Plane Collision Narrowly Averted in Power Outages

After power failures at the Burbank airport blacked out radar and radios and left one corporate jet speeding rapidly toward another, a resourceful air traffic controller relayed a warning through a third plane and prevented a possible collision over Gorman, an air safety official said Friday.

Thursday’s blackouts also were blamed for forcing at least one airliner to divert to Los Angeles International Airport and halted takeoffs briefly at both the Van Nuys and Burbank airports.

Air traffic controllers--based in San Diego--were twice left with no radar or radio contact with aircraft over the San Fernando Valley. The power outages in the Burbank control tower also kept runway lights dark.

During the outages, control of planes in the air was switched from San Diego--which controls flights within the Los Angeles area--to controllers at a Palmdale facility, which normally handles flights arriving in or leaving the area.

Two corporate jets involved in the switch remained on the San Diego frequency that had gone dead. Controllers in Palmdale, who use different frequencies, could see the jets on radar but were unable to communicate with either plane.

“Both planes were at 15,000 feet, one directly behind the other, about nine miles apart,” said Hamid Ghaffari, a controllers union safety officer at the Palmdale facility. “Unfortunately, the plane in the back was going faster, closing on the one in front at almost two miles a minute.”

As the controllers in Palmdale tried futilely to contact the jets, the plane at the rear steadily gained on the one in front. Broken clouds covered the area, and it was not known whether the planes would have been visible to one another.

While controllers can’t broadcast on a wide range of frequencies, pilots can. Realizing this, a controller in Palmdale contacted a third plane on the Palmdale frequency and that plane, in turn, relayed a warning to the two corporate jets on the San Diego frequency.

Less than 30 seconds from a possible collision, the faster jet changed course.

The event was one of a series that kept controllers on a high-tension ride Thursday.

“Losing air-to-ground communications is exactly what we do not want to happen,” said one FAA official who declined to be identified. “When communications stop, these airplanes are still moving. You can just imagine what was going on.”

Officials are still investigating the cause of the outages.

FAA spokesman Mitch Barker attributed them to a failure in a system that accepts commercial power from the city of Burbank and sends it to the airport control tower and facilities.

“The Burbank Department of Water and Power told us there was a loss of a 35,000-volt feeder to the Clybourn station, at the corner of Burbank airport, and that may have put a power spike on the line,” Barker said. A circuit breaker at the control tower--which protects against power surges--also was found tripped.

But the sequence of airport troubles and a city power surge do not appear to match, according to interviews with officials.

A cable failure in Burbank’s power supply occurred at 2:50 p.m., but power was automatically switched and there was no outage to customers, including the airport, said Ron Stassi, general manager of the Burbank Department of Public Service.

The control tower had additional outages at 3:54 and 4:51 p.m., during which it switched to backup generators. The troubles continued into the evening, when runway lights failed to come on at sunset.

That failure forced the diversion of at least one airliner, Alaska Airlines Flight 40 from Seattle with 96 passengers aboard. The plane was ordered to land instead at Los Angeles International.

After the runway lights were restored at 8:13 p.m., the Alaska flight took off from that airport and returned to Burbank, arriving 80 minutes behind schedule, said Jack Evans, a spokesman for the airline.

Officials said no additional problems were reported on Friday.