The Federal Aviation Administration is investigating a weekend runway safety breach at LAX in what apparently was the second such incident at the airport in less than two weeks, officials said Monday.
The latest episode, which occurred shortly before 10 p.m. Saturday, involved two Boeing 737s at the north airfield of Los Angeles International Airport.
Officials said a Continental plane that had arrived from Newark, N.J., crossed the so-called hold bars where it was supposed on stop on its runway.
The aircraft, Flight 1502, apparently encroached into the runway area of an American Airlines plane, Flight 1254, that was leaving for Miami.
It was unclear Monday night whether the American Airlines plane was already rolling, in the air or just cleared for takeoff.
FAA spokeswoman Laura Brown said a preliminary investigation found that the two aircraft were at least 1,000 feet apart and possibly were never closer than 3,000 feet.
Officials noted that the previous incident, which occurred Aug. 16 and was officially designated a "runway incursion," was a near-collision in which two airliners were only 37 feet apart.
Brown said it was not determined whether Saturday night's incident also would be officially characterized as a runway incursion, a serious safety breach involving encroachments affecting incoming or outgoing aircraft.
Although officials said the incident apparently was in the "lower severity" category, it was serious enough to sound a safety alarm in the LAX control tower.
If the incident is officially labeled a runway incursion, it would be the eighth such event since Jan. 1.
LAX officials declined to comment.
In the Aug. 16 incursion, a WestJet Boeing 737 that had arrived from Calgary, Canada, was crossing the runway when it almost collided with a Northwest Airlines Airbus A320 speeding toward takeoff, according to a preliminary report by the National Transportation Safety Board.
The WestJet pilot switched to a different radio frequency before being cleared by tower controllers to taxi across the Northwest plane's runway. A ground controller then mistakenly instructed the pilot to proceed across the runway.
The WestJet plane traveled slowly toward the Northwest plane, which sped up to about 150 mph in preparation for takeoff, according to the FAA.
Of the roughly 657,000 takeoffs and landings during the 12-month reporting period from Oct. 1, 2005, to Sept. 30, 2006, there were eight incursions, officials said.
Among the 35 busiest commercial airports nationwide, LAX has the fifth-highest rate of such close calls, the FAA said.
As part of a $330-million project, a runway on the south airfield has been moved to help reduce such problems, but similar plans to revamp the north airfield have stalled because of community opposition.
In a separate incident Monday, an Alaska Airlines jetliner bumped into one of the same carrier's parked planes.
The incident occurred about 1 p.m. as the slowly moving plane was being pushed away from a departure gate at Terminal 3, authorities said. A wing tip of the moving craft struck a stabilizer on the other jet.
Officials described the incident -- which involved two Boeing 737s -- as minor, and said there were no injuries to passengers or crew and little damage.
The two aircraft were grounded but passengers were transferred to other flights, an Alaska Airlines spokeswoman said.
The cause of the mishap was under investigation.