Published Monday, January 8, 2001

Radar glitch found at S.F. airport

Officials say they know why collision alarms sounded during a test last fall; corrective software is on the way By Aaron Davis SAN JOSE MERCURY NEWS

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SAN FRANCISCO -- Federal aviation officials say they have pinpointed the snag in a ground radar system that erroneously sounded collision alarms six times in the air traffic control tower at San Francisco International Airport during a test run last fall.

The glitch in the Airport Movement Area Safety System, or AMASS, had threatened to delay the rollout of the ground radar system, designed to electronically track the location of aircraft on runways and taxiways, and sound alarms when they are on a collision course with another plane or object.

The government hopes AMASS will prevent the kind of ground collision that killed 81 people in Taiwan in October.

A team of engineers from the Federal Aviation Administration will return to San Francisco next month to install new software and resume testing the system. If all goes well, the radar could be up and running at the airport in June, leaving the FAA on track to meet its goal of outfitting all major U.S. airports with the technology by November 2002.

"It's a very complicated system and we expected some problems," said FAA's Michael Huffman, who's orchestrating the government's $152 million AMASS program from Washington. "We built those into the time line so we are still striving toward our June goal."

However, some air traffic controllers say they won't hold their breath for a June unveiling.

Representatives for the National Association of Air Traffic Controllers say they want the system working flawlessly before it is activated at San Francisco's airport. It's still unclear whether the system will ever be perfect. Occasional false alarms may be inevitable.

San Francisco will be the first airport in the nation to use the new ground radar system, with airports in Detroit and Atlanta next in line. Federal aviation officials say they picked San Francisco because "it's one of the airports that would stress the system the most," Huffman said. "If it works here, we're very confident it will work just about anywhere."

San Francisco's intersecting runways present a natural problem for the computer system, because during routine take-off and landing procedures, airplanes cross the same pavement within 30 seconds of one another.

The AMASS system combines radar images from machines on the ground at San Francisco and from the Bay Area's regionwide radar control center in Oakland to pinpoint the exact position of aircraft.

In November, the system was tested for 28 consecutive days at San Francisco airport, during which 32,000 flights arrived and departed. During six of those, AMASS incorrectly sounded collision alarms when planes were in no danger.

While that number may seem low, air traffic controllers say even one mistake is too many because it forces them to react to imaginary problems when flights are still approaching the airport.

Federal aviation officials now believe an AMASS component in Oakland created the ghost images of those six flights, making it appear as though two planes were headed for the same runway.

Technicians have recalibrated the Oakland system and will install new software there in February in preparation for another month-long test.

"We have indications from the work we've done that this will fix the problem," Huffman said. "It's nothing I'd hang our hat on, but it looks good. We'll know soon."

http://www.contracostatimes.com/news/bayarea/stories/sjradar_20010108.htm

-- Martin Thompson (mthom1927@aol.com), January 08, 2001

Answers

After working with the FAA for 17 years I don't think I would hang my hat on it either!

-- Martin Thompson (mthom1927@aol.com), January 08, 2001.