WASHINGTON — The Federal Aviation Administration is studying whether to again change takeoff and landing procedures at John F. Kennedy International Airport after a second near-collision of aircraft in less than a week.

At a news conference today, the acting FAA Administrator, Robert Sturgell, said a change ordered on Friday for the New York airport might not be permanent.

“Given that we had two in this short a time frame, we’re going to take a look at the procedure, we’re going to see if there are additional considerations we should add to the procedure, and in the meantime the airport will be using a different configuration,” Mr. Sturgell said.

The FAA directed a change in the way takeoffs and landings are sequenced on perpendicular runways after two passenger airliners — one taking off, one landing — came within a half-mile of each other. Six days earlier, a similar incident occurred.

Mr. Sturgell said a preliminary investigation found that both incidents were due to communication problems.

The landing and takeoff procedures put in place Friday at JFK are designed to allow an aircraft taking off from one runway to get clear of the path of the other, intersecting runway before the second flight attempts to land. The procedure is normally used by the airport during the winter months.

Mr. Sturgell said that a preliminary study found that both incidents were due to communication problems with the aircrafts’ pilots. He said that the incidents were not caused by understaffing or lack of experience of air traffic controllers.

On Friday, a Delta Air Lines Boeing 757 was arriving at the airport when the pilot decided to abort his landing and execute a “go-around” — a routine procedure often used during heavy congestion. That caused the Delta flight to intersect with the flight path of Comair Bombardier CRJ9 that was taking off on another runway. The two aircraft came within 600 feet of each other vertically and a half-mile horizontally, the FAA said.

On July 5, a Cayman Airways flight was landing at JFK when the pilot decided to abort the landing as a LAN Chile jet was taking off. Their flight paths crossed, bringing the planes within about 200 feet of each other vertically and a half-mile horizontally.

In both instances, air traffic controllers intervened and directed the pilots to take flight paths away from the other aircraft.

“In this case, particularly the most recent one, the air traffic controller did a great job, precisely what they were supposed to do,” Mr. Sturgell said.

The comments from Mr. Sturgell came during his announcement of measures to improve runway safety for taxiing aircraft, including the installation at major airports of lights that signal pilots when a runway is safe to enter.

The FAA has drawn criticism from federal lawmakers and others over an alarming rate of runway incursions — which defined as an event in which any aircraft, vehicle or person intrudes in space reserved for takeoff or landing.

Mr. Sturgell noted that over the past year there were 24 serious runway incursions, an all-time low. So far this year, there have been 19, four involving commercial aircraft, which he said is on track with the previous year. Mr. Sturgell said the recent JFK incidents were not runway incursions.

“So we continue to see good results,” Mr. Sturgell said. “But I do think we can do better and we are. The steps we’re announcing today, I think will help us get there.”

Since 1990, 63 people have died in six American runway collisions.

The runway safety system announced today involves lighting systems to be installed at 19 more airports over the next three years. The lights change color to signal when a runway is safe to enter or cross.

The system of warning lights has been tested at the Dallas-Fort Worth and San Diego airports. Similar systems will be installed at airports in Atlanta, Baltimore-Washington, Boston, Charlotte, Chicago-O’Hare, Denver, Detroit, Ft. Lauderdale, Houston Intercontinental, John F. Kennedy, LaGuardia, Las Vegas, Los Angeles, Minneapolis, Newark, Orlando, Philadelphia, Seattle, and Washington-Dulles.