Bad fast roping video
 

Wonder what the story is here? Anyone have more details? Coming in hot!

Wow....out of airspeed, altitude and ideas. Appears to be a UH-1Y.

nope, that is a Bell 412 of some form.

is it just me or does that look a bit fake?

They surely neglected the 2-minute cool down - Shame on them!

Someone hasn't learned how to finish off a quickstop properly...........

It's just you!

I can see clearly now the wine has gone :}

No need to fast-rope when you're sitting on the ground!

I agree with Winnie... two blades on the tail rotor and the main rotor hub configuration give it away as being a Bell 412.

Otter

Sorta hard on the Troops....having to step up to get off the aircraft while looking at a piled up Fast Rope!

Is this a good example of vortex ring state or settling with power?

Most probably VRS but a clear example of what happens if you don't get your power in early enough towards the end of a quickstop.

It depends when you think he ran out if power - was it before the descent started and he didn't have enough for OGE, drooped the NR and began to descend (SWP) or was it as he hauled in the lever while he had low airspeed and an effective rate of descent due to the flare which then led him to ingest his own downwash and develop VRS?

A bit of a moot point really - he just porked a simple manoeuvre very badly and was lucky enough to walk (or limp) away from it.

Crab

Not sure he would have caught up with his own downwash as presumably fairly heavy so a large downwash speed. Looks more like poor flying, too aggressive flare with power coming in way too late, evidenced by the ac descending while still in the flare. So poor technique

Hughes500 - poor technique definitely but the harsh flare is one of the classically referenced methods of getting into VRS since the disc is seeing airflow from beneath so as the flare effect reduces and you add power (especially with that much nose up) you effectively satisfy the criteria for VRS. You have a RoD flow, low speed and power being applied.

Not saying it definitely is but it is a strong contender.

There isn't anything about this arrival that can be blamed on aerodynamic effects, unless you are referring to the the airflow between the ears :E

Crab
As an aside Was told years ago by someone from Sikorsky that a CH53 was impossible to put into VRS as it pushed air down so rapidly you couldn't physical catch it up. Personally I think he just ran out of power or air underneath depending on how you want to look at it

Flying like you are using your belly button for a peep hole I would suggest!

Hughes500 - that could well be true about the 53, it has a very high disc loading and therefore a powerful and fast downwash. they were probably talking about a vertical descent from a free air hover where the downwash would be at its maximum rather than a quickstop where flare effect is giving you relative airflow from beneath the disc and also masking your real power requirements.

However the 412 is nothing like as heavy nor has such a high disc loading - it is possible he just ran out of power but there isn't any noticeable Nr decay (well to my ears) - I think we can all agree it was a very poor piece of piloting whatever happened.

Vortex Ring State (VRS) is a condition where the rotor ingests it's own vortices (over simplification). During powered flight the airflow moves through the rotor system from above to below. When airflow is moving from below to above the rotor, it’s called autorotation. VRS is entered when the flow is roughly between these two states. So it follows, to enter VRS, the airflow through the rotor needs to approach that of the rotor downwash. The rate of downwash is related to disc loading—I haven’t calculated the induced velocity of the aircraft, but I doubt his speed nears Vi. And more importantly, the movement of air needs to be nearly vertical through the rotor system. How far up is the nose during the quick stop? 45 degrees?

Most likely Settling with Power or "over-pitching".

Cran
Realise the difference between the machines. Still think he wouldn't have caught up the downwash to get into VRS just didn't have enough power or height to arrest the descent

Try a quickstop with 25 to 30 degrees nose up, tightening the flare with the collective almost fully down - the extra rotor thrust from the flare effect is holding you up and you have a RoD flow opposing the very small amount of induced flow through the rotor, Therefore the amount of downwash, and its speed are greatly reduced from the normal hover values.

Then you realise you have held the flare too long, the speed is very low and you are about to lose ETL.

Now you grab a big handful of lever just as the aircraft is starting to descend.

So you have 1. Low speed, 2. a RoD flow opposing the induced flow just as if you were in a vertical descent and 3. Power applied to try and stop that RoD. You have caught up wit your downwash because it wasn't moving very fast.

If you are really 'unlucky' or an even worse pilot you might even have a downwind component for good measure.

I didn't say it was VRS but all the ingredients for the recipe are there.

Jim - if you have 20 degrees nose up and the lever almost fully down, where is the airflow meeting the rotor? VRS doesn't need a vertical descent, steep but not vertical.

If he over-pitched, is there evidence that the Nr decayed?

The myths of VRS have been debunked on this forum before, the aircraft would need to be moving through it's downwash at near downwash velocity which is quite difficult to do.
The video doesn't show what wind conditions were.
He came in too hot and when the lever hit the armpit, the earth rose up to meet him.
It's not the first time this has happened due to an exercise with an audience, he wanted to put on a show. Mission accomplished.
Here is another example from elsewhere in Africa.
https://www.facebook.com/groups/iFly...5736238893015/

I have tried to explain how that can happen in a situation where the downwash velocity is very low.

VRS certainly isn't a myth.

It maybe in this case that he didn't overpitch but just stopped pulling at his normal power maximum - which wasn't enough

It does of course exist, just the probability of you running into it or have an accident as a result is slim to naught.
Like LTE, the common DNA is a sudden and unexpected loss of talent, usually demanding too much power, too quickly from the aircraft.
While VRS in it's early stages may increase power demands, a properly flown approach, within the capabilities of the aircraft (or pilot) should leave sufficient power to cope.
When you tend to see these accidents that get blamed on VRS, it always is a case of power required > power available.
In the more third-world nations there seems to be a desire to fully demonstrate the bounds of ones abilities, this usually ends with the local Agusta, Bell or Sikorsky rep buying a new sportscar.

VRS must feel awfully put upon here at Rotorheads....as it seems to get blamed for every incident no matter the evidence or aerodynamics existing at the time.

Yes VRS exists and can cause you problems if encountered.....but dressing it up in disguise and blaming it for what actually happened is very unfair to it.

LTE has been the lucky villain....with many of its victims being described as having fallen prey too many other perils when it is the design of the helicopter that did in its occupants.

But this is PPRuNe where opinions do not have to have any basis in fact.

respectfully disagree with that - the chances of encountering it have reduced as disc loadings on modern helicopters have increased as a result of more powerful engines and smaller, more efficient rotors but the threat is still there.

Absolutely, the lack of talent is what puts you in the ballpark but at some point aerodynamics do have to have their say - whether you choose to believe it or not.

Yes, not enough power is more often than not the reason for such mishaps but if he applies enough power and still goes down without Nr decay, what will you call it then?

if it's not really a factor., why are so many simulators hard wired to give you the red screen of death when you hit the parameters?

Thank you for the text book definition of settling with power.

Then you have a different textbook from me - that is a definition of VRS But we have discussed on these pages before that in the USA, the terms and definitions are freely swapped, settling with power implies insufficient power to hover and subsequent overpitching.

Never let the rotor rise or the free wheel disengage in a quick stop. It's a fine line between nose up pitch and descent rate. The more the nose rises, the less descent rate is acceptable.

A graduated entry with small corrections early and a progressive increase in collective pitch is better than an aggressive entry with a descent and a large collective increase as TL is lost especially where the engines are idling due to free wheel disengagement.

I always get nervous with students who try to recover to a descending hover at the end of the maneuver. Stay at the entry altitude or climb. Never descend. If you mess it up, throw it away and nose down to accelerate again. SF troops are harder to replace than most pilots.

if you recall your training practice doing quick stops, at least in EASA world, your instructor will get angry if any of the following happen
1/ if you altitude fluctuate during the flare either way (loss of altitude or ballooning up)
2/ if you keep the flare too long and the aircraft feel like sitting on its tail toward the end
3/ if you don't terminate the manoeuver with a nice controlled slow forward hover to the ground

in this video, I see all three points to get slammed by your instructor.

I think the pilot was already trying to save a lousy setup,
wind might have been slightly on tail = landing termination come sooner than expected = more flare to recover and no leveling to trying not to overshoot.
it was time to go around

Only acronym here is PPP. Piss Poor Piloting!

Sooo...
 

The technical discussion is fine but who the heck are these guys? No markings I can see, nothing in the background for clues. Where are they? Just curious.