A mechanic taxied a cargo jet across a Logan International Airport runway just as a passenger jet was getting ready to take off there, the latest in a series of safety lapses at the airport, officials said.
In all, there have been four such lapses since June 9, and authorities are discussing ways to improve safety at the airport, whose runway layout is particularly cramped.
A FedEx cargo jet was being moved for maintenance when it crossed a runway without clearance about 8 a.m. Monday, Federal Aviation Administration spokesman Jim Peters said.
A Florida-bound JetBlue jet with 130 people on board had already been given clearance to take off from that runway. Air traffic controllers spotted the FedEx plane and told the crew of the JetBlue craft, which had not yet begun rolling, to hold off, Peters said.
FedEx spokeswoman Sally Davenport said the company was cooperating with the FAA's investigation.
Too many close calls
The worst incident was June 9, when a US Airways Jet traveling at 167 mph came within 171 feet of the intersection where an Aer Lingus plane was taking off at 198 mph. The planes were cleared to take off within five seconds of each other, according to a preliminary report by the National Transportation Safety Board.
Two air traffic controllers were suspended and had to undergo 15 days of retraining.
On July 20, a Cessna taxied across a runway where another plane had already been cleared for takeoff. And on Saturday, a Delta Air Lines jet crossed a runway without permission from air traffic controllers.
The July 20 incident happened the same day the same day as federal aviation officials, Logan officials, air traffic controllers and airline representatives were meeting to identify runway safety hotspots.
"Ongoing discussions are talking place, and we are going to look at every possible solution," said Danny Levy, a spokeswoman for the Massachusetts Port Authority, the agency that oversees the airport.
Poorly designed airport may be responsible
The unique cramped layout of Logan, which juts into Boston Harbor, may contribute to the high rate of incidents, said Tom Coronite, president of the National Air Traffic Controllers Association Boston Tower local.
"Five runways, and they all intersect," he said. "And we're soon to have a sixth, also intersecting."
Logan, with 375,000 takeoffs and landings a year, is the nation's 17th busiest airport.