Videos show US Air crash-landing | Hacker News Reader

Videos show US Air crash-landing

cnn.com

25 pointskqr229 comments

As a pilot, it's great to watch a guy make something hair-raising into something that looks like a milk run.

I'd be interested to see if the pilot had a float rating. I'd also be curious as to how the wind was in relation to the river. Ideally the plane would be pointing directly upwind as it hit the water.

However the details worked out (and we pilots love the details) the crew had only seconds to configure and land the plane. Kudos to them for being able to change context and execute a fairly rare maneuver without flaw. There are some great stories about commercial jets doing just fine without engines (check out the Gimli Glider for instance http://en.wikipedia.org/wiki/Gimli_Glider) I remember one from South America that involved going through a cloud deck to land on a levee. This pilot gets to add his name to some of the best of the breed. Completely outstanding.

There was also Air Transat flight 236 that landed in the Azores: http://en.wikipedia.org/wiki/Air_Transat_Flight_236

Do you remember what air line was involved in the South American incident?

There's a wiki page, but this discussion page is better

http://www.airliners.net/aviation-forums/general_aviation/re...

The pilots requested permission to fly the plane off the levee (!) but were denied.

There's a whole series of interesting power-out landings, including the DC-9 at Sioux City. A recap would be a good idea for a blog post for someone....

The Gimli Glider incident sounds incredible. I can't imagine how spooky it would be to be in a jet at 40,000 feet and have the engines go silent. How much of the noise in a jet is engine noise vs. air resistance?

It varies according to whether the plane is climbing, cruising or descending. From flying gliders, I'd guess about 50/50 during cruise. The sounds occupy different parts of the spectrum - wind noise is pretty white, but more in the higher part of the spectrum. Engine noise is a very deep, black-ish noise. You can hear the difference between a jet in climb and approach - the former makes a much louder, deeper noise. The latter sounds just like a skydiver, incidentally - if you stay at a quiet drop zone, you'll often wonder if there's a jet somewhere high up in the sky.

That seems like it worked really well. There's been a lot of gnashing of teeth about the fact that jet engines can't survive ingesting birds, but it seems like all you have to do is have a body of water past the end of the runway and a rescue boat ready, and a failed engine is just an inconvenience.

That is a seriously talented pilot. He makes it look like a natural maneuver but the margin for error was incredibly low.

According to news reports about him, Chesley Sullenberger is an excellent pilot. Yesterday's Times article about him (http://www.nytimes.com/2009/01/17/nyregion/17pilot.html) says that he won the Outstanding Cadet in Airmanship award when he was at the Air Force Academy.

Is he? If he had to do that 100 times, how many times would he succeed? What would be the average across all pilots for that type? What would be the variance?

I'm happy he succeeded, this time, but I can't resist nitpicking the flaw in your argument. Can you tell I'm reading Fooled by Randomness?

Ya, those are fair questions. I don't have the information to answer them objectively since I'm just a dirt farmer from Alabama but noonespecial explains it pretty well.

I'm not a pilot but if you replace the water with the runway you've got what seems like a perfect landing.

Any HN'ers with aviation experience care to comment?

Water is much harder. The drag as soon as you touch is incredible so the deceleration is nearly instant. He had to know to keep the gear up, the flaps not extended and touch at the perfect angle. Even then, there is a large element of chance. Most water ditchings end with the plane catching a surface in the water, cartwheeling and then breaking apart.

Its hard enough to land planes that are designed with floats on the water. This was the perfect combination of luck and much skill, like an NBA player getting that buzzer shot from 3/4 court to win the game.

It was an incredible feat, but I don't think that knowing to keep the gear up when landing on water is particularly remarkable.

noonespecial is not talking about landing gear, he's probably talking about things like this: http://www.metacafe.com/watch/48376/plane_crashes_on_water/

Good find. I was actually looking for that to illustrate the fate of most aircraft that attempt to ditch in water.

And yes, I should have been more clear, "gear" would include landing gear (duh), engines, flaps, elevators, or anything else that might "snag" on contact with the water and cause this sort of outcome. The larger the aircraft, the harder it is to prevent this. There is a water landing emergency checklist that usually includes retracting the wheels, pulling in the flaps, etc but the angle and levelness of contact here was all art. Very cool to watch. I'm glad there were some security cameras that caught the actual landing.

That's a wreck in Ethopia where the hijacker grabbed the controls at the last moment before ditching and crashed the plane.

I know, but it's a nice visual demonstration of how quickly things can go south in a water landing. Dip something into the water and it's just all over.

Here's one that shows the quick evacuation of passengers onto the wing then how long it took for boat to reach them. You have to forward some thru vid to see.

http://snackfeed.com/videos/detail/84bdb03e-3621-102c-a525-0...

Perfect landing. And he was lucky the river was so empty. There are often large oil barges moving slowly or moored in the center of the river.

Very impressive how slow he got the plane to go. Without using the engines for reverse thrust, I don't know how one would slow down.

They reverse the engines when they land.

http://en.wikipedia.org/wiki/Thrust_reversal

The wiki article on ditching is a little rough,

http://en.wikipedia.org/wiki/Ditching#Commercial_aircraft

...but it seems like this procedure isn't done often enough with jets that we could honestly assess how difficult it might be. I suppose it's just like a normal landing, but doing it so gently that it doesn't break apart.

Very impressive how slow he got the plane to go.

He used ground-effect to ride the plane on a cushion of air. http://news.google.com/news?q=%22ground%20effect%22

Um. It's easier to go slow when you have no thrust.

I think they don't use engines to slow down. I have seen some parts of the wings (like the rear half of the wings..) along its length standing up right ( something like right angle to the direction of motion of plane) putting a lot of resistance to the air while planes need to slow down.

Using the engine to slow down is like using the reverse gear of your car to slow down, which no one does, which never works (because of possible breakdown of the engine) and should not be done to save the engine from damage.

[ I am not a mechanical or automobile engineer. But this is my knowledge ]

They have three things:

Those surfaces as you call them. Thrust reversers (basically fins that push over the end of the jet and redirect the thrust forward), and the brakes on the wheels.

All planes must (by FAA regs), be able to land without using the thrust reversers (using the brakes instead), but thrust reversers are what's used in normal cases (since it saves wear on the brakes).

The engine itself does not change direction. Surfaces are deployed to redirect its thrust forward instead of backward. And that is only done after the plane is on the ground.

Anyone know what they're throwing from the ferry near the end? Life preservers to people in the water, maybe?

I think they're getting rid of the life preservers, because they're bulky and would allow fewer people to squeeze into the boat.

Very cool. I ride my bike right by there when the weather is nice.

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