As more and more airplanes are jammed into the nation's airports, safety experts have become increasingly concerned that the time an aircraft spends on the ground is becoming the most hazardous part of any flight.
A near-collision between two big jets at New York's Kennedy Airport last June that sent air traffic controllers' hearts into their throats was not an isolated incident. Last year, there were nearly a dozen critically close calls involving large passenger jets missing one another by a few hundred feet or less at the nation's airports. Runway incursions - when a plane or a truck causes a collision hazard for an airplane barreling down the runway - have increased more than 70 percent since 1993. Last year, there were 322 such incidents nationwide.
"The concern we have is that just one of those ... could be a horrible catastrophic accident," said Pat Cariseo, spokesman for the National Transportation Safety Board, which has been pressing the Federal Aviation Administration to do more runway safety since 1991.
Just last week, a single-engine plane taking off from Sarasota-Bradenton Airport collided with another single-engine aircraft on the runway, killing four people. But the aviation industry is well aware that ground collisions can bring much higher death tolls - higher than most airline crashes since two planes are involved. In fact, the worst accident in the history of commercial aviation occurred on a runway, when a KLM Boeing 747 took off on top of a Pan Am 747 at Tenerife in the Canary Islands in 1977, killing 583 people.
Last April in Chicago, a Boeing 747 cargo plane made a wrong turn and taxied onto a runway in front of a Korean Air 747 that was about to take off. The Korean Air plane had to veer sharply, barely missing the other 747 by 25 to 50 feet.
The problem has not gone unnoticed. An industry-government task force studying safety issues last year moved runway near-collisions up on its priority list. New technology to warn controllers in the tower of a potential accident is over budget and two years behind schedule. But FAA administrator Jane Garvey last fall gave new executive authority to the director, and the agency is expected to announce new initiatives this week.
The FAA first began a program to improve runway safety in 1991. But beginning in 1993, the number of incursions rose steadily,reaching a peak in 1998 and with a slight decrease in 1999.