A procedural lapse on the part of MServ, a Meralco subsidiary, caused the 37-minute power interruption that occurred at the Ninoy Aquino International Airport (NAIA) Terminal 3 on Friday, a Manila International Airport Authority (MIAA) official said.

In a press briefing, MIAA acting general manager Bryan Co explained that MServ conducted a full electrical audit at NAIA-3 as part of MIAA's improvement initiative at around 7:45 AM.

During the audit, Co said two substations were shut down for testing. However, when airport technicians were about to re-energize the substations, test equipment was left in Substation Roadway No. 2.

“One of MServ crew inadvertently left a test cable na naka-attached [to one of the electric equipment]. So, that caused the power shortage that affected the power system of NAIA terminal 3,” he said.

According to MIAA's acting general manager, they were able to restore the normal Meralco power by 1:29 PM.

“But of course, after we restore our system, some of them have to reboot and repower katulad ng ating air conditioning system na it will take 30 minutes para ma-fully power ang systems natin. Same goes sa Immigration systems and of course, our x-ray system, that’s why there’s a built up of passengers during that time,” he added.

Co said that the personnel behind the procedural lapse would be “dealt with accordingly.”

He apologized to the public for the incident.

Co said no flights were canceled but seven were delayed — 5 domestic flights and 2 international flights.

This is the third time that NAIA encountered a power interruption this year.

On the first day of January, New Year’s day, the Philippine airspace was shut down after a malfunction of air traffic control. A total of 282 flights were either delayed, canceled or diverted to other regional airports, affecting around 56,000 passengers.

The second outage occurred on May 1, Labor Day, which also caused delayed and canceled flights.