Jun. 22--WASHINGTON -- A snowstorm like the one that sent a Southwest Airlines jet skidding off the runway in December could effectively shut down Midway Airport under new federal rules, accident investigators said Wednesday.
The new Federal Aviation Administration regulations will require pilots to add a buffer of at least 15 percent to their stopping-distance estimates on wet or icy runways.
In some cases that could require several thousand additional feet of runway that space-constrained airports such as Midway simply do not have, forcing flights to land elsewhere.
Chicago Aviation Commissioner Nuria Fernandez said the new rules mean Midway's snow-removal crews will need to be "much more aggressive" about keeping runways clean and dry.
The alternative would be tie-ups that would inconvenience thousands of passengers bound for or stuck in Chicago, National Transportation Safety Board officials were told as they concluded a two-day hearing into the Dec. 8 crash at Midway in which Flight 1248 left the runway and crushed a car, killing a 6-year-old boy.
The hearing brought to light worries the pilots had about trying to land the Boeing 737-700 in marginal conditions and the anguish that followed.
In a document released during the proceedings, the pilot who made the decision to land departed from the formal tone of his report to express his remorse over the death of the boy, Joshua Woods.
"Myself, I deeply regret the loss of life of that young boy and like any grandfather I would replace my life for his if I could," Capt. Bruce Sutherland, 59, wrote in a three-page report he composed about a week after the accident.
"I am ashamed that this happened and regret the loss off our aircraft and the position this has put our company. We are so blest to be working for Southwest airlines and these last few days have only strengthened that belief.
"I am sorry I have let so many people down."
The crash has triggered changes that travelers will encounter next winter.
"It's clear there is going to be impact," Fernandez said. She said the city would look at purchasing new equipment and sweeping the runways more frequently during bad weather.
But she insisted that "the airlines do have options. It's not a matter of having to land in a condition if they are not comfortable with the conditions. They can delay the flight at the origin."
More than 4,300 flights bound for Midway were diverted to other airports in 2005, according to the U.S. Bureau of Transportation Statistics. Two percent of the airport's 2.3 million flights were canceled last year.
Under the new rules, a stopping distance of 8,535 feet must be available for a plane comparable in weight and landing speed to the Southwest 737-700 involved in the Dec. 8 accident, based on the poor braking conditions at the time, FAA officials testified at the hearing.
But the runway where the accident occurred--Midway's longest runway--is only 6,522 feet long. Planes are prohibited from landing on the first 696 feet because of obstructions outside the airfield.
The new rules also mandate that when conflicting or mixed assessments of runway conditions are issued, pilots must use the worst-case scenario, effectively erring on the conservative side, according to FAA airplane performance engineer Don Stimson.
The FAA issued the new landing rules this month. They will take effect in October.
The pilots of Flight 1248 had calculated much shorter stopping distances for their landing at Midway, from 5,778 feet under poor runway conditions to 5,253 feet under fair conditions.
Sutherland told investigators he relied on the more favorable condition assessment to attempt a landing.
Had the captain opted for the poorer assessment, the plane would have been prohibited from landing that night under Southwest's in-house rules, Brian Gleason, director of flight operations at the airline, said at the hearing.
Gleason said tailwinds can be no stronger than 5 knots when the runway condition is poor, according to Southwest's policy. Tailwinds of 8 to 9 knots buffeted the Southwest plane last December, the NTSB said.
Transcripts of Flight 1248's cockpit voice tapes revealed that Sutherland talked extensively with his co-pilot, Steven Oliver, about diverting to St. Louis or Kansas City because of the dicey landing conditions at Midway.
City officials at Midway reported that the runway's condition was good, based on friction tests designed to correlate with aircraft braking power.
Pilots and safety board investigators, however, rated the first half of the runway as fair and the second half poor before and after the accident.
Safety board Chairman Marc Rosenker said he hopes the board is able to issue its final report and safety recommendations on the Midway accident later this year or in early 2007.