luvthe9
Veteran
- Aug 30, 2002
- 9,464
- 14,119
Looks like pilot error?
- Thread starter luvthe9
- Start date
- Status
Horrific.
Report: Plane overshot landing
NTSB says pilot needed 800 more feet
By Jon Hilkevitch, Tribune transportation reporter. Tribune staff reporter Andrew L. Wang contributed to this report
December 16, 2005
After deciding it was safe to land in a snowstorm, the pilots of Southwest Airlines Flight 1248 overran the zone where the plane needed to touch down and lost hundreds of feet of runway that would have helped stop the jet before it skidded outside the airport and killed a 6-year-old boy, federal investigators said Thursday.
The plane glided over the runway, wasting precious stopping distance, before the captain planted the landing-gear wheels more than 2,000 feet beyond the edge of the 6,522-foot runway. The pilots needed at least 800 more feet of runway to avoid a collision, according to the National Transportation Safety Board, which released a report Thursday updating the status of its investigation.
As they approached the airport Dec. 8, the pilots and a Southwest dispatcher were confident a landing could be accomplished, despite contending with low visibility, a nettlesome tailwind chasing their plane and reports of poor braking power on snowy Runway 31 Center, they later told NTSB investigators.
The pilots based their decision to land on the dispatcher's positive assessment, their piloting experience and flight data they entered into a cockpit computer, investigators said. Weather updates indicated a freezing fog was setting in, but the computer confirmed the difficult landing would be within the capability of the Boeing 737-700 and would conform to Southwest's procedures.
The 59-year-old captain, who was flying the plane, missed the landing zone, according to the report.
Preliminary calculations, using radar information and the flight data recorder onboard the plane, show the aircraft touched down with about 4,500 feet of runway remaining.
The aircraft needed about 5,300 feet of stopping distance under the slick conditions to avoid a collision, the report said.
It also is unclear whether it was legal for Southwest Flight 1248 to land in the heavy snow.
About 20 minutes before the accident, visibility was only one-half mile--less than the three-quarter mile of visibility the Federal Aviation Administration requires for an approach to 31 Center, the report said.
Making a landing with only a half-mile of visibility would violate FAA regulations.
The safety board did not provide the visibility reading at the time of the accident. But about 23 minutes after the accident, "a special observation revealed" that visibility was only one-fourth mile, the safety board said.
An attorney for the Woods family said the safety board's report gives him grounds for a lawsuit that holds Southwest and the city of Chicago responsible for the accident.
"What this says is that there shouldn't have been a landing. The flight should have been diverted. The fallacy here is that the aircraft can land in a snowstorm," Ronald A. Stearney Jr., the lawyer, said.
"Given the egregious nature of what we're finding out, there's only one thing to do--for Southwest to admit liability. They ought to come to the table and help this family put this behind them," he said.
The Woods family's reaction to the safety board's report was "that Southwest murdered Joshua," Stearney said.
Air-traffic controllers who were in the Midway tower Dec. 8 told investigators they did not see the plane land, but they spotted the aircraft's lights penetrating the falling snow and ground fog.
The plane hit the runway at 152 m.p.h., investigators said. It bounced and became momentarily airborne again during the 29-second landing attempt.
The aircraft's thrust-reversers, which help the automatic-braking system the pilots used to stop the plane on the ground, were not functional until more than midway through the landing, investigators said. The delay was much longer than the safety board previously reported, based on interviews with the pilots two days after the crash, the first fatal accident in Southwest's history.
"The first officer reached over and pulled the thrust-reverser switch. He also moved his seat forward to help the captain apply maximum foot-pedal braking," said Keith Holloway, a safety board spokesman.
After slipping off the runway, the plane carrying 98 passengers was slowed by rolling through a fence designed to absorb jet blasts, an airport perimeter fence and onto the street, where it hit two vehicles. The impact killed Joshua Woods, 6, of Leroy, Ind., who was in one vehicle with his family en route to visit his grandmother in Chicago.
From the time the plane landed to when it came to an abrupt, colliding stop, it traveled about 5,000 feet, the safety board said.
The stopping distance for a landing would have been about 1,000 feet less if the plane landed into the wind from the other end of the runway, instead of landing with a tailwind that hindered its ability to stop, the safety board report said.
But a landing into the wind was not an option. The visibility pilots needed to descend in the thick fog from that direction did not meet Federal Aviation Administration rules, according to the safety board.
It remained unclear whether the failure of the thrust-reversers was caused by a mechanical problem or possible pilot error. The safety board is testing the thrust-reverser systems.
The captain told investigators he had trouble moving the lever that activates the thrust reversers, which are supposed to begin working as soon as activated upon landing.
In a separate post-accident interview, the first officer said he reached over after "a few seconds" and was able to engage the lever for the thrust reversers.
But data from the plane's flight data recorder now show the thrust reversers did not activate until about 18 seconds after landing, the safety board said. The delay meant the thrust reversers were working to redirect air from the jet engines up and forward for only about 14 seconds before the plane hit the blast fence.
Many pilots who have flown into Midway during inclement weather have questioned the judgment of the Southwest crew. The update on the accident from the NTSB did not alter their views.
"My question is very simple, Mr. Captain. Why did you decide to land on that airport when the runway conditions were at a bare minimum and there was a tailwind component?" said Javed Sheikh, 60, a retired commuter airline pilot who flew for 26 years.
"There was no impending emergency, no compulsion that evening for anybody to land on that runway," Sheikh said.
----------
[email protected]
Copyright © 2005, Chicago Tribune
Report: Plane overshot landing
NTSB says pilot needed 800 more feet
By Jon Hilkevitch, Tribune transportation reporter. Tribune staff reporter Andrew L. Wang contributed to this report
December 16, 2005
After deciding it was safe to land in a snowstorm, the pilots of Southwest Airlines Flight 1248 overran the zone where the plane needed to touch down and lost hundreds of feet of runway that would have helped stop the jet before it skidded outside the airport and killed a 6-year-old boy, federal investigators said Thursday.
The plane glided over the runway, wasting precious stopping distance, before the captain planted the landing-gear wheels more than 2,000 feet beyond the edge of the 6,522-foot runway. The pilots needed at least 800 more feet of runway to avoid a collision, according to the National Transportation Safety Board, which released a report Thursday updating the status of its investigation.
As they approached the airport Dec. 8, the pilots and a Southwest dispatcher were confident a landing could be accomplished, despite contending with low visibility, a nettlesome tailwind chasing their plane and reports of poor braking power on snowy Runway 31 Center, they later told NTSB investigators.
The pilots based their decision to land on the dispatcher's positive assessment, their piloting experience and flight data they entered into a cockpit computer, investigators said. Weather updates indicated a freezing fog was setting in, but the computer confirmed the difficult landing would be within the capability of the Boeing 737-700 and would conform to Southwest's procedures.
The 59-year-old captain, who was flying the plane, missed the landing zone, according to the report.
Preliminary calculations, using radar information and the flight data recorder onboard the plane, show the aircraft touched down with about 4,500 feet of runway remaining.
The aircraft needed about 5,300 feet of stopping distance under the slick conditions to avoid a collision, the report said.
It also is unclear whether it was legal for Southwest Flight 1248 to land in the heavy snow.
About 20 minutes before the accident, visibility was only one-half mile--less than the three-quarter mile of visibility the Federal Aviation Administration requires for an approach to 31 Center, the report said.
Making a landing with only a half-mile of visibility would violate FAA regulations.
The safety board did not provide the visibility reading at the time of the accident. But about 23 minutes after the accident, "a special observation revealed" that visibility was only one-fourth mile, the safety board said.
An attorney for the Woods family said the safety board's report gives him grounds for a lawsuit that holds Southwest and the city of Chicago responsible for the accident.
"What this says is that there shouldn't have been a landing. The flight should have been diverted. The fallacy here is that the aircraft can land in a snowstorm," Ronald A. Stearney Jr., the lawyer, said.
"Given the egregious nature of what we're finding out, there's only one thing to do--for Southwest to admit liability. They ought to come to the table and help this family put this behind them," he said.
The Woods family's reaction to the safety board's report was "that Southwest murdered Joshua," Stearney said.
Air-traffic controllers who were in the Midway tower Dec. 8 told investigators they did not see the plane land, but they spotted the aircraft's lights penetrating the falling snow and ground fog.
The plane hit the runway at 152 m.p.h., investigators said. It bounced and became momentarily airborne again during the 29-second landing attempt.
The aircraft's thrust-reversers, which help the automatic-braking system the pilots used to stop the plane on the ground, were not functional until more than midway through the landing, investigators said. The delay was much longer than the safety board previously reported, based on interviews with the pilots two days after the crash, the first fatal accident in Southwest's history.
"The first officer reached over and pulled the thrust-reverser switch. He also moved his seat forward to help the captain apply maximum foot-pedal braking," said Keith Holloway, a safety board spokesman.
After slipping off the runway, the plane carrying 98 passengers was slowed by rolling through a fence designed to absorb jet blasts, an airport perimeter fence and onto the street, where it hit two vehicles. The impact killed Joshua Woods, 6, of Leroy, Ind., who was in one vehicle with his family en route to visit his grandmother in Chicago.
From the time the plane landed to when it came to an abrupt, colliding stop, it traveled about 5,000 feet, the safety board said.
The stopping distance for a landing would have been about 1,000 feet less if the plane landed into the wind from the other end of the runway, instead of landing with a tailwind that hindered its ability to stop, the safety board report said.
But a landing into the wind was not an option. The visibility pilots needed to descend in the thick fog from that direction did not meet Federal Aviation Administration rules, according to the safety board.
It remained unclear whether the failure of the thrust-reversers was caused by a mechanical problem or possible pilot error. The safety board is testing the thrust-reverser systems.
The captain told investigators he had trouble moving the lever that activates the thrust reversers, which are supposed to begin working as soon as activated upon landing.
In a separate post-accident interview, the first officer said he reached over after "a few seconds" and was able to engage the lever for the thrust reversers.
But data from the plane's flight data recorder now show the thrust reversers did not activate until about 18 seconds after landing, the safety board said. The delay meant the thrust reversers were working to redirect air from the jet engines up and forward for only about 14 seconds before the plane hit the blast fence.
Many pilots who have flown into Midway during inclement weather have questioned the judgment of the Southwest crew. The update on the accident from the NTSB did not alter their views.
"My question is very simple, Mr. Captain. Why did you decide to land on that airport when the runway conditions were at a bare minimum and there was a tailwind component?" said Javed Sheikh, 60, a retired commuter airline pilot who flew for 26 years.
"There was no impending emergency, no compulsion that evening for anybody to land on that runway," Sheikh said.
----------
[email protected]
Copyright © 2005, Chicago Tribune
lovedandlost
Newbie
- Dec 10, 2005
- 10
- 0
robbedagain
Veteran
- Oct 13, 2003
- 11,125
- 2,676
what are possibilities that could cause the thrust reversers to not work until more than halfway down the runway? is it possible that the thrust reversers only activate once the plane is on the ground?
Some Clown
Member
The thrust reversers on the 737 classic and NG's have to be less that 10 ft RA or on the ground. Either input will allow reverse. But the 10 ft RA logic will only allow IDLE Reverse till WOW.
jimntx
Veteran
The article is obviously a hatchet job written by AA supporters. Anyone with half a brain would know that SWA employees could not possibly be in error or at fault.
A very poorly written article--but only someone with an aviation background and knowledge of Midway and 737's would realize. Pretty much just a PR piece for the lawyers. Still, an accident--though this trash piece does little to put it into actual perspective.
I can tell you for certain that when ALL the facts come out and ALL the inquiry is done, there will be some facts that will surprise you and mitigate some of the present premature thinking of pilot error. Easy, though not correct to come to certain conclusions with partial information.
Some Clown
Member
"Looks like pilot error?"
Looks like we should wait till the investigation is complete before making ASSumptions.
jimntx
"The article is obviously a hatchet job written by AA supporters. Anyone with half a brain would know that SWA employees could not possibly be in error or at fault."
Who on here has ever said SWA employee's are perfect? Man you sure do wield a big spoon for that pot you're always stirring.
Looks like we should wait till the investigation is complete before making ASSumptions.
jimntx
"The article is obviously a hatchet job written by AA supporters. Anyone with half a brain would know that SWA employees could not possibly be in error or at fault."
Who on here has ever said SWA employee's are perfect? Man you sure do wield a big spoon for that pot you're always stirring.
NewHampshire Black Bears
Veteran
- Aug 20, 2002
- 10,154
- 681
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
jimntx,
I'm with you 98.5% of the time, and I too "suspect" that PE will be the largest "official" "ingredient", in this horrible "receipe" (SP?)
But speaking only for myself, I'm going to wait a bit longer, to allow more facts to become official.
NH/BB's
lovedandlost
Newbie
- Dec 10, 2005
- 10
- 0
I agree. Some facts will come out that mitigate the conclusion of pilot error. Some will also ameliorate the conclusion of pilot error. Some others will have no effect on the conclusion of pilot error. Don't you think so, or have you come to an easy conclusion with partial information?
PRINCESS KIDAGAKASH
Veteran
- Oct 9, 2003
- 1,401
- 2
Using the available facts at the present time and using the translunar mathematical universal accident computer. It seems that this accident was caused by a variety of factors that caused a time warp in the universal fabric of gravitational effect. Wheras the aircraft lost mass and gained velocity, the runway lost length due to the relativity of the velocity of the aircraft. This leads the computer to only one conclusion. The accident must have been caused by accident.
lovedandlost
Newbie
- Dec 10, 2005
- 10
- 0
NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
December 15, 2005
NTSB UPDATE ON SOUTHWEST AIRLINES RUNWAY OVERRUN AT MIDWAY AIRPORT
--------------------------------------------------------------------------------
The National Transportation Safety Board today released the following update on its investigation into the accident involving Southwest Airlines flight 1248, a Boeing 737-700 on December 8, 2005, at Midway Airport in Chicago, Illinois. The airplane overran runway 31C during the landing rollout.
The accident occurred about 7:14 pm central standard time. The airplane departed the end of the runway, rolled through a blast fence, a perimeter fence, and onto a roadway. The airplane came to a stop after impacting two automobiles. One automobile occupant was fatally injured and another seriously injured. The flight was conducted under 14 CFR Part 121 and had departed from the Baltimore/Washington International Thurgood Marshall Airport, Maryland.
The on-scene portion of the investigation has been completed. Additional fact-finding, including tests and research, will be conducted at various component manufacturers. The Safety Board staff continues to examine the information provided by the flight data recorder and the cockpit voice recorder.
Operations/Human Performance
The two pilots in the cockpit were interviewed on Saturday. Each interview took approximately three hours.
The pilots stated that everything was normal through the point of touchdown. Approaching the airport, weather was of concern to them, and they listened to the ATIS (the recorded weather update) four times during the latter portion of the flight. They stated that they agreed with the dispatcher's assessment of the conditions for landing on runway 31C and backed up that assessment by inputting the numbers into the on-board laptop computer tool.
The computer confirmed that the landing would be within the operational parameters of the airplane and Southwest's procedures, they said. Autobrakes were set on MAX, and they activated after a "firm" touchdown. The flying pilot (Captain) stated that he could not get the reverse thrust levers out of the stowed position. The first officer, after several seconds, noticed that the thrust reversers were not deployed and activated the reversers without a problem. At some point, the Captain noticed that the airplane was not decelerating normally and applied maximum braking manually. The first officer also became aware of the poor braking effectiveness, moved his seat farther forward, and also applied maximum braking. They stated that they continued to apply maximum pressure to the brakes as the airplane went straight off the end of the runway and came to a stop.
Interviews were conducted with a number of other Southwest Airlines flight crews, including the crew of the last Southwest flight to land at Midway and a subsequent crew that diverted to St. Louis.
Airplane Performance
Preliminary calculations show that the airplane touched down with about 4,500 feet of remaining runway and was on the runway for about 29 seconds. Preliminary calculations also show that, for the runway conditions and use of brakes and thrust reverser that occurred, the stopping distance without hitting obstructions would have been about 5,300 feet (the actual stopping distance was about 5,000 feet). In addition, had the airplane landing into the wind, rather than with a tail wind, the stopping distance for a landing would have been about 1,000 feet less.
Documentation of aircraft performance from the scene has been completed to the maximum extent possible. It was not possible to observe tire marks from much of the landing rollout due to the fact that the aircraft landed on a snow-covered runway and snow fell on the runway immediately following the accident.
FDR data show that autobrakes were active and provided high brake pressure upon touchdown. Autobrakes and manual braking continued to provide high brake pressure throughout the landing roll.
FDR data show that thrust reversers were activated about 18 seconds after touchdown or about 14 seconds before contact with the blast fence. Testing and examination of the thrust reverser systems will continue.
Investigators have obtained the laptop computer tool used by the accident flight crew. It will be examined and calculations of landing performance will be compared to flight manual data.
Eleven security-type video cameras were identified on the airport that may show imagery of the airplane rollout or the surface of the runway and taxiway at the time of the accident. The videos will be reviewed.
Meteorology
National Weather Service forecasters and other personnel were interviewed. An enhanced snow band was in the area producing localized heavy snow due to lake enhancement. This apparently is a somewhat unusual weather phenomenon, as the band swath was only 20 to 30 miles wide with snow accumulations of 10 inches right over Midway Airport.
Midway Airport weather observation equipment and records were examined and all equipment was working normally during the evening of the accident.
Southwest Airlines dispatchers who were associated with the accident flight were interviewed. Prior to the takeoff from Baltimore, when weather conditions deteriorated and the runway switched to runway 31C, the dispatcher determined that runway 31C was approved for landing for flight 1248. Runway conditions, braking action, wind speed and direction, airplane weight and mechanical condition of the aircraft are typical factors considered in making such decisions. The flight was contacted twice on the way to Midway and the appropriateness of using the runway for landing was reaffirmed during both contacts.
Official weather observations:
Approximately 20 minutes prior to the accident, the winds were from 100 degrees at 11 knots, visibility was 1/2 mile in moderate snow and freezing fog, the ceiling was broken at 400 feet, and overcast at 1400 feet, temperature -3C, dew point -5C, altimeter setting 30.06 in. Hg. Remarks - runway 31C rvr (runway visual range) 4500 feet, snow increment - 1 inch of new show in the last hour, 10 inches on the ground.
Approximately 23 minutes after the accident, a special observation revealed winds out of 160 degrees at 5 knots, visibility 1/4 mile in heavy snow, freezing fog, sky obscured with a vertical visibility of 200 feet, temperature -4C, dewpoint -5C. Remarks - runway 31C, rvr 3000 feet.
Toxicology
Blood and urine samples were obtained from both pilots. The disposition of the blood samples is being reviewed.
Structures
The aircraft has been removed from the accident site and was transferred to a hangar at Midway Airport. The maintenance log revealed no writeups or deferred items for the accident flight or several previous flights.
Professional surveyors completed a survey of the accident scene and the geography leading up to the site to include the locations of parts shed by the aircraft after it left the paved runway surface and the blast fence destroyed during the accident sequence.
Powerplants
Both engines were visually examined at the accident site. Although the first stage compressor blades of both engines showed foreign object damage, they were all intact and present. Wood from the blast fence and other debris was present in both engines. A visual examination of the turbine sections revealed no missing blades.
The 60-day engine history revealed no deferrals or writeups. Each engine has two thrust reverser sleeves. FDR data indicated that all four sleeves were deployed until after the airplane left the paved runway overrun surface. Hydraulic system B (that runs the thrust reversers) revealed no leaks.
Systems
The Systems Group documented the switches, circuit breakers and controls in the cockpit. The leading edge slat, flap, and trailing edge flap extension measurements were taken and revealed symmetrical extension of all devices. The measurements will be compared to Boeing documentation to determine exact extension.
Chicago Fire Department personnel were interviewed to determine if any switch positions or other items were altered during the rescue effort. The Fire Department Chief stated that the only things his people did were disconnect the battery and turn off the crew oxygen source.
The brakes were found in good condition with adequate wear remaining. The main landing gear tires had acceptable tread depth and no indication of flat spots.
Air Traffic Control
The local controller, two tower controllers, and the tower supervisor were interviewed. All controllers stated that they saw the aircraft lights during the landing roll, but did not see the actual touchdown.
The investigation has revealed that runway 31C was used as the landing runway because it contained lower landing minimums for aircraft using the ILS approach. If runway 13C was used, the runway most aligned with the wind, pilots would have been unable to land because of insufficient landing minimums.
Survival Factors/Airports
All flight attendants were interviewed. They all said that they noted a smooth landing but that the deceleration feeling thereafter seem less than usual. They noted that the emergency lighting came on after the airplane came to rest, and one flight attendant opened the L1 door to begin the evacuation. The emergency slide deployed automatically, but its angle in relation to the ground was less than ideal. This caused passengers to begin to pile up around the bottom of the slide. Rescue personnel assisted people away from the slide. The first officer deplaned after about 5 passengers and also assisted in getting people away from the airplane.
Further factual updates will be issued when appropriate.
NTSB Media Contact: Keith Holloway, 202-314-6100
National Transportation Safety Board
Washington, DC 20594
December 15, 2005
NTSB UPDATE ON SOUTHWEST AIRLINES RUNWAY OVERRUN AT MIDWAY AIRPORT
--------------------------------------------------------------------------------
The National Transportation Safety Board today released the following update on its investigation into the accident involving Southwest Airlines flight 1248, a Boeing 737-700 on December 8, 2005, at Midway Airport in Chicago, Illinois. The airplane overran runway 31C during the landing rollout.
The accident occurred about 7:14 pm central standard time. The airplane departed the end of the runway, rolled through a blast fence, a perimeter fence, and onto a roadway. The airplane came to a stop after impacting two automobiles. One automobile occupant was fatally injured and another seriously injured. The flight was conducted under 14 CFR Part 121 and had departed from the Baltimore/Washington International Thurgood Marshall Airport, Maryland.
The on-scene portion of the investigation has been completed. Additional fact-finding, including tests and research, will be conducted at various component manufacturers. The Safety Board staff continues to examine the information provided by the flight data recorder and the cockpit voice recorder.
Operations/Human Performance
The two pilots in the cockpit were interviewed on Saturday. Each interview took approximately three hours.
The pilots stated that everything was normal through the point of touchdown. Approaching the airport, weather was of concern to them, and they listened to the ATIS (the recorded weather update) four times during the latter portion of the flight. They stated that they agreed with the dispatcher's assessment of the conditions for landing on runway 31C and backed up that assessment by inputting the numbers into the on-board laptop computer tool.
The computer confirmed that the landing would be within the operational parameters of the airplane and Southwest's procedures, they said. Autobrakes were set on MAX, and they activated after a "firm" touchdown. The flying pilot (Captain) stated that he could not get the reverse thrust levers out of the stowed position. The first officer, after several seconds, noticed that the thrust reversers were not deployed and activated the reversers without a problem. At some point, the Captain noticed that the airplane was not decelerating normally and applied maximum braking manually. The first officer also became aware of the poor braking effectiveness, moved his seat farther forward, and also applied maximum braking. They stated that they continued to apply maximum pressure to the brakes as the airplane went straight off the end of the runway and came to a stop.
Interviews were conducted with a number of other Southwest Airlines flight crews, including the crew of the last Southwest flight to land at Midway and a subsequent crew that diverted to St. Louis.
Airplane Performance
Preliminary calculations show that the airplane touched down with about 4,500 feet of remaining runway and was on the runway for about 29 seconds. Preliminary calculations also show that, for the runway conditions and use of brakes and thrust reverser that occurred, the stopping distance without hitting obstructions would have been about 5,300 feet (the actual stopping distance was about 5,000 feet). In addition, had the airplane landing into the wind, rather than with a tail wind, the stopping distance for a landing would have been about 1,000 feet less.
Documentation of aircraft performance from the scene has been completed to the maximum extent possible. It was not possible to observe tire marks from much of the landing rollout due to the fact that the aircraft landed on a snow-covered runway and snow fell on the runway immediately following the accident.
FDR data show that autobrakes were active and provided high brake pressure upon touchdown. Autobrakes and manual braking continued to provide high brake pressure throughout the landing roll.
FDR data show that thrust reversers were activated about 18 seconds after touchdown or about 14 seconds before contact with the blast fence. Testing and examination of the thrust reverser systems will continue.
Investigators have obtained the laptop computer tool used by the accident flight crew. It will be examined and calculations of landing performance will be compared to flight manual data.
Eleven security-type video cameras were identified on the airport that may show imagery of the airplane rollout or the surface of the runway and taxiway at the time of the accident. The videos will be reviewed.
Meteorology
National Weather Service forecasters and other personnel were interviewed. An enhanced snow band was in the area producing localized heavy snow due to lake enhancement. This apparently is a somewhat unusual weather phenomenon, as the band swath was only 20 to 30 miles wide with snow accumulations of 10 inches right over Midway Airport.
Midway Airport weather observation equipment and records were examined and all equipment was working normally during the evening of the accident.
Southwest Airlines dispatchers who were associated with the accident flight were interviewed. Prior to the takeoff from Baltimore, when weather conditions deteriorated and the runway switched to runway 31C, the dispatcher determined that runway 31C was approved for landing for flight 1248. Runway conditions, braking action, wind speed and direction, airplane weight and mechanical condition of the aircraft are typical factors considered in making such decisions. The flight was contacted twice on the way to Midway and the appropriateness of using the runway for landing was reaffirmed during both contacts.
Official weather observations:
Approximately 20 minutes prior to the accident, the winds were from 100 degrees at 11 knots, visibility was 1/2 mile in moderate snow and freezing fog, the ceiling was broken at 400 feet, and overcast at 1400 feet, temperature -3C, dew point -5C, altimeter setting 30.06 in. Hg. Remarks - runway 31C rvr (runway visual range) 4500 feet, snow increment - 1 inch of new show in the last hour, 10 inches on the ground.
Approximately 23 minutes after the accident, a special observation revealed winds out of 160 degrees at 5 knots, visibility 1/4 mile in heavy snow, freezing fog, sky obscured with a vertical visibility of 200 feet, temperature -4C, dewpoint -5C. Remarks - runway 31C, rvr 3000 feet.
Toxicology
Blood and urine samples were obtained from both pilots. The disposition of the blood samples is being reviewed.
Structures
The aircraft has been removed from the accident site and was transferred to a hangar at Midway Airport. The maintenance log revealed no writeups or deferred items for the accident flight or several previous flights.
Professional surveyors completed a survey of the accident scene and the geography leading up to the site to include the locations of parts shed by the aircraft after it left the paved runway surface and the blast fence destroyed during the accident sequence.
Powerplants
Both engines were visually examined at the accident site. Although the first stage compressor blades of both engines showed foreign object damage, they were all intact and present. Wood from the blast fence and other debris was present in both engines. A visual examination of the turbine sections revealed no missing blades.
The 60-day engine history revealed no deferrals or writeups. Each engine has two thrust reverser sleeves. FDR data indicated that all four sleeves were deployed until after the airplane left the paved runway overrun surface. Hydraulic system B (that runs the thrust reversers) revealed no leaks.
Systems
The Systems Group documented the switches, circuit breakers and controls in the cockpit. The leading edge slat, flap, and trailing edge flap extension measurements were taken and revealed symmetrical extension of all devices. The measurements will be compared to Boeing documentation to determine exact extension.
Chicago Fire Department personnel were interviewed to determine if any switch positions or other items were altered during the rescue effort. The Fire Department Chief stated that the only things his people did were disconnect the battery and turn off the crew oxygen source.
The brakes were found in good condition with adequate wear remaining. The main landing gear tires had acceptable tread depth and no indication of flat spots.
Air Traffic Control
The local controller, two tower controllers, and the tower supervisor were interviewed. All controllers stated that they saw the aircraft lights during the landing roll, but did not see the actual touchdown.
The investigation has revealed that runway 31C was used as the landing runway because it contained lower landing minimums for aircraft using the ILS approach. If runway 13C was used, the runway most aligned with the wind, pilots would have been unable to land because of insufficient landing minimums.
Survival Factors/Airports
All flight attendants were interviewed. They all said that they noted a smooth landing but that the deceleration feeling thereafter seem less than usual. They noted that the emergency lighting came on after the airplane came to rest, and one flight attendant opened the L1 door to begin the evacuation. The emergency slide deployed automatically, but its angle in relation to the ground was less than ideal. This caused passengers to begin to pile up around the bottom of the slide. Rescue personnel assisted people away from the slide. The first officer deplaned after about 5 passengers and also assisted in getting people away from the airplane.
Further factual updates will be issued when appropriate.
NTSB Media Contact: Keith Holloway, 202-314-6100
ramper_in_las
Senior
- Jul 13, 2004
- 310
- 6
nothing like kicking someone when they are down. get some class.
- Status
