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Edson AB crash, VRS?

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Edson AB crash, VRS?

Old 23rd May 2023, 14:13
  #121 (permalink)  
 
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Originally Posted by [email protected]
I have taught those young drivers for nearly 40 years in a variety of roles and never once have I been asked for mathematical proof for what I have demonstrated or explained because for 99.9% of the time it is irrelevant. .
Getting back to the topic of this thread, would you teach one of those young drivers to do a down wind landing (to a hover) in the manner shown in the example video?
(I'll bet two pints of Guinness that you would not!)
As interesting as this thread has been, in parts, some pilots a few pages back (to include yourself and Robbie) pointed to what appears to me to be a root cause:
Either a poor choice to try to land downwind, or, a poor technique in attempting to accomplish a downwind landing.

Which I think is the takeaway from this crash, if lessons are to be learned.
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Old 23rd May 2023, 17:04
  #122 (permalink)  
 
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If one uses the reported winds as posted and the runway lay out for the landing location....and the only other reference is the short video with limited perspective and visual references to confirm the relativity of the wind to landing azimuth.....perhaps some of the discussion is misplaced.

Was was the cross wind component if any"

Perhaps the immediate take away might be would be that that commonly used phrase of "WTF" was he thinking (referring to the Pilot at the controls"?

It does seem an occasion for an old fashioned down wind approach with a polite turn back into wind at the bottom kind of situation that did not happen that way for some reason.

Was there a reason beyond just simply not doing it?

Is there anyone here that KNOWS what the pilot was thinking or KNOW. why he did what he did?

This discussion should have ended immediately upon the first mention of VRS or SWP and a new thread....perhaps we should see a Jet Blast like "SWP/VRS Hamster Wheel" thread starts for Rotorheads.

All in favor....say "Aye"....."Nay's" remain silent please!
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Old 23rd May 2023, 17:48
  #123 (permalink)  
 
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With respect to SASless''s question about the mindset of the Astar pilot...

He came in from over the town; and that ripping tailwind probably had him doing a pretty good clip. How could a Commercial pilot (or any pilot for that matter) *not* realize that he had a big, stinking tailwind? It seems astonishing. So we know that wind direction was not in the forefront of his mind, as it should have been. If it had, he would've just extended out a bit and done a simple 180 to come back into the wind to get to his pad (see Google Maps view for orientation). So again, it's not important to know what he *was* thinking about - we know confidently what he was *not* thinking about. That's pretty obvious. No sane, awake, competent pilot would deliberately conduct such an approach. There doesn't seem to be any good, compelling reason for him to have done that (unless he had to pee, really, REALLY badly). And hey, it's harsh, but maybe that guy (gal?) was in the wrong line of work? Not all of us can be Chuck Yeager/Aaron, and I've met some really, um, "less than stellar" pilots in my day. You're lying if you say you haven't too.

Then, of course, after every one of these accidents, the discussion devolves into the old VRS/SWP argument. It's silly, because IT DOES NOT MATTER if it was one or the other. If you're making a downwind approach, whether you run out of engine power or rotor power, the end result is usually the same. If you're shallow, you might get away with an unplanned running landing and the resultant change of shorts. If you're steep: Boom. Soooooo, was this Astar accident the result of SWP or VRS? I say, "Who cares? It makes no difference."
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Old 23rd May 2023, 18:44
  #124 (permalink)  
 
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Originally Posted by SASless
If one uses the reported winds as posted and the runway lay out for the landing location....and the only other reference is the short video with limited perspective and visual references to confirm the relativity of the wind to landing azimuth.....perhaps some of the discussion is misplaced.

Was was the cross wind component if any"

Perhaps the immediate take away might be would be that that commonly used phrase of "WTF" was he thinking (referring to the Pilot at the controls"?

It does seem an occasion for an old fashioned down wind approach with a polite turn back into wind at the bottom kind of situation that did not happen that way for some reason.

Was there a reason beyond just simply not doing it?

Is there anyone here that KNOWS what the pilot was thinking or KNOW. why he did what he did?

This discussion should have ended immediately upon the first mention of VRS or SWP and a new thread....perhaps we should see a Jet Blast like "SWP/VRS Hamster Wheel" thread starts for Rotorheads.

All in favor....say "Aye"....."Nay's" remain silent please!

“Aye”!


Although I have said to use ASN with care earlier, some of the info could explain the decision of the pilot. Maybe a long day out?! At least the pilot has probably given as much information as needed for TC to do their investigation.

The updated info of this crash is saying:

Range Helicopters Inc Eurocopter AS 350B2 Ecureuil, was returning to the Edson Airport (YET/CYET), Alberta, from a staging area supporting firefighting operations to the east of Edson, AB.
On approach to CYET the pilot elected to expedite his arrival routing due to incoming fixed wing air traffic. On the final approach to landing, the helicopter entered a descent that resulted in a hard landing and roll-over”
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Old 23rd May 2023, 18:54
  #125 (permalink)  
 
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LW 50 - in answer to your question, yes I would and have taught lots of pilots to make a downwind approach in those conditions BUT NOT in the manner he did it.

Being able to conduct a safe downwind approach is a basic pilot skill because sometimes it is the only way in (terrain, obstacles, tactics etc etc).

Never ever taught it as a limited power exercise and always with an emphasis on keeping the RoD and closure speed nicely under control. Once in the hover turn into wind and land. At any stage if you are not happy with RoD/closure speed or power requirement GO AROUND early.

Plenty of other options, some I mentioned before - a downwind approach maintaining ETL with a co-ordinated yaw/roll/pitch turn through 180 when abeam the LS (more advanced but not rocket science) or simply a curving, descent to end up into wind facing the spot.

You can expedite the crossing of the airfield/runway without ending up in a heap at the end. I would call it a downwind flare and turn quickstop.

Not much value to those who need the info and knowledge in relegating the discussion to jetblast just because some are bored with it. I don't mind repeating myself if some of it eventually goes in and prevents another pilot making the same dumb mistakes.

So NAY.
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Old 23rd May 2023, 20:09
  #126 (permalink)  
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Crab It appears you overlooked what was said.

Yes.a typo where "starts" appears for "started"

I bolded the one word just to draw your attention to that word....as it was not in bold in the original post.

This discussion should have ended immediately upon the first mention of VRS or SWP and a new thread....perhaps we should see a Jet Blast like "SWP/VRS Hamster Wheel" thread starts for Rotorheads.
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Old 23rd May 2023, 22:56
  #127 (permalink)  
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Presented as a Mod/Admin:
I am of mixed thinking on the suggestion about a bundling of the VRS discussions, since I'd not like to see a "JB" style penetrate the hallowed halls of Rotorheads.
One JB is enough, thank you.

Perhaps a VRS sticky thread at the top with links to the salient threads?
What do you all think of that, dear colleagues of Rotorheads?
This is in many ways your pub, your crew room, so I'd like to know what you all think.
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Old 24th May 2023, 01:19
  #128 (permalink)  
 
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Not all of us can be Chuck Yeager
And thank God for that, his NF-104 crash illustrated all his failings, main one being arrogance and unwillingness to accept training from an individual of subordinate rank. Also his attempt to make Neil Armstrong look a fool at Edwards.
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Old 24th May 2023, 06:02
  #129 (permalink)  
 
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Chock puller and T28B - if you mix down all the VRS/SWP threads into one hamster wheel then the analysis of individual incidents like the Edson one will disappear and everyone will just say 'oh no here we go again'.

The fact that the confusion between the two still exists is the main reason to keep debating it and reinforcing the difference.

If I was in my 'pub' and someone was confused about the difference, I would try to educate them not push them to another room to be ignored.

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Old 24th May 2023, 06:30
  #130 (permalink)  
 
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Originally Posted by [email protected]

The fact that the confusion between the two still exists is the main reason to keep debating it and reinforcing the difference.
There was never really a confusion over the two terms, only the refusal by some to accept that different cultures use the same words to describe different things.
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Old 24th May 2023, 10:38
  #131 (permalink)  
 
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Originally Posted by Ascend Charlie
...here is a gathering of Nick Lappos's Urban Myths, plus some notes from the late Shawn Coyle, both these gents being highly qualified test pilots:Helicopter Urban Myths
These Urban Myths pervade our understanding of helicopters and how they operate. Each is fundamentally incorrect, but most are generally held as gospel, because training, lore and reference documents have repeated them long enough that they are simply accepted.
...
5) Winds affect the power we require when we are in forward flight
...
At the risk of further "thread drift" from the original accident, I wanted to challenge this specific supposed 'myth'.

What was the original claim? Was it comparing identical helicopters achieving the same speed over the ground, one in still air, the others in a headwind or tailwind? Or was it comparing helicopters all achieving the same airspeed even if their ground speeds all differ? If the former, this wouldn't be a myth. If the latter, I would agree the statement is a myth. To elaborate for the case of constant ground speed:

* Helicopter A flying in still air at 110 knots ground speed hence airspeed also 110 knots. Resistance roughly proportional to velocity squared, so call this 100% resistance case.

* Helicopter B flying at 110 knots ground speed into 20 knot headwind, so airspeed 130 knots. Its resistance will be ~140% of Helicopter A.

* Helicopter C flying at 110 knots ground speed with 20 knot tailwind, so airspeed 90 knots. Its resistance will be ~67% of Helicopter A.

Power required from engine will be related to the combination of generating lift to support the helicopter and rotor thrust to overcome its resistance, so certainly changes. The differences in power demand are more stark the slower the helicopter ground speed and the higher the wind speed.

If I am wrong here, I would obviously like to be corrected.

I can't see an ideal solution for managing where discussions on SWP / VRS / LTE etc, etc, turn up. But I am learning regardless of which thread such exchanges appear in.
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Old 24th May 2023, 15:05
  #132 (permalink)  
 
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Originally Posted by megan
And thank God for that, his NF-104 crash illustrated all his failings, main one being arrogance and unwillingness to accept training from an individual of subordinate rank. Also his attempt to make Neil Armstrong look a fool at Edwards.
Oh Megan... Missy, you may be too young to know the importance and history of the brave aviators who came before you, and I don't really fault you for that. The "innocent hubris of youth" and all. And I know that it's fashionable these days for you gals to denigrate and devalue all men in general, especially the ballsy, hyper-masculine test-pilots who blazed the trails for the rest of us. But despite all of his purported "failings" as you call them, I don't think that there's any question or doubt that General Yeager was a superlative pilot...one that we all can try to emulate. The Astar driver who is the subject of this here thread? Not so much.
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Old 24th May 2023, 16:44
  #133 (permalink)  
 
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Originally Posted by Robbiee
There was never really a confusion over the two terms, only the refusal by some to accept that different cultures use the same words to describe different things.
That was exactly the cause of the confusion. And the refusal of some to acknowledge that VRS and SWP are different.

In answer to your question about the R22 lateral trim - I believe it is to help with Inflow Roll (roll towards the advancing side) - usually perceived as being purely a low speed phenomenon but present in smaller measure throughout forward flight. The airflow entering the front of the disc has a different inflow angle to the air entering the rear of the disc (more time travelling across the disc to be affected by it) creating an inequality of lift between front and rear and resulting in a right roll tendency.
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Old 24th May 2023, 17:16
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Originally Posted by [email protected]
That was exactly the cause of the confusion. And the refusal of some to acknowledge that VRS and SWP are different.

In answer to your question about the R22 lateral trim - I believe it is to help with Inflow Roll (roll towards the advancing side) - usually perceived as being purely a low speed phenomenon but present in smaller measure throughout forward flight. The airflow entering the front of the disc has a different inflow angle to the air entering the rear of the disc (more time travelling across the disc to be affected by it) creating an inequality of lift between front and rear and resulting in a right roll tendency.
I'm not going to get into that argument again. I'll only say that it seems rather stubborn to hold onto a term that clearly has multiple definitions of which no one can agree on which is the "one true definition". Which is why I am with the FAA and Robinson in that I simply no longer use the term anymore.

So, if you have a hard landing despite still having a fully functional running engine, it is because,...
1) You entered VRS
2) You came in hot and waited too long to put on the breaks
3) You're too heavy to do what you are trying to do
4) You're in a tailwind and simply using the wrong technique
5) You are overpitching

As for the rt trim nob? Its to alleviate right cyclic pressure countering a left roll tendency. What you are describing is Transverse Flow Effect. Besides, the rt trim knob is used primarily in cruise, not low speed flight.
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