Going back to the OP who begins with a quote for a techinque to address settling with power:
.
The message that needs to be out there is that IT IS THE WRONG TECHNIQUE for recovering from either IVRS or VRS.
It is bad enough trying to pronounce this guys name never mind trying to remember whether to PULL power or LOWER the lever.
[Although - technically in VERY powerful turbine engined helos - there is a case for removing oneself from VRS using 'application of power'].
In MOST cases, when in VRS, the following is observed:
Vibration.
Sloppy feedback response in the controls.
Pitching, rolling and yawing to some extent.
Blade slapping.

Recovery technique for VRS:
Select smooth (do not "ram") and progressive nose fwd using cyclic to around 20 degrees n/d.
As the a/c departs the turbulent VR, controls become more responsive.
Feed in collective power to minimise height loss. (Usually >8kt fwd speed).

VRS requires most helo's to be in a RoD of around 800 - 2500 feet per minute. Anything greater than this is due to the a/c simply 'falling' out of the sky. In fact, >2500fpm pushes the descending helo out of the VR.

WHILST IN A VRS DO NOT RAISE THE COLLECTIVE -it will aggravate the VRS.

http://www.pprune.org/rotorheads/116...-merged-3.html
refers (post 51+)

Quote from N Lappos:

.

Please make sure you are 100% certain you know how to avoid VRS in the first instance (IE: Identify IVRS early and recover with N/d and power ).
IF you are unfortunate to find yourself in fully developed VRS (and you have the height beneath you to recover) - select >20 degrees n/d, check down on collective, clear the VR, then and only then pull power.:ok:

So Monsieur Vuichard, whoever and wherever you may be, it seems your 'technique' has been sent to room 101, never to see the light of day again.

It might have been an interesting idea if it wasn't for the 'apply full power' part which, as TC has highlighted will just make things worse in VRS and, since the definition of SWP is that you don't have any power left, is pointless when dealing with SWP.

Since modern rotor systems with bigger hinge offsets retain control power much better than teetering heads, it is possible that the lateral cyclic might help, but no more than forward cyclic will.

Application of pedal may or may not be effective but not as effective as pushing the nose down.

Short answer - stick to the basics as described by TC and others.

This recovery technique has been proven to be working during official test flights for the Swiss CAA. You can inquire more information from Mr Vuichard directly if you want, his contact data are available in the Swiss CAAs helicopter examiner list:
FOCA - Examiners for pilot examinations


The whole point is: this technique can save lives, e.g. the 4 people which got killed by the CHC crash in 2013. And it is counter-intuitive, because we were all taught pulling collective up during VRS is wrong, as Thomas coupling reiterated. However, it does work because you can get out quickly of the vortex column into undisturbed air left or right of you by applying a 20 degree bank.

Any data to support this? test configuration, aircraft type, AUM, IAS, RoD?

Seems strange that only the Swiss advocate this method or is it wider spread than that?

The CHC crash would not have been avoided using this technique - you have to recognise you are in VRS first. There were a whole lot of other factors which could have prevented it.

The wikipedia article says it is in the (2013 edition) R22\R44 Flight Training Guide (FTG), which is the fifth manual listed at Robinson Helicopter Co.

Whilst, I can find html versions of all the POH's Robinson website (and it isn't in those), there doesn't appear to be a html version of the FTG and I don't have access to a hard copy.

Maybe it's because they have a different relationship with the holes in the cheese?

(Sorry, couldn't help it. And thanks for all the contributions to this thread, it's all quite amazing actually - and also the reference to the ancient (by Internet standards) contributions by Nick Lappos et al).

There seem to be a lot of parallels between FDVRS and fully developed fixed-wing spins. They both have a fairly simple aerodynamic explanation, on the face of it. They both behave predictably about 95% of the time, so you're not really prepared for the 20th time when it turns around and bites. And it's only when you get into deeper analysis of exactly what is going on that you realise just how complex the whole thing it is.

From a pilot training pov, there's no reason ever to be in either, just to know what causes it and to recognise the onset so you can NEVER go there. (That said, I've done a lot more spins than I ever intend to do FDVRS, for which my target is zero unless one day I'm lucky enough to fly with one of the handful of people who could safely demonstrate one).

Thanks again for all the quality input and reflection on here...

John

A random Question Not an excuse to Take me out at Dawn.!! :eek:

Would VRS and or Ivrs be the fixed wing equivalent of a Full stall ?

Now moved away from the screen, to watch from a safe distance..!

Peter-RB :ooh:

It's all well and good to talk about theoreticals like how many thousands of feet it takes to recover from FDVRS. But it doesn't really matter. Conditions like VRS and SWP do not typically occur up at altitude where the hapless pilot has plenty of time and altitude to figure out what's happening. No, these things usually happen down low, at the bottom of a mucked-up approach. And then it's over pretty quickly. BAM! as Emeril Lagasse would say.

Using the Sr. Vuichard's method might work for a VRS encounter (although I personally have not yet tried it). But what would happen if you were just running out of power to stop an increasing rate of descent? You feed in a bunch of right cyclic and push the left pedal...and...you hit the ground sideways.

Remember, there's not a lot of time to sort things out. Either way, it'll probably be over before you know it.

Then there's the feelings of panic, denial and the resultant "this can't be happening" inaction. Even just a couple of seconds of that can mean the difference between saving the day and crashing. Oh, we all like to think we're some magic combination of the Chucks: Yeager and Aaron, but sadly we pilots can sometimes be very, very human. I know I can. And my name ain't Chuck.

And anyway, why are we even discussing this? Are helicopters still crashing due to VRS?

Aircraft was an AS350, that's all I know. But again: feel free to contact Mr Vuichard directly yourself, I'm pretty sure he can give you all those details.

Sure, this is all speculation at the end. But from what I read, it kind of fits the scenario in my opinion:

So the pilots didn't have much altitude left, certainly not enough for doing a standard vortex recovery.

Why should Britain tremble..............................................:ugh:

Well between TC's rather definitive response, FH's astute point about altitude and rolling the aircraft while crashing, and I totally missed the increase in collective part of the original post; I'm done exploring this on an academic level. It was fun gents, thanks for letting me play.

I have spent most of my 11,000 ish hours looking down a longline, flying in the mountains in Western Canada. In my world we work upwind, downwind, uphill, downhill and nasty combinations of downwind and downhill. We work in a "Production based" environment and we get very accustomed to working in conditions that are conducive VRS.

When VRS happens close to the ground it's usually immediately following a power increase and the first thing you will feel is that you ass gets lighter in the seat. You will feel lightness in the seat way before you feel rotor vibration or sloppiness in the controls. Usually when you add power your ass gets heavier in the seat... if you pull the collective and you get lighter you need to take corrective action immediately.

Obviously not for "normal" helicopters, but can't those with excessive amounts of power(an unladen UH60, for example), power themselves out of VR?

MG, I wouldn't rely on trying to power out of VRS. When I experienced it, albeit in a Puma rather than a Blackhawk, we were just about at max continuous power when the aircraft entered (the HP was trying to achieve an OGE hover at high altitude in the dark). The rate of descent was very impressive and we lost a lot of altitude during the event.

Thinking about this, an analogy is having a powerful car at full throttle but having wheel spin and little traction.

Bollocks
 

Tried the Vuichard technique & it's complete bollocks :yuk: firstly in settling with power (SWP) there is no emergency & recovery is to pull more power (if You have extra) or just pole forward.......end of story :8 If in IVRS or VRS, in my humble opinion; simply pole forward, as the shake/rattle/roll dissipates apply more power to climb away ;)

If it ain't broke...............don't try & fix it!!! :}

I wouldn't, but I'm pretty sure that Nick Lappos mentioned it in one of his posts on the subject.

No, because power is actually a factor causing the problem. In the vortex ring state, the helicopter is trapped in a recirulation of its own wake. The more power you apply, the faster the recirulation goes and the faster you sink.

However, the point many people seem to miss here is that the vortex ring does not only consist of a downdraft, but also an updraft and the core idea of the Vuichard recovery technique is to use the updraft to get out of the vortex as quickly as possible.

It this wouldn't work, then Tim Tucker wouldn't have put it in the Robinson Flight Training guide.

Well, it is "broke" as long as we see unnecessary VRS accidents happen, the latest just being the Rega A109 crash last month.

Hey jymil

I meant the recovery technique, works no need to reinvent the wheel. :8 If someone is (still) getting into VRS & crashing then they don't understand the causes of entering VRS & blindly bumbling on oblivious :* It's there flying technique that needs adjustment & not the recovery technique :ok:

Happy Happy avoid VRS :)

With older type helicopters with limited max power, in VRS pulling more power did increase the ROD. However when the Wessex 5 came on line, especially at low weights, by pulling max power it would blast its way our of VRS & climb. Do that in a Whirlwind & big trouble!

A few years ago a Puma 330 made a steep slow night descent to a ship & got into VRS. From 500 feet to splash was about 15 seconds & that's with 2 experienced Puma instructors on board! Luckily both survived.

I flew the R44 again today (a different one, no floats or glass panel). My instructor hadn't heard of the Vuichard technique by name, but when I explained it, he said, "we've just started teaching something very similar". Just using right cyclic to slide out of the VRS, no pedal. We tried it, it certainly works (for incipient VRS, not the fully developed beast) - whether it works faster/better than forward cyclic is hard to say.

Between the point you make there, and the post by dammyneckhurts, the takeaway is "catch it early and recover" to avoid it getting worse ... regardless of your recovery technique.

Recently flew with a utility guy who also instructs. discussing VRS, he argued that most pilots will encounter it at low altitude, so conventional rcovery is problematic. Utility is frequently in that low/slow/high power, so often tried alternates. His point was get out of the VRS losing as little altitude as possible, lateral cyclic, that's it.
On my expressing doubt, we did a full VRS, conventional recovery, lots of altitude lost, perhaps a couple thousand feet.
Repeat maneuver, VRS, right cyclic and almost immediate recovery. Jaw drop. I can't say that the VRS was as fully developed the second time...
Explanation offered was that maneuvering laterally adds airspeed, but unlike reducing power and nosing down, the lateral move gets you into a normal airflow with minimal altitude loss.

Same here. Just tried it last month for the first time and it works

Why not just pole forward? :8

:ok::D I do....

Still yet to be convinced that this technique works in fully developed VRS any better than the conventional recovery.

How did Mr Vuichard get into VRS so often that he needed to develop a 'new' technique for recovery from it?

Lets see some empirical testing with proper criteria for entry, steady state (if that can be described as steady) VRS and then a comparison of recovery techniques.

The big danger with this technique is that it will lull pilots into a false sense of security that they can push their RoD limits at low speed and altitude believing they have a magic bullet of a recovery to save them if they screw it up.

As ever - avoidance of VRS is the real skill of a helicopter pilot, not the recovery from it.

suggestion (for side cyclic instead fwd.): rotational inertia

A helicopter requires much less force to turn around its longitudinal axis (a.k.a. roll) than around its vertical (yaw) or lateral (pitch) axis.
(Only in part due to the horizontal stabilizer, it's mainly a question of mean distance of affected mass from the rotational axis)

Proof: grab your household broom and
first twist it 90° along its broomstick's axis
then twist it 90° perpendicular to said axis (watch out for your ceiling lamps).
If undecided remove brush and repeat with the stick alone.

Thus if we want to redirect rotor downwash away from our VRS descend path
rolling the ac might work much faster than pitching.

How effective is this technique in an ac with a fenestron TR?

From the description, the lateral thrust produced by the tail rotor is an important factor of this recovery. A fenestron has different characteristics to a TR, and also the tail of of a fenestron equipped ac will act as a blade which would(?) oppose any lateral thrust more than a traditional TR ac.

I can't see any references to using this technique in any other aircraft than a R22\R44.

Matthew

Reely - that might be an issue in a rotor system with limited control power - eg teetering head (or close to) on R22 but anything with even a slight hinge offset will have control power to spare.

Also, any helo with a horizontal stabiliser will have natural nose-down pitch in a low speed descent.

That's a good point, but there is also the inertia of the entire mass of the aircraft with its load moving in the direction of intended flight. The lift vector (when changed in the direction of lateral movement) has to overcome that ... and is doing so (if one is actually entering VRS or in it) with a less effective "bite" into the air. As I've not flown Robinsons, no further ideas.

My first FI, a veteran of 2 wars, would frequently tell me that while training for emergency procedures were necessary, the fundamental approach was not to get the helicopter into a situation that led to you needing to implement those procedures. Obviously he was referring to thing like VRS, SWP etc but his advice has stuck with me.

Vuichard Recovery?
 

I stumbled upon this article describing an alternate way of getting out of vortex ring state. The conventional recovery I've been taught is to reduce collective and establish forward airspeed. The article suggests applying left pedal, right cyclic and cruise torque to fly out with minimal altitude loss (on a CCW rotor system).

Anyone had experience utilizing this type of recovery? For some reason I find it difficult to believe that no one's considered sideward cyclic application before, but the idea seems to make sense. Link below:

Aviation Today

Thanks!

Edit: forgot to search before asking... Sorry folks!

See here:

http://www.pprune.org/rotorheads/557...ing-power.html

VR
 

You need (again) air speed, so then; why pole Left or Right to recover to only again need to pole forward to regain critical speed? 'if it ain't broke, don't fix it" The old basics of pole forward for air-speed whilst leaving power ON, is the fastest & most effective recovery from VR & regain a Safe Flight configuration :8

You can't always "pole forward"...approach to elevated pad etc. Always nice to have another trick in the bag. I was taught this by Bristow back in '07, to avoid smashing into a deck offshore should you get into vortex ring state on short final. So it's hardly a new trick at all.

Hey TIMTS, yep good point, similar to making a confined mountain pad approach with no way out forward or to the side........so approach in a way to avoid the risk of VR, yep it's another technique that in a confined I'd use :ok: actually in 30 years only had it once whilst HOGEing for a film shoot when I over flew an area of massive updraft which inducing VR & not ROD :eek: but I had somewhere to pole forward too, so walked away on wobbly legs :hmm:

Happy Landings :cool:

@VR
That is not correct (assuming you have HOGE power). All you need is to get into undisturbed air which doesn't exert a downward force on you through recirculation.

Hey jyml; so the Vuichard stops the VR, great news & now You have now airspeed & a high rate of descent & then.......the circle begins again; VR due high rate of descent, no airspeed & power on hmmmmmmm :ouch:

Seems as if you have a misconception of the procedure somehow. The rate of descent is quickly stopped to zero, so you cannot get into another vortex.

This might also help:
Rotor & Wing Magazine :: Flying Through the Vortex