Southwest B737 Overrun @ Chcago MDW
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Just.n.av8r
No rocket scientists seem forthcoming, so I'll have one last go...
Rather an effective increase in L/D ratio and, since the lift is constant (= weight) in the float, this implies a reduction in drag.
Parasite (or profile) drag is actually increased slightly by the winglets -- it is the induced drag that is reduced. Whatever, as someone else said earlier, the wing on the -700 is "new"; the guys at Boeing will have optimised it for presence of winglets. The upshot is that, all other things being equal,the overall reduction in drag will make it float further.
But I don't fly 'em, so what would I know
No rocket scientists seem forthcoming, so I'll have one last go...
Ground effect is an increase in effetcive lift due to the negation of wingtip vortices by the ground.
It reduces drag and requires less thrust for the same airspeed/glidepath. When you have winglets this effect is less noticeable since your parasite drag is already reduced at the wingtips.
But I don't fly 'em, so what would I know
Usually winglet design is quite closely tailored to specific design points. The two biggies being either to reduce cruise drag for range/SAR type purposes, or to improve best L/D or CLmax for the lift-off/takeoff cases. It'd be quite unusual to have the landing case as a major design goal, since the thing winglets tend to be best at - improving L/D - is almost exactly what you don't want on approach.
All that taken into account, I suspect the winglets on this (and many other) aircraft are not very (or at all) efficient during the flare; it's entirely possible that they are increasing drag over an "unwingleted type" under similar conditions.
More importantly, the field performance demonstration will have been conducted for the specific configuration, and from that will have been derived the "air distance" portion of the landing distance data. That will include, necessarily, any tendency to float that may or may not exist on a type (from whatever cause) and, if found necessary, design changes would have been made or recommended procedures amended.
So whether a type has winglets or not, whether it flares differently or not, should all be already accounted for.
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NTSB Says touchdown was 750'
This touchdown would be very normal for MDW, particularly with the wx /runway conditions. If indeed this is true and the NTSB quoted touchdown speed was, in fact 124knots and the aircraft systems were operating normally, something is not adding up? Airport authority people are saying the runway condition was good 20 minutes prior and immediately after, but that doesn't seem to jive with pilot reports which called braking fair and poor at the departure end. Wonder how long it had been since runway was plowed? I've seen some reports from passengers who say that after evacuating the aircraft they couldn't discern the difference between the field and the runway. Weather reports and statements from people on the scene say snow was falling at about two inches per hour. Wonder if it was wet or dry snow. Could the data the crew used have been erroneous? If the runway condition was ,in fact, worse than reported in the ATIS, would that not make the landing data erroneous? It would be interesting to know how long the aircraft was at 40knots prior to exiting the runway. Might tell us something about how slick the departure end actually was.
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After the tragic crash of AA587 in 2001 the NTSB figured out that the Training-Standards and operational Procedures of American did not comply with the Standards/Procedures set by Airbus
Pilot's unions and professional groups here in the US representing those flying the 110 A300's wanted more NTSB investigation into the computerized control system, which according to testimony of numerous maintenance technicians and engineers , was problematic on these aircraft.
We all know how government safety boards are loathe to blame the equipment. It's kind of like when a Navy ship is lost or damaged, the Captain will always be at fault and the loss of his command is nearly 100% certain.
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Pilot's unions and professional groups here in the US representing those flying the 110 A300's wanted more NTSB investigation into the computerized control system, which according to testimony of numerous maintenance technicians and engineers , was problematic on these aircraft.
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.
Absolutely ! Multiple pilot's groups did voice concerns over the 737 rudder design in the early days. I think that the 747 center fuel tank is a bad example. It is the proverbial 'another story'.
I think we all agree, that if there is a potentially life-threatening flaw within any technology, the flaw must be fixed or mitigated or the technology should be abandoned and a lesson learned.
As we know, fixes are achieved through revised operational guidelines or refits, or most often a combination of both. To achieve the highest degree of safety, the foreknowledge of design, manufacture and/or implementation shortcomings must be exported. Sharing this critical data with our partners is paramount if we are to prevent an otherwise avoidable tragedy.
You see, it is the minds of engineers, the hands of highly skilled craftsmen, the cunning of financiers all working for the visionaries who founded enterprises that build what we fly today. They may not be 100 % perfect, but are as perfect as they can be within the current system. The problem comes when ultimate control over safety disclosures is taken from our creative team - by the most unqualified branch of the enterprise for this task.
The legal and politically-motivated executives are the rotten apples of the bunch. Misguided fear and blinding greed has spoilt them - leading them to some
poor choices, choices that some of which eventually will bring consequences, sometimes deadly consequences as history shows.
I think our collective fates would be best served by taking the reins of corporate aviation safety away from the Harvard MBA's and corporate attorneys at the top and giving them over to those who can best serve our pursuit of safety - the INSA Lyon, UC Davis, Oxford at Cambridge or Edinburgh University-trained engineers.
The previously mentioned misguided corporate governance happens all around - A or B.
I may be naive, but Integrity always trumps money and politics, doesn't it ?
Much like pilots should want fuel tanks blowing up and rudder hardovers should be investigate in certain Boeings, eh?!
I think we all agree, that if there is a potentially life-threatening flaw within any technology, the flaw must be fixed or mitigated or the technology should be abandoned and a lesson learned.
As we know, fixes are achieved through revised operational guidelines or refits, or most often a combination of both. To achieve the highest degree of safety, the foreknowledge of design, manufacture and/or implementation shortcomings must be exported. Sharing this critical data with our partners is paramount if we are to prevent an otherwise avoidable tragedy.
You see, it is the minds of engineers, the hands of highly skilled craftsmen, the cunning of financiers all working for the visionaries who founded enterprises that build what we fly today. They may not be 100 % perfect, but are as perfect as they can be within the current system. The problem comes when ultimate control over safety disclosures is taken from our creative team - by the most unqualified branch of the enterprise for this task.
The legal and politically-motivated executives are the rotten apples of the bunch. Misguided fear and blinding greed has spoilt them - leading them to some
poor choices, choices that some of which eventually will bring consequences, sometimes deadly consequences as history shows.I think our collective fates would be best served by taking the reins of corporate aviation safety away from the Harvard MBA's and corporate attorneys at the top and giving them over to those who can best serve our pursuit of safety - the INSA Lyon, UC Davis, Oxford at Cambridge or Edinburgh University-trained engineers.
The previously mentioned misguided corporate governance happens all around - A or B.
I may be naive, but Integrity always trumps money and politics, doesn't it ?
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A throttle not in full idle after a gusty (or gutsy) approach? Ice on the microswitches preventing reverse in one of the engines? I've had both of those at times in winter conditions...
Or possibly no below 5 feet RA signal?
______________________________________
December 10, 2005
Reverse Thrusters Eyed in Midway Accident
By THE ASSOCIATED PRESS
Filed at 10:06 p.m. ET
CHICAGO (AP) -- The reverse thrusters that should have slowed a Southwest Airlines jetliner before it slid off a runway at Midway Airport and into the street didn't immediately kick in when the pilots tried to deploy them, federal investigators said Saturday after interviewing the crew.
How much of a role that braking equipment played in Thursday's deadly accident wasn't immediately clear, though, and the investigation is continuing.
The plane's flight attendants told investigators that the Boeing 737 didn't appear to slow after it touched down at Midway in a snowstorm Thursday, said Robert Benzon, the National Transportation Safety Board's investigator in charge.
''They all said it was a smooth landing but they could sense a lack of deceleration,'' Benzon said.
He said the pilots told investigators they began applying the brakes manually as soon as they noticed that the plane wasn't slowing properly...
http://www.nytimes.com/aponline/nati...-Accident.html
Or possibly no below 5 feet RA signal?
______________________________________
December 10, 2005
Reverse Thrusters Eyed in Midway Accident
By THE ASSOCIATED PRESS
Filed at 10:06 p.m. ET
CHICAGO (AP) -- The reverse thrusters that should have slowed a Southwest Airlines jetliner before it slid off a runway at Midway Airport and into the street didn't immediately kick in when the pilots tried to deploy them, federal investigators said Saturday after interviewing the crew.
How much of a role that braking equipment played in Thursday's deadly accident wasn't immediately clear, though, and the investigation is continuing.
The plane's flight attendants told investigators that the Boeing 737 didn't appear to slow after it touched down at Midway in a snowstorm Thursday, said Robert Benzon, the National Transportation Safety Board's investigator in charge.
''They all said it was a smooth landing but they could sense a lack of deceleration,'' Benzon said.
He said the pilots told investigators they began applying the brakes manually as soon as they noticed that the plane wasn't slowing properly...
http://www.nytimes.com/aponline/nati...-Accident.html
Last edited by Airbubba; 11th Dec 2005 at 03:59.
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I`m going to ask a silly question.
Why is it that in the Northern Hemisphere , ( hello WINTER ! )we don`t have more efficient systems to keep runways contaminant - free even during the worst of snowstorms ?
Or why even bother the approach at all ? Commercial pressure ?
Why is it that in the Northern Hemisphere , ( hello WINTER ! )we don`t have more efficient systems to keep runways contaminant - free even during the worst of snowstorms ?
Or why even bother the approach at all ? Commercial pressure ?
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With flaps 40,max manual braking,and zero tailwind you need about 4200 feet to stop.Thats at 112,000 lbs with good braking action.But with poor braking action,it shoots up to around 6700,well outside Midway.You lose anything from 70 to 190 feet for each knot of tailwind,depending on braking action.
Runway condition reports arent cast in stone;they're a good indicator but the roll-out coefficient may well not be as good as the touchdown or mid-point.Pilot reports of runway condition are usually a more reliable source.
Avoiding overruns in this kind of weather is a real test of judgement;if at any stage in the deliberation process you're not convinced that sufficient margins exist,divert.Its that simple.If it can happen to SWA,it can happen to anyone.
Runway condition reports arent cast in stone;they're a good indicator but the roll-out coefficient may well not be as good as the touchdown or mid-point.Pilot reports of runway condition are usually a more reliable source.
Avoiding overruns in this kind of weather is a real test of judgement;if at any stage in the deliberation process you're not convinced that sufficient margins exist,divert.Its that simple.If it can happen to SWA,it can happen to anyone.
Just. n . av8r:
You might be aware of this.
Southwest pilots are the highest-paid B-737 pilots in the US, possibly in the western hemisphere (no pay cuts, so far). Check huge pay cuts at most US majors right now. And Southwest is not a low-cost airline (and has been heavily-unionized for many years), if one looks at certain hourly labor costs. But they are an efficient, productive company.
As for using assymetric reverse on slippery runways, I have never heard of this being recommended in a jet.
A different problem which is never discussed involves using inter-mixed engines. With equal, vertical positions on both thrust reverser levers, one Pratt & Whitney JT8-D engine can give you 1.0 EPR but the OTHER engine can jump up to about 1.7 or 1.8!
Unless you can land with no tailwind on a slippery runway and know when the latest braking action report was made-by a swept-wing transport jet, and what is the latest MU value, you had better plan on diverting to another airport with longer runways (also, when was the last time they were plowed, and were chemicals sprayed, or runways just sanded?). Even a gust of wind at 30 feet AGL can push you a good bit above the glideslope and create a long touchdown point.
Flying Phil:
Were there not unexplained incidents involving A-310/300 rudder control systems at former eastern German ("DDR") airline Interflug, and also with Air France, or another French airline? I read somewhere on Pprune months ago that American Airlines was not notified about these alleged incidents, at least until after the crash of flight 587 in Long Island. Did the NTSB (safety board) learn about it during the investigation?
Incidents/accidents have involved foreign aircraft in the past and the US FAA keeps the news very quiet (i.e. ATR-42 aileron "snatch", the extra sensitivity of leading-edge icing on a Canadian F-28), until bloody passenger bodies
are removed from the wreckage, i.e. from the ATR in Roselawn, Indiana, and from the USAir F-28 at LaGuardia (LGA). Read up on creation of the FIRST rest periods for US standby/reserve crewmembers (what previous, designated rest existed, except for 24 hours each 7 days?) after the tragedy in Little Rock (LIT).
Having only dead, mutilated crewmembers is never any big deal. These have no real media value, and therefore do not pose a public relations danger to a huge, politicized agency, whose top bureaucrats are appointed by whoever lives in the White House.
You might be aware of this.
Southwest pilots are the highest-paid B-737 pilots in the US, possibly in the western hemisphere (no pay cuts, so far). Check huge pay cuts at most US majors right now. And Southwest is not a low-cost airline (and has been heavily-unionized for many years), if one looks at certain hourly labor costs. But they are an efficient, productive company.
As for using assymetric reverse on slippery runways, I have never heard of this being recommended in a jet.
A different problem which is never discussed involves using inter-mixed engines. With equal, vertical positions on both thrust reverser levers, one Pratt & Whitney JT8-D engine can give you 1.0 EPR but the OTHER engine can jump up to about 1.7 or 1.8!
Unless you can land with no tailwind on a slippery runway and know when the latest braking action report was made-by a swept-wing transport jet, and what is the latest MU value, you had better plan on diverting to another airport with longer runways (also, when was the last time they were plowed, and were chemicals sprayed, or runways just sanded?). Even a gust of wind at 30 feet AGL can push you a good bit above the glideslope and create a long touchdown point.
Flying Phil:
Were there not unexplained incidents involving A-310/300 rudder control systems at former eastern German ("DDR") airline Interflug, and also with Air France, or another French airline? I read somewhere on Pprune months ago that American Airlines was not notified about these alleged incidents, at least until after the crash of flight 587 in Long Island. Did the NTSB (safety board) learn about it during the investigation?
Incidents/accidents have involved foreign aircraft in the past and the US FAA keeps the news very quiet (i.e. ATR-42 aileron "snatch", the extra sensitivity of leading-edge icing on a Canadian F-28), until bloody passenger bodies
are removed from the wreckage, i.e. from the ATR in Roselawn, Indiana, and from the USAir F-28 at LaGuardia (LGA). Read up on creation of the FIRST rest periods for US standby/reserve crewmembers (what previous, designated rest existed, except for 24 hours each 7 days?) after the tragedy in Little Rock (LIT).Having only dead, mutilated crewmembers is never any big deal. These have no real media value, and therefore do not pose a public relations danger to a huge, politicized agency, whose top bureaucrats are appointed by whoever lives in the White House.
Last edited by Ignition Override; 11th Dec 2005 at 04:37.
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750ft touch down point? ok slightly less than the 1000 footer but this should have worked in the crews favour and not against it!!
I cannot see the crew getting caned for this.
cheers
coco
I cannot see the crew getting caned for this.
cheers
coco
Last edited by coco-nuts; 11th Dec 2005 at 14:44.
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@Ignition Override
So you have different information than me.
It is correct, there was an Incident in Moscow by Interflug just months before the Wall of Berlin was broken
I don't see any parallel to AA since the final outcome of that Incident was that the Autopilot was wrongly programmed by the crew.
I don't know about a similar incident with AF, what I know for sure is that the crash of a Tarom-A310 in 1992(?) was also related to the same basic problem.
My statement is based on the fact that I was able to speak with an Acc-Rep of Airbus who was temporarely Member of the AA587-Invest-Group.
He clearly told me that the Procedures used by AA were updatet several years ago and that AA and the FAA were informed about that by a Bulletin.
Conclusion:
1. Mistake wiz tragic consequence:
AA did not change the procedures
2. The FAA did not check the Procedures of AA and so could not require AA to do so!
I don't wanna discuss on AA with you, the only think I would like to say is that
the FAA at least one time with dramatic consequences forgot to monitor the Airlines and I was thinking about that fact again since -I assume everyone agree's- this might has happened for a second time if it is true that the WN-Operations exclude Autobraking - even in poor WX-Condition
Have a nice Sunday
So you have different information than me.
It is correct, there was an Incident in Moscow by Interflug just months before the Wall of Berlin was broken
I don't see any parallel to AA since the final outcome of that Incident was that the Autopilot was wrongly programmed by the crew.
I don't know about a similar incident with AF, what I know for sure is that the crash of a Tarom-A310 in 1992(?) was also related to the same basic problem.
My statement is based on the fact that I was able to speak with an Acc-Rep of Airbus who was temporarely Member of the AA587-Invest-Group.
He clearly told me that the Procedures used by AA were updatet several years ago and that AA and the FAA were informed about that by a Bulletin.
Conclusion:
1. Mistake wiz tragic consequence:
AA did not change the procedures
2. The FAA did not check the Procedures of AA and so could not require AA to do so!
I don't wanna discuss on AA with you, the only think I would like to say is that
the FAA at least one time with dramatic consequences forgot to monitor the Airlines and I was thinking about that fact again since -I assume everyone agree's- this might has happened for a second time if it is true that the WN-Operations exclude Autobraking - even in poor WX-Condition
Have a nice Sunday
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autobrakes
Don't know about the AA situation with the Airbus, but it would seem that comparing that situation you described to SWA and autobrakes is like comparing apples to oranges.
Does the FAA mandate the use of autobrakes for all carriers in any meteorological conditions? Does Boeing refuse to sell aircraft to companies with the knowledge the company will not use the autobraking system? Is the FAA required to approve a 121 Carrier's FOM procedures?
The -700 has an outstanding FDR which taken in conjuction with thw CVR info will allow the NTSB to accurately determine exactly when braking commenced after touchdown and if braking was a factor. If so, they will make recommendations to the FAA.
If it is determined the use of autobrakes would have precluded this accident or might preclude one in the future, you can bet the FAA will mandate the use of autobrakes in inclement wx with no MEL relief.
Does the FAA mandate the use of autobrakes for all carriers in any meteorological conditions? Does Boeing refuse to sell aircraft to companies with the knowledge the company will not use the autobraking system? Is the FAA required to approve a 121 Carrier's FOM procedures?
The -700 has an outstanding FDR which taken in conjuction with thw CVR info will allow the NTSB to accurately determine exactly when braking commenced after touchdown and if braking was a factor. If so, they will make recommendations to the FAA.
If it is determined the use of autobrakes would have precluded this accident or might preclude one in the future, you can bet the FAA will mandate the use of autobrakes in inclement wx with no MEL relief.
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Guys
The approach plate below states "landing length" available for 31-C is 5826 feet.
http://myairplane.com/databases/appr...0081ILD31C.PDF
It also says RVR 4000. The press claims the viz was 1/4 mile when they landed. Would this not be below the approach viz?
With a tailwind component of 10 knots, plus fair to poor braking (how many pilots really report NIL, knowing the runway may be closed after that...), etc etc, and I think the deck was stacked against the crew that night.
The thurst reversers are being looked at, but the NTSB press conference stated when they landed, there was a slight bounce. Could this delay the deployment of the TR's?
I wonder what the outcome would have been if Auto-Braking was used by SWA.
The approach plate below states "landing length" available for 31-C is 5826 feet.
http://myairplane.com/databases/appr...0081ILD31C.PDF
It also says RVR 4000. The press claims the viz was 1/4 mile when they landed. Would this not be below the approach viz?
With a tailwind component of 10 knots, plus fair to poor braking (how many pilots really report NIL, knowing the runway may be closed after that...), etc etc, and I think the deck was stacked against the crew that night.
The thurst reversers are being looked at, but the NTSB press conference stated when they landed, there was a slight bounce. Could this delay the deployment of the TR's?
I wonder what the outcome would have been if Auto-Braking was used by SWA.
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news article
http://www.chicagotribune.com/news/l...l=chi-news-hed
--------------------------------------------------------------------------------
Stuck jet switch cited in accident
Pilots' efforts to stop plane were delayed, investigators say
By Jon Hilkevitch, Tribune transportation reporter. Tribune staff reporters Brendan McCarthy, Lisa Fleisher, Jonathon E. Briggs and Dave Wischnowsky contributed to this report
Published December 11, 2005
Vital seconds were lost while trying to bring a Southwest Airlines plane to a halt on a slick runway at Midway Airport because a balky switch delayed deployment of devices that reverse the thrust of the jet's powerful engines, investigators said Saturday.
In the first account by the pilots of the Thursday night accident, the captain of Southwest Flight 1248 told investigators the flight from Baltimore was "completely normal" until he landed the plane at the Southwest Side airport.
A control on the throttle to activate the twin-engine plane's thrust reversers would not slide into place, the 59-year-old veteran pilot told investigators from the National Transportation Safety Board.
At that point, the first officer in the right seat of the cockpit leaned over and was able to deploy the thrust reversers while the captain applied full braking power to try stopping the plane.
The thrust reversers redirect engine power forward to slow the aircraft, and work in conjunction with automatic brakes that investigators said activated immediately upon landing the 737-700. Flaps on the wings, called spoilers, also help kill speed. Investigators say the spoilers were working.
When the captain saw that they were running out of runway, he also used his brake pedals to provide extra stopping power, said Robert Benzon, the investigator in charge.
The captain told safety board investigators he was concerned about the weather in Chicago, but was unaware of the "unique weather phenomenon" that was occurring around them. National Weather Service forecasters told the safety board that an "enhanced snowbank" was coming into the Chicago area at the same time the plane was flying toward the Midwest.
Officials are not releasing the pilots' names.
Visibility was about two-thirds the length of the runway at Midway when Flight 1248 descended through low-hanging clouds, and the flashing lights of the airfield below became visible in the blowing snow, according to new data received Saturday.
Working backward from Thursday night, when the aircraft smashed through an airfield barrier and rammed vehicles on Central Avenue, investigators have sifted through data from the cockpit and flight recorders, air-traffic radar and weather advisories to create a second-by-second chronology.
One major unanswered question is where the plane, gaining speed due to a tailwind, touched down in the landing zone on the first third of the 6,522-foot runway.
The plane needed to land within about the first 2,170 feet of the runway to stop on the snow-slicked surface, which was rated "fair" to "poor" for aircraft-braking ability by the pilot who landed several minutes in front of Flight 1248, transportation officials said.
Investigators still want to know whether the plane crossed the runway threshold at the correct altitude and speed--or if it was too high and too fast--and how much those factors reduced the pilots' ability to bring the aircraft to a safe stop.
Joshua Woods, 6, was killed, and his parents, Leroy and Lisa, and two brothers were injured when their car was crushed by the plane. Their attorney Ronald Stearney said Leroy Woods was released Saturday from Advocate Christ Medical Center in Oak Lawn. He said Leroy Woods suffered one fracture at the back of his skull and four under his right eye.
Steven Peters, Joshua Woods' uncle, said the family's main focus is now on preparing to bury Joshua. Funeral arrangements are pending.
Saturday's snowfall and weather conditions, although drastically less threatening than Thursday's conditions, contributed to many airline delays and cancellations at both Chicago airports.
At Midway, Southwest Airlines had canceled all flights by about 6 p.m. Saturday, said company spokeswoman Linda Rutherford. She said Thursday's crash did not factor into the company's decision.
"For our type of operations, the airport went below minimums [in visibility]," Rutherford said. "On Thursday ... it was not below our minimum visibility."
Rich Brumer, a meteorologist in the National Weather Service office in Romeoville, said Saturday's conditions were more conducive to airplane travel.
"The temperature is about the same, but the snowfall is much less," Brumer said. "The winds are a little stronger, but visibility and the ceiling is much better."
As of 7 p.m. Saturday, the Chicago Department of Aviation said about 60 Midway flights had been canceled and at least seven flights diverted elsewhere because of poor weather conditions and only one operable runway.
On average, Midway has about 300 departures a day.
At O'Hare, United Airlines and American Airlines reported delays of up to 90 minutes and at least six cancellations.
Meanwhile, the Federal Aviation Administration worked Saturday to replace an aircraft-guidance antenna that was knocked out during the crash. The equipment, which guides planes down a glide path to the airport, is needed before the runway on which the accident occurred, 31 Center, can be reopened. The runway was expected to be back in service Sunday.
Mayor Richard Daley said Saturday that he did not want to examine the idea of expanding runway safety areas at Midway until the board completes its investigation.
"This airport has been very safe. Southwest Airlines has been a safe company," Daley said at a news conference.
Daley sought to reassure residents living around the airport that the area is safe.
"They've lived there for so many years and there's not been many accidents," he said. "More people are killed on expressways, so would we shut down expressways?"
----------
[email protected]
Copyright © 2005, Chicago Tribune
--------------------------------------------------------------------------------
Stuck jet switch cited in accident
Pilots' efforts to stop plane were delayed, investigators say
By Jon Hilkevitch, Tribune transportation reporter. Tribune staff reporters Brendan McCarthy, Lisa Fleisher, Jonathon E. Briggs and Dave Wischnowsky contributed to this report
Published December 11, 2005
Vital seconds were lost while trying to bring a Southwest Airlines plane to a halt on a slick runway at Midway Airport because a balky switch delayed deployment of devices that reverse the thrust of the jet's powerful engines, investigators said Saturday.
In the first account by the pilots of the Thursday night accident, the captain of Southwest Flight 1248 told investigators the flight from Baltimore was "completely normal" until he landed the plane at the Southwest Side airport.
A control on the throttle to activate the twin-engine plane's thrust reversers would not slide into place, the 59-year-old veteran pilot told investigators from the National Transportation Safety Board.
At that point, the first officer in the right seat of the cockpit leaned over and was able to deploy the thrust reversers while the captain applied full braking power to try stopping the plane.
The thrust reversers redirect engine power forward to slow the aircraft, and work in conjunction with automatic brakes that investigators said activated immediately upon landing the 737-700. Flaps on the wings, called spoilers, also help kill speed. Investigators say the spoilers were working.
When the captain saw that they were running out of runway, he also used his brake pedals to provide extra stopping power, said Robert Benzon, the investigator in charge.
The captain told safety board investigators he was concerned about the weather in Chicago, but was unaware of the "unique weather phenomenon" that was occurring around them. National Weather Service forecasters told the safety board that an "enhanced snowbank" was coming into the Chicago area at the same time the plane was flying toward the Midwest.
Officials are not releasing the pilots' names.
Visibility was about two-thirds the length of the runway at Midway when Flight 1248 descended through low-hanging clouds, and the flashing lights of the airfield below became visible in the blowing snow, according to new data received Saturday.
Working backward from Thursday night, when the aircraft smashed through an airfield barrier and rammed vehicles on Central Avenue, investigators have sifted through data from the cockpit and flight recorders, air-traffic radar and weather advisories to create a second-by-second chronology.
One major unanswered question is where the plane, gaining speed due to a tailwind, touched down in the landing zone on the first third of the 6,522-foot runway.
The plane needed to land within about the first 2,170 feet of the runway to stop on the snow-slicked surface, which was rated "fair" to "poor" for aircraft-braking ability by the pilot who landed several minutes in front of Flight 1248, transportation officials said.
Investigators still want to know whether the plane crossed the runway threshold at the correct altitude and speed--or if it was too high and too fast--and how much those factors reduced the pilots' ability to bring the aircraft to a safe stop.
Joshua Woods, 6, was killed, and his parents, Leroy and Lisa, and two brothers were injured when their car was crushed by the plane. Their attorney Ronald Stearney said Leroy Woods was released Saturday from Advocate Christ Medical Center in Oak Lawn. He said Leroy Woods suffered one fracture at the back of his skull and four under his right eye.
Steven Peters, Joshua Woods' uncle, said the family's main focus is now on preparing to bury Joshua. Funeral arrangements are pending.
Saturday's snowfall and weather conditions, although drastically less threatening than Thursday's conditions, contributed to many airline delays and cancellations at both Chicago airports.
At Midway, Southwest Airlines had canceled all flights by about 6 p.m. Saturday, said company spokeswoman Linda Rutherford. She said Thursday's crash did not factor into the company's decision.
"For our type of operations, the airport went below minimums [in visibility]," Rutherford said. "On Thursday ... it was not below our minimum visibility."
Rich Brumer, a meteorologist in the National Weather Service office in Romeoville, said Saturday's conditions were more conducive to airplane travel.
"The temperature is about the same, but the snowfall is much less," Brumer said. "The winds are a little stronger, but visibility and the ceiling is much better."
As of 7 p.m. Saturday, the Chicago Department of Aviation said about 60 Midway flights had been canceled and at least seven flights diverted elsewhere because of poor weather conditions and only one operable runway.
On average, Midway has about 300 departures a day.
At O'Hare, United Airlines and American Airlines reported delays of up to 90 minutes and at least six cancellations.
Meanwhile, the Federal Aviation Administration worked Saturday to replace an aircraft-guidance antenna that was knocked out during the crash. The equipment, which guides planes down a glide path to the airport, is needed before the runway on which the accident occurred, 31 Center, can be reopened. The runway was expected to be back in service Sunday.
Mayor Richard Daley said Saturday that he did not want to examine the idea of expanding runway safety areas at Midway until the board completes its investigation.
"This airport has been very safe. Southwest Airlines has been a safe company," Daley said at a news conference.
Daley sought to reassure residents living around the airport that the area is safe.
"They've lived there for so many years and there's not been many accidents," he said. "More people are killed on expressways, so would we shut down expressways?"
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Does SWA include TEM in their indoc and recurrent training???
It seems to me that this SWA crew was probably just as intelligent as most Second Guessers on this forum. With that in mind, I wonder:
1.) Does SWA use the 700's Auto Brake System for landings as an SOP?
2.) Does SWA have a policy regarding the use of ABS when landing on contaminated runways?
I understand the ABS isn't much help on a dirty runway if you don't plant it on the numbers.
3.) What's the deal with no thrust reverser deployment? News articles suggest the crew had difficulty using it on landing. I conclude they used it at some point in the landing roll. Yet we haven't we seen a single photo with both thrust reversers deployed?
Wouldn't the crew have used all available braking to get it stopped? (My answer is yes on that one BTW) It's difficult to tell from the photos (inconclusive evidence by any means) but it looks to me like there are no spoilers deployed, no thrust reversers deployed and you'd think these componenets would be deployed in light of the fact they were headed for an 'off airport' intersection.
(were they stowed when everything came to rest?)
Anyway, I'm off to look at an AOM.
My deepest sympathy to young family who's car was crushed and their loss.
It seems to me that this SWA crew was probably just as intelligent as most Second Guessers on this forum. With that in mind, I wonder:
1.) Does SWA use the 700's Auto Brake System for landings as an SOP?
2.) Does SWA have a policy regarding the use of ABS when landing on contaminated runways?
I understand the ABS isn't much help on a dirty runway if you don't plant it on the numbers.
3.) What's the deal with no thrust reverser deployment? News articles suggest the crew had difficulty using it on landing. I conclude they used it at some point in the landing roll. Yet we haven't we seen a single photo with both thrust reversers deployed?
Wouldn't the crew have used all available braking to get it stopped? (My answer is yes on that one BTW) It's difficult to tell from the photos (inconclusive evidence by any means) but it looks to me like there are no spoilers deployed, no thrust reversers deployed and you'd think these componenets would be deployed in light of the fact they were headed for an 'off airport' intersection.
(were they stowed when everything came to rest?)
Anyway, I'm off to look at an AOM.
My deepest sympathy to young family who's car was crushed and their loss.
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Hi Just'n - sorry I didn't get back to you earlier, I was on a trip. No beef against SWA, just it seems to me that they needlessly push the envelope for no reason. If you're landing at ELP, 4000 ft asl in warm conditions with a 12kt tailwind component on 22, it just seems to me that that's just not as safe as it could be which has always been my mantra. Just because you can doesn't mean you should. Ditto with tailwind onto short rwy at night in snow.
If you are the #1 airline in any given market, there is simply no need to push it; just sit back and let the opposition stew in their own mess. I don't understand why SWA crews still rush everywhere - they're #1, no need to risk anything. Commercial pressures should certainly no longer be a factor, as this can lead to 'press-on-itis'.
The quote from the SWA official came from a CH5 reporter outside SWA headquarters here in DAL, who said that he had just spoke to a member of the assembling go-team who said the comment. Give CH5 a call and ask for their archival report.
By the way, folks, I may be wrong, but in the FAA isn't there no credit for reversers in calculating stopping distances?
Also, have to concur with previous about assym. rev. use on slick surface - can actually increase instability in directional control due to adverse component of the thrust vector...
If you are the #1 airline in any given market, there is simply no need to push it; just sit back and let the opposition stew in their own mess. I don't understand why SWA crews still rush everywhere - they're #1, no need to risk anything. Commercial pressures should certainly no longer be a factor, as this can lead to 'press-on-itis'.
The quote from the SWA official came from a CH5 reporter outside SWA headquarters here in DAL, who said that he had just spoke to a member of the assembling go-team who said the comment. Give CH5 a call and ask for their archival report.
By the way, folks, I may be wrong, but in the FAA isn't there no credit for reversers in calculating stopping distances?
Also, have to concur with previous about assym. rev. use on slick surface - can actually increase instability in directional control due to adverse component of the thrust vector...
Per Ardua ad Astraeus
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WE -
- I do not wish to add any conjecture to this sad accident, except to remind all (as you SHOULD know from your profile) that it is NORMAL procedure for pax evacuation to stow both the reversers and spoilers in preparation - as you correctly hinted, and I believe the same comments were made following the AF 340 over-run?
but it looks to me like there are no spoilers deployed, no thrust reversers deployed
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Sadly, it is all too easy for someone to make up 'porkies' in their profile. It is precisely comments by the likes of Willie Everlearn that exposes those fakers or pretenders as to their real levels of experience. No thanks to the likes of Wille and quite a few others on this thread they have demeaned this forum.
Why can't those of you who have no understanding of the job go away and leave this forum to those of us who do. At least limit your posts to questions rather than pig ignorant statements and assumptions based on little or no experience except that gained from watching Discovery Wings.
Thanks BOAC for being so polite but it is very infuriating when these threads are ruined for the majority by nerds who only like the computer equivalent of hearing their own voices. If you're going to speculate then at least make sure you do so from a position of experience otherwise you just come across as an 'anorak' pretender.
Why can't those of you who have no understanding of the job go away and leave this forum to those of us who do. At least limit your posts to questions rather than pig ignorant statements and assumptions based on little or no experience except that gained from watching Discovery Wings.
Thanks BOAC for being so polite but it is very infuriating when these threads are ruined for the majority by nerds who only like the computer equivalent of hearing their own voices. If you're going to speculate then at least make sure you do so from a position of experience otherwise you just come across as an 'anorak' pretender.
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RRAMJET
From what I've seen in the last few years SWA has slowed down significantly. Look at their ontime performance today as opposed to the late 90s.
The NTSB will build a very accurate profile from the FDR. They should be able to determine the touchdown point within a few feet and whether or not the aircraft was on speed and on glidepath. From the profile they will generate a computer animation which, I'm sure, we'll all get a chance to view.
From what I've seen in the last few years SWA has slowed down significantly. Look at their ontime performance today as opposed to the late 90s.
The NTSB will build a very accurate profile from the FDR. They should be able to determine the touchdown point within a few feet and whether or not the aircraft was on speed and on glidepath. From the profile they will generate a computer animation which, I'm sure, we'll all get a chance to view.