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Helicopter crashes into the Hudson River NYC

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Helicopter crashes into the Hudson River NYC

Old 25th May 2019, 12:07
  #21 (permalink)  
 
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LTE per the pilot....
https://app.ntsb.gov/pdfgenerator/Re...=HTML&IType=LA
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Old 25th May 2019, 12:27
  #22 (permalink)  
 
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Sorry , just doesn’t ring true to me . The t/r effectiveness doesn’t explain the downwind quickstop manoeuvre at all .... I fact if I thought I felt the onset of so called LTE I would have immediately gone nose down and reduce power a little which he had plenty of height for . It looks to me like a ham fisted pilot im afraid but we will see . Even the eventual auto didn’t seem to go very well ( in the best auto machine in the business) so God help him if he had been in a 350 or 500 !!!!
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Old 25th May 2019, 13:45
  #23 (permalink)  
 
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Compare the Statement of the Pilot to what you see in the video....very carefully.

I find the commentary about the Wind Conditions to be interesting especially with the presence of a visual wind indicator (the US Flag flying on the nearby Flag Pole).

It seems interesting that after sensing the onset of LTE (using the pilot's own words), he then tries to land in the same direction a second time.

Mind you....he was in an empty helicopter that was full of fuel and him being the only occupant.
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Old 25th May 2019, 14:55
  #24 (permalink)  
 
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Hi,
I'm an airline pilot and came across this accident and was just curious what the pilot could have done, once he put himself into this position?
Bearing in mind I just know the aerodynamics of a plane;
Could he have powered himself out of this position or was the plane essentially stalling?

Thanks in advance.
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Old 25th May 2019, 15:18
  #25 (permalink)  
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Originally Posted by lennystyles View Post
Hi,
I'm an airline pilot and came across this accident and was just curious what the pilot could have done, once he put himself into this position?
Bearing in mind I just know the aerodynamics of a plane;
Could he have powered himself out of this position or was the plane essentially stalling?

Thanks in advance.
The problem was when he lost forward airspeed, the torque reaction from the main rotor began to overcome the anti-torque moment provided by the tail rotor. This caused the aircraft to yaw to the right despite full left pedal. The combination of a tail wind component, high power and zero airspeed overcame the tail rotor authority. The application of more power simply made the situation worse and increased the torque driven yaw, so no, he couldn't (and didn't!) "power" his way out of it. He had a number of options, all of them poor. He could have lowered the nose and attempted to regain positive airspeed, this would have provided aerodynamic forces to counter the yaw, but in this case he would have been descending and accelerating towards the river bank and structures, so this may not have been appealing. He could have reduced the power until the anti-torque force countered the yaw, but again, this meant descending towards the river and the bank waiting for the rotation to stop, not an obvious choice. Or, if he could have maintained a more stable platform, the rotational speed might have decayed as the aircraft came back into the wind, allowing him to transition away into the wind and regain positive airspeed quicker, but again, it's a brave man who can hold it in a level flat spin waiting for the rotation to slow down.

As you see from the video, all this happened very quickly, and this guy was only thinking of repositioning to a spot following a refuel. He probably wasn't considering the finer points of countering an unstable rotational acceleration with a limited anti-torque force following the loss of translational lift in a down wind configuration. But he will next time.
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Old 25th May 2019, 16:54
  #26 (permalink)  
 
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Originally Posted by wrench1 View Post
Sad, that this day and age, a 2 year old, empty aircraft, at sea level, can't handle:

KTEB 151851Z 29010G16KT 10SM FEW070 21/05 A2979 RMK AO2 SLP087
KEWR 151851Z 27014G18KT 10SM SCT070 22/04 A2980 RMK AO2 SLP090
KLGA 151851Z 32008G22KT 10SM SCT060 19/04 A2980 RMK AO2 SLP090
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Old 25th May 2019, 17:00
  #27 (permalink)  
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I think the aircraft could handle it maybe another factor involved couldn’t..... just saying
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Old 25th May 2019, 17:27
  #28 (permalink)  
 
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Originally Posted by Two's in View Post
The problem was when he lost forward airspeed, the torque reaction from the main rotor began to overcome the anti-torque moment provided by the tail rotor. This caused the aircraft to yaw to the right despite full left pedal. The combination of a tail wind component, high power and zero airspeed overcame the tail rotor authority. The application of more power simply made the situation worse and increased the torque driven yaw, so no, he couldn't (and didn't!) "power" his way out of it. He had a number of options, all of them poor. He could have lowered the nose and attempted to regain positive airspeed, this would have provided aerodynamic forces to counter the yaw, but in this case he would have been descending and accelerating towards the river bank and structures, so this may not have been appealing. He could have reduced the power until the anti-torque force countered the yaw, but again, this meant descending towards the river and the bank waiting for the rotation to stop, not an obvious choice. Or, if he could have maintained a more stable platform, the rotational speed might have decayed as the aircraft came back into the wind, allowing him to transition away into the wind and regain positive airspeed quicker, but again, it's a brave man who can hold it in a level flat spin waiting for the rotation to slow down.

As you see from the video, all this happened very quickly, and this guy was only thinking of repositioning to a spot following a refuel. He probably wasn't considering the finer points of countering an unstable rotational acceleration with a limited anti-torque force following the loss of translational lift in a down wind configuration. But he will next time.
Thanks for the detailed explanation. Really appreciated. I' ack some of the basics such as the interaction between main rotor and tail rotor etc so i'll be checking google/youtube. The rest I did understand.
I find it interesting to see, that for the eye, these are two similar jobs, but if you just take a bit of time to think about it, there are several more dimensions you guys have to think about.
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Old 25th May 2019, 19:55
  #29 (permalink)  
 
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Lousy approach in the first place not to mention that he didn’t learn from his first attempt. A L4 with no pax can definitely handle more wind than that.
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Old 26th May 2019, 13:16
  #30 (permalink)  
 
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If we assume that the pilot is being truthful...that he used FULL left pedal and the rotation did not stop...then this one goes into the history books as "just another 206 LTE accident."

But many of us have time in the 206L. Some of us here have LOTS of time in the 206L. Some of us can say...well, let's say we "doubt the pilot's recollection." Let's not say that he's lying about his use of full left pedal. Let's cut him some slack and say he is, umm, "misremembering." And, come on, admit it, what he said is what we'd all say.

If you are in an OGE downwind hover in any helicopter (but especially a LongRanger with that long tail boom) then you MUST expect that the ship will want to swap ends. You MUST be ready to counter any unanticipated, uncommanded yaw with whatever combination of controls works to stop it. Might be full pedal does the trick. Maybe a reduction in torque will do it if you're already at full pedal. Maybe moving the cyclic to the right or forward can be the solution. Maybe it takes all of those things. Trouble is, you have to do them NOW. You can't sit there and think about it until it's too late. Because if you're so clueless that you put your ship into an downwind OGE hover and you get unanticipated, uncommanded yaw, it's already really damn close to being too late.

Last edited by FH1100 Pilot; 26th May 2019 at 19:36.
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Old 26th May 2019, 13:18
  #31 (permalink)  
 
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Not knowing what happened here, I just want to point that many times it has been reported in other accidents pilots never really pushed the pedal to the floor during the onset or recovery...
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Old 26th May 2019, 23:18
  #32 (permalink)  
 
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Aser, indeed...

From 11 years ago:
This is something I posted in a discussion on an R44 accident that was labelled LTE.
There is one phenomenon I’ve never seen addressed in these “LTE / LTA” accident investigations that most of us, certainly those who have spent time giving primary instruction are familiar with. It has no “official” name but my vote would be FOC, for

Freezing on the Controls.

From my own primary flight training efforts I recall (with cheeks burning) those occasions where despite my pushing that left pedal for all my 200 lbs. was worth the nose merrily kept trundling to the right – until the instructor took over, I lifted my trembling right leg off the pedal, and miraculously another 2 or 3 inches of pedal travel materialized.

I experienced an even more extreme example of this while giving instruction a few years later. My student was a slightly-built PPL rated gentleman in his 60s; I was in my 30s and outweighed him by over 50 lbs. Nevertheless, on several occasions after I called “I have the controls” I could not budge any of them – not the pedals, not the collective, not the cyclic – because of how tensed up he was. I terminated the lesson early because I was afraid we’d crash while wrestling for the controls; next morning he flew with another instructor who outweighed me by about 40 lbs. thanks to his weight-lifting hobby, and despite my warnings about this student he thought the pedals had jammed the first time he tried to take over.

These experiences have led me to believe that in a lot of cases where the accident report read “despite application of full left pedal” it should have read “despite the application of what the pilot believed to be full left pedal but was somewhat less than that”. Typical scenario: low-time and/or out-of-practice pilot, already somewhat tense, tail- or cross-wind hover, a little gust and the nose whips right, pilot really tenses up then pushes the left pedal, but against his tensed-up, immovable right leg, pilot now believes he has full pedal in and why doesn’t this spin stop? The remedy here would be enough clarity of mind to consciously lift the right foot off the pedal, but in a high-pressure and rapidly-changing situation, that’s an awful lot to expect from a relative neophyte. If the investigators asked “did you have your right foot on the floor?” and the pilot answered in the affirmative I’d have to believe he really had full left pedal in, but so far I’ve never seen this confirmed either way in accident reports.

As for my personal experience in type: in 250 hours in the R44 including hovering in and out of ground effect in any relative wind angle, I’ve never encountered the pedal stops. The tail rotor authority was always excellent. Please note that “twitchy in yaw” is not the same as “poor tail rotor authority”.

If the subjects of discussion are “Gazelle” and “fenestron stall” replace left with right and vice versa in the above.
Then recently I saw an in-cockpit video of a B206 accident, which rolled over after spinning out of control during taxi. A fraction of a second before ground contact the camera happened on the pilot's feet and the pedals were neutral.

All this led me to conclude that the first step in an LTE/LTA scenario should be: take your right foot off the pedal.

My roughly 1300 hours of flying B206L models at high-ish DA (up to 10,000 ft) showed that what we were told during training was correct: "Lead power application with up to full left pedal".
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Old 27th May 2019, 01:46
  #33 (permalink)  
 
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The pilot didn't have much experience. 100 hours on type. 900 hours total. With that emerging level of experience he might have been feeling over confident leading up to the loss of control, but was overwhelmed by it all when his skill level was found to be less than that required to recover from the situation he got himself in. From the video I saw, the pilot was responsible for the demise of the helicopter.
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Old 27th May 2019, 08:58
  #34 (permalink)  
 
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Oooh - must confess - as soon as I saw the ham-phished approach and wind direction I could see where the vid was going. Looks like an outstanding disregard for aerodynamics.
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Old 29th May 2019, 12:06
  #35 (permalink)  
 
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Without casting any judgement on this incident, I think that the window when pilots are about 500-1500 hours is the most dangerous. Confidence is up, but you simply don't know what you don't know.

I'm grateful I survived this time, given some of the antics I got up to in this window, very much unaware of the true risks, and definitely without the presence or the skills to manage them.
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Old 29th May 2019, 18:40
  #36 (permalink)  
 
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Originally Posted by the coyote View Post
Without casting any judgement on this incident, I think that the window when pilots are about 500-1500 hours is the most dangerous. Confidence is up, but you simply don't know what you don't know.

I'm grateful I survived this time, given some of the antics I got up to in this window, very much unaware of the true risks, and definitely without the presence or the skills to manage them.
If you don't know what is going to happen when you turn the tail into a downwind hover (or close to it) by 500 hours you need to hand in your licence and do something else for a living!
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Old 30th May 2019, 07:03
  #37 (permalink)  
 
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Well, sort of, but not quite. I can point the tail of a 206L into 15 knots of downwind hover no problem at all (as can everybody else). What I can't do without the risk of seriously messing up is a downwind quick stop so close to the ground, and terminating downwind. That is the real issue here: if you don't know that then yeah, serious lack of training or airmanship, time for a reassessment of your career options.
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Old 30th May 2019, 12:10
  #38 (permalink)  
 
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Agree with Spunk
The pilot said that he attempted one approach to pad #4 but felt the onset of LTE (loss of tail rotor effectiveness) and aborted the approach and went around. He climbed the helicopter over the water, turned the helicopter back toward an easterly heading to the helipad and again felt the onset of LTE.
not learning from the first approach and doing exactly the same thing again is crass stupidity.
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Old 30th May 2019, 14:22
  #39 (permalink)  
 
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We can't be too hard on this guy. Those of us with umpteen-thousands of hours in 206's can smugly sit here saying, "Saw that one coming a mile off!" But everybody's got to learn at their own pace and peril. But let's be honest here: This was *not* a case of LTE. It was merely a case of a helicopter wanting to weathervane into the wind. As soon as it started to yaw, the pilot should have stomped on that left pedal and arrested the yaw. He did not. Perhaps he was thinking that his tail rotor had "stalled" and now he was "in LTE." Once it got going around, he still did not stop it although there were a couple of things he could have done.. And I assure you, a lightly-loaded 206L (one person on board, even topped-off) at sea level was absolutely capable of doing what he did, provided he'd been aggressive enough on the controls. It still might have swapped ends on him, but... show of hands...who hasn't had *that* happen once or twice in his career? This accident can and should be chalked up to "Uncommanded right yaw that was left uncorrected and the aircraft departed controlled flight." Blaming this one on LTE is not accurate nor fair to the 206.

LTE...or, "Tail rotor VRS" if you will is not a stable condition which persists as the aircraft goes around. The tail rotor never stops working. However, once the yawing momentum starts to build, then we run into LTA, or "loss of tail rotor authority" in which the tail rotor just might not be strong enough at that point. A fixed-wing airplane can get into a similar situation if it gets too slow when at too low of an altitude - even if it is above its stall speed.. At some point you cannot "power-out" of your situation and you MUST lower the nose and regain some airpspeed. But if the plane impacted the ground first, we would not blame the aircraft.

It is possible that had this guy been over flat, level ground, he might not have even spread the skids (if his cushion timing had been exquisite) and we just would've had an exciting near-miss video to watch.

Buitenzorg has it exactly right. The pilot will swear that he was pushing full left pedal. But most likely he was just pushing against his stiff right leg
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Old 30th May 2019, 17:26
  #40 (permalink)  
 
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Originally Posted by FH1100 Pilot View Post
But let's be honest here: This was *not* a case of LTE. It was merely a case of a helicopter wanting to weathervane into the wind. As soon as it started to yaw, the pilot should have stomped on that left pedal and arrested the yaw. He did not.
From the Helicopter Flying Handbook, on LTE
Weathercock Stability (120–240°) In this region, the helicopter attempts to weathervane, or weathercock, its nose into the relative wind. [Figure 11-12] Unless a resisting pedal input is made, the helicopter starts a slow, uncommanded turn either to the right or left, depending upon the wind direction. If the pilot allows a right yaw rate to develop and the tail of the helicopter moves into this region, the yaw rate can accelerate rapidly. In order to avoid the onset of LTE in this downwind condition, it is imperative to maintain positive control of the yaw rate and devote full attention to flying the helicopter.
You say its *not* LTE, then you practically give the textbook definition of LTE? Well,...ok dude
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