Plane Down in Hudson River - NYC

[bubbers44]

Also double the chance of a bird strike in one of the engines. Maybe looking out the window more in VMC conditions would help more than banking when it is too late to avoid them.

[Christodoulidesd]

On a side-note (and i apologize if it was posted before) here's a very interesting set of close-up pictures of the plane during and after the hauling up

LiveLeak.com - Miracle on the Hudson Jpegs

[Pontius Navigator]

Originally Posted by bubbers44

Also double the chance of a bird strike in one of the engines. Maybe looking out the window more in VMC conditions would help more than banking when it is too late to avoid them.

Whilst there is nothing wrong with a good lokout in VMC, when flying IFR it is inevitable that the PF will be looking in for some of the time. It has also been mentioned that objects on a constant line of bearing will be less easily seen than ones with a changing angular displacement.

Then the combination of a climbing aircraft and birds in level flight makes a collision assessment it a difficult judgement.

The aircrat would have been some 1300 feet from collision at the 3 second point. Assume detection had been at 6 seconds it would have been at 2600 feet and possibly at the edge of visual detection range.

Anyway any solution must allow for night and IMC as well and so far radar would appear the best option.

[ChristiaanJ]

I'm frankly baffled by all this "three seconds" nonsense.

Repeat after me: "twenty and one, twenty and two, twenty and three". That's how long three seconds are.

Then BANGBANGBANG.

All the waffle on the subject supposes that the pilots (with a workload, remember) were looking in the right direction at the right moment. Then they identified those stationary dots as birds... since they were on a collision course, they would have been stationary. Then they could take evasive action? All in three seconds?
Try the other one, it's got bells on.

I would even surmise the BANGBANGBANG came first, followed by a "what the was.... Did you see that?" when the implications of the dots and the UFOs streaking past hit home, and ripped them away from the job they were doing.

Try again: "twenty and one, twenty and two, twenty and three".

If you disagree, tell me why.

CJ

[lomapaseo]

I'm saddened to see we've reverted back to solving the problem by steering around birds. There seems to be a great presumption about bird behaviour.

Forget about computer simulations, you need observations and data first.

The birds have been around a long time because they have learned to avoid most predation. Their response is not to just fly along in a flat plane. In fact they can move out of their flight pattern to esacpe a lot faster than the aircraft can.

Most of the available data is recorded bird strike damage to the aircraft and its engines. In an attempt to understand this statitical data some experiments have been made to confirm bird behaviour. I'll leave it to the data collectors and scientists among us to expand on this. But really folks we ought to stop speculating about birds trying to solve a safety of flight problem.

[robdean]

ChristiaanJ - it's on record that the birds were seen before impact and identified as such... I'm not sure Sully got as far as twenty-and-three before they hit though...

[patrickal]

ChristiaanJ - it's on record that the birds were seen before impact and identified as such... I'm not sure Sully got as far as twenty-and-three before they hit though...

And even if he did get to twenty and three, does snapping the side stick of an A320 into a dive or a roll get you that immediate and dramatic response? What is the computer going to think you are doing, and is it going to allow such a drastic manuever?

[Pugilistic Animus]

I really beleive that I saw all of the prior post, but this thread is now a bit disorienting---

My comment is early on i heard the new people saying " why didn't he go to TEB or back to LGA or, then he was told by ATC?

because in a glide configuration a pilot looks ahead toward a stationary spot near the selected landing area---the glide line--- if anything is beyond that spot you wont get there and if there's obstructions in the flight path- you may well end up in the St. John the divine in no time!!!---that's perhaps why---media

he and the crew did the best he could ---it's academic to second guess an out of certifiaction scenario such as this incident and unlike at sea where the captain ALWAYS goes down with the ship so it' in their best interest no to crash

as an aside L/Dmax on a jet =Vx = V max glide but not necesarily the best speed in a dual---due to excess GS or ROD


and don't drop the gear ---especially for a ditching

CJ -I agree

[Pontius Navigator]

Originally Posted by robdean

ChristiaanJ - it's on record that the birds were seen before impact and identified as such... I'm not sure Sully got as far as twenty-and-three before they hit though...

Rob, this may be true but it is also a physiological fact that while the brain my place the birds to the front of the observer the observers motion in the time between the image striking the retina and the brain decoding that image could put the birds behind the observer.

This delay loop is all part and parcel of 'thinking distance' when applied to a car breaking. Now the 'thinking distance' has been accepted as 0.67 seconds - 300 feet? - but

<<Those of us who have the misfortune of having to investigate and analyse road crashes have long realised through numerous studies that an approximate thinking time for driver's is about 1.5 seconds not the 0.67 seconds you are suggesting.

The 1.5 seconds quote is an estimation only as many factors do come into play as pointed out be 'Joe'. >>

Applying 1.5 seconds to your 250 k example will give a distance of about 700 feet.

Now consider the correct as opposed to instrinctive reaction.

[vanHorck]

YouTube - bird hits 180mph car

Bird hits car driving at 180 mph. Not much time to evade....

[ChristiaanJ]

Originally Posted by robdean

ChristiaanJ - it's on record that the birds were seen before impact and identified as such... I'm not sure Sully got as far as twenty-and-three before they hit though...

Thanks, my point entirely.
Now think about it.
They SAW them before impact, which is how they 'remembered' (sorry, there may be another better term for it) them seconds after impact and became fully aware of what happened.

Again, assuming you're even looking in the right direction (you know about peripheral vision, no?) try to go through how long your brain would take through "what's that" and "oh !!!!, looks like birds" and calling on all your 19,000 hours to devise a manoeuvre to avoid them .... give us a break, it's not three seconds.

CJ

PS: I'm not a physiologist or opthamologist, just an aeronautical engineer. But I have learned how to count on my fingers, or how to go "twenty and one, twenty and two, twenty and three" to assess time....

[NigelOnDraft]

ChristiaanJ

Sorry - not quite following your post above? Are you seriously suggesting that you'd expect airliner crews to dodge birds I really hope not...

NoD

[protectthehornet]

avoidance maneuver

JUST FOR FUN, let's assume that instead of a bird, it was a plane, without a transponder that the crew saw. what avoidance maneuver would you use if the bogey was one o'clock level?

I would pull up, hard.

Earlier I mentioned a bird avoidance maneuver and now I will tell you what I developed over the last 34 years. One advantage I had was learning to fly at an airport next to a bird sanctuary, with every approach over ''the duck pond''.

Birds seem to dive when approached by a plane, at least that is what I have personally observed. (if they are on the runway, they seem to takeoff, but I am speaking of an airborne encounter).

My maneuver is: simultaneously pull up, slightly bank and cover your face.

I know a guy who was hit in the face by a bird through the windscreen...he is ok now.

Pulling up changes the altitude of course, it also changes the pitch and the angle at which the bird might hit the engine or windscreen...banking may save one of the two engines if pulling up doesn't help. remember, all we have to do is miss by an inch! also pulling up slightly slows the plane giving just a slight change to the intercept solution.

My first instructor told me birds dive...I told my students the same thing and it seems to have worked...again from learning to fly near a bird sancturary, near the bay of san francisco.

remember too that the copilot has reported that he felt the plane would outclimb the birds...pulling up would have enhanced that.

[NigelOnDraft]

protectthehornet

I would pull up, hard.

How many passengers / Cabin Crew are you willing to injure, or even kill, to possibly avoid a (possible) birdstrike (that even if it occurs, results in no damage 90%+ of the time)?

NoD

[bubbers44]

Actually over the years flying into Tegucigalpa, Honduras we got quite good at evading turkey buzzards by the thousands in huge flocks sometimes and individually. With a few seconds notice we have avoided multiple flocks and been pretty successful at missing them. Pointing them out to the pilot flying in time to to avoid them is the key. If you wait until they are filling up your windscreen it is too late. At 200 knots which was about our initial speed entering the valley we had the best maneuverability but even down below 150 knots dirty in the B757 we did a pretty good job of missing them. Every once in a while we would get a bird strike on one of our aircraft but most were prevented by maneuvering clear of them. True story. We were totally VMC then so attention was concentrated on staying clear of them starting when they were small dots, not when they were big birds in the windscreen. After about 600 approaches into that valley of birds the only one we hit was on departure at 500 ft when we turned right to avoid and the bird followed us into my windscreen brow.

[bubbers44]

As far as hitting the buzzard at 500 feet, we both agreed since the bird turned with our right turn that they always dive so we climbed. Guess what? This buzzard climbed. He must have not gone to bird school.

[protectthehornet]

Oh Nigel, Please!

in my first example I said you were avoiding a plane. so you would avoid a possible injury to someone in back and accept a mid air collision?

ALSO nigel, at about 3000' after takeoff, a plane under my command would still have the seat belt sign illuminated (all passengers seated). It is the custom in my airline to advise the flight attendants when it is safe to serve...and I wait till well above 3000'.

sorry nigel, you seem to be off base here.

when do you allow cabin service? when do you turn off the seatbelt sign?

tell me nigel, if you got a TCAS RA, would you not maneuver as needed?

[BEagle]

Some years ago, some poor army chap in a plastic bubble helicopter collided with rather a large vulture.

Unfortunately it wasn't killed by the impact, but was lodged in the structure of the cockpit. From whence it proceded to peck the chaps legs very aggressively.

Being in a helicopter, he wasn't able to take his feet off the pedals and kick $hit out of his feathered assailant immediately. Or let go of the controls for long enough to find something to clout it with.

Eventually, after several painful minutes, he managed to wedge the pedals for long enough to despatch it with a well aimed kick. By which time the helicopter cockpit was drenched in blood, some of it was the vulture's and some of it the pilots.

Most aircraft are tested for flight deck window impact resistance with a chicken gun. A (dead) hen is fired at the window and the effects noted. Legend has it that one day a manufacturer had no chicken to hand, so sent an apprentice off to the supermarket. He came back with a frozen chicken....

This error was spotted before the gun was fired; otherwise its target would have been totally destroyed. So the chicken was allowed to thaw out; to prevent it making a mess, it was left in the gun tube for a few hours.

When the gun was finally fired, the resulting damage to the windscreen was considerably worse than predicted. Which puzzled the engineers somewhat - but even more puzzling was the ginger coloured material splattered all over the remains of the windscreen.

Then the truth dawned. It seemed that the 'hangar cat', a crotchety old ginger tom, had smelled the thawing chicken and hopped into the gun for a free lunch. Before coming out backwards at 250 knots plus, closely pursued by the remains of a supermarket chicken, then becoming briefly sandwiched between windscreen and chicken.

Probably an urban myth, but one can only wonder at the surprised expression on the cat's face as it hurtled backwards towards the test item!

[ChristiaanJ]

Originally Posted by NigelOnDraft

ChristiaanJ
Sorry - not quite following your post above? Are you seriously suggesting that you'd expect airliner crews to dodge birds I really hope not...

You must have misread. That was NOT what I was suggesting, rather the contrary! Read again.

But... latest posts seem to suggest things aren't always as simple.

CJ

[NigelOnDraft]

CJ

You must have misread. That was NOT what I was suggesting, rather the contrary! Read again

Thanks for clarifying... As I suggested, I could not quite understand if you were, or were not, advocating avoiding action?

protectthehornet

when do you allow cabin service?

Our airline's policy is unless otherwise instructed, they are free to move when they wish... Passenger's should of course be strapped in at 3000', but then 3000' is when the USAir plane had a birdstrike, but recent posts have not specified we only discussing 3000'.

tell me nigel, if you got a TCAS RA, would you not maneuver as needed?

I would... but as the training emphasises, the manoeuvre required for an RA is usually fairly gentle, and most Sim debriefs concern "overcontrol", not under...

My concern was your comment over Pull Up Hard... although as you state it was an aircraft... I would not necessarily pull up "Hard" for an aicraft, pull up as required...

However, for birds, I have tended to find, both by experience and training:

• As you say, they tend to break down
• You see them far later than aircraft
• They tend to be far better than we are at avoiding things
• Even when it seem inevitable you are going to hit them, you often do not...
• Very few Birdstrikes, as a %, result in (serious) damage

NoD