MANILA, Philippines – At least 38 domestic flights and 21 international flights were delayed, and 3 flights were canceled, due to “software issues” affecting the Air Traffic Management Center on Monday, May 20.

The Civil Aviation Authority of the Philippines (CAAP) said that, at around 11:30 am, a software issue was discovered with the air traffic management system’s flight data processing system (FDPS), which processes flight plan information used for air traffic control. This system covered flights operations in the country’s main international airport, the Ninoy Aquino International Airport (NAIA).

“During the course of the assessment, personnel discovered that the FDPS was unable to send flight data to the controller workstations as expected. This issue impacted traffic flow in and out of Manila,” CAAP said in a statement released at 10 pm on Monday.

Although the communications, navigation, and surveillance equipment used in air traffic operations remained operational, CAAP decided to increase separation intervals for departing flights to approximately 10 minutes as a safety measure.

CAAP managed to restore the FDPS to full operation by 1:40 pm. However, the disruption caused by the technical glitch had already affected dozens of flights. 

Here is the list of flights delayed and canceled on Monday, as of 8:20 pm.

Consequential delays, cancellations

Besides flights directly affected by the issue, local airlines reported several more flight delays and cancellations as they attempted to normalize operations.

The Manila International Airport Authority, which operates NAIA, said that it would keep the airport’s runways open for 24 hours straight to facilitate airline flight recovery operations.

Passengers are advised to check with their airline’s social media platforms and websites for timely updates.

Cebu Pacific has announced the cancellation of 13 flights, explaining that it “will take some time normalize,” especially as some destination airports are subjected to sunset limitations. Here are the cancelled flights:

• 5J 389/390: Manila – Cagayan De Oro – Manila
• 5J 455/456: Manila – Iloilo – Manila
• 5J 487/488: Manila – Bacolod – Manila
• 5J 557/558: Manila – Cebu – Manila
• 5J 955/956: Manila – Davao – Manila
• DG 6839/6840: Manila – Siargao – Manila
• 5J 647/648: Manila – Puerto Princesa – Manila
• 5J 651/652: Manila – Tacloban – Manila
• 5J 653/654: Manila – Tacloban – Manila
• 5J 746/747: Manila – Hanoi – Manila
• 5J 759/760: Manila – Jakarta – Manila
• 5J 773/774: Manila – Pagadian – Manila
• 5J 915/916: Clark – Boracay – Clark

Philippine Airlines also said that it had to cancel the following domestic flights even as its flight operations were “normalizing” after the disruption caused by the software issue:

• PR 2135/2136: Manila – Bacolod – Manila
• PR 2045/2046: Manila – Caticlan – Manila
• PR 2043/2044: Manila – Caticlan – Manila
• PR 2823/2824: Manila – Davao – Manila

CAAP has apologized for the disruption and said that “similar incidents in the future can be prevented once the ongoing upgrade to the [Communications, Navigation, and Surveillance/Air Traffic Management] system is completed to enhance its self-detection capabilities for such issues.”

A technical issue with CAAP’s air traffic management system also temporarily shut down Philippine airspace for hours on January 1, 2023, affecting the flights of more than 78,000 passengers. (READ: What caused the January 1 air traffic mess and what should be done about it?) – Rappler.com