DALLAS — Up to three passenger-carrying American Airlines jets will be outfitted this spring with laser technology being developed to protect planes from missiles fired by terrorists.

Officials said yesterday the anti-missile systems won't be tested on passenger flights. But the tests, which could involve more than 1,000 flights, will determine how well the technology holds up under the rigors of flight, they said.

The first Boeing 767-200 will be equipped in April or later, American spokesman Tim Wagner said. American operates that Boeing model mostly between New York and San Francisco and Los Angeles.

American said it is "not in favor" of putting anti-missile systems on commercial planes but agreed to take part in the tests to understand technologies that might be available in the future.

The anti-missile technology was developed for military planes, and U.K.-based BAE Systems PLC said yesterday it won a $29 million contract from the Department of Homeland Security to test it on passenger planes.

The technology is intended to stop a missile attack by detecting heat from the rocket, then responding in a fraction of a second by firing a laser beam that jams the missile's guidance system.

The device on the belly of the Boeing 767-200 aircraft will be operational but won't be tested on regular flights, Wagner said. The use of a signal to mimic a missile attack has already been tested in the air, Wagner said.

Those tests also showed that the anti-missile systems didn't interfere with the jet's other controls, officials said.

American, the nation's largest carrier, has been working with BAE on the project for a couple years. In 2006, BAE installed its hardware on a Boeing 767 that wasn't used to fly paying passengers.

About a year ago, BAE invited reporters to American's maintenance base in Fort Worth to see a jet outfitted with the laser-jamming device called Jeteye.

"We are now entering the next phase," Wagner said, which is "to see how the system holds up on an aircraft in real-time conditions — weather, continuous takeoffs and landings, etc. — and to test its maintenance reliability."

Burt Keirstead, director of BAE's commercial airline protection program, said BAE's contract requires it to prove that Jeteye will operate without failure for 3,000 hours of flight and sets a goal of 4,500 hours.

"If there is one aspect of performance that is hardest to satisfy, it's reliability," Keirstead said. "We predict we'll meet the (3,000-hour) threshold, and we hope to get to the (4,500-hour) goal."

BAE expects to test the device through 7,000 hours of flying in 2008 and early 2009, he said.

With the latest contract, BAE has received more than $100 million in funding for aircraft-protection systems. Keirstead said BAE's technology will cost $500,000 to $1 million per plane to install.

Congress has approved funding for anti-missile research partly out of fear that terrorists armed with shoulder-fired weapons could hit jetliners as they take off and land.

American has said anti-missile defense is best handled by stopping terrorists from getting missiles that could shoot down commercial jets and by improving security around airports.