Flight disruptions ease at Newark and Philadelphia after equipment outage

• On Tuesday, Newark had about 60 cancellations (5% of schedule) and Philadelphia had 30 (2%), down sharply from over 600 Newark cancellations the previous day
• A NJ Transit construction crew accidentally cut a fiber-optic line needed for backup systems at an air traffic control facility; the issue was discovered after the main system failed and switched to the damaged backup
• United Airlines offered flight attendants extra pay to pick up Newark trips to help ease delays, while over 100 incoming flights were diverted to cities including Detroit, Washington D.C., and Boston

Summary: Newark and Philadelphia Airport Disruptions Ease After Equipment Outage

Key Incident:

Flight operations at Newark Liberty International Airport and Philadelphia International Airport improved on Tuesday following severe disruptions caused by a severed fiber-optic cable on Monday, May 12, 2025. A NJ Transit construction crew in central New Jersey accidentally cut a backup fiber cable that provided critical radio and radar feeds to air traffic controllers.

Impact by Numbers:

• Tuesday (Recovery): Newark saw approximately 60 flight cancellations (~5% of daily schedule), while Philadelphia had about 30 cancellations (~2% of schedule) as of 7:10 a.m. ET
• Monday (Peak Disruption): Over 600 flights were canceled at Newark, with more than 100 inbound flights forced to divert to alternative cities including Detroit, Washington D.C., and Boston

Technical Details:

The outage occurred when the main air traffic control system failed and automatically switched to the backup system, which had been unknowingly damaged by the construction crew. The severed line supported the backup radio and radar feeds essential for guiding aircraft.

Company Response:

United Airlines (UAL), which operates a major hub at Newark, offered flight attendants additional compensation to pick up Newark-based trips to help manage ongoing delays and crew scheduling challenges.

Market Implications:

The incident affected thousands of travelers, particularly those on international flights into Newark. While operations normalized within 24 hours, the disruption highlights infrastructure vulnerabilities at critical transportation hubs and potential operational costs for carriers like United Airlines during recovery periods.