Thousands of flights across the United States experienced delays and cancellations on Monday, 21 September 2026, following a telecommunications outage. The disruption was caused by a telecom switch failure and an accidentally cut fibre optic cable.
The Federal Aviation Administration (FAA) was forced to ground flights for hours to major East Coast cities including New York, Philadelphia, Boston, and Washington. The incident began around 9:45 a.m. Monday when a New Jersey telecom line used by the FAA was accidentally cut by workers.
Over 600 flights were cancelled at Newark Liberty on Monday. By 10:30 a.m. on Tuesday, approximately 60 flights were cancelled and 70 delayed. Operations were largely back to normal by Tuesday.
The incident exposed vulnerabilities in the US air traffic control network. Congress allocated $12.5 billion last year for system modernisations, with estimated costs for telecommunications improvements rising from $4.75 billion to $5.91 billion. FAA Administrator Bryan Bedford stated that outdated copper lines are expected to be fully replaced by September 2027.