Air traffic system outage grounds flights at JFK, LaGuardia and other US airports

The FAA issued ground stops at Philadelphia, Newark, Teterboro and later New York's JFK and LaGuardia after frequency failures at Philadelphia TRACON. The primary circuit failed and a backup fiber line was severed during construction in New Jersey; more than 600 flights were delayed by 1 p.m. ET.

• Failure hit certain frequencies at Philadelphia TRACON handling regional arrivals and departures
• Over 600 flights delayed at Newark and Philadelphia by 1 p.m. ET, about 20% of schedules
• Primary circuit failed and backup fiber was cut during New Jersey construction work
• The GAO published a report on FAA communications vulnerabilities the same day