Helicopter Down in NY East River

Posted by: airballrad

Helicopter Down in NY East River - 10/04/11 08:36 PM

Helicopter Crash

Latest report, 1 dead, 4 injured.
Posted by: chaosmagnet

Re: Helicopter Down in NY East River - 10/05/11 08:59 AM

I don't know how to prepare for this without military helicopter ditching training.
Posted by: airballrad

Re: Helicopter Down in NY East River - 10/05/11 10:01 AM

I dunno either. I've seen several stories on ETS about surviving water landings in a place, but don't recall any addressing helicopter ditchings. I wonder what, if any, procedures are discussed/demonstrated when boarding a helicopter charter.
Posted by: Russ

Re: Helicopter Down in NY East River - 10/05/11 12:53 PM

Originally Posted By: chaosmagnet
I don't know how to prepare for this without military helicopter ditching training.
First if you don't know how now, learn to swim, really well and underwater. Learn how to get to and open the escape hatch (over-wing, overhead, whatever) of the aircraft you fly in and learn to get to and open them by touch because you can't be assured of visibility once you go under.

Many helicopters are top heavy so be prepared to do this after the aircraft rolls inverted (with you securely strapped inside) with dark, cold water swirling around. Finding doors and opening them underwater in the dark can be done if you stay calm and just do it.

The last time I did this the pool was set up like the South Pacific, saltwater @ 84 deg F -- most comfortable pool I'd ever been in and very coral reef like. Trust me the water in the East River or any of the other rivers in/around NYC is not that pristine.
Posted by: hikermor

Re: Helicopter Down in NY East River - 10/05/11 01:49 PM

When working at Channel Islands Nat'l Park, we were required to take training in emergency ditching procedures periodically. We did a lot of over water flights (! - I guess that'shy they are islands....) in both fixed wing and helicopters.

At one of these sessions, we used an invertible cage in a swimming pool. The key was to get a grip on the door latch preimpact, so that you maintained your orientation as you inverted and went in the water. If the latch was to you left, you reached across your body and gripped with the right hand. Once everything had stopped moving, and that is critical, you opened the door and exited.

Easy enough and kind of fun in a swimming pool. I've never had a chance to try it for real, nor have I talked with anyone who has.
Posted by: gonewiththewind

Re: Helicopter Down in NY East River - 10/05/11 01:51 PM

Helicopters ALWAYS roll upside down in the water. Hold on, survive the impact, wait for the roll, find an exit and follow the bubbles. It is a bit disorienting the first time and you may not know which way is up, follow the bubbles.
Posted by: AKSAR

Re: Helicopter Down in NY East River - 10/05/11 02:41 PM

Originally Posted By: Montanero
Helicopters ALWAYS roll upside down in the water. Hold on, survive the impact, wait for the roll, find an exit and follow the bubbles. It is a bit disorienting the first time and you may not know which way is up, follow the bubbles.
I would add what I learned in dunker training: hold on and maintain a reference point, then work your way hand over hand to the exit. It will likely be dark and you will loose your orientation if you don't always hold on to a point of reference. If you loose your orientation you will probably drown.

Whenever I get on any aircraft, helo or fixed wing, I always take a moment to look around and fix in my mind where the possible exits are, and how to open them.
Posted by: Arney

Re: Helicopter Down in NY East River - 10/05/11 03:15 PM

Originally Posted By: hikermor
The key was to get a grip on the door latch preimpact, so that you maintained your orientation as you inverted and went in the water.

Wouldn't doing this be an unfortunate way to render that door inoperable, if you end up ripping off the door latch on impact? Finding a grab handle makes sense, but not the actual latch.
Posted by: Russ

Re: Helicopter Down in NY East River - 10/05/11 03:20 PM

Agree, the door may not be within reach while you are strapped in. The idea is to hold onto a reference point, not necessarily the door handle. You may need to swim to the door, but never without a handhold.

There's a thought process involved; mentally take yourself through the steps and various handholds to get to the door. Once underwater and inverted, the handholds are still where they were relatively speaking.
Posted by: hikermor

Re: Helicopter Down in NY East River - 10/05/11 03:27 PM

My instructors were very specific about this point; you grab the door handle, which is not a particularly wimpy piece of gear. You are also belted into your seat, so you won't be flying about the cabin.

As I say, this is all training; it would be nice to hear from someone with actual experience.
Posted by: Russ

Re: Helicopter Down in NY East River - 10/05/11 03:51 PM

In my last training/qualification swim, I had to swim underwater to the "door", manipulate various door latches, open the door and swim through. Your qual seems to have been for a specific aircraft where you always sat next to the door. I've never had a survival swim qual that easy.
Posted by: Colourful

Re: Helicopter Down in NY East River - 10/05/11 04:22 PM

Dit it have inflatable floats?
Posted by: hikermor

Re: Helicopter Down in NY East River - 10/05/11 04:31 PM

Quite true. We were typically flying Bell Jet Rangers or smaller, and you were always next to a door. The training was not particularly taxing (although way better than nothing).
Posted by: Arney

Re: Helicopter Down in NY East River - 10/05/11 04:43 PM

I just thought it was imprecise writing yesterday, but as I read a couple more articles today, it really does seem that the helicopter hit the water upside down, according to the eyewitnesses, instead of tipping over after hitting the water. It seems impossible that the aircraft could be upside down when it hit considering that it had just lifted off, so perhaps a rotor tip caught the water on the way in and that then flipped the aircraft over into the water?

In any case, the eyewitnesses also mentioned that the aircraft was spinning around before the crash, making it even more nightmarish for everyone on board.

Anyone ever had dunk training where they spin you around the vertical axis, then flip you upside down and then slam you into the water on your head? Scary.
Posted by: gonewiththewind

Re: Helicopter Down in NY East River - 10/05/11 04:45 PM

Originally Posted By: Russ
In my last training/qualification swim, I had to swim underwater to the "door", manipulate various door latches, open the door and swim through. Your qual seems to have been for a specific aircraft where you always sat next to the door. I've never had a survival swim qual that easy.


Ours was a Blackhawk sized fuselage and we packed it full. The doors were closed and we had to get out after it rolled over. It was quite interesting, and we all came out with bruises and cuts, but we all got out without aid from the safety divers. It was very realistic; we did not have seats (as is normally done on operations), we were in full kit and it hit the water hard. We did have inflatable flotation devices for once you cleared the door.
Posted by: Russ

Re: Helicopter Down in NY East River - 10/05/11 05:06 PM

Sounds like fun wink The first helo dunker I did (circa 1986), we had seats and were all strapped in. They did the crawl, walk, run thing, which meant you needed to go through the process multiple times. 1) any window/door, eyes open; 2) any window/door, wearing opaque goggles; 3) (everyone) main cabin door, eyes open; 4) (everyone) main cabin door, wearing opaque goggles.

I tended to take my time and wait for the feet to clear. Being able to relax and take your time under water is huge. Once panic sets in your clock starts running much faster.
Posted by: Glock-A-Roo

Re: Helicopter Down in NY East River - 10/05/11 06:00 PM

Wow, the water egress training you guys describe sounds daunting. Of course I am uninitiated but even with rescue divers, it seems like the risk of a student getting hung up and sucking down a lungful of water is high. What kind of accident rates did you see in those evolutions?
Posted by: Russ

Re: Helicopter Down in NY East River - 10/05/11 06:27 PM

Personally I never saw any instance of rescue guys having to pull students, but the Naval aviation groups I was with had already been through earlier training/testing and students with issues were weeded out early. Nonetheless, the rescue swimmers were always there. They wouldn't even begin the real testing before I demonstrated an ability to meet certain benchmarks. They are very careful, but I have no doubt there have been accidents.

The last time I did this I was literally the only "student"; there were four instructors on the sides evaluating, with two rescue swimmers and me in the water. Without the lines created by having lots of students, it was all over in an hour and was a real work-out. In prior quals there was time between tasks to catch your breath, but it took all afternoon. In the pool at 8 AM and done by 9 AM was a vast improvement and probably more realistic.
Posted by: Susan

Re: Helicopter Down in NY East River - 10/05/11 07:05 PM

Quote:
It seems impossible that the aircraft could be upside down when it hit considering that it had just lifted off, so perhaps a rotor tip caught the water on the way in and that then flipped the aircraft over into the water?


I don't know anything about that crash (or helicopters), but according to the info below, I'm wondering if the rotors stop for some reason, the helicopter would FALL upside down?

From The Space Review [quote][/quote]

"Because the heaviest part of a helicopter is the engines mounted over the cabin, most helicopters immediately tip over when they hit the water and crews are trained to exit a sinking upside down helicopter."

Also (same source): "And one of the dangerous aspects about helicopters is that bad goes to worse very quickly."

Sue
Posted by: MostlyHarmless

Re: Helicopter Down in NY East River - 10/05/11 07:19 PM

Originally Posted By: Susan

I don't know anything about that crash (or helicopters), but according to the info below, I'm wondering if the rotors stop for some reason, the helicopter would FALL upside down?


I don't know much about helicopters either, but I've heard repeatedly from several sources that DO know much about helicopters that loss of engine power don't mean you loose controll. Obviously, you go down, but you can pretty much control where and how you land the thing. The principle is called autorotation: As the helicopter falls, the movement relatively to the air causes the rotor to spin at great speed, which gives you enough lift to slow the descent to survivable speeds and also gives you limited control over the heli.

Once in the water the heli flips over, yes.

And there are probably a bunch of other things than engine that can go wrong with a heli.
Posted by: Glock-A-Roo

Re: Helicopter Down in NY East River - 10/05/11 08:51 PM

I recall seeing somewhere that an airplane is a machine that wants to fly, the engine and controls just help it along. A helicopter is a machine that desperately wants to crash, the engine and controls constantly fight against this.
Posted by: chaosmagnet

Re: Helicopter Down in NY East River - 10/05/11 09:29 PM

A helicopter that loses power at altitude can often still land safely due to autorotation. I am no pilot but I've read that the JetRanger is particularly competent in this flight envelope. See http://en.wikipedia.org/wiki/Autorotation and http://en.wikipedia.org/wiki/Height-velocity_diagram for more info.

On the other hand, losing the tail rotor is always Very Bad and quite difficult to survive. It's possible that this is what happened in NYC.
Posted by: AKSAR

Re: Helicopter Down in NY East River - 10/05/11 09:30 PM

Originally Posted By: Glock-A-Roo
I recall seeing somewhere that an airplane is a machine that wants to fly, the engine and controls just help it along. A helicopter is a machine that desperately wants to crash, the engine and controls constantly fight against this.

You are probably thinking of Harry Reasoner's quote:

"The thing is, helicopters are different from planes. An airplane by its nature wants to fly, and if not interfered with too strongly by unusual events or by a deliberately incompetent pilot, it will fly. A helicopter does not want to fly. It is maintained in the air by a variety of forces and controls working in opposition to each other, and if there is any disturbance in this delicate balance the helicopter stops flying; immediately and disastrously. There is no such thing as a gliding helicopter.

This is why being a helicopter pilot is so different from being an airplane pilot, and why in generality, airplane pilots are open, clear-eyed, buoyant extroverts and helicopter pilots are brooding introspective anticipators of trouble. They know if something bad has not happened it is about to."

-Harry Reasoner

(I got the quote from http://www.ga-vhpa.org/musings.html, and also Tim Setnicka quoted part of it in his book 'Wilderness Search and Rescue')
Posted by: Arney

Re: Helicopter Down in NY East River - 10/06/11 05:38 PM

Originally Posted By: Susan
I don't know anything about that crash (or helicopters), but according to the info below, I'm wondering if the rotors stop for some reason, the helicopter would FALL upside down?

In a hypothetical situation with loss of engine power, although it might be possible for a falling helicopter to flip over due to wind shear or some other violent turbulence, I don't recall ever hearing of a helicopter flip over like that. Since the engines are quite heavy and autorotation (even upside down) tends to create drag from the rotors, I think the tendency of an upside down falling helicopter would be to flip back over, rightside up again assuming there was enough altitude and time.

But that's different from the hypothetical I mentioned, where the rotor strikes something that physically stops the rotor so that the momentum and torque present in the rotor suddenly needs to find something else to turn, namely the rest of the helicopter.

Once in the water, however, the dynamics totally change. The body of the aircraft then becomes a top heavy floating object and the weight of the engine and main rotors will want to go to the bottom, the same way that a car in the water typically sinks nose first. It's kind of like trying to lie on top of a big beach ball in the water--the tendency is for the heavy object, i.e. you, to go under while the buoyant ball is pushed upwards by the water.

I've always been amazed that people continued to try and develop the helicopter until they got it to work. Unlike the way a fixed wing aircraft works, a helicopter is just brute force exerted against gravity in a battle to stay aloft. Then again, we do have hummingbirds and other hovering birds in Nature, too.