The distance between relief and disaster can be measured in feet or in seconds.
When an airliner skids off the end of a major runway at Mitchell International Airport - as one did Sunday - it has less than 1,000 feet to stop and often very little to prevent it from slamming into a busy street or railroad tracks.
It's a situation that airport managers and elected leaders should correct as soon as possible, Jim Hall, a former top federal safety official, said Monday.
The solution could be years away, however, because the airport must navigate through environmental, financial and technical issues as it weighs the options in a federally mandated study, Airport Director C. Barry Bateman said.
No one was seriously injured when Northwest Airlines Flight 1726 came to rest 400 feet past the end of the runway after an engine problem suddenly interrupted the DC-9's takeoff.
But two other crashes - one at Chicago's Midway Airport and one at Mitchell - illustrate how fortunate the passengers and crew were that the flight did not end much worse.
In December 2005, a Southwest Airlines flight was landing at Midway when it slid off the end of the runway and then crashed through a fence and into a street, where it hit a car and killed a 6-year-old boy.
In September 1985, a Midwest Express Airlines flight crashed in Oak Creek shortly after taking off from Mitchell, killing all 31 people aboard.
Like Sunday's incident, the Midway crash drew attention to the hundreds of major airport runways that lack federally required safety zones at each end. The 1985 crash, meanwhile, on the airline now known as Midwest Airlines, demonstrated the added danger of a mechanical failure in the critical moments after takeoff - a takeoff that was seconds away for Sunday's Northwest flight.
A week before the Midway crash, President Bush signed a law that gave U.S. airports until 2015 to ensure that every runway used by airliners either has a 1,000-foot safety zone at each end or a bed of crushed concrete to stop careening aircraft.
Three of Mitchell's five runways are out of compliance, according to a Federal Aviation Administration study released in November. Nationwide, that's a problem at 507 of 1,017 major runways and at 325 of 573 commercial airports, the report says. In Wisconsin, the safety zones are lacking at 16 runways at eight of the state's top 10 airports, the FAA says.
Of the three Mitchell runways without adequate safety zones, one runway, with its west end pointing at S. Howell Ave., could be reclassified to exempt it from the federal requirements, because airliners do not use it as frequently as the other two, Bateman said. But the other two are Mitchell's main east-west and north-south runways, and together they handle nearly all of the airport's airline traffic, he said.
The east-west runway was where the Northwest flight was aborted, stopping about 250 feet from an embankment that is topped by Union Pacific railroad tracks. It's just 650 feet from the runway to the tracks, and S. 6th St. is at the runway's other end. The north-south runway, meanwhile, has W. College Ave. on one end and W. Layton Ave. on the other.
Hall, former chairman of the National Transportation Safety Board, finds that unacceptable.
"There is no reason that . . . any airport that doesn't have an adequate safety area wouldn't have an arrester bed" of crushed concrete at the runway's end, said Hall, now a consultant. "The Milwaukee airport and the elected officials should be doing everything they can to get an arrester bed there."
Bateman said officials are doing what they can but it's not that easy. Consultants considered about 20 options and ruled out the most difficult - such as moving the railroad tracks - before focusing their study on the most likely choices, he said.
Federal officials insist on steps to ensure that airliners don't skid off runways into traffic on nearby streets.
Air freight company blames federal air traffic controllers for fiery ground collision between two planes at Mitchell International Airport.
The current $14.5 million system is focused only on runways. Two cargo planes collided last week at the intersection of three taxiways.