L3Harris update suspected in FAA system crash. Nationwide ground stop lasted until 11 p.m

A software update to L3Harris equipment is now suspected of crashing the communications network used by air traffic controllers. CBS News reports the update triggered a reboot and system failure. CNN says the FAA blamed network routers. The FAA has officially described it as a telecommunications outage.

The ground stop began at 3:54 p.m. and was expected to last until 11 p.m., nearly seven hours. More than 1,000 flights were canceled and nearly 10,000 delayed. Some US-bound flights were also grounded overseas. It was the second nationwide ground stop since 9/11.

Claims that ADS-B displays showed false aircraft targets remain unconfirmed. The FAA’s new SMART AI system and Microsoft’s outage have also been ruled out by their respective developers as causes. A September GAO report had already warned about gaps in FAA monitoring for communications interference.