Alan Staats/PHOENIX

Hotel and casino operators in Las Vegas have been ordered to suspend their laser displays following an incident involving a Southwest Airlines Boeing 737 first officer being temporarily blinded by a burst of laser light.

The event occurred even though the hotel involved uses a traffic-collision-avoidance system (TCAS) to turn off the laser when aircraft approach.

The incident, which took place on 30 October 1995, happened as the 737 was passing through 7,000ft (2,000m) in a right turnout after leaving Las Vegas McCarran Airport. The first officer, who was flying the aircraft at the time, was "...unable to see for about 2min" because of the light, according to Brian Calendine, the US Federal Aviation Administration flight-safety official in Las Vegas.

Following an investigation by the FAA and the US Food and Drug Administration, (which licenses the lasers), operators have been ordered to suspend their use temporarily, pending the establishment of new aiming, beam dispersion and power-output guidelines for users within 30km (20 miles) of McCarran Airport.

"One of the biggest problems with these displays," Calendine says, "is the fact that the beams of light are so narrow and concentrated that, even ten miles out from the source, the beam spread is still only 20-30ft wide in some cases."

While there has been no official determination, of the beam's origin, it is widely believed to have been generated, by the Las Vegas Hilton's outdoor laser show. According to hotel president Gary Gregg, the hotel's "...primary concern is safety".

He says that, in addition to compliance measures, "...we have made every effort to ensure that our laser attraction, built for entertainment, went beyond safety guidelines".

Gregg says that those efforts have included the installation, in June 1995, of a TCAS.

The system has also been modified to establish a protective zone around each of the laser fountain's beams.

Once an aircraft enters the zone, the beam automatically shuts off until the aircraft has traveled a safe distance from the beam. It is not known whether the system was in operation at the time of the Southwest Airlines incident.

According to sources at the McCarran Airport tower, the episode was the 51st to be reported to air traffic control and tower personnel in the two years since the first display was installed.

Similar incidents have been reported elsewhere in the world. The first officer, whose name was not released, was treated by an opthamologist and subsequently cleared for flight operations shortly after the event.

Source: Flight International