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Condition for Vortex Ring

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Condition for Vortex Ring

Old 24th Nov 2017, 02:29
  #61 (permalink)  
 
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Crab and Charlie are exactly correct on all counts - end of story full stop.
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Old 24th Nov 2017, 08:32
  #62 (permalink)  
 
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I love a good slanging match especially when it comes to 'us' and 'them'.

FH100: Sorry big guy - you're talking boll o cks (like the FAA do - much of the time). Europe and Canada bow to the superiority of the FAA (not).
As Ascend Charlie said - there's a lot of mischief in those FAA manuals.

And this is definitely one of them: SWP.

For the record, this clip is perfect SWP from a very well trained and probably experienced yank driver. He's done these approaches numerous times and is aware of many of the gottcha's out there, I would argue, especially vortex ring.
Which is why he wasn't expecting this:

https://www.youtube.com/watch?v=1DDDpI263qE

And do you know why he wasn't expecting this? Because it wasn't VRS it wasn't even close to VRS. The conditions for VRS were a million miles from this guys approach (into wind/ >30kts to start with / minimal RoD), I bet he wasn't even close to IVRS (vibration, increasing RoD).

This is THE perfect example of SWP and you yanks really do need to wake up and smell the coffee - the rest of the world (for once) aren't wrong with this.

[Day after day - more and more "experienced" pilots come on here and display a level of ignorance which is becoming more and more endemic as we speak. Christ, if experienced driver's are behaving like this - how, in the name of faith can we ever slag off lesser mortals???].


If helicopter pilots don't understand basic aerodynamic/ engine related phenomena like : VRS / IVRS / SWP / PS / LTE / LTA, they should be ashamed to call themselves pilots.

Newfieboy - don't get where you are coming from? Is there a link to God - through long line - to VRS, or something? Is long line the dog's boll o x, then? Are longline pilots world experts in VRS? Keen to know more about this band of brothers gospel according to?
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Old 24th Nov 2017, 12:51
  #63 (permalink)  
 
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TC,
If that video was an example of SWP, how come there was enough power to lift off again?
Looks more like SPE (simple pilot error).
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Old 24th Nov 2017, 15:46
  #64 (permalink)  
 
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TC, sorry to break it to you, but the CH-46 accident wasn't even SWP. It was merely a misjudged approach. He probably had plenty of power. But he screwed up. His approach angle was nice and constant, but the boat was moving up and down - something obviously not taken into account. The '46 pilot came in way too shallow and caught a wheel on the fencing. Oops! Happens. It's why PHI taught us to come into oil platforms steep and slow, never shallow and fast - just for that reason. Worked for me.

To those of you who say the US FAA is wrong about this or that...well...whatever. If it makes you guys feel superior or something, that's fine.

If you guys want to narrowly define SWP as something other than VRS...well...I think y'all are wrong.
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Old 24th Nov 2017, 16:43
  #65 (permalink)  
 
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Its always the internet "pilots" bragging about how "experienced" they are who say the textbook is wrong,...always!

In the real world, I have never met a pilot who thinks SWP is anything other than VRS!

,...but carry on God's gifts to aviation!
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Old 24th Nov 2017, 18:18
  #66 (permalink)  
 
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Havent met me then !
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Old 24th Nov 2017, 19:39
  #67 (permalink)  
 
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This link provides some detailed background for the 1999 CH-46 accident:

Sea Knight off San Diego
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Old 24th Nov 2017, 20:21
  #68 (permalink)  
 
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Butters, as you admit on that other forum, your real world experiences weren't particularly successful, were they?

And what you said tells me that the pilots you have met have been poorly taught. There is a huge difference between SWP and VRS.
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Old 24th Nov 2017, 22:02
  #69 (permalink)  
 
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Ascend charlie: you are wasting your time i'm afraid.
A pilots ego is often bigger than his brain.
What a shame because so called experienced pilots have so much to offer those who look up to them. It's a big responsibility ensuring those coming up behind you do it properly.
It is literally a life saver.
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Old 25th Nov 2017, 09:44
  #70 (permalink)  
 
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Butter you meet all Helicopter pilot in the world ?

Sure if you talk only with ATPLH pilot flying from base A to baseB and back with AP on.... It's really rare for them to meet Mr SWP and VRS...
but for the utility pilot long line and many others, is the reality.. For myself i experiment both situations. In both case i finish my flight safe, but maybe have to change my pants... I teach really my studient about VRS above 1000 ft. I want they feel the vibrations and the stick dribble. I simulate the power limit for the SWP.... And i am happy when they understand what happen...
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Old 25th Nov 2017, 14:44
  #71 (permalink)  
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Originally Posted by r22butters View Post
Its always the internet "pilots" bragging about how "experienced" they are who say the textbook is wrong,...always!

In the real world, I have never met a pilot who thinks SWP is anything other than VRS!

,...but carry on God's gifts to aviation!

Your ignorance and inexperience is showing. My memory is that we taught VRS as 'settling with power' in 68-70 US Army. I was taught to teach it in exactly the conditions of VRS, including the application of power accelerating the descent. It was hard to reliably induce the fully developed state in a TH55, as zero airspeed is hard to determine at the altitudes we did this. We, the pilots in my cohort, interchanged the terms until the late '70s early '80s when the recirculating rotor down wash was broadly taught. This I think lead to the confusion.

My memory may be wrong, but VRS signals subtly that something is happening, vibrations and uncommanded attitude changes and then when in the fully developed VRS, the aircraft feels 'sloppy', less crisp in response. SWP seemed to be more normal aircraft response in the descent, you ran out of power (or NR in the Huey) . We didn't intentionally fly into full SWP, but demonstrated it with power limitation.

Final point: In the real world, I have never had a textbook defined issue in flight. One teaches somewhat simplistic, defined issues in primary instruction to teach the most appropriate resolution clearly and emphatically. The flying part of the instruction is especially simplistic in my opinion, insisting on specific airspeed, altitude and approach procedures as though that kept hobgoblins away. It ain't that clear and easy when you're working the line...
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Old 25th Nov 2017, 15:54
  #72 (permalink)  
 
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Originally Posted by Devil 49 View Post
It ain't that clear and easy when you're working the line...
An important point has been made here by Devil - in longline work when things don’t go to plan there’s just no time to consider if your in VRS, SWP, over pitching, or any other plethora of situations which ruin our day. You just need to react, listen to what the aircraft is telling you through your backside/eyes/ears & fix it. You need to be aware of this BEFORE the condition develops, almost subconsciously, firstly to avoid it but also to ensure you take the correct action should you fail in the avoiding part.
I think I’ve been in a VRS situation once, I say “think” deliberately as I didn’t hear a change in aircraft power train noise & couldn’t tell you what the gauges were saying (didn’t look!) as within a few seconds I had to fix it or hit the ground therefore my eyes were outside the cockpit & apparently my hands & feet were busy fixing this problem I had created. I’m happy to report I fixed it. There won’t be a second time.
There has been many comments on this thread re “here we go again” & I get that, but personally I enjoy reading all of these opinions & using the information to cross check & confirm that what I thought I knew still makes sense to me so that when my hands & feet need to react there’s no delay. Keep the discussion alive, it shouldn’t matter what our instructor said, once we have the licence it’s up to us to continue to learn, challenge what we were taught & verify, verify, verify. Theology can be debated, but physics & aerodynamics in 2017 are pretty well understood - VRS is VRS, SWP is SWP, over pitching is overpitching.
Misinformation is widespread though; despite Transport Canada differentiating between VRS & SWP I noticed yesterday that the Saskatchewan & Alberta National Aerial Pesticide Application Manuals both state that rotary pilots should pay particular attention to “vortex ring state(settling with power)”. Here we go again.
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Old 25th Nov 2017, 17:17
  #73 (permalink)  
 
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Originally Posted by Devil 49 View Post
Your ignorance and inexperience is showing. My memory is that we taught VRS as 'settling with power' in 68-70 US Army. I was taught to teach it in exactly the conditions of VRS, including the application of power accelerating the descent. It was hard to reliably induce the fully developed state in a TH55, as zero airspeed is hard to determine at the altitudes we did this. We, the pilots in my cohort, interchanged the terms until the late '70s early '80s when the recirculating rotor down wash was broadly taught. This I think lead to the confusion.

My memory may be wrong, but VRS signals subtly that something is happening, vibrations and uncommanded attitude changes and then when in the fully developed VRS, the aircraft feels 'sloppy', less crisp in response. SWP seemed to be more normal aircraft response in the descent, you ran out of power (or NR in the Huey) . We didn't intentionally fly into full SWP, but demonstrated it with power limitation.

Final point: In the real world, I have never had a textbook defined issue in flight. One teaches somewhat simplistic, defined issues in primary instruction to teach the most appropriate resolution clearly and emphatically. The flying part of the instruction is especially simplistic in my opinion, insisting on specific airspeed, altitude and approach procedures as though that kept hobgoblins away. It ain't that clear and easy when you're working the line...
,...and you just made my point!

You call running out of power "settling with power",...even a college dropout can tell that makes no sense!

,...but I know, keep stroking your egos and looking down your noses at the poor little, gullible, Robby guy who dares to believe the logical explanation given in the textbook!
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Old 26th Nov 2017, 01:11
  #74 (permalink)  
 
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Posters may wish to peruse this thread, and note Nick Lappos's input. I'm not about to argue with Nick.

http://www.pprune.org/rotorheads/676...-settling.html
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Old 26th Nov 2017, 02:49
  #75 (permalink)  
 
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Originally Posted by megan View Post
Posters may wish to peruse this thread, and note Nick Lappos's input. I'm not about to argue with Nick.
I did find this point of his a nice read!

Nick Lappos , 2nd Jun 2002 04:32
Blenderpilot,
I have to agree with squirrel. You and sultan are mixing up the fundamental problem of having too little power with the other aerodynamic condition specifically related to reingestion of the downwash known as Vortex Ring State or settling with power.

What I think you are concerned about is a true issue for pilots - the behavior of the machine when you are severely performance limited. That causes most helicopter accidents that occur on landing, is especially a problem at altitude and high temperature, and has nothing at all to do with settling with power
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Old 26th Nov 2017, 16:31
  #76 (permalink)  
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Originally Posted by r22butters View Post
,...and you just made my point!

You call running out of power "settling with power",...even a college dropout can tell that makes no sense!

,...but I know, keep stroking your egos and looking down your noses at the poor little, gullible, Robby guy who dares to believe the logical explanation given in the textbook!
Dude, the point I was attempting to make was that the textbook was wrong. If that single mistake, identifying SWP and VRS as one and the same, wasn't sufficiently problematic, it added to the confusion for, what? Five decades now?

VRS is NOT SWP, even though several tens of thousands of pilots were taught to interchange the terms. Knowing the difference is the important point. It's especially important as you may expose yourself to conditions that could lead to bad outcomes from either or both in professional flying while in sanitary school settings you may not, or you may be taught by the book answers that aren't inclusive of ALL options. Example- my last several recurrent sessions did not include anything that wasn't in the FAA syllabus- until I asked for demonstration, practice. Vuichard recovery technique chief among them. The check airman was very familiar with it, he was a long line mountain pilot and an exceptional teacher...
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Old 26th Nov 2017, 17:23
  #77 (permalink)  
 
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So, I mess up my pre-flight planning and make an approach to a OGE hover a few hundred pounds above my RFM MAUM for OGE hover at that temp and pressure. I am aiming for a 70' hover to confirm my ground position before descending vertically into a smallish LS with some obstacles around it.

As I get to 70' in a level decel and start to lose translational lift, I raise the lever and pull as much power as the engine will give me but the aircraft starts to sink - I raise the lever some more but the engine has topped out and I hear the Nr start to decay and I keep going down - I am clearly going to hit the ground but why?

Is the answer

a - I have settled with power because I don't have enough to hover OGE but tried it anyway?

or b - I have entered VRS because aerodynamics weren't on my side today?

I have ended up in an overpitching state trying to arrest the descent but I am going down with full power applied and the Nr decaying. I haven't caught up with my downwash because the RoD is fairly low and I might just be saved from a hard impact by ground effect.

On a different day, I have done my pre-flight planning perfectly and I know I have OGE hover performance plus some in hand for the wife and kids. I make my approach with a slight tailwind that I didn't notice and I end up a bit steeper on finals to my OGE hover point than I intended. I have some forward speed when I look out of the window so I accept the higher rate of descent thinking that a combination of flare effect and power will sort things out near the bottom. I feel a sink and some vibration I don't much like so I grab a handful of lever - the aircraft shakes some more and sinks a bit faster so I add more collective. Suddenly I feel as though I am falling out of the sky and the ground is coming up really fast. I am clearly going to hit the ground but why?

Is the answer

a. I have run out of power and am therefore settling with it?

or b - I have entered VRS because I didn't realise I was downwind and let the external references fool me into thinking I still had forward airspeed on? I allowed a high RoD to develop with very low airspeed and tried to recover with lever. I may or may not end up with max power applied and I might even get to the point where I get Nr decay as well but that is a symptom a long way down the list and not the cause of my problem.


There may still be some who can't tell the difference and all I can say is I don't want to go flying with you.
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Old 26th Nov 2017, 18:58
  #78 (permalink)  
 
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Originally Posted by [email protected] View Post
So, I mess up my pre-flight planning and make an approach to a OGE hover a few hundred pounds above my RFM MAUM for OGE hover at that temp and pressure. I am aiming for a 70' hover to confirm my ground position before descending vertically into a smallish LS with some obstacles around it.

As I get to 70' in a level decel and start to lose translational lift, I raise the lever and pull as much power as the engine will give me but the aircraft starts to sink - I raise the lever some more but the engine has topped out and I hear the Nr start to decay and I keep going down - I am clearly going to hit the ground but why?

Is the answer

a - I have settled with power because I don't have enough to hover OGE but tried it anyway?

or b - I have entered VRS because aerodynamics weren't on my side today?

I have ended up in an overpitching state trying to arrest the descent but I am going down with full power applied and the Nr decaying. I haven't caught up with my downwash because the RoD is fairly low and I might just be saved from a hard impact by ground effect.

On a different day, I have done my pre-flight planning perfectly and I know I have OGE hover performance plus some in hand for the wife and kids. I make my approach with a slight tailwind that I didn't notice and I end up a bit steeper on finals to my OGE hover point than I intended. I have some forward speed when I look out of the window so I accept the higher rate of descent thinking that a combination of flare effect and power will sort things out near the bottom. I feel a sink and some vibration I don't much like so I grab a handful of lever - the aircraft shakes some more and sinks a bit faster so I add more collective. Suddenly I feel as though I am falling out of the sky and the ground is coming up really fast. I am clearly going to hit the ground but why?

Is the answer

a. I have run out of power and am therefore settling with it?

or b - I have entered VRS because I didn't realise I was downwind and let the external references fool me into thinking I still had forward airspeed on? I allowed a high RoD to develop with very low airspeed and tried to recover with lever. I may or may not end up with max power applied and I might even get to the point where I get Nr decay as well but that is a symptom a long way down the list and not the cause of my problem.


There may still be some who can't tell the difference and all I can say is I don't want to go flying with you.
This first one is called Full Throttle, which if you continue pulling, will lead to Low-rpm Rotor Stall, which would most likely happen before you reach settling with power (vortex ring state)!

In the second one you have clearly induced settling with power (vortex ring state) because you chose to ignore the warning signs and began settling into your own downwash!

Perhaps if we gave you all a Full Throttle Lite that would end your confusion?
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Old 26th Nov 2017, 20:39
  #79 (permalink)  
 
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R22butters - if you don't want to learn (and possibly save your life) then carry on.

The first one is a classic for underpowered helos like the R22 - you end up with the lever under your armpit and hitting the ground hard - usually without getting anywhere near rotor stall - it is a function of poor piloting skills and only a partial decay since the engine is still pushing max power - it's not like an EOL where there is no power. It is this scenario that is often attributed to VRS when it absolutely is not the case.

The second one is where your confusion arises because you can't see that you haven't reached a power limit - it is simply VRS.
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Old 26th Nov 2017, 22:23
  #80 (permalink)  
 
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Err...TC
No there is no link to God, being a competent safe longline pilot. Just thousands of hours doing it for real.
My question was pretty simple, here I'll rephrase it. How much experience you got in the mountains,(not the UK titties) on a line doing production stuff, single pilot. If I was a betting man I would say Zero!!!
Merry Christmas and all the best for the New Year. I'm outta here going to go on a drill job, just packing my bags....ooh longline TC. Guess I'm a God. Funny that my bday is on Xmas Day....!!!
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