NTSB Final Report on US Airways 1549
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Japan Airlines Flight 2 - Wikipedia, the free encyclopedia -
might be some info on the DC8 I mentioned there.
they built them really well then. DC8 was taken supersonic during flight testing...boeing and airbus don't do that
might be some info on the DC8 I mentioned there.
they built them really well then. DC8 was taken supersonic during flight testing...boeing and airbus don't do that
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protectthehornet:
If memory serves me correctly they determine that he was following the flight director to the exclusion of raw data. The FD was tracking the localizer but the pitch mode was in vertical speed.
The brief NTSB statement of probable cause says he was auto-pilot coupled but, if so, it was vertical speed for the pitch mode.
might be some info on the DC8 I mentioned there.
The brief NTSB statement of probable cause says he was auto-pilot coupled but, if so, it was vertical speed for the pitch mode.
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Originally Posted by lederhosen
I just read 'Fly by Wire' by William Langewiesche ... Interestingly there are very few differences between his version of events written last year and the official report just published.
Would he be the messenger from Airbus to publicize how great is the technology ?
There is not much to be proud of as the protections prevented the pilot to flare the airplane as he would have loved. For a ditching, Airbus recommends a touchdown with approximately 11 degrees of pitch and minimum aircraft vertical speed, but despite the full backstick, the protections did not allow more than 9.5 degrees and the pilots could do nothing to decrease that impressive vertical speed of 750 feet a minute.
"The Truth About the Miracle on the Hudson" would have been an inappropriate subtitle as there was certainly no miracle due to the technology, but the positive outcome is entirely due to the experience of pilots who took the only viable option.
Despite what pretend Mister Langewiesche or the BEA in the Appendix D, I believe Sully would have obtained a better touchdown on his own without the protections interfering with his experience.
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1. I don't think he stalled it in.
2. I do think additional speed for flare would have helped, but who cares if the plane ever flys again...I don't...as long as the people are ok.
3. I do think he made the following mistakes:
a. going back for the maintenance log book
b. not grabbing a portable PA system (bullhorn/powered megaphone)
C. not specifically warning cabin crew and passengers that the landing would be on water.
d. not using correct radio call sign...ATC made the same mistake.
e. not attempting evasive action for birds. pulling up or/and banking would have put the engines in a slightly different path of birds.
F. bidding the airbus ...I think an older jet like the DC9/md80 with aft mounted engines with smaller air intakes might have continued to produce meaningful thrust....the wings and fuselage would have intercepted a portion of the flock of birds.
G. not closing the outlfow valve/ditch switch.
if memory serves, an airbus pilot told me you could change laws by flicking a couple of switches or circuit breakers.
2. I do think additional speed for flare would have helped, but who cares if the plane ever flys again...I don't...as long as the people are ok.
3. I do think he made the following mistakes:
a. going back for the maintenance log book
b. not grabbing a portable PA system (bullhorn/powered megaphone)
C. not specifically warning cabin crew and passengers that the landing would be on water.
d. not using correct radio call sign...ATC made the same mistake.
e. not attempting evasive action for birds. pulling up or/and banking would have put the engines in a slightly different path of birds.
F. bidding the airbus ...I think an older jet like the DC9/md80 with aft mounted engines with smaller air intakes might have continued to produce meaningful thrust....the wings and fuselage would have intercepted a portion of the flock of birds.
G. not closing the outlfow valve/ditch switch.
if memory serves, an airbus pilot told me you could change laws by flicking a couple of switches or circuit breakers.
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Conf,
Not criticising just looking at the facts. Because speed had not been maintained to allow for a flare, the aircraft effectively flew into the water without the pitch axis under control. In the bus if you back stick it with power it max performs, with no power it sets maximum AoA and goes splash! You can argue all you like that it is in controlled flight but effectively it is on the cusp of a stall with no opportunity to improve the situation, a bit like a carrier landing.
Where are your data ekwhistleblower ?
The NTSB concludes that the captain’s difficulty maintaining his intended airspeed during the final approach resulted in high AOAs, which contributed to the difficulties in flaring the airplane, the high descent rate at touchdown, and the fuselage damage.
The airplane’s airspeed in the last 150 feet of the descent was low enough to activate the alpha-protection mode of the airplane’s fly-by-wire envelope protection features. The captain progressively pulled aft on the sidestick as the airplane descended below 100 feet, and he pulled the sidestick to its aft stop in the last 50 feet, indicating that he was attempting to raise the airplane nose to flare and soften the touchdown on the water.
Hang on a moment guys! How many of you have tried landing a jet deadstick? Everyone agrees (including Sullenberger who was apparently surprised by the flight recording) that the speed was lower than intended during the final part of the flight. He claims to have been aiming for a margin above VLS, (lowest selectable speed). The experts point out that green dot would have given a better glide.
But think about it, you flamed out over a big city and are trying a restart, max L/D is in this case pretty irrelevant compared to minimum sink. The fact that with hindsight the engines were too damaged for a restart to be possible cannot be held against him. In the final hundred feet he let the speed decay further making a flare difficult. As pointed out by earlier posters judging height above water can be tricky. He got it a bit wrong, but not so wrong (arguably with the help of Airbus) that the landing turned into a disaster.
He did the important bit right and selected the most suitable place to land. As Napoleon said 'give me lucky generals'. All in all he did a lot more right than wrong.
But think about it, you flamed out over a big city and are trying a restart, max L/D is in this case pretty irrelevant compared to minimum sink. The fact that with hindsight the engines were too damaged for a restart to be possible cannot be held against him. In the final hundred feet he let the speed decay further making a flare difficult. As pointed out by earlier posters judging height above water can be tricky. He got it a bit wrong, but not so wrong (arguably with the help of Airbus) that the landing turned into a disaster.
He did the important bit right and selected the most suitable place to land. As Napoleon said 'give me lucky generals'. All in all he did a lot more right than wrong.
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PTH: C. not specifically warning cabin crew and passengers that the landing would be on water.
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interesting...but when I heard the interview from the FA's they didn't know they were landing on water.
how many people would unbuckle their seatbelts with: Brace for impact/water landing. vs. brace for impact.????? Brace for impact/ditching??
life jackets were beneath the seats...when you are hugging your heels, you might see it>
how many people would unbuckle their seatbelts with: Brace for impact/water landing. vs. brace for impact.????? Brace for impact/ditching??
life jackets were beneath the seats...when you are hugging your heels, you might see it>
What struck me was that target airspeeds on the Engine-dual-failure checklist were on the second page - AFTER the engine restart and other procedures.
It was always drummed into me in primary that the very first thing you do with engine failure is nail best-glide speed - even climbing slightly to slow up if you are above best-glide. THEN you have the maximum amount of glide available to make restart attempts, landing-point decisions, the other checklist stuff.
Sully seems to have thought ahead of the checklist in this regard, as he did with the APU. Even if he picked a speed different than the NTSB would have liked.
I understand that engine restart is a much higher priority in a transport jet: pressurization, hydraulics, computer power, maintaining "normal law," etc. But it does seem as though a top-of-page-one headline
"IAS........below 10,000 ft. Green Dot, above 10,000 ft. 300 kts for re-light"
would not delay moving on to restart attempts by more than a couple of seconds - whereas following the checklist as written (spending 40 sec. on restart) meant this crew never even saw the recommended speed on page 2.
Comments?
It was always drummed into me in primary that the very first thing you do with engine failure is nail best-glide speed - even climbing slightly to slow up if you are above best-glide. THEN you have the maximum amount of glide available to make restart attempts, landing-point decisions, the other checklist stuff.
Sully seems to have thought ahead of the checklist in this regard, as he did with the APU. Even if he picked a speed different than the NTSB would have liked.
I understand that engine restart is a much higher priority in a transport jet: pressurization, hydraulics, computer power, maintaining "normal law," etc. But it does seem as though a top-of-page-one headline
"IAS........below 10,000 ft. Green Dot, above 10,000 ft. 300 kts for re-light"
would not delay moving on to restart attempts by more than a couple of seconds - whereas following the checklist as written (spending 40 sec. on restart) meant this crew never even saw the recommended speed on page 2.
Comments?
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pattern is full makes a fine point.
and, in the older jets without ''glass'', on an ''all engines'' failure situation, you flew minimum clean maneuveing.
as we had the ''speeds'' on a nice little flip card kind of book, it was on top of the radar screen and available at all times.
So, we have taken a giant leap backwards with ''glass''.
We practiced ''dead sticking'' our DC9's in the simulator. Our speeds were fine and we made the field...with gear down on the runway.
relights/restarts were simple...as we took off with ignition "on'' ( actually over ride) if there was fuel and rotation, it would relight...if we were not going fast enough...it probably wouldn't relight...and while there might be assisted starts on some engines with APU air...well, as ''pattern" said...set up for a glide and if things don't work, you are in the best position to land.
Starting the apu is no major thinking...you lose ONE engine, you start the APU and it takes a minute or so to get rolling. The really nutty thing is, I would leave the APU running for takeoff till 10,000' except for bean counters wanting to save a few gallons of fuel.
and, in the older jets without ''glass'', on an ''all engines'' failure situation, you flew minimum clean maneuveing.
as we had the ''speeds'' on a nice little flip card kind of book, it was on top of the radar screen and available at all times.
So, we have taken a giant leap backwards with ''glass''.
We practiced ''dead sticking'' our DC9's in the simulator. Our speeds were fine and we made the field...with gear down on the runway.
relights/restarts were simple...as we took off with ignition "on'' ( actually over ride) if there was fuel and rotation, it would relight...if we were not going fast enough...it probably wouldn't relight...and while there might be assisted starts on some engines with APU air...well, as ''pattern" said...set up for a glide and if things don't work, you are in the best position to land.
Starting the apu is no major thinking...you lose ONE engine, you start the APU and it takes a minute or so to get rolling. The really nutty thing is, I would leave the APU running for takeoff till 10,000' except for bean counters wanting to save a few gallons of fuel.
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Remember the Mohawk BAC One-Eleven that went in from altitude because they left the APU running and it started a fire? Late '60s, as I remember without doing a search. Irrelevant, but interesting...the CVR was horrifying, I was told by 'hawker who heard it.
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I remember the BAC111 that you mention.
but of course there are dozens of planes flying with the apu on for the whole flight to substitute for a generator problem or the like.
but of course there are dozens of planes flying with the apu on for the whole flight to substitute for a generator problem or the like.
Originally Posted by pattern is full
What struck me was that target airspeeds on the Engine-dual-failure checklist were on the second page - AFTER the engine restart and other procedures.
It was always drummed into me in primary that the very first thing you do with engine failure is nail best-glide speed - even climbing slightly to slow up if you are above best-glide. THEN you have the maximum amount of glide available to make restart attempts, landing-point decisions, the other checklist stuff.
It was always drummed into me in primary that the very first thing you do with engine failure is nail best-glide speed - even climbing slightly to slow up if you are above best-glide. THEN you have the maximum amount of glide available to make restart attempts, landing-point decisions, the other checklist stuff.
We used to teach both High Alt Power Loss, and Low Alt power loss, but both began with getting your airspeed set to X first, then all else, depending on altitude (time) available.
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PTH, I think you're being a little unfair to our modern engineers when you assert things like
For a start, the fact that the A320 survived an improvised water landing with no thrust is a testament to the fact that they still build 'em pretty damn well. The reason the old Diesel was taken to those kind of limits was largely down to manufacturers not having the technology in those days to simulate that kind of structural loading non-destructively as they can today, as well as knowing less about taking jet airframes to their extremes in general - the hardest lesson there being learned by De Havilland.
The electrical and hydraulic systems maintained by the RAT and APU meant that the ref speeds were quite happily displayed throughout the incident, and they're still available in dead tree format to hand if necessary. Capt. Sullenberger was improvising because he had the knowledge anyway. While the RAT and APU supplying power to the controls could be considered an inelegant workaround to a flameout, the mechanical flight controls of the DC-9 - and all jets of that era - had their own drawbacks, as evidenced by the dreadful ValuJet crash - same with all-hydraulic controls and the Sioux City DC-10.
It's pretty clear that you do prefer things the way they were when it came to aircraft technology, and you're not the only one - but the fact is that those days had their problems too.
they built them really well then. DC8 was taken supersonic during flight testing...boeing and airbus don't do that
So, we have taken a giant leap backwards with ''glass''.
The electrical and hydraulic systems maintained by the RAT and APU meant that the ref speeds were quite happily displayed throughout the incident, and they're still available in dead tree format to hand if necessary. Capt. Sullenberger was improvising because he had the knowledge anyway. While the RAT and APU supplying power to the controls could be considered an inelegant workaround to a flameout, the mechanical flight controls of the DC-9 - and all jets of that era - had their own drawbacks, as evidenced by the dreadful ValuJet crash - same with all-hydraulic controls and the Sioux City DC-10.
It's pretty clear that you do prefer things the way they were when it came to aircraft technology, and you're not the only one - but the fact is that those days had their problems too.
Paxing All Over The World
As a pax, I am in no position to judge ANYTHING but the one certainty is in the luck factor. The Hudson was not just calm - but it was on the ebb tide. Those that have observed the river during the flood - when the rising tide is fighting the big flow of water downstream ... will know just how lucky they were.
If the tide had been on the flood - then I think that debates about how strong they build them would be irrelevant. It may be that the Captain would still have opted for the river - even if it was choppy - but he might not have known how smooth/choppy it was until long after his decision.
As to warning the cabin that it was going to be a ditching? I understand that it might have been good to have warned the senior CC who could then have phoned the other crew positions to warn them - but I doubt that many of the pax would have benefitted from the information. I would not be surprised to learn that some had taken their cabin baggage out with them (or tried to) because we are that stupid.
If the tide had been on the flood - then I think that debates about how strong they build them would be irrelevant. It may be that the Captain would still have opted for the river - even if it was choppy - but he might not have known how smooth/choppy it was until long after his decision.
As to warning the cabin that it was going to be a ditching? I understand that it might have been good to have warned the senior CC who could then have phoned the other crew positions to warn them - but I doubt that many of the pax would have benefitted from the information. I would not be surprised to learn that some had taken their cabin baggage out with them (or tried to) because we are that stupid.
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Dozywannabe
why did I point to the DC8 in san francisco bay vs the airbus in the hudson? the airbus did not survive to fly again.
the DC8 did.
that's the difference.
hydraulics are useful in the DC8, DC9 and the airbus. and why you plucked the Valujet in the Everglades out of thin air (excuse the pun() I don't understand. The control failure there was due to heat exceeding the meltiing point of steel. I don't think the airbus ''wires' would have withstood that kind of heat.
Paxboy...passengers do the darndest things. One guy stripped down to his underwear and started swimming. Though everyone else was on the wing or in pseudo life rafts.
If I were a passenger, I would have wanted to know it was in the river. If I was a deadheading pilot, I would have wanted to know (thought I might have figured it out if I was near a window).
why did I point to the DC8 in san francisco bay vs the airbus in the hudson? the airbus did not survive to fly again.
the DC8 did.
that's the difference.
hydraulics are useful in the DC8, DC9 and the airbus. and why you plucked the Valujet in the Everglades out of thin air (excuse the pun() I don't understand. The control failure there was due to heat exceeding the meltiing point of steel. I don't think the airbus ''wires' would have withstood that kind of heat.
Paxboy...passengers do the darndest things. One guy stripped down to his underwear and started swimming. Though everyone else was on the wing or in pseudo life rafts.
If I were a passenger, I would have wanted to know it was in the river. If I was a deadheading pilot, I would have wanted to know (thought I might have figured it out if I was near a window).
Last edited by protectthehornet; 16th Jun 2010 at 00:16.