Chicago Trib Article

wnbubbleboy

Veteran
Aug 21, 2002
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By God Indiana
Poles, other obstacles reduce landing zone on Midway runway

BY JON HILKEVITCH
Chicago Tribune

CHICAGO - Light poles, utility lines and other obstacles prevent planes from using the first 696 feet of the already short runway at Midway Airport where a Southwest Airlines Boeing 737 skidded and crashed in a swirling snowstorm last week, city and federal officials said Tuesday.

Landing a big plane on the remaining 5,826 feet of the 6,522-foot runway requires precision even in good weather. But touching down safely in sloppy, icy conditions on Midway's Runway 31 Center, where the accident occurred, tests the abilities of an airline's best pilots, according to veteran aviators.

Swept along by a gusting tailwind while being told by air-traffic control that the aircraft braking ability on the runway was dicey, the captain of Southwest Flight 1248 descended fast on Dec. 8, according to an account culled from radar tapes under review by the National Transportation Safety Board.

Data from the onboard flight recorder indicate that the plane touched down harder than normal - reflecting an apparent attempt by the captain to hit the intended runway-landing markings dead-on so the maximum amount of remaining runway was available to stop the plane. The hard landing also explains the previously reported bounce that the plane made before sliding across the concrete, crashing through barriers after racing through a dangerously short runway protection zone and exiting the airport.

"When you break out of the clouds on a snowy night like that, you don't try to do a nice squeaky smooth landing. You plant the plane down onto the runway," said Robert Mark, a former airline and corporate pilot who flew for the original Midway Airlines.

The Southwest plane came to rest on Central Avenue after hitting several vehicles and spearing a fire hydrant. A child inside one of the cars was killed and 10 people were injured in the worst accident in Southwest Airlines history.

Federal investigators who are recreating the flight's events say they don't know yet whether the captain hit the landing mark - 696 feet from the edge of the runway - or floated farther down the runway before touching down.

"We expect to have the information soon," said Keith Holloway, a spokesman for the safety board. "A lot of issues involving the runway and runway safety are being looked at."

Midway air-traffic controllers told investigators that blowing snow prevented them from seeing where the plane landed on the runway.

Obstacles on and off the airport, coupled with the angle of the plane's descent on an instrument-guided glide slope, prevent pilots from using the full length of the runway during landings.

It is called a displaced threshold, meaning the landing zone is at a point that is not the physical end of the runway - in this case, 696 feet away. The portion of the runway displaced may be used for takeoffs only. Landing aircraft may use the displaced area when touching down on the opposite end of the runway.

The opposite end of 31 Center, called 13 Center, allows for 6,059 feet of landing space - 233 feet more for pilots to use. The extra distance would have been helpful in the case of Flight 1248, but 13 Center was not the landing configuration in use.

Holloway said the safety board is probing to determine why 13 Center was not used.

Runway 13 Center met the minimum requirements of a 300-foot cloud ceiling during the snowstorm. But the runway was 500 feet under the 5,000-foot minimum visual range for that runway. A minimum visual range is the distance a pilot sitting on the runway would be able to see straight ahead, according to officials at the Federal Aviation Administration.

Runway 31 Center requires a minimum runway visual range of 4,000 feet.

Some veteran Midway pilots, who asked not to be identified, questioned the FAA explanation, saying rules are often stretched a bit at the Southwest Side airport to allow for what is known as a "Midway mile."

These pilots said the extra 233 feet in runway stopping distance would have been more than worth giving up the 500 feet visually for the pilots of Flight 1248.

Meanwhile, the Federal Aviation Administration reopened Runway 31 Center at 6:30 p.m. Tuesday for the first time since the accident. Equipment that aligns planes on the middle of the runway was damaged in the crash. Some fencing at the airport's perimeter also was replaced.

In addition, Chicago aviation officials responded to criticism from the FAA that the city isn't doing enough to improve safety on the edges of Midway runways.

The Chicago Tribune reported Tuesday that the FAA ordered city airport officials early last year to come up with a better plan to prevent planes from over-running runways. The city submitted a study that the FAA rejected as unacceptable, but airport officials did not follow up with new recommendations.

Longtime FAA standards call for obstacle-free safety zones at the margins of runways. The safety zones are supposed to be at least 1,000 feet long and 500 feet wide.

Most of the runway safety areas at Midway, which opened in 1927 next door to a Chicago public school, measure less than 100 feet long.

Almost 700 homes and more than 100 businesses would be uprooted if the city complied with the FAA standards, said Erin O'Donnell, a deputy Chicago aviation commissioner who manages Midway.

"We are not going to go on an aggressive land-acquisition program (to build runway safety areas)," O'Donnell said. "Instead of busting up stable neighborhoods, the city will continue to work with the FAA to find the appropriate technologies and safety measures at an airport that has been hailed as one of the safest in the nation."

She pointed out that an FAA report in 2000 on runway safety never specifically called for Midway officials to build safety zones, and in fact called the zones impractical at the space-constrained airport.

The FAA, however, did not take Midway off the hook. The FAA report said the city needs to conduct a detailed study of alternatives to provide a safety net to minimize the damage, deaths and injuries caused by a plane skipping off a runway.

A number of options exist, ranging from pits filled with soft, crushable concrete to stop out-of-control planes to barrier systems that more gently absorb the impact of a crash.

O'Donnell pledged the city would step up its review to remove objects from runway perimeters and from surrounding streets that could endanger airline passengers and vehicle occupants in a crash, and it will explore emerging technologies.

"There is no magical solution at airports with short runways today. But I am confident" answers will be found, she said.
 
Swept along by a gusting tailwind while being told by air-traffic control that the aircraft braking ability on the runway was dicey, the captain of Southwest Flight 1248 descended fast on Dec. 8, according to an account culled from radar tapes under review by the National Transportation Safety Board.
I've heard "Good" "Fair" "Poor" and "Nil" but I've never heard "Dicey".
 
I've heard "Good" "Fair" "Poor" and "Nil" but I've never heard "Dicey".

Dicey -- term used by reporters when then have absolutley no idea what the appropriate word is but still want to elicit the most emotional response from the general public. Frequently used to intentionally draw a comparison to gambling and thus guide their audience toward believing an action was an absolute risk.

Press corps, gotta love 'em ... or not.
 
NTSB: Plane touched down too late

By Jon Hilkevitch
Tribune transportation reporter
Published December 15, 2005, 5:16 PM CST


After agreeing with a Southwest Airlines dispatcher that it was safe to land amid a blowing lake-effect snowstorm, the pilots of Flight 1248 that crashed at Midway Airport touched down long---more than 2,000 feet beyond the edge of the 6,522-foot runway, the National Transportation Safety Board said Thursday.

The plane hit the runway forcefully, bouncing and becoming momentarily airborne again, during a 29-second landing attempt that needed at least another 800 feet of runway to avoid hitting anything or anyone.

There was also a longer delay than previously reported in deploying the aircraft's thrust reversers, which are designed to assist the braking system in stopping the plane.

The captain told investigators that he had trouble moving the lever that activates the thrust reversers, which are supposed to begin working as soon as the plane lands. In a separate post-accident interview, the first officer said he reached over after "a few seconds'' and was able to trip the thrust reverser release.

But data from the plane's flight data recorder now show that the thrust reversers did not activate until about 18 seconds after landing, the safety board said. The delay meant that the thrust reversers were working to redirect air from the jet engines in a forward-upwardly direction for only about 14 seconds before the plane hit the fence.

Preliminary calculations, using radar information and the flight data recorder onboard the Boeing 737-700, show that the plane touched down with about 4,500 feet of runway remaining, said a factual report issued by the safety board.

The aircraft needed about 5,300 feet stopping distance to avoid hitting obstructions, the report said.

After skidding off the runway, the plane carrying 98 passengers was slowed by rolling through a blast fence, an airport perimeter fence and onto Central Avenue where it struck two vehicles, killing a 6-year-old boy. Between landing on the runway and coming to an abrupt, colliding stop, the plane traveled about 5,000 feet, the safety board said.