasons many of us get confused/mixed up over:
SWP and PS,
and
LTE and LTA

I think Vuichard et al is using VRS to cover IVRS.

Just think about it. He harps on about side slipping out of the tunnel of vortices below the tip path plane and making a miraculous recovery between: "20 - 50 feet".
Let's analyse this shall we - IF Vuichard insists he is talking about FULLY DEVELOPED VRS, we would have an aircraft descending at around 3,4,5000 feet per minute, oscillating around pitch, roll and yaw and he then swiftly drags the cab sideways out of the disc effect and arrests this descent and wayward aircraft movement within 20 to 50 feet. That would suggest a massive stop effectively, of the entire descending helicopter which in reality would break something, I would suggest!
This leads me to suspect that all along, Mr Vuichard is really discussing IVRS where (even in asociated videos) he rarely descends greater than 1 or 2000fpm. His beautiful web based video looks like a descent of hundreds of feet - maximum and a relatively stable helicopter platform.

So, in summary: If Mr V really means IVRS, yes, his technique would work (although even then, 20-50 feet halt distance is still unlikely).

But if he insists he is demonstrating FDVRS, he is either:
A liar.
Stupid.
Incompetent.

[cattletruck]

But if he insists he is demonstrating FDVRS, he is either:
A liar.
Stupid.
Incompetent.

It smells of salesmanship to me by creating a little contentious controversy to what is considered common lore which brings attention to his other activities. Yes, he must be discussing IVRS in which case being a little less smooth on the controls would often keep you out of the poo. I've heard the Aaaaa-Chooo recovery technique works just as well for IVRS.

Nice web site but.

[Rotorbee]

And we go in circles ... again. No reason to spare you my five cents.
A few things you might consider.

We have to parties here, one party consisting of mostly very or less experienced Robinson pilots who claim the darn thing works. And I think we can trust Paul Cantrells judgement when he says he thinks it works quite well.

In the other corner some very known figures in our business with a lot of experience and knowledge. Many of those would not touch a Robby with a pole.
I also think we can trust Vertical Freedom that he also knows what he is saying, and crab, and TC and so on.

Might it be possible, that the Vuichard Technique is more effective in a Robinson? Or in two bladed rotor systems?

Next question. What the h*** is the point?
I personally find it rather appalling that Vuichard is calling it his technique, when we know he was not the first. Apart from that fact, it is just very, very bad style (let's just say not everybody in Switzerland sees the greates helicopter pilot of all times in him). But aerodynamically why not let the thing work in certain circumstances? Who cares? It is not going to help a lot of people because it solves a problem that isn't really there. Only Vuichard claims hundreds of accidents happen because of VRS. Nobody else. Probably he almost died once a week because he did not realise what was going on when the controls get sluggish and the ride more uncomfortable. He probably always thought what a hero he is making through these terrible turbulences when in reality he did not recognise VRS ... again. Until the day he pushed the pedal and voilà, he was saved from the daily terror.
And with all those videos that are a lot of show and few substance, he just makes an a** of himself.

I find it rather strange when the chief instructor of Robinson demonstrates IVRS happily from 1'000 ft. But thinking about it, he lost 400 ft. Well, nice demo, but what students should learn is to loose no feet whatsoever. It would be a rare event if you have 400 feet below you while hovering and descending. That is not a place we like to be, and if we have to, we try to do that very gently. It just isn't something that is common place (You may demo VRS till the cows come home, but that isn't the point when learning about how to avoid it).
Therefore who cares what technique you are using to get out of it, when the height lost to get into it is far more important. Because it takes quite a while to get even a Robinson to shake like a bull in a rodeo.
What a student must learn is to recognise the danger early and then just a gentle forward pressure on the stick will already have saved the day. There is not point of neither dropping the collective to the floor and shoving the stick to the forward stop nor pushing the pedal one direction (powerpedal apparently) and the stick in the other - something that does not come naturally to us rotorheads and even Robinson does not like you to do it in a mariner with the floats on, because the thing can flip, given enough sideward speed.
Therefore guys, let it rest. Vuichard and his disciples will not stop. As he said, he is pursuing a place in the Smithsonian alongside Lindberg. People like that are hard to argue with.

[[email protected]]

The website press-release has a hint of the paranoid 'The system knows this is the answer but they're keeping it quiet' conspiracy theory.

Fist it references the Sumburgh accident which was caused by mismanagement of the AP and poor CRM, the fact that they eventually entered VRS was just seconds before impact.

I would love to see him use his famous recovery technique in a situation like that.

His only other example of the Every year, numerous helicopter accidents happen due to the vortex ring state. which is the opening gambit is an instance when he frightened himself in the mountains on long-line work.

They talk a lot about the 'suction' from underneath the rotor and how you need to get away from it - are they really the words of an aviation professional?

So the only other person to 'validate' this technique is Tim Tucker who may or may not have a vested interest in adding something that looks like good value to the Robinson Safety Course other than 'don't chop the tail off'.

It would be interesting to know how many other manufacturers have been offered/shown this technique since no-one else seems to be interested in it.

Perhaps the secret lies in the words of the website However, the
certification specifications CS27 and CS29, analogical to the FAR27/29 in the United States, do not require a defined maneuver in order to escape the
“vortex ring state”. since the FAA helicopter flying handbook defines
VRS as A transient condition of downward flight (descending through air after just previously being accelerated downward by the rotor) during which an appreciable portion of the main rotor system is being forced to operate at angles of attack above maximum. Blade stall starts near the hub and progresses outward as the rate of descent increases.it would be quite difficult to specify such a manoeuvre.

Therefore you can call any low speed descent VRS and claim a recovery technique for it.

[FlimsyFan]

http://sendvid.com/wemap6we

A further video from last year's training. In spite of all the arguing, I've actually found this thread quite informative.

[Flying Binghi]

...In spite of all the arguing, I've actually found this thread quite informative.


2nd that..:ok:

I find arguing is good, makes yer think about it in a more in depth way.





.

[[email protected]]

PPrune - the virtual crewroom:)

[aytoo]

...so, where is the Uckers board then?

[chopjock]

Once aaaat!

[[email protected]]

Any one for a mixyblob?

[Lonewolf_50]

OK, whose turn is it to make a new pot of coffee?

[Thomas coupling]

Up board........