Helicopter down in East River, NYC
Because if you are applying that to helicopter EOL generally, the S76 RFM would disagree with you on that. And I would also, having done many hundreds of EOL in the 76. 100kts and 90% RRPM will get you considerably further than 75kts (or 100kts) and 107% RRPM.
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TC
Are you saying max glide speed in Auto at max Nr will take you further than max glide speed at min Nr?
Hate to break it to him but the only way to improve your glide range in auto is to increase your speed and NOT decay Nr.
If the pilot was looking outside, which is where you tend to look when looking for an emergency landing spot, a pilot sitting in the right seat should see that the floats on the right side were not inflated. And the flight asymmetry I should think would be a pretty good clue.
skadi
TC - do you not remember the extended range auto demo on the Gazelle?
Enter auto at 95 kts and 380 Nr - when you were sure of making the landing area, chop the throttle and droop the Nr to not below 330Nr.
Once you had shown the LP moving down the screen and that you were clearly going further, recover the Nr to 380 in the flare back to 60 kts for the EOL.
it very much depends on the shape of your blades as modern assymmetric profile blades might not perform as well with the change in relative airflow as the symmetrical Gazelle ones did.
The Squirrel has the same capability I am reliably informed.
I suspect he was reluctant to lower the lever enough in the flare to fully recover the Nr for the EOL. Not surprising when you are going down quickly towards a dark river for real!
Enter auto at 95 kts and 380 Nr - when you were sure of making the landing area, chop the throttle and droop the Nr to not below 330Nr.
Once you had shown the LP moving down the screen and that you were clearly going further, recover the Nr to 380 in the flare back to 60 kts for the EOL.
it very much depends on the shape of your blades as modern assymmetric profile blades might not perform as well with the change in relative airflow as the symmetrical Gazelle ones did.
The Squirrel has the same capability I am reliably informed.
I suspect he was reluctant to lower the lever enough in the flare to fully recover the Nr for the EOL. Not surprising when you are going down quickly towards a dark river for real!
I always found ...best range auto was achieved ( using 206 numbers) using Min RPM, 80 KTS plus 1/2 the wind ...once spot is made slight flare to reduce speed while lowering collective to regain max rpm before the big flare and landing. If necessary you could maintain min RPM and high speed to the flare but you needed to make a really BIG flare at the bottom and maybe even a run on. ( highly not recommended in a ditching scenario ) the same in 205/212, 350, 355, ect.
I used to teach going immediately to best range numbers if altitude allowed . ( I was training high time pilots not ab initio guys.)
Used to demonstrate a full on auto using max RPM and 60 then enter from the same spot using the long range settings ...amazing how much farther we would go. (NO we did not do full ons in twin engine aircraft).
Min Rate was RPM at the bottom of the green and 60kts. However in this scenario collective would need to be lowered at a sane altitude to return RPM to the top of the arc ..otherwise it was not going to be nice at the bottom.
In this case I am amazed at how much the pilot was able to after the engine quit! I had an engine resign at 750' feet one time and had to do a 270 degree auto. However the loud explosion and chip light coming on led me to believe that a relight was not going to happen so I did not attempt one. Still it was a busy time.
I used to teach going immediately to best range numbers if altitude allowed . ( I was training high time pilots not ab initio guys.)
Used to demonstrate a full on auto using max RPM and 60 then enter from the same spot using the long range settings ...amazing how much farther we would go. (NO we did not do full ons in twin engine aircraft).
Min Rate was RPM at the bottom of the green and 60kts. However in this scenario collective would need to be lowered at a sane altitude to return RPM to the top of the arc ..otherwise it was not going to be nice at the bottom.
In this case I am amazed at how much the pilot was able to after the engine quit! I had an engine resign at 750' feet one time and had to do a 270 degree auto. However the loud explosion and chip light coming on led me to believe that a relight was not going to happen so I did not attempt one. Still it was a busy time.
Last edited by albatross; 27th Mar 2018 at 15:11.
Yes you're right - it comes across like that - apologies.
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
I always said getting rpm (collective full down until recovering back into the green) first was the first priority. I thought the guy was at 2000' before when the engine failed. That should have allowed him to go to either Min descent or max range and lower collective at +_ 500 to recover full rpm for a full stop auto flare at the bottom end. He had a lot on his plate but first priority should be a successful auto.
Also hitting the starter with the throttle in the fly position would lead to some interesting numbers re temps! ( never flew a B but you would cook the engine big time on a D.)
Also hitting the starter with the throttle in the fly position would lead to some interesting numbers re temps! ( never flew a B but you would cook the engine big time on a D.)
Yes you're right - it comes across like that - apologies.
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
Last edited by albatross; 27th Mar 2018 at 16:34.
I realize that the float situation was a contributing factor to why the aircraft rolled. I've installed 2 of these float systems, and found the cables and boxes to be hokey at best. I think the design could have been better. But alas, somehow, this one was rigged incorrectly or something wasn't right, and failed to activate the right float. There is a transfer line, but clearly there isn't enough capacity in one bottle to fully fill all six bags, or at least transfer enough to the opposite side fast enough. Perhaps more time would have helped, maybe not.
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In that case it's the most stupid design point of any helicopter I have ever seen in my 26 years of flying. I bet that one bottle had enough gas in it to partially inflate both sides sufficient for the helicopter to have floated upright after landing.
If the floats only inflated on one side of the helicopter in flight, I imagine the asymmetric drag wouldn't have been helpful for directional control.
If the floats only inflated on one side of the helicopter in flight, I imagine the asymmetric drag wouldn't have been helpful for directional control.
What I'm finding difficult to comprehend is, the pilot must have known prior to 500' that the floats on one side of the aircraft had failed to inflate, so why continue to a water landing? Those passengers were all doomed from the moment the decision was made to continue with the water landing after the floats had failed to inflate properly.
Well, about that time he was managing an emergency autorotation, and at the same time, also processing a bunch or new and interesting information, like the fact that the passengers tether had been looped around the fuel shutoff, and that it was now in the off position, and pondering how that tidbit altered his current situation. But you're right, as he passed through 500 feet, he should have noticed that the right side floats were only partially inflated and climbed to a safe altitude and flown off to land elsewhere.
Last edited by A Squared; 27th Mar 2018 at 20:32.
Yes you're right - it comes across like that - apologies.
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
I'm thinking, go for speed first not Nr. If you are already below your optimim speed for an auto already, bleeding Nr might not be the way round it. Accelerate and gain speed while maintaining Nr, I would suggest before tweaking Nr.
But at the height he was in, speed increase was not an option, so why bleed Nr off?
How's he going to get it back?
Extended glide procedure: NR in the green (after establishing AUTO), set airspeed to 90 to 100kts(max) first and slowly pull NR down to 320. This will make your glide considerably longer than just to auto at higher speed, and normal NR. Once you are sure you will reach your spot, but at no lower than 500AGL, reduce collective, AFT cyclic to regain 65kts airspeed and NR mid to top of the green and continue normal auto.
500 feet, he should have noticed that the right side floats were only partially inflated and climbed to a safe altitude and flown off to land elsewhere.
As for inflating the floats at 800 ft, that’s about 15-20 seconds before ditching and if - as he said - he was committed to landing in the river it seems a good decision. Inflating lower would just mean landing a few more meters further up the river!
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Sorry, I was expecting an emoticon, like head banging perhaps, so wasn’t sure. Frankly nothing surprises me on this forum hence my question.
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Indeed tough call. You have to imagine when he activated the floats and he hears a bang and sees yellow pop up all around him that he has assumed the floats had deployed correctly. The worse fear would be to pull the handle and have nothing happen at all, silence.
We have always taught, to get the floats out early rather than late for a few reasons. One reason being if you have the choice of a large open area of water for an easy auto vs a tight spot on the land and you hit the floats and nothing happens. Then you at least have some potential altitude for a change of spot, that field you didn't think you would fit the aircraft into without a more dramatic flare/pilot skill suddenly just became a little more doable vs a no float water landing.
If the water is still the only option you have then you might try to force it to the shore, even if that shore is not a flat open area or any number of things that your pilot mind is able to come up with in 15-20 seconds or more. Finding out at 40-50 feet that the floats have chosen not to deploy is going to be a real panic maker and you have quite literally zero options, you are along for the ride.
These Apical floats have a pull cable system and you need to shear a pin in the handle, this ends up being a two hand operation. Left hand comes off the collective to hold the cyclic, right hand grabs a hold of the handle pull with all you got. Its a solid 45 degrees or more of throw you need to pull them full travel. That's not a move you want to be doing at 40-50 feet either. The book will tell you the floats will want to take about 10 rpms off the rotor speed. Again if you have still a few hundred feet of altitude to play with and the rotor at 390 with a touch of pitch check in the collective,..... pop the floats.....loud noises, covers go flying, yellow appears, rotor decreases slowly to 380 as you rob the driving region of airflow....apply a touch of down collective and they come right back up, the lose of rotor rpm from float deployment is not a major concern.
Only concern most manufactures have is high speed flight with floats deployed and then getting it out of trim in a big way, the machine may attempt to tuck on you. The video shows all of the right side floats inflated, the back ones we would later see from images of it upside down were squishy, not firm. The video did show the very front of the front right float flopped over and not firmly inflated.
I don't know if in those last few hundred feet if I would have turned my head fully down and to the right so check the firmness of the bags. I would have seen the big ball of yellow emerge out of the corner of my eye when I pulled the handle and probably said something along the lines of, "well at least the floats deployed." His mind must have had so much going on at the bottom end that i don't think I would have been able to pick up and been aware enough that my right side bags were not as firm as they should be. Of course pretty much anywhere in NYC an engine failure means you are going to the water and you have to do whatever it takes to makes sure you make the rivers.
There are a few places where sometimes you have other options but those are few and far between. So even at 800' if he became instantly aware of the floats not being fully inflated on his side there is nothing he could do. You have no options at 800' descending over the east river to do anything other than picking where you are getting wet.
Hind sight will always be 20/20, a brand new pilot trying to do an air restart might have needed to look down to grab the FFCL to attempt a restart and might have caught visually that the emergency fuel shut off was pulled up and gotten it down earlier and had enough time for a restart. In this case a more experienced pilot is eyes outside trying to find a spot to land and reaches down by muscle memory to the FFCL to do the restart and does not look down and as such misses the emergency fuel cut off. Making decisions on if central park was a safe spot or not. Deciding to go to the river and turning the aircraft around to aim for it. Then making absolutely sure he would clear the buildings on the upper east side he droops the rotor to get better range out of the machine. Telling his passengers to get back up in the their seats. Two mayday calls, first one is stepped on, second one LGA proved to be useless. Then once he knows he is clearing the buildings and he's not going to be sliding down 1st avenue he remembers to get the floats out, bang! Yellow appears in peripheral vision, thank god. From there i can only assume focusing on not screwing up the bottom end and falling from 100 feet. I'm sure the first time trying to judge his flare and collective pull to flat water as the sun is setting behind the buildings made the seat cushion get sucked up into you know where. Finally hit the water and surprise the aircraft instantly rolls rights and whatever thoughts you had for what you were going to do when you hit the water are gone. Watching the video of the landing that was shot from behind shows the aircraft from impact skids level rolling to 45 degrees in 5 seconds, then another 5 seconds the aircraft is at 90 degrees, another 5 seconds aircraft fully inverts. The video continues for another 6 seconds and the pilot is still not out of the aircraft. So he was face under for at least 16 seconds before the video cuts.
As a pilot flying over water you do put a certain amount of trust in the float system, that as long as you can get the aircraft safely to the water, pull off a decent flare and not auger in at 70 knots you trust those floats will fire and you will be upright. There is a great video out there from Apical testing float systems on many types of aircraft. A few aircraft hitting with similar splashdowns to the accident aircraft. Aircraft would have bobbed right back up and been perfectly fine. The last engine failure over NYC was a long ranger on a tour when the engine quite literally blew up and the pilot made a great auto, the floats fired and the aircraft was upright in the water. Passengers never even got their feet wet. They towed it to the dock, craned it on a barge and the aircraft is still flying around after getting repaired. Having that vital emergency piece of equipment fail on you will forever stick in your mind. You will second guess your decision not to try and force it down in central park among the people for the rest of your life. I know most of us who fly will do everything they can to not injure/kill someone on the ground. If the scenario is you take it to central park and barely make it and your botched auto takes out 4 people on the ground but all of your passengers walk away or.... you auto to the river and your 5 passengers drown which one would you take? I've always felt that climbing into an aircraft you have a certain amount of assumed risk, the person walking in central park did not sign up for a helicopter to fall out of the sky and take them out.
We have always taught, to get the floats out early rather than late for a few reasons. One reason being if you have the choice of a large open area of water for an easy auto vs a tight spot on the land and you hit the floats and nothing happens. Then you at least have some potential altitude for a change of spot, that field you didn't think you would fit the aircraft into without a more dramatic flare/pilot skill suddenly just became a little more doable vs a no float water landing.
If the water is still the only option you have then you might try to force it to the shore, even if that shore is not a flat open area or any number of things that your pilot mind is able to come up with in 15-20 seconds or more. Finding out at 40-50 feet that the floats have chosen not to deploy is going to be a real panic maker and you have quite literally zero options, you are along for the ride.
These Apical floats have a pull cable system and you need to shear a pin in the handle, this ends up being a two hand operation. Left hand comes off the collective to hold the cyclic, right hand grabs a hold of the handle pull with all you got. Its a solid 45 degrees or more of throw you need to pull them full travel. That's not a move you want to be doing at 40-50 feet either. The book will tell you the floats will want to take about 10 rpms off the rotor speed. Again if you have still a few hundred feet of altitude to play with and the rotor at 390 with a touch of pitch check in the collective,..... pop the floats.....loud noises, covers go flying, yellow appears, rotor decreases slowly to 380 as you rob the driving region of airflow....apply a touch of down collective and they come right back up, the lose of rotor rpm from float deployment is not a major concern.
Only concern most manufactures have is high speed flight with floats deployed and then getting it out of trim in a big way, the machine may attempt to tuck on you. The video shows all of the right side floats inflated, the back ones we would later see from images of it upside down were squishy, not firm. The video did show the very front of the front right float flopped over and not firmly inflated.
I don't know if in those last few hundred feet if I would have turned my head fully down and to the right so check the firmness of the bags. I would have seen the big ball of yellow emerge out of the corner of my eye when I pulled the handle and probably said something along the lines of, "well at least the floats deployed." His mind must have had so much going on at the bottom end that i don't think I would have been able to pick up and been aware enough that my right side bags were not as firm as they should be. Of course pretty much anywhere in NYC an engine failure means you are going to the water and you have to do whatever it takes to makes sure you make the rivers.
There are a few places where sometimes you have other options but those are few and far between. So even at 800' if he became instantly aware of the floats not being fully inflated on his side there is nothing he could do. You have no options at 800' descending over the east river to do anything other than picking where you are getting wet.
Hind sight will always be 20/20, a brand new pilot trying to do an air restart might have needed to look down to grab the FFCL to attempt a restart and might have caught visually that the emergency fuel shut off was pulled up and gotten it down earlier and had enough time for a restart. In this case a more experienced pilot is eyes outside trying to find a spot to land and reaches down by muscle memory to the FFCL to do the restart and does not look down and as such misses the emergency fuel cut off. Making decisions on if central park was a safe spot or not. Deciding to go to the river and turning the aircraft around to aim for it. Then making absolutely sure he would clear the buildings on the upper east side he droops the rotor to get better range out of the machine. Telling his passengers to get back up in the their seats. Two mayday calls, first one is stepped on, second one LGA proved to be useless. Then once he knows he is clearing the buildings and he's not going to be sliding down 1st avenue he remembers to get the floats out, bang! Yellow appears in peripheral vision, thank god. From there i can only assume focusing on not screwing up the bottom end and falling from 100 feet. I'm sure the first time trying to judge his flare and collective pull to flat water as the sun is setting behind the buildings made the seat cushion get sucked up into you know where. Finally hit the water and surprise the aircraft instantly rolls rights and whatever thoughts you had for what you were going to do when you hit the water are gone. Watching the video of the landing that was shot from behind shows the aircraft from impact skids level rolling to 45 degrees in 5 seconds, then another 5 seconds the aircraft is at 90 degrees, another 5 seconds aircraft fully inverts. The video continues for another 6 seconds and the pilot is still not out of the aircraft. So he was face under for at least 16 seconds before the video cuts.
As a pilot flying over water you do put a certain amount of trust in the float system, that as long as you can get the aircraft safely to the water, pull off a decent flare and not auger in at 70 knots you trust those floats will fire and you will be upright. There is a great video out there from Apical testing float systems on many types of aircraft. A few aircraft hitting with similar splashdowns to the accident aircraft. Aircraft would have bobbed right back up and been perfectly fine. The last engine failure over NYC was a long ranger on a tour when the engine quite literally blew up and the pilot made a great auto, the floats fired and the aircraft was upright in the water. Passengers never even got their feet wet. They towed it to the dock, craned it on a barge and the aircraft is still flying around after getting repaired. Having that vital emergency piece of equipment fail on you will forever stick in your mind. You will second guess your decision not to try and force it down in central park among the people for the rest of your life. I know most of us who fly will do everything they can to not injure/kill someone on the ground. If the scenario is you take it to central park and barely make it and your botched auto takes out 4 people on the ground but all of your passengers walk away or.... you auto to the river and your 5 passengers drown which one would you take? I've always felt that climbing into an aircraft you have a certain amount of assumed risk, the person walking in central park did not sign up for a helicopter to fall out of the sky and take them out.
Last edited by surfandturf; 28th Mar 2018 at 02:20.
..These Apical floats have a pull cable system and you need to shear a pin in the handle, this ends up being a two hand operation. Left hand comes off the collective to hold the cyclic, right hand grabs a hold of the handle pull with all you got. Its a solid 45 degrees or more of throw you need to pull them full travel. That's not a move you want to be doing at 40-50 feet either...
Just so we're all on the same page... I was told that the East River Astar was a left-hand drive model. Which means that he very likely could *not* have seen that his right-hand floats were not fully inflated. Not that it would really have made a difference. Aside from Central Park, there are precious few areas big enough to land a helicopter on NY's upper east side.