Edson AB crash, VRS?
This was VRS. Those saying the decent rate doesn't match VRS I'm sure would have a different opinion from inside the helicopter at the time. He didn't have much altitude to build up a descent rate, but it was more than enough to smash the aircraft to pieces. That counts as "high rate of descent" for me.
Practicing VRS recovery (at a safe altitude) is simple, reliable, and eye opening for those who think it only happens if the wind is a certain way or expect there to be some noticeable feeling in the aircraft.
1. At a safe altitude (say 2,000') fly level at roughly max endurance with power also roughly at max endurance. (It doesn't matter which way the wind is blowing, and you're not maneuvering in relation to ground references.)
2. Without changing anything else, pitch up about 5-8 degrees.
3. Simply hold that attitude as airspeed bleeds off. Don't change power.
4. Altitude might increase briefly, but then decrease. Hold the "wings" level, nose slightly up attitude, and moderate power setting. As airspeed bleeds off the rate of descent increases until you recover with a change of attitude (with decent rate above 300'/min you can also notice the ineffectiveness of adding power).
5. You won't "feel" it (unless you're too low and have ground rush) and the aircraft doesn't feel out of sorts, despite the alarming behavior of the altimeter and VSI. This is important to know for those who think they'll get some kind of seat-of-the-pants warning before VRS.
6. Recover (pitch down or bank/roll).
Fly safe (i.e. paranoid)
Practicing VRS recovery (at a safe altitude) is simple, reliable, and eye opening for those who think it only happens if the wind is a certain way or expect there to be some noticeable feeling in the aircraft.
1. At a safe altitude (say 2,000') fly level at roughly max endurance with power also roughly at max endurance. (It doesn't matter which way the wind is blowing, and you're not maneuvering in relation to ground references.)
2. Without changing anything else, pitch up about 5-8 degrees.
3. Simply hold that attitude as airspeed bleeds off. Don't change power.
4. Altitude might increase briefly, but then decrease. Hold the "wings" level, nose slightly up attitude, and moderate power setting. As airspeed bleeds off the rate of descent increases until you recover with a change of attitude (with decent rate above 300'/min you can also notice the ineffectiveness of adding power).
5. You won't "feel" it (unless you're too low and have ground rush) and the aircraft doesn't feel out of sorts, despite the alarming behavior of the altimeter and VSI. This is important to know for those who think they'll get some kind of seat-of-the-pants warning before VRS.
6. Recover (pitch down or bank/roll).
Fly safe (i.e. paranoid)
Hi staycalm. Nice to see a new face here. Just that you know, you are a bit late to the VRS party. We have beaten that dead horse to mush by now in several several threads and most of us get sweaty palms when "VRS" shows up in a title. And for "save" in VRS demos, since I have seen the flight test data of an ONERA VRS research, I will not feel completely save in a VRS demo ever again. The increased flapping is just too much for my taste and too close to the tail boom.
BTW, has anybody heard anything about the R44 crash a few years ago, where the ship fell out of the sky with a young CFI, probably demoing VRS?
BTW, has anybody heard anything about the R44 crash a few years ago, where the ship fell out of the sky with a young CFI, probably demoing VRS?
Yeah, I've seen the arguments over semantics and acronyms here and elsewhere. There are issues of physics/momentum, and issues of aerodynamics. Sometimes they occur separately, other times together. Not going further on that. 
VRS is serious business, and I am opposed to anyone taking a demo to an unnecessary extreme, thinking it's safe to do so. But that goes for all the other maneuvers in a helicopter, too. Right? There's a middle ground to work within, giving us the opportunity to do cool stuff and earn a paycheck. But there's also a point to "knock it off" in any aviation operation. Perhaps the R44 doesn't have much of that middle ground. I would guess otherwise, but that community can decide for themselves.
I think it's valuable to experience how easy it is to slip into VRS, and that the entry is much more insidious than is typically assumed. The practice method I described is seemingly benign, yet results in undeniable VRS. Pilots should not be fooled into thinking it only happens with a tailwind, or flaring a certain way, only when you're heavy, or this or that... Those can all be factors, but the three ingredient of VRS can also combine under seemingly tame situations. It will bite when you're not thinking about it because of task saturation or complacency with something you've done 1,000 times. When you see the ground rush, believe it, abandon your pride and immediately make whatever ugly, aggressive recovery maneuver the situation allows for.
VRS is serious business, and I am opposed to anyone taking a demo to an unnecessary extreme, thinking it's safe to do so. But that goes for all the other maneuvers in a helicopter, too. Right? There's a middle ground to work within, giving us the opportunity to do cool stuff and earn a paycheck. But there's also a point to "knock it off" in any aviation operation. Perhaps the R44 doesn't have much of that middle ground. I would guess otherwise, but that community can decide for themselves.
I think it's valuable to experience how easy it is to slip into VRS, and that the entry is much more insidious than is typically assumed. The practice method I described is seemingly benign, yet results in undeniable VRS. Pilots should not be fooled into thinking it only happens with a tailwind, or flaring a certain way, only when you're heavy, or this or that... Those can all be factors, but the three ingredient of VRS can also combine under seemingly tame situations. It will bite when you're not thinking about it because of task saturation or complacency with something you've done 1,000 times. When you see the ground rush, believe it, abandon your pride and immediately make whatever ugly, aggressive recovery maneuver the situation allows for.
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This was VRS. Those saying the decent rate doesn't match VRS I'm sure would have a different opinion from inside the helicopter at the time. He didn't have much altitude to build up a descent rate, but it was more than enough to smash the aircraft to pieces. That counts as "high rate of descent" for me.
Practicing VRS recovery (at a safe altitude) is simple, reliable, and eye opening for those who think it only happens if the wind is a certain way or expect there to be some noticeable feeling in the aircraft.
1. At a safe altitude (say 2,000') fly level at roughly max endurance with power also roughly at max endurance. (It doesn't matter which way the wind is blowing, and you're not maneuvering in relation to ground references.)
2. Without changing anything else, pitch up about 5-8 degrees.
3. Simply hold that attitude as airspeed bleeds off. Don't change power.
4. Altitude might increase briefly, but then decrease. Hold the "wings" level, nose slightly up attitude, and moderate power setting. As airspeed bleeds off the rate of descent increases until you recover with a change of attitude (with decent rate above 300'/min you can also notice the ineffectiveness of adding power).
5. You won't "feel" it (unless you're too low and have ground rush) and the aircraft doesn't feel out of sorts, despite the alarming behavior of the altimeter and VSI. This is important to know for those who think they'll get some kind of seat-of-the-pants warning before VRS.
6. Recover (pitch down or bank/roll).
Fly safe (i.e. paranoid)
Practicing VRS recovery (at a safe altitude) is simple, reliable, and eye opening for those who think it only happens if the wind is a certain way or expect there to be some noticeable feeling in the aircraft.
1. At a safe altitude (say 2,000') fly level at roughly max endurance with power also roughly at max endurance. (It doesn't matter which way the wind is blowing, and you're not maneuvering in relation to ground references.)
2. Without changing anything else, pitch up about 5-8 degrees.
3. Simply hold that attitude as airspeed bleeds off. Don't change power.
4. Altitude might increase briefly, but then decrease. Hold the "wings" level, nose slightly up attitude, and moderate power setting. As airspeed bleeds off the rate of descent increases until you recover with a change of attitude (with decent rate above 300'/min you can also notice the ineffectiveness of adding power).
5. You won't "feel" it (unless you're too low and have ground rush) and the aircraft doesn't feel out of sorts, despite the alarming behavior of the altimeter and VSI. This is important to know for those who think they'll get some kind of seat-of-the-pants warning before VRS.
6. Recover (pitch down or bank/roll).
Fly safe (i.e. paranoid)
Good (please insert your preferred deity here) H500. Do you really want to trigger that discussion again?
Just so everybody knows, in a few years we will see the effectiveness of the different recovery techniques, because EASA has initiated a research program to find out what it is all about.
VRS (Helicopter Vortex Ring State Experimental Research)
Now we can lean back and wait for the results.
Just so everybody knows, in a few years we will see the effectiveness of the different recovery techniques, because EASA has initiated a research program to find out what it is all about.
VRS (Helicopter Vortex Ring State Experimental Research)
Now we can lean back and wait for the results.
HAHAHAHAH! I laugh. Pilots arguing over whether a crash was "caused" by VRS or SWP. HAHAHAHAH. So silly. I've said for a long time that IT DOES NOT MATTER which is which. The end-results are the same: If you come in downwind, chances are good that you will crash and the geeks on PPRUNE will argue interminably about which particular anomaly you experienced. You can go up to altitude and do VRS demonstrations all you like - but that's not where the accidents happen, is it? Nope, they happen at the bottom of f'ed-up approaches. When you pull the collective up but the helicopter keeps descending, the dynamics of what's happening are pretty moot. Who cares?
1. Does wind always blow horizontally, or can there be vertical components that might affect and compromise that scientific and sacrosanct "300 fpm" RoD that people think is so vital and absolute in exciting VRS? (Exciting it, not exiting it.)
2. People talk about "overpitching." Will a B3 droop its rotor if you pull 100% power?
Argue on, my brothers. Me, I'll just keep laughing and landing into the wind, thank you. Which is what our foolish Astar pilot should have done. (Or at least, if he knew that he had a ripping tailwind and needed to go into that spot anyway, he should have performed the technique properly. Sadly, he - or she! - knows that now.)
Repeat after me: "It doesn't matter how many hours you have; helicopters are very easy to crash." Learn it, live it.
1. Does wind always blow horizontally, or can there be vertical components that might affect and compromise that scientific and sacrosanct "300 fpm" RoD that people think is so vital and absolute in exciting VRS? (Exciting it, not exiting it.)
2. People talk about "overpitching." Will a B3 droop its rotor if you pull 100% power?
Argue on, my brothers. Me, I'll just keep laughing and landing into the wind, thank you. Which is what our foolish Astar pilot should have done. (Or at least, if he knew that he had a ripping tailwind and needed to go into that spot anyway, he should have performed the technique properly. Sadly, he - or she! - knows that now.)
Repeat after me: "It doesn't matter how many hours you have; helicopters are very easy to crash." Learn it, live it.
Staycalm, 300ft rate of decent, just pull the collective and the aircraft will climb, so not VRS. Dont believe it come to UK and I will show you ( or read Nick Lappos post many years ago ). Feel it, oh yes you do, before you ask, Yes I have been in full VRS with a ROD of 3000 ft a minute, scary !
If you say that you can add power as RoD exceeds 300'/min and recover (while maintaining the attitude I described), I won't disagree with you as long as you acknowledge that it takes a lot more power than it normally would (VRS has reduced the efficiency of the rotor system). That's just the approximate point at which a change of attitude becomes necessary to effect recovery from VRS.
And yes, I'm sure you are feeling things at 3000'/min. I don't see much training value beyond half that. The proper response is the same. Unless your experience was an intentional demo, it's hard to imagine why someone would be dinking around at high altitude/low airspeed to allow room to get that extreme and still be able to recover.
I won't deviate from the intention I had in my original message. Others can argue semantics and personal terminology preferences.
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Nubian posted the following:
Looking at the smoke trail post impact....it does appear to be a downwind approach across the runway (if the wind was as posted and the smoke trail representing the wind direction....and approach direction).
If one assumes an average wind of 165/19 gust to 33knots the question begged is why would any experienced pilot make a downwind approach to an airfield with such winds being reported and discernible by means of the wind sock and other visual indicators?
All this talk about VRS etc ignores the root cause of the accident.
Is there a rearwards flight airspeed limitation on the aircraft involved?
Could a flat approach with gradual deceleration have worked?
If one tried an OGE hover at altitude.....could VRS be avoided or escaped by accelerating rearwards out of the rotor downwash column of air?
Playing the "what if" game as is being played....why not debate this line of thought.
If you are not descending into your downwash....does it matter which direction you are moving re VRS?
As for relevant info for this thread.
METARs UTC -6 DST
CYET 050156Z AUTO 16022G32KT
CYET 050211Z AUTO 17016G34KT
Runway is 07/25 and the buildings in the background are located on the north side of centreline.
METARs UTC -6 DST
CYET 050156Z AUTO 16022G32KT
CYET 050211Z AUTO 17016G34KT
Runway is 07/25 and the buildings in the background are located on the north side of centreline.
If one assumes an average wind of 165/19 gust to 33knots the question begged is why would any experienced pilot make a downwind approach to an airfield with such winds being reported and discernible by means of the wind sock and other visual indicators?
All this talk about VRS etc ignores the root cause of the accident.
Is there a rearwards flight airspeed limitation on the aircraft involved?
Could a flat approach with gradual deceleration have worked?
If one tried an OGE hover at altitude.....could VRS be avoided or escaped by accelerating rearwards out of the rotor downwash column of air?
Playing the "what if" game as is being played....why not debate this line of thought.
If you are not descending into your downwash....does it matter which direction you are moving re VRS?
SASless (BTW where is that nice lady that always called you SASSY Darling), you are certainly right, the root cause of the accident has nothing to do with VRS or overpitching. Robbiee said it, FH1100 and others. But VRS is such a nice subject to disagree on. And in the final report, there will be the reason, why he choose that kind of approach. Maybe it was mandatory, or he was confident enough to be sure to pull it of? We will see.
The rotor does not care which direction you go to get out of VRS, but do you really want to bring the disk closer to the tail boom by going backwards, when flapping is easily double the normal amplitude? Even worse with gusty winds?
The rotor does not care which direction you go to get out of VRS, but do you really want to bring the disk closer to the tail boom by going backwards, when flapping is easily double the normal amplitude? Even worse with gusty winds?
He could have avoided the crash in many ways, making his approach to the spot into wind being the most simple.
However, life and ATC aren’t always that simple and he could have made the same downwind approach safely by coming in slower and more shallow and getting the power in early and keeping the RoD nicely under control providing he had OGE performance plus a decent excess above that figure, say 10-15% Tq in hand.
Or, approach to the left of the spot, but not steep, and make a gentle right turn maintaining ETL until getting an into wind component - a curving approach.
I won’t be surprised if fatigue features in the accident analysis, its insidious nature can cause competent pilots to make very poor decisions and if you are single pilot you have no one to recognise your fatigue level.
However, life and ATC aren’t always that simple and he could have made the same downwind approach safely by coming in slower and more shallow and getting the power in early and keeping the RoD nicely under control providing he had OGE performance plus a decent excess above that figure, say 10-15% Tq in hand.
Or, approach to the left of the spot, but not steep, and make a gentle right turn maintaining ETL until getting an into wind component - a curving approach.
I won’t be surprised if fatigue features in the accident analysis, its insidious nature can cause competent pilots to make very poor decisions and if you are single pilot you have no one to recognise your fatigue level.
Had the aircraft been parked facing down wind could it have been started and brought to a hover to begin a flight with such a wind of the strength and direction?
Or, would flying be cancelled for the day if there was no way to turn it around using ground handling wheels?
Or, would flying be cancelled for the day if there was no way to turn it around using ground handling wheels?
Had the aircraft been parked facing down wind could it have been started and brought to a hover to begin a flight with such a wind of the strength and direction?
Or, would flying be cancelled for the day if there was no way to turn it around using ground handling wheels?
Or, would flying be cancelled for the day if there was no way to turn it around using ground handling wheels?
Starting and stopping wind envelope is 40kts from any directions, 50 in headwind. The 350 has an extremely good t/r authority and very capable in tailwind conditions compared to the competetors in the class.
Originally Posted by [email protected]
I won’t be surprised if fatigue features in the accident analysis, its insidious nature can cause competent pilots to make very poor decisions and if you are single pilot you have no one to recognise your fatigue level.
Yes, quite possibly. Northern Alberta has been experiencing a very active early fire season and fatigue might well be a contributing factor. Having said that though, if working fires and returning to an airport on a windy day like that if the pilot was unaware of the wind strength and direction (even without the aid of a wind sock etc etc), then one has demonstrated a total lack of situational awareness.
I have read on another site who the owner/operator is and being a small company with 206’s plus that one Astar suggests that there might have been a new 350 pilot who was enjoying the power and flexibility that a 206 does not offer and got caught…(this is not meant as a slam directed at the outfit; there’s no reason why they can’t provide a quality service based on size alone).
That is supposition on my part but I can’t imagine why someone would make such a poor decision.
Hopefully the pilot makes a full recovery, is able to move on past this and may we all remember that no amount of power will let you get away with mistakes of this magnitude…
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If you're driving up a steep icy hill, it doesn't do any good to mash the throttle. The engine roars and the wheels spin, but if the tires have no traction, gravity will win.
Good (please insert your preferred deity here) H500. Do you really want to trigger that discussion again?
...EASA has initiated a research program to find out what it is all about.
VRS (Helicopter Vortex Ring State Experimental Research)
Now we can lean back and wait for the results.
...EASA has initiated a research program to find out what it is all about.
VRS (Helicopter Vortex Ring State Experimental Research)
Now we can lean back and wait for the results.
I did read the link to the EASA VRS experimental study. It mentions "shall include an experimental flight test activity on at least two different helicopter types having different kinds of main rotor systems". It occurs to me that with all the fantastic scale model helicopters now available, complete with scale rotorheads and small gas turbines, experimental program could be conducted at model scale where risks to people are negligible (unless a model tumbled on their head in full VRS). Model mass dynamics as well as control system and engine responses 'just' need to be properly scaled. That should be possible as I have worked in a similar field of scale model testing, not aviation. A model test program (at least initially) should also permit a wider spread of helicopter types and load states (eg: rotor disk loadings) at a much lower cost. This doesn't stop subsequent (careful) verification of findings at full scale on a more limited number of cases.
@helispotter: I very much doubt, that a model helicopter would be appropriate for this kind of test. The problem does not lie in the mass and engine response, but in the dynamics of the main rotor. Building a scaled down model of the rotor with all the correct flexing and flapping isn't as easy as it sounds. The commercially available models lack a lot of components of a real rotor. No flapping- or lead/lag hinges for example. Not even virtual hinges in the blade root. Model helicopters do not need that. And then there is the Reynolds number.
But it has been done to visualise VRS in wind tunnels. But here they want to fly certain manoeuvres and that is difficult in a wind tunnel.
The budget isn't very high. I think for that money it is cheaper to use a real helicopter.
But it has been done to visualise VRS in wind tunnels. But here they want to fly certain manoeuvres and that is difficult in a wind tunnel.
The budget isn't very high. I think for that money it is cheaper to use a real helicopter.