Report links LAX work to outages

Several equipment failures that delayed hundreds of flights in Southern California last summer and raised questions about systemic problems with the region’s vast air traffic control network were caused in part by runway construction at Los Angeles International Airport, a federal report has found.

The investigation by a watchdog agency also urged the Federal Aviation Administration, which operates air traffic control facilities, to maintain aging systems better.

“Clearly, the FAA is not doing enough to proactively monitor some of its critical equipment,” Sen. Barbara Boxer (D-Calif.) said in a statement. She requested the report from the U.S. Department of Transportation’s Office of Inspector General.

In a five-page letter to Boxer, Inspector General Calvin L. Scovel III did not find a common thread among the outages, which occurred in July at a Palmdale facility that handles the region’s high-altitude traffic and in July and August at LAX. The equipment failures, however, revealed important lessons, he wrote.

“Runway construction can have an unintended but significant impact on critical systems,” the letter said.

On July 29, hundreds of trucks started hauling dirt and concrete from LAX’s south airfield past FAA equipment. The southernmost runway is being moved 55 feet to improve safety.

Construction traffic near a key instrument landing system, or ILS, interfered with its signal, the report found.

The finding surprised airport officials, who said FAA technicians told them there was no relationship between construction and the outages.

“While FAA technicians were repairing” the landing system, “LAX did not make any changes to its construction truck routes or movements,” airport spokeswoman Nancy Castles said in a statement. “In fact, since August, the number of construction trucks has doubled on the same route -- with no impacts to ILS signals.”

The landing system at LAX, which helps pilots guide aircraft when visibility is poor, failed five times in July and August, delaying flights and confounding FAA technicians for weeks. The agency eventually replaced many of the system’s components. The inspector general also found that other parts in the 10-year-old system must be replaced, in part due to corrosion because of its proximity to the ocean.

“Aging equipment in harsh environments requires proactive monitoring,” Scovel wrote.

In reacting to the outages, the FAA said earlier it had not performed routine maintenance on the landing system, saying it wasn’t needed. On Wednesday, the agency said it has a maintenance plan for the landing system at LAX and has stationed a full-time technician there.

Construction activity also contributed to problems with radar that alerts controllers to close calls, the report found. On July 24, the system gave off a false alarm, prompting controllers to turn off its aural alert. Two days later, a turboprop taking off narrowly missed a regional jet that had strayed onto its runway.

Controllers had disabled the safety system because construction interfered with the radar, causing it to give off a false alert, Scovel wrote. Again, airport officials said they had no knowledge of runway construction causing equipment malfunctions, saying the LAX control tower never told them about the false alert.

The inspector general also concluded that the FAA must launch a national program to address problems with a backup power system that failed July 18 at the Los Angeles Air Route Traffic Control Center in Palmdale, leaving controllers briefly unable to track aircraft.

The outage, which delayed 348 flights, was caused by a faulty circuit board in a system that acts to protect sensitive equipment from power spikes. The FAA said it is working to redesign the system, used at facilities across the country, so it can withstand power surges.

The inspector general’s office said it hadn’t finished its work at LAX and expected to send investigators to the airport this month to research the July 26 close call between aircraft on the ground, as well as a more severe incident on Sept. 30.

jennifer.oldham@latimes.com