Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

NTSB Final Report on US Airways 1549

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

NTSB Final Report on US Airways 1549

Old 16th Jun 2010, 01:17
  #61 (permalink)  
 
Join Date: Aug 2007
Location: USA
Posts: 23
In the DC-8 accident, the jet never lost engine power! That makes it an apples to oranges comparison.
glob99 is offline  
Old 16th Jun 2010, 01:27
  #62 (permalink)  
 
Join Date: Jun 2001
Location: East of the Sun & West of the Moon
Posts: 286
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.
Well that's about the most meaningless comparison that anyone could come up with ... congratulations!

Do you really think that if Sully had dunked a DC8 into the Hudson that it would be allowed to fly again in the current regulatory environment?

Do you really think that if semi-conductors were widely available when the DC8 was built that it wouldn't have had at least a few of them and associated wiring that would be trashed by water making repair more costly?

Do you really think that the potential for an aircraft to be restorable to flying condition after a ~700 fpm impact with water has much to do with anything but luck and then an owner with sufficent patience and resources to attempt the job?

Get real. No one designs an aircraft with the objective that it will fly again after after a forced landing on water. If it does, great, but that 's purely incidental, everyone else is satisfied if the passengers and crew emerge from the event uninjured, just as they did in this case.

ELAC

Last edited by ELAC; 16th Jun 2010 at 04:16.
ELAC is offline  
Old 16th Jun 2010, 04:12
  #63 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
glob 99

oh please...they both touched down at idle thrust. one by neccesity one by mistake.

the DC8 guys didn't even know they were landing on water...no pre planning...they even had their gear down and flaps set for landing.

ELAC

oh please...I think a DC8 in the late 1960's had semiconductors. Transistors have been around quite awhile...

and what of seaplanes making forced landings? someone thinks of everything...even the DC3 was designed to survive gear up landings by having the wheels stick out a bit.

The airbus didn't fly again because of regulations...it didn't fly again because it was wrecked beyond repair.

the DC8 was repairable and flew again.
protectthehornet is offline  
Old 16th Jun 2010, 04:35
  #64 (permalink)  
 
Join Date: Jan 2008
Location: Denver
Posts: 1,047
Well, in defense of the glass cockpit, I'd note that the Green Dot (or F symbol in some configurations) on the airspeed tape do serve more or less the same function as PTHornet's flip-book of target speeds.

It was there - the checklist just didn't get around to mentioning it very quickly.

The other thing that struck me regards the simulations done to see if 1549 could have reached TEB or LGA. They did 20 runs with an IMMEDIATE turn towards the airports (with a 53% success rate) but only one (1) with a delayed turn to simulate real-world reaction time to an unexpected collision (35 seconds).

One wonders just how disastrously that one trial turned out - that they did not think it worthwhile trying it even one more time. Must have resulted in a heck of a (simulated) burning hole in the Bronx, Harlem or Weehawken.
pattern_is_full is offline  
Old 16th Jun 2010, 06:52
  #65 (permalink)  
 
Join Date: Jun 2001
Location: East of the Sun & West of the Moon
Posts: 286
someone thinks of everything...even the DC3 was designed to survive gear up landings by having the wheels stick out a bit.
Now, why haven't Boeing and Airbus caught onto that one! We really should get in touch with them so that they can modify the 787 & A350 to take advantage of that idea. While we're at it we can go back and recreate DC3 level safety in all of the aircraft's systems. What a boon to aviation that will be.

For Pete's sake pth, give it up. Your entire argument is a trivial irrelevance that simply illustrates that you have a bias that's got little to do with the actual level of safety and reliability of the particular equipment or the design principles involved.

ELAC
ELAC is offline  
Old 16th Jun 2010, 07:19
  #66 (permalink)  
 
Join Date: Jul 2000
Location: Austria
Age: 59
Posts: 65
A passenger wrote:

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

These comments are an example for a lot of vivid discussion about announcements to passengers and cabin of US 1549. The dicussion is interesting but due to - understandable - lack of practical experience it is missing the point.

If a pilot dead sticks a damaged 100.000ibs airliner to a crash landing he simply faces death starring in his very eyes. Under that gaze he must keep control over the plane and decide for the least deadly spot to crashland within barly a minute.

In the history of aviation many a crew froze and did not pass the ultimate test. Many pilots succeded staying in what was left of control of their plane. Transswede or Austrian 111 would be recent examples for that. The reports of surviving pilots show that everything they had was needed to keep the plane flying and the crash survivable.

No crew I ever heard of had the capacity left for a cabin announcement - and nobody ever blamed them.

When pilots first heard the braking news of the landing in the Hudson we knew that the crew must have been up to the task. But by chance we were able to tell just two hours later that a least the captain had been outstanding. A passenger of US1549 told CNN in an interview about the "brace for impact" command. (and by now we even learned that the crew did regular checklist work including standard challenge and response)

To have that extra capacity is really outstanding. You will never know if you are that good until the very moment of a similar challenge.
Hope I´ll never find out.
maxrpm is offline  
Old 16th Jun 2010, 09:26
  #67 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
elac, you missed the point.

I'm saying that people/engineers think of scenarios and how to deal with them and gave the example of how the DC3 dealt with one scenario.

it must frost people to actually consider that things could have been done better in this hudson landing.

it is not a sin to say that we could learn from the pluses and minuses of this event.
protectthehornet is offline  
Old 16th Jun 2010, 10:08
  #68 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
PTH : The JAL DC-8 was repaired because it was practically brand new, and because JAL didn't want a hull-loss on their record (especially one which had produced so little revenue so far) - not because of any inherent construction strength. Qantas did the same when their 744 went for a round of golf, despite being borderline economical to repair.
DozyWannabe is offline  
Old 16th Jun 2010, 11:11
  #69 (permalink)  
 
Join Date: Feb 2003
Location: Old Lyme, Connecticut
Posts: 34
In this interview from last October The Leonard Lopate Show: Highest Duty - WNYC Capt. Sullenberger describes his decision-making process. With only a minute to go before impact he "spent several seconds choosing my words carefully, which is a lot of time given how time-compressed our experience was", and said "This is the Captain, brace for impact." He says "I chose not to announce we were landing on water, because I didn't have time to give the full explanation, and the situation I wanted to avoid was where the passengers might be reaching under their seats for life vests, maybe even attempting to put them on, instead of bracing for landing, when they might have been injured during the touchdown."

The relevant passage starts 25:45 into the interview.
vaneyck is online now  
Old 16th Jun 2010, 14:18
  #70 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
dozywannabe

ok, let me put it this way. was the airbus in question capable of being repaired to fly another 20 years?
protectthehornet is offline  
Old 16th Jun 2010, 15:30
  #71 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
PTH : Does it really matter? This is a major tangent from the main thread - though if you look it up you'll find that a significant amount of the JAL DC-8's airframe was replaced, as well as all electrical systems. It's an apples-to-oranges comparison anyway as the A320 likely had a much heftier impact with the water.
DozyWannabe is offline  
Old 16th Jun 2010, 16:10
  #72 (permalink)  
 
Join Date: Jan 2008
Location: Atlanta, GA, USA
Posts: 349
I would like to point out a parallel story with a different ending - Southern Airways outside Atlanta, 1977. A hailstorm had rendered both engines of a DC-9 inoperable. The crew spent considerable time in confusion trying to get a restart while vectoring to any suitable field. The results were bad. "We're putting it down on the highway..." Nine people on the ground died an awful fiery death at a destroyed gas station. Three fourths of those on the plane as well.

But Atlanta is fairly surrounded by large, calm bodies of water! My instincts certainly would have been - you're engines are dead, the airfields are beyond glide distance, it's still raining to beat the band - put it down on the water somewhere, anywhere, if for no other reason than to spare the passengers the ordeal of fire and those on the ground sudden death from above. It could have worked - Lake Altoona was easily in reach - but the PIC would have had to have a switch go off in his head as soon as the second engine failure happened - "put it on the water." That's what Sullenberger did - and regardless of how he flew in technical terms, he made absolutely the right decision.

I think survival must often be about these instantaneous decisions - procedures are fine but somehow you must recognize when the hand you've been dealt can't be played.

If the captain of Southern 242 had instantly decided - "My windshield's busted, my engines are dead, let's put it on Lake Altoona.." - the outcome could have been far different. But obviously, you can't train anyone for that sort of thinking.

In the end, I think what saved US Air was Sullenberger's casual glance at the Hudson on climb out - which fixed his mind on the solution even before there was any emergency.

-drl
deSitter is offline  
Old 16th Jun 2010, 17:51
  #73 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
dozzy

you just said the airbus had a much heftier impact...and earlier in this thread I spoke of increasing airspeed early on in the glide in order to be sure you had enough speed to reduce descent rate just prior to touchdown (flare reserve as I call it).

you have made my case for me. the dc8 flew again because it touched down at a proper speed and normal descent rate and because it was a stronger air frame.

the airbus touched down at a greater descent rate and was really pretty badly torn up.

look, sully did fine, is that what you want me to say? but anyone of us in the future just might hold an extra 10 knots to cushion the flare...after all, he wasn't gliding to any point in particular, just to the hudson.

The DC9 / hail incident is a very good one to look at. I do remind the poster that the windshield was obliterated by hail and hard to see through. I doubt if they could have found a lake to set her down in.

also, weather conditions causing hail are more predictable and avoidable right now and way in the past, then bird enocounters.

right now, the best advice to all pilots is the same from a piper cherokee to a 747..

If you lose all engine power, trim for best glide and head for your PRE SELECTED FIELD for a power off landing. Always be thinking...where will I land right now if things go bad with the engines? Takeoff until over the fence for landing.


After you are trimmed for best glide (and in jets this is often near min clean maneuvering speed) and heading for your PRE SELECTED FIELD, THEN attempt a restart, advise atc and the cabin.

FLY the plane first and then do the checks.

Jet engines are very reliable. I honestly think most pilots don't consider the all engine out scenario on EVERY flight.

And, just as a reminder, you can glide ABOUT 2-3 nautical miles per 1000 feet above the terrain depending on wind.

For high altitude all engine failure, you may lose pressurization and don't forget your oxygen mask.

All of the above should be in your brain and not on a checklist. Just like the musicians of the US Marine Corps Band know the "Star Spangled Banner" by heart, a pilot better know the above by heart.
protectthehornet is offline  
Old 16th Jun 2010, 19:38
  #74 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
PTH:

1549's pre-selected field was Teterboro, and they worked out relatively quickly that they had neither the height nor the airspeed to make it there. My concern was that you were bashing modern airframes in comparison to your favoured Douglas jets - that's your opinion and you're welcome to it. From the article "The DC-8 That Was Too Young To Die" :

* Replacement of two engine pylons at a cost of $125,000 each, plus repairs to a third.
* Removal, reworking, and corrosion treatment of control surfaces. The left outboard flap was replaced at a cost of $52,500, as well as both inboard flaps, for $21,400.
* Replacement of left landing gear cylinder and bogie for $53,000.
* Replacement of aft galley units at a cost of $100,000.


In addition, all hydraulic units, as well as 90% of the pneumatic and air conditioning systems, were removed and repaired or replaced. All instrument panels were removed and instruments tested. Fuel valves and pumps were removed, fuel tanks were flushed and samples taken to make sure no salt was present.
It really wasn't a case of just dragging her out of the water and being able to use her again, she was pretty badly beat up! Also the situation was different in many more ways:

- In 1968, order books for jets were full, there were no boneyards for easy, cheap replacements as there are now.
- California in November is a very different prospect weather-wise from NYC in February (as I'm sure you're aware, being Bay Area-based yourself) - moving the A320 was a much more difficult operation.
- The A320 touched down in much deeper water, to the extent that she sank completely - far more damage to the cabin and hardware.
- Earlier jets tended to be designed to hold together around the engine pylons, whereas later jets are designed so that the pins shear to prevent a failed engine causing drag in the event of a catastrophic failure in the air. Even then, two engine pylons on the DC-8 needed replacing (see above).

Regarding the ditching plan:

- Airspace around the Hudson in 2008 was considerably busier than airspace around the Bay Area in 1968 - the crew had a major see-and-avoid problem on top of everything else.
- They couldn't trade altitude or airspeed earlier in the glide because they had to clear the George Washington Bridge, which they managed with approx. 900ft to spare.
- Capt. Sullenberger did weigh up the options regarding changing heading for Teterboro and came to the conclusion that landing on the Hudson was safer. He decided this because another major failure, or a miscalculation after changing heading would have left them low and slow over a built-up area.

At the end of the day I'm not trying to get you to say anything, or change your mind - as I said, your opinions are perfectly valid. But it seems to me that the crew of 1549 *did* have the knowledge you're talking about in their heads. Capt. Sullenberger also made the decision very early on that his passengers took priority over the airframe - I happen to agree with him, not least because the economic reality is that the airframe was never likely to fly again even if she'd been pulled from the Hudson nearly pristine.
DozyWannabe is offline  
Old 16th Jun 2010, 19:55
  #75 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
your see and avoid argument is prretty weak.

once clear of the bridge, the airspeed could have been increased resulting in a touchdown slightly shorter than where it actually was...so,?

The DC8 was in salt water, and the amount of repairs is so small as to be insignificant.
It made sense to repair it. the Airbus was badly ripped up and may have had stress problems that didn't even show.

Teterboro was not his preselected field, as it was too far away...while it did occur to ask about it, a pre selected field is KNOWN to be reachable.

On a side note, ATC seemed to think that the airbus should be able to make a downwind, base and final to runway 1 at Teterboro...I would have thought that going direct to the nearest runway threshold would have been the thing to do.

you seem like a nice person...but the whole point of this forum is to do things better next time.

I also wonder if sully's choice to land witht he flaps set the way they were was the best choice...

but, it all worked out....everyone was a hero except the goose.

I also think evasive action should be part of pilot training...avoid birds
protectthehornet is offline  
Old 16th Jun 2010, 20:09
  #76 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,182
$4 million in 1968 dollars ain't exactly chump change!

I also recall from the documentary that the speed and flare angle he picked were chosen carefully to put the rear fuselage down in the water first and give the drag from the water enough of a chance to slow her down. This was to prevent the engines dragging the front of the fuselage underwater on contact, risking possible breakup.

You may consider his decision-making regarding an alternate deadstick airfield landing on the pessimistic side, but as you say, it all came out OK in the end.
DozyWannabe is offline  
Old 20th Aug 2010, 18:52
  #77 (permalink)  
 
Join Date: Apr 2005
Location: Southeast USA
Posts: 802
Originally Posted by protectthehornet
”…but anyone of us in the future just might hold an extra 10 knots to cushion the flare...after all, he wasn't gliding to any point in particular, just to the hudson.
Forgive me if this has been brought up before … but as I understand the situation, while neither engine was producing any thrust – only one engine was actually “shut down.” The other engine was still operating (producing no thrust, but still operating enough to keep the generator on-line), which prevented the computers from reverting to operation in “direct law.” I believe that Capt. Sullenberger mentioned that he was looking for an increase in pitch attitude just prior to “spash-”down, and he had the side stick in the full aft position. But, in either “normal law” or “degraded law” (sorry, I’m not exactly sure of the terms – I’m not a “bus” driver) the protection system was maintaining the airspeed, and therefore, without the availability of additional thrust to maintain that airspeed at a higher pitch attitude, the airplane was maintaining the pitch attitude that equated to the airspeed the computer calculated as the minimum acceptable. That’s not what Sullenberger wanted – he apparently wanted to increase the pitch, reduce the airspeed slightly, and get a slower rate of descent to contact the water with less momentum – both forward and downward. Unfortunately, the airplane was still doing its best to make the decisions.
AirRabbit is offline  
Old 21st Aug 2010, 00:45
  #78 (permalink)  
 
Join Date: Jan 2009
Location: alameda
Posts: 1,053
air rabbit

my whole point is this...if a pilot wants to stall a plane, he shouldn't have to say: pretty please let me stall.

and sully wanted to arrest the descent a bit...but couldn't because the plane thought he might get too close to the stall.

ok...you shouldn't be fULLY stalled in this situation, but a few knots closer to the stall and he could have cut his descent rate in half.
protectthehornet is offline  
Old 21st Aug 2010, 01:01
  #79 (permalink)  
 
Join Date: Jun 2009
Location: US
Posts: 497
Is it just me or didn't I see him do a full flare to a splash down with minimum descent when he touched down on the videos. I always bid Boeings so didn't have to compete with the computer on what we were going to do. He did the ditching like I would do manually in a Boeing. He did a great job and I think we all would think we could do the same..
p51guy is offline  
Old 21st Aug 2010, 20:08
  #80 (permalink)  
 
Join Date: Apr 2005
Location: Southeast USA
Posts: 802
Originally Posted by protectthehornet
air rabbit
my whole point is this...if a pilot wants to stall a plane, he shouldn't have to say: pretty please let me stall.
and sully wanted to arrest the descent a bit...but couldn't because the plane thought he might get too close to the stall.
ok...you shouldn't be fULLY stalled in this situation, but a few knots closer to the stall and he could have cut his descent rate in half.
I agree with you! Of course, I'll probably never know for sure, but I'm under the impression that Sullenberger wanted to pull the nose up more, but the airplane was going to have no part of that.

The point I was making - not disagreeing with your comment - was that while Sullenberger was very likely trying to do just what you said - the computers on board were controlling AoA to maintain it where the computers thought was best. Had there been thrust available, the back pressure on the side stick would have had the computers adjust the pitch attitude UP, but the computers would have added thrust to maintain that AoA. In that there was NO thrust, the computers wouldn't allow an increase in pitch, as that would have allowed the airspeed to decrease, putting the airplane closer to the critical AoA -- apparently a "no-no" as programmed by the engineers.

Whether or not I think that is a mistake is probably not of interest to too many folks. However, there are tons of "bus drivers" out there who will extol the virtues of what the airplane's computers will do FOR the pilot, not TO the pilot. I have to agree with most of what they would be saying - but, while leaving the "driving" to a circuit board isn't terribly bad in general (I'm not as consistent as "George") -- leaving the decsion making to such an entity IS something I'm NOT very comfortable doing.
AirRabbit is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.