Plane crashes into the Hudson River, NY.
#91
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Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
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Just got back from NY this afternoon (should have been this morning but flight delayed for 3 hours whilst they cleared the runways withthe snow ploughs and had to join a queue for the De-Icing park prior to take off
Here are a couple of pics of the plane when we wandered down towards Battery Park
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00281.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00283.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00287.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00288.jpg)
Pretty scarey stuff, and happened the our first morning there, probably less than a mile from our hotel too
Here are a couple of pics of the plane when we wandered down towards Battery Park
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00281.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00283.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00287.jpg)
![](http://img.photobucket.com/albums/v442/Beanchimp/IMG00288.jpg)
Pretty scarey stuff, and happened the our first morning there, probably less than a mile from our hotel too
![EEK!](images/smilies/eek.gif)
#93
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The weight of the bird is laid down in the specification of the airworthiness authorities - although the engine could cope with a slightly more weighty bird, it would be pointless to use one for the cirtification test just to prove a point.....the test isn't cheap, especially if the engine doesn't pass!
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
Cheers for that Dave, makes sense now, very interesting to know the background, cheers !
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Good snaps Sonic ![Smile](images/smilies/smile.gif)
What were your feelings about getting back on a plane after that?
Not trying to be sarcastic, just wondered what its like to see whats left after a plane crash, then get on one.
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What were your feelings about getting back on a plane after that?
Not trying to be sarcastic, just wondered what its like to see whats left after a plane crash, then get on one.
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The weight of the bird is laid down in the specification of the airworthiness authorities - although the engine could cope with a slightly more weighty bird, it would be pointless to use one for the cirtification test just to prove a point.....the test isn't cheap, especially if the engine doesn't pass!
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
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#98
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The weight of the bird is laid down in the specification of the airworthiness authorities - although the engine could cope with a slightly more weighty bird, it would be pointless to use one for the cirtification test just to prove a point.....the test isn't cheap, especially if the engine doesn't pass!
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
Therefore the ducks are specially bred, and several are chosen for being the correct weight. They are then x-rayed (apparently they like to eat the odd stone to help thier digestion!) before being used for the test. There are two separate tests - large bird and small flocking bird.
The objective of each test is that the engine should maintian full thrust following the simulated bird strike. I think the engine then does a simulated aborted landing (another bout of full thrust) and landing.
The test may seem to be artificial, but no two birds are the same, so this is accepted as being representative of a typical strike.
This is not just Duck, this is Specially Selected, Flash Fried, Guaranteed Stone Free Pratt and Whitney Duck in an Jet A1 "Jus"
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It didnt bother me at all getting back on a plane after that
It was Donna's first time ever on a plane, so to be confronted by that the day after we landed she really wasn't keen on getting back on a plane
The wing of the plane was under the concrete we stood on, as the water goes right underneath the main walk area
We managed to get talking to a nice NYPD officer, and we had gone there late in the day when most people had gone
It was Donna's first time ever on a plane, so to be confronted by that the day after we landed she really wasn't keen on getting back on a plane
The wing of the plane was under the concrete we stood on, as the water goes right underneath the main walk area
We managed to get talking to a nice NYPD officer, and we had gone there late in the day when most people had gone
#100
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This surge could also be caused by a fault in the fuel supply engine system which can lead to the same effects. I have heard a few of those without a bird strike being the cause.
If there was such a fault it is most likely to be to only one of the engines which would not have led to the necessity for a ditching from 2800 feet which is where the aircraft was reported to be. Very unlikely to be both engines so the most likely cause is the geese in the engines as first reported.
We shall see what comes out of the investigation anyway.
Les
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If you get a large bird into a jet engine which has damaged the compressor, then the engine is very likely to suffer a surge which leads to air flow reversal in the engine. At that moment the fuel supply to the engine is too much for the air being supplied and that will lead to the above surge. The effect of that is a pretty loud bang as was reported.
This surge could also be caused by a fault in the fuel supply engine system which can lead to the same effects. I have heard a few of those without a bird strike being the cause.
If there was such a fault it is most likely to be to only one of the engines which would not have led to the necessity for a ditching from 2800 feet which is where the aircraft was reported to be. Very unlikely to be both engines so the most likely cause is the geese in the engines as first reported.
We shall see what comes out of the investigation anyway.
Les
This surge could also be caused by a fault in the fuel supply engine system which can lead to the same effects. I have heard a few of those without a bird strike being the cause.
If there was such a fault it is most likely to be to only one of the engines which would not have led to the necessity for a ditching from 2800 feet which is where the aircraft was reported to be. Very unlikely to be both engines so the most likely cause is the geese in the engines as first reported.
We shall see what comes out of the investigation anyway.
Les
Leslie, just a question:
Would you know if wake turbulence (or any other turbulence at that) may cause an engine surge?
Myself not being sure of exactly how modern(ish) turbofans measure the amount of airflow into the engine (hot wire/film MAF sensors? With their troublesome reliability on car engines, I hope not
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Last edited by ALi-B; 21 January 2009 at 02:40 PM.
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Leslie, just a question:
Would you know if wake turbulence (or any other turbulence at that) may cause an engine surge?
Myself not being sure of exactly how modern(ish) turbofans measure the amount of airflow into the engine (hot wire/film MAF sensors? With their troublesome reliability on car engines, I hope not![Big Grin](images/smilies/biggrin.gif)
), I presume there must be an automated method of controlling fuel mixture should for whatever reason the airflow through the engine not be what is expected at that particular speed/altitude/RPM etc.
Would you know if wake turbulence (or any other turbulence at that) may cause an engine surge?
Myself not being sure of exactly how modern(ish) turbofans measure the amount of airflow into the engine (hot wire/film MAF sensors? With their troublesome reliability on car engines, I hope not
![Big Grin](images/smilies/biggrin.gif)
![Wink](images/smilies/wink.gif)
In theory, yes, wake turbulance could cause an engine to surge. The sudden drop in inlet pressure will mean that there is insufficient air being drawn through the compressors, and instead of air being drawn into the combustor, it will be coughed back out the front of the engine.
However, that would probably require a fairly large disturbance.
Modern jet engines use Full Authority Digital Engine Control (FADEC) controllers to operate the engine. This basically means that all the fuelling, operation of various bleed valves etc, is controlled by software. The software has many routines built into it to cope with most expected events - engine surge being one of them. The sudden drop in pressure from the compressors would be detected by the controller, and it would instantly all but cut the fuel supply to the engine to allow things to settle down and recover. The pilot would not have to do anything.
Jet engines don't use MAF sensors - they work out the fuelling to maintain an EPR pressure ratio (or TPR on the most recent, very high bypass engines) which is basically equivalent to thrust (what the pilot and passengers are really intersted in!). The mass flow is calculated during development testing by measuring temperature and the depression at the inlet to the engine - a production engine fitted to an aircraft doesn't really need to know the actual mass flow, but does calculate an approximation from inlet pressure & temperature, fan speed and altitude.
HTH
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Whilst flying to the US we went as low at 350mph (ground speed) at 33,000 feet with a 200mph head wind
Coming back we hit 667mph (ground speed) with an 85mph tail wind at 33,000 feet
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Whilst flying to the US we went as low at 350mph (ground speed) at 33,000 feet with a 200mph head wind
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It's the IAS that's important not ground speed...
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It's like the old question, if a plane was on a runway and you had a big fan that blew 200 mph wind at it, would it take off?
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I just got back from Cuba. Twin engined A300 (I think). Was doing 450 knots outbound and took 10hrs. But had 190 tailwind coming back and it was doing almost 700knots and did it in 7 hours - barely time for a kip!!!
So. MY question is, at what mph does the world rotate?
D
So. MY question is, at what mph does the world rotate?
D
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Is the ground speed (once airbourne) including the relevant head or tail wind, as the book states that the maximum cruising speed for a 757-200 is approx 560mph IIRC
Now add / subtract the tail / head winds to the max cruising speed and you get the figures shown on the TV screen during flight
Now add / subtract the tail / head winds to the max cruising speed and you get the figures shown on the TV screen during flight
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So. MY question is, at what mph does the world rotate?