Danger lurks on increasingly busy runways

August 29, 2006|By Meredith Cohn | Meredith Cohn,Sun reporter

Commercial airplanes rarely take off from the wrong runway and crash as a Comair commuter jet did Sunday in Lexington, Ky. But more frequently, planes swipe or come close to hitting other aircraft or equipment on the nation's increasingly crowded runways, according to aviation experts.

Most mistakes are corrected before there is an accident because of the work of pilots, air traffic controllers and their equipment. And the near misses are not always recorded in federal accident databases, experts said.

In all, incidents involving large commercial aircraft amounted to less than two dozen of the approximately 850 incidents on or near runways last year recorded by the National Transportation Safety Board. Most of the incidents, averaging close to two a day, involved small, general aviation planes whose pilots erred or equipment failed.

Problems for pilots of large airliners can arise at smaller airports, which don't always have sophisticated tracking equipment. And big airports can be complex and crowded, experts said.

"It's not uncommon at all to get on the wrong pavement, a runway or taxiway," said William Waldock, a professor of safety science at Embry Riddle Aeronautical University and a pilot. "But to take off from the wrong runway ... bells should have been ringing in Lexington."

Without enough runway length to gather speed, Comair Flight 5191 to Atlanta crashed and killed all but one of the 50 people aboard. Federal investigators said yesterday that recordings indicate that the pilot and air traffic controller discussed only Runway 22, though the crash site shows the Bombardier CRJ-100 went off Runway 26.

Pilots have equipment such as compasses and global positioning systems that tell them where they are. There are signs along the way that identify runway crossings, and voice directions from air traffic controllers are provided. The controllers at large airports have ground radar to keep track of traffic. At smaller airports such as Lexington's Blue Grass Airport, where the accident occurred, the controllers can generally see the whole runway.

Waldock said there have been only a few major accidents on runways in the past couple of decades.

The deadliest recent crash involving a missed runway assignment occurred on Oct. 31, 2000, when a Singapore Airlines jet rolled down a closed runway in Taiwan. The Los Angeles-bound plane struck construction equipment on the runway, killing 83 people. In 1979, a Western Airlines jet landed on a closed runway in Mexico City and struck a parked vehicle, killing 72.

Ground radar was unveiled at most large airports after a 1991 accident in Los Angeles when a USAir jetliner struck a commuter plane, killing 34. An air traffic controller couldn't see the end of the runway and didn't know the smaller plane was there, Waldock said.

In Sunday's crash, the experts say there are a host of unanswered questions about the pilots' and the controllers' preflight actions. There also are questions about the physical state of the runway, including the amount of lighting.

Airports are frequently designed with runways that crisscross, and Lexington is no exception. A 7,000-foot runway there is used by commercial jets. A separate 3,500-foot runway accommodates smaller, general aviation planes that are affected by wind at their sides, said Chris Dancy, a spokesman for the Airline Owners and Pilots Association.

The runways are numbered according to the direction in which they are heading, Dancy said. Runway 26 in Lexington is pointing almost due west. The difference between the runway the Comair flight took off from and the one it was supposed to be on was 40 degrees - and the pilot and controllers should have been able to distinguish them.

"At an airport like Lexington's, they were probably more likely relying on the controller being able to see the ends of the runway," he said. "For some reason, the pilot may not have seen the signs and the controller didn't see the plane. It's so uncommon for this to happen; investigators have their work cut out for them."

Depending on space, not all airports are able to separate their runways.

But many larger airports such as Baltimore-Washington International Thurgood Marshall Airport do. Its shorter general aviation runway is separated from the longer ones used by commercial jets. The airport also is equipped with ground radar that helps the controllers keep planes apart. All airports have radar to monitor planes in the air.

"We've taken care of a lot of problems in the air with radar and weather monitoring," said Michael Goldfarb, former chief of staff at the Federal Aviation Administration and now a consultant. "Now we have a growing problem with ground congestion."

There is new technology in the works that can help controllers and pilots keep track of air and ground traffic, but it's slow to be rolled out, he said.

Aaron J. Gellman, a professor and transportation expert at Northwestern University's Kellogg School of Management, said federal authorities are working on that. But he agreed that upgrades in technology are paramount to handling the growing traffic.

"When things are in motion you're going to have some accidents," he said. "We can only continue packing the airspace if computers are doing the work. We need a less labor-intensive system, not because we don't like labor but because the human mind isn't good enough to keep the airspace the way it has to be."

meredith.cohn@baltsun.com

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