Plane Down in Hudson River - NYC
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hmmmmm
You take off, your doing 200 kts in the climb, you hit about 3400 feet, you lose your engines...you look around, nothing but buildings, a big river, and the runway behind you.
You have two choices, 180 back to the runway, at 3000 + ft, you get about a 3 mile glide in clean configuration...you take your chances there isn't a plane on the runway, that you judge it correctly and don't land long or short....
Or you go for the river...you don't have to pick a landing spot, you have miles to glide over water, with the longest flare you can imagine, to land as softly and smoothly as you can. This latter choice guarantees no post crash fire, this aircraft is designed for ditching, and river rescue, ferries, boats are literaly minutes away.
The skill here wasn't in flying, gliding, landing, picking a spot, airspeed control, but choosing to land there, vs all these other guys that have figured yet another way to fly an airliner to the scene of the accident.
Hat's off to the the pilot who chose to ditch, and put lives before trying to save the equipment
Birds: Fact of life, we can't regulate them away, train them to fly around airports.
You have two choices, 180 back to the runway, at 3000 + ft, you get about a 3 mile glide in clean configuration...you take your chances there isn't a plane on the runway, that you judge it correctly and don't land long or short....
Or you go for the river...you don't have to pick a landing spot, you have miles to glide over water, with the longest flare you can imagine, to land as softly and smoothly as you can. This latter choice guarantees no post crash fire, this aircraft is designed for ditching, and river rescue, ferries, boats are literaly minutes away.
The skill here wasn't in flying, gliding, landing, picking a spot, airspeed control, but choosing to land there, vs all these other guys that have figured yet another way to fly an airliner to the scene of the accident.
Hat's off to the the pilot who chose to ditch, and put lives before trying to save the equipment
Birds: Fact of life, we can't regulate them away, train them to fly around airports.
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The first is the tendency for the eye to focus at infinity. This was probably not a factor here at low altitude.
Next is the processor time. From an object becoming detectable by the eye to the brain recognising that there is an object there is a finite time - we are not talking reaction here, just the time before the brain has acknowledged the object's presence. In a military study of aircraft closing at I believe over 1000 kts (may be a bit less) it was determined that the observed aircraft would actually be behind the observer by the time the brain acknowledged its presence. Again that is unlikely to be the case in a 'low speed' bird strike.
The last factor is human. Was there a sufficiently large structure in the forward area to cause a blind spot? An object in the blind spot will remain hidden if it is on a collision course. To avoid this it is necessary for an active external scan and moving the head to look around a blind spot. If the PF was head down then the PNF would be looking out - this would also reduce the time available for reaction and avoidance. I am sure that this will be considered here.
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Gannet Fan
GF thanks for the pics showing the ac being recovered - just a thought, why didn't someone lower the undercarriage whilst it was up in the air? I am sure it would have been happier standing on the barge on its wheels....
I accept that the airframe is a write-off but it might save un-necesary secondary damage.
MB
I accept that the airframe is a write-off but it might save un-necesary secondary damage.
MB
Airframe Distortion
Given that the airframe probably experienced some very unusual loads in various places, there would be a chance that one or more gear would not drop. That would be a worse situation than having all three up.
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I beg all your pardon, but why at 3:29 are we turning down the Hudson and not back to LGA?
- An alignment with a runway - preferably into wind
- Knowledge that the chosen runway is clear of other aircraft
- Judgement / skill / co-ordination to arrive at the threshold of that runway at less than 50', at Vapp - Vapp + 20K, with (nearly) Full Flap and Gear down
I might add that none of the above is trained for either... from starting the process from such a low height (we do double engine failure training from high altitude, but with a lot of planning between both crew, and with both concentrating on the forced landing, not one trying to restart engine(s) ).
I am reluctant to state this crew showed "extraordinary" levels of skill in what they did, since that might imply that "most" airline crews would not have achieved it, and we do not yet know enough about what they did. However, the "decision" to go for the water does seem crucial to the outcome.
I am surprised by the numbers here who seemed to think an airliner would break up on ditching, many's the time I had considered it the better option than an off airfield forced landing if required, and requiring much less skill (luck?) than a successfull "on airfield" forced landing. Whether in the past I or they were in error is irrelevant - we now have evidence that water is a definite option
NoD
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In the 70s we were shown a film of a model HS-801 ditching in a water tank. The recommended profile was a wheels up landing with the rear fuselage rake entering the water first. As the aircraft slowed the nose 'hammered' down in what we were told was 25g (IIRC) and in the actual aircraft would lead to floor failure and the nose breaking off.
The first time we susspected that a ditching was actually survivable was when a Dutch Atlantic had his engine cowling blow open in flight. All survived the ditching. The next time it was proven was when Art Stacey ditched one in the Moray Firth.
So perceived wisdom was that ditchings were not survivable in modern jets and many are perhaps unaware of those instances that were successful.
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It will interesting to learn if any pitch control remained available after the empennage entered the water, thereby slowing down the tendency for the nose to drop quickly. It looked reasonably controlled and not too violent in the video ,which was of course a large plus in the survivability.
Again thumbs up
to Airbus if the integrity of the flight controls was not compromised by the initial impact with the water.
Again thumbs up
to Airbus if the integrity of the flight controls was not compromised by the initial impact with the water.
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wader
It is my belief that an object observed in the windscreen field, if on a "collision course", has no "movement" (other than an increase in size with time), and can be "determined to be not a threat by the Brain"
"Where is my aircraft moving".... Toward the part of the scenery that is "still".
AF
"Where is my aircraft moving".... Toward the part of the scenery that is "still".
AF
Can I ask the question about the turn back a different way?
I guess I must be wrong, but I had understood the sequence to be a) rejection of return to LGA (involving a long turn to port off the initial near-northbound track and back on to a easterly heading); b) rejection of TEB, lying pretty much on the initial northerly track (though not aligned to it); c) decision to turn southerly and ditch in the Hudson.
The track shown suggests that the rejection of LGA came after the rejection of TEB - so, over Inwood Park, the the long turn to port onto a southeasterly course pointing roughly back to to LGA is corrected somewhat to starboard so as to to line up with the river. So, up to a fraction of a second before 3.29 did the guys think that a return to LGA was somewhat possible?
AGB
I guess I must be wrong, but I had understood the sequence to be a) rejection of return to LGA (involving a long turn to port off the initial near-northbound track and back on to a easterly heading); b) rejection of TEB, lying pretty much on the initial northerly track (though not aligned to it); c) decision to turn southerly and ditch in the Hudson.
The track shown suggests that the rejection of LGA came after the rejection of TEB - so, over Inwood Park, the the long turn to port onto a southeasterly course pointing roughly back to to LGA is corrected somewhat to starboard so as to to line up with the river. So, up to a fraction of a second before 3.29 did the guys think that a return to LGA was somewhat possible?
AGB
Latest video
The latest video on BBC shows in a wide shot, what looks like the complete length of the wake, from the point the tail skimmed the water taken just as the aircraft comes to a halt. Any comments on the length of the "water roll"?
Linked here again
BBC NEWS | Americas | New footage of Hudson plane
Seeing the forward slide deploy and then settle at a reasonable angle for a passenger to slide down, I wondered how many passengers chose not to exit onto the slide because they did not consider it a life raft?
Maybe some who had a choice, initially went to the wing exit as they thought the slide would send them into the water?
This could explain why the rafts were under utilised?
Only after a few people sit in it does it flatten out and look like a raft?
Mickjoebill
Linked here again
BBC NEWS | Americas | New footage of Hudson plane
Seeing the forward slide deploy and then settle at a reasonable angle for a passenger to slide down, I wondered how many passengers chose not to exit onto the slide because they did not consider it a life raft?
Maybe some who had a choice, initially went to the wing exit as they thought the slide would send them into the water?
This could explain why the rafts were under utilised?
Only after a few people sit in it does it flatten out and look like a raft?
Mickjoebill
Return to LGA
From the AvWeb map it looks possible to proceed down the Harlem River Parkway and turn final to LGA at 1200-1300 or so.
It even looks like they might have to add drag to avoid overshooting.
Now what's the glide ratio when you drop the gear? What if that leaves you a bit short?
Rashly asuming that the gear comes down in time and does not drop you short, then you will need to ask the hydraulics for flap to steepen the glide and lower the landing speed.
Again what happens if adding flaps leaves you short? Retracting flaps generally incurs an immediate height loss (keeping in mind that in BA038 reducing the last increment of flaps got rid of a bunch of drag for not much loss of lift).
A successful landing at LGA or TEB, as many have already noted, requires crossing a precise point in space at a precise speed. A hundred yards or so short would likely lose all aboard.
On the Hudson, a mile plus or minus wouldn't have made much difference.
It even looks like they might have to add drag to avoid overshooting.
Now what's the glide ratio when you drop the gear? What if that leaves you a bit short?
Rashly asuming that the gear comes down in time and does not drop you short, then you will need to ask the hydraulics for flap to steepen the glide and lower the landing speed.
Again what happens if adding flaps leaves you short? Retracting flaps generally incurs an immediate height loss (keeping in mind that in BA038 reducing the last increment of flaps got rid of a bunch of drag for not much loss of lift).
A successful landing at LGA or TEB, as many have already noted, requires crossing a precise point in space at a precise speed. A hundred yards or so short would likely lose all aboard.
On the Hudson, a mile plus or minus wouldn't have made much difference.
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Mad /bob
"GF thanks for the pics showing the ac being recovered - just a thought, why didn't someone lower the undercarriage whilst it was up in the air? I am sure it would have been happier standing on the barge on its wheels....
I accept that the airframe is a write-off but it might save un-necesary secondary damage."
The damage to the panels under the belly is reportedly extensive. That will have included the landing gear doors which will probably be jammed in the paneling around them. Even if they had managed to get the 3 gears down someone would have had to go in there and make sure they are locked. It would be a brave man and for not a worthwhile reason.
I accept that the airframe is a write-off but it might save un-necesary secondary damage."
The damage to the panels under the belly is reportedly extensive. That will have included the landing gear doors which will probably be jammed in the paneling around them. Even if they had managed to get the 3 gears down someone would have had to go in there and make sure they are locked. It would be a brave man and for not a worthwhile reason.
I don't own this space under my name. I should have leased it while I still could
Better would have been inflatable crash bags. They are used to jack up a damaged airframe and could have been used here too.
Footage
This shows the impact (albeit from a way off)
Newly released video shows plane landing on Hudson River - Truveo Video Search
Newly released video shows plane landing on Hudson River - Truveo Video Search
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Are there any reports of bird in the left engine, which the divers recovered?
If APU was still working why would the RAT deploy?
Would APU be off already at this stage of flight?
And why not gear down for the ditching? Increased drag, yes, if long glide is the goal, but otherwise gear would surely absorb much energy on impact before being sheared and make the halt less violent than the engines "scooping" the water.
If APU was still working why would the RAT deploy?
Would APU be off already at this stage of flight?
And why not gear down for the ditching? Increased drag, yes, if long glide is the goal, but otherwise gear would surely absorb much energy on impact before being sheared and make the halt less violent than the engines "scooping" the water.