2 Planes Avert Near Collision After Airport Loses Power

Power failures at Burbank Airport sporadically interrupted air traffic control operations Thursday, forcing controllers to use alternative communications and radar systems and bringing two corporate jets over Gorman within 30 seconds of a possible collision before a resourceful controller used a third plane to relay a warning.

The control blackouts also were blamed for forcing at least one airliner to divert to Los Angeles International Airport and halted takeoffs briefly at both 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 hampered operations, silencing radios and keeping runway lights dark.

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

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In one of the outages, the blacked-out radar screens and silenced radios left one plane speeding rapidly toward another because the pilots could not hear warnings from air traffic controllers. A resourceful controller pinch-hitting in Palmdale used a third plane to relay a warning that possibly prevented a collision, said Hamid Ghaffari, a controllers union safety officer at the Palmdale site.

Ghaffari said that about 4:45 p.m., a Palmdale supervisor was told to take charge of two planes that Burbank controllers could no longer track or talk to because of the outage. “We had two planes at the same altitude--15,000 feet. The one in front was a Cessna Citation jet and the one in back was a Challenger jet.

“One was directly behind the other, but unfortunately, the faster one was behind the slower one.

“There were nine miles between them, but with 100-knot differentials in speed, they were closing at almost two miles a minute,” Ghaffari said.

The pilots were still tuned to the Burbank radio frequency, which they did not realize had ceased functioning. The Palmdale center is not equipped to transmit on the Burbank frequency.

However, knowing that aircraft pilots can tune to any frequency, a Palmdale controller quickly asked another pilot tuned to the center to tell the pilots to switch frequencies.

“We got them on frequency with one mile of separation,” Ghaffari said. “The plane behind climbed and turned out of the way.”

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, which may take several days to determine, said FAA spokesman Mitch Barker. However, he attributes the outages to a failure in a power conditioning system, which 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 into our facility,” Barker said. A circuit breaker at the control tower that protects against power surges also was found tripped, he said.

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The sequence of airport troubles, however, and a city power surge do not appear to match, according to interviews with officials. Power first failed in the control tower at 2:28 p.m. and did not return until 29 minutes later, at 2:57 p.m., according to Barker. The radar system to San Diego also went down during that period, halting all takeoffs at Burbank and Van Nuys airports, Barker said.

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.

“That dip could have caused a problem with the radar because of its sensitivity to voltage,” Stassi said. “The only thing we know for sure is that we had that one interruption. We are not aware of any other spikes that occurred.”

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

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That failure forced the diversion of at least one airliner--Alaska Flight 40 from Seattle with 96 passengers aboard. The plane, scheduled to arrive at Burbank at 7:56 p.m., was ordered to land instead at LAX.

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

Officials said no new problems occurred Friday.

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Air Traffic Troubles

Sporadic power failures at Burbank Airport knock out radar, silence radios, halt takeoffs, cause two planes to come dangerously close and force airliner to divert to LAX. Federal aviation officials are investigating.

Time: 2:28 p.m.

Problem: Power fails in control tower at Burbank Airport and is not restored to normal until 2:57 p.m., a 29-minute lapse. During six minutes in that period, air traffic controllers, based in San Diego, loose radar images and radio contact with aircraft in flight over the San Fernando Valley.

Alternative: Controllers track traffic using the Palmdale-based radar and radio.

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Time: 2:50 p.m.

Problem: A Burbank city power cable fails. Surge is suspected of affecting airport radar.

Alternative: Power is switched automatically and there is no outage to customers.

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Time: 3:54 p.m.

Problem: Second outage shuts down power at airport control tower.

Alternative: Operation is switched to gasoline-powered backup generators.

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Time: 4:45 p.m.

Problem: Air traffic controllers in San Diego again loose radar and radio contact with flights over the Valley. Two corporate jets over Gorman come dangerously close to colliding.

Alternative: Palmdale controllers take over; utilize a third pilot to contact and warn jets on collision course.

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Time: 4:51 p.m.

Problem: Power again fails at airport control tower, with outage lasting three minutes.

Alternative: Backup generators used.

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Time: Sundown to 8:13 p.m.

Problem: Airport runway lights fail to come on.

Alternative: Alaska Flight 40 carrying 96 passengers from Seattle, scheduled to arrive at Burbank at 7:56 p.m., was diverted to LAX.