2023 Philippine airspace closure

On January 1, 2023, at 9:49 a.m. Philippine Standard Time (1:50 a.m. UTC), the Civil Aviation Authority of the Philippines (CAAP) detected issues with its Air Traffic Management Center (ATMC) at Ninoy Aquino International Airport (NAIA) in Pasay, Metro Manila. Electrical problems brought the center's radios and radars offline. Shortly after, nearly all flights towards major airports in the Philippine airspace were put on hold or diverted. Flights that were about to enter the Philippine airspace were either diverted to neighboring countries, returned to point of origin, or rerouted to neighboring airspaces. By noon, no commercial aircraft were inside the Philippine airspace. Around 282 flights to and from various Philippine airports and over 56,000 passengers, many of whom were travelling to or from the country following the New Year's Day holiday, were affected.

The electrical problems were traced back to the power substation of NAIA Terminal 3. A cooling fan for one of the ATMC's uninterruptible power supplies (UPS) had failed and a backup power supply did not start, cutting power to the building. As technicians attempted bypass the UPS units to restore power to the ATMC, they triggered an inadvertent overvoltage, which damaged equipment in the center. Service was partially restored at 4:00 p.m. later that day, and fully restored at 7:45 p.m.

The airspace was closed again for two hours on January 22 to replace the broken cooling fan of one of the power supplies. Two more closures were performed on May 3 and May 17, both lasting two hours, to perform upgrades on the ATMC's power supply systems.