As runway near-misses surge, radar that keeps planes apart is aging and unreliable

A crucial safety system that’s relied on to avoid potentially fatal collisions at major US airports is aging and plagued by outages that have left travelers unprotected for months at a time. At some airports, it hasn’t ever been installed. The technology — which tracks vehicles on or near runways to alert controllers before impending crashes — often uses decades-old radar equipment for which spare parts are difficult to find, according to government data and the president of the union representing air-traffic controllers. Keeping track of ground traffic at airports is particularly important at a time when runway-safety incidents appear to be surging. This year, there have been at least eight incidents involving airliners that aviation regulators ranked as severe, or that prompted probes by US accident investigators. That’s almost double the average for each full year since 2018. While none of those near collisions have been directly linked to an outage of Airport Surface Detection Equipment-Model X, or ASDE-X, gaps in service can leave the aviation system vulnerable. With no clear alternative available, advocates are pushing to add the system — which is highly effective when it’s functioning well — to more landing strips after some of the most serious incidents happened at airports without the technology. “They are the last line of defense in preventing a massive collision between two airliners,” said Jeff Guzzetti, former head of accident investigations at the Federal Aviation Administration. “I’m shocked that it hasn’t been put in more airports.” Three people familiar with the runway safety systems said that they have suffered multiple failures in recent years. They asked not to be identified discussing malfunctions that aren’t public. At Dallas-Fort Worth International in Texas, the third-busiest US airport by number of flights, the ASDE-X system was out of service for at least six days last May and June, according to one of the people. At Chicago O’Hare, an outage last July lasted as long as a week. At Los Angeles International, 39 separate failures meant that the system was unavailable for a total of 160 days from 2016 through 2018, according to an FAA report reviewed by Bloomberg. Together, the three airports processed more than 80m travelers in 2021, according to FAA data.<br/>