All commercial flights in, out, and across the United States yesterday were grounded, after a breakdown occurred causing interrupted radar and radio frequencies, making Federal air traffic control and related systems unworkable. The four hour ground stop was then lifted, after the cancellation of some 3500 flights, and thousands of delays. The impact will continue for days, even weeks. This was the longest aviation shut down since the Sept. 11 attacks in 2001.

The going explanation is that in a localized region, new technology being patched into the underlying antiquated air traffic management system caused a failure, whose effects spread. The Federal Aviation Administration (FAA) issued a statement on Saturday saying that actions of the contractors involved, including L3Harris, are being investigated. But the FAA also said that, “L3Harris, together with its telco partners and the FAA, have completed more than 70% of the planned airspace communications conversion from legacy copper wires to a fiber optic system.” Ironically, the FAA just publicized on Nov. 10 a new AI-driven air traffic tool, named “SMART,” which is in use in the Washington DC area.