Power outage and the ensuing power surge when the electricity was restored were traced as the reasons behind the technical glitch on the air traffic management system at the Ninoy Aquino International Airport (NAIA) on Sunday, Jan. 1, which affected around 65,000 passengers from almost 300 domestic and international flights.
Department of Transportation (DOTr) Secretary Jaime Bautista said the technical glitch on the Air Traffic Management Center (ATMC) under the Civil Aviation Authority of the Philippines (CAAP) also affected the flight operations in other airports across the country, particularly from the international airports in Davao City, Cebu and Clark.
"The primary cause identified was a problem with the power supply and the degraded uninterrupted power supply which had no link to the commercial power and had to be connected to the latter manually," said Bautista in a press briefing on Sunday night.
"The secondary problem was the power surge which resulted in the power outage affecting the equipment," he added.
According to Bautista, the two incidents shut down the ATMC due to internal power outage which resulted in loss of communication, radio, radar, and internet.
The ATMC went down at 9:49 a.m. on Sunday but the CAAP said the operation was fully restored at 7:45 p.m.
"We acknowledge and apologize for any inconvenience brought by the incident, and assure the public that DOTr, with CAAP, MIAA (Manila International Airport Authority), and other airport stakeholders, are working tirelessly to safely bring all affected passengers to their respective destinations. We graciously appeal for everyone’s patience and understanding," said Bautista.
What went wrong
Following the power outage and the ensuing power surge after the restoration, almost all of the communication at the CAAP-run ATMC went down as a result.
The ATMC, or the Air Traffic Management Center, serves as the facility for controlling and overseeing all inbound and outbound flights and overflights within the Philippine airspace.
CAAP Director General Manuel Tamayo explained that power supply is not actually the main issue since they have two major sources of electricity to run the operations at NAIA--the commercial electricity from the Manila Electric Company (Meralco) and the standby generator which has the capability of operating the equipment 24/7.
The problem, he said, was that the power outage and the ensuing power surge affected the equipment being used by the NAIA for Communication, Navigation and Surveillance/Air Traffic Management, or the CNS/ATM.
The operation of the CNS/ATM primarily depends on the commercial power supply and is backed up by standby generators, which actually form part of the uninterrupted power supply (UPS) design supposedly to ensure that the entire operation would not fail.
"What happened is that when one of the power sources failed (as a result of the power outage), both the supply from the commercial and standby generator eventually did not power the system," said Tamayo.
Tamayo said that trouble shooting had to be done and the initial result revealed that one of the blowers of the UPS gave out a warning and eventually conked out. It happened at 9:49 a.m.
"Supposedly, there should be no problem because it is supposed to be fail-safe due to two UPS systems. But for one reason or another, the other UPS did not come online so troubleshooting had to be done," said Tamayo.
He said CAAP personnel then bypassed the UPS that conked out to reconnect the supply from the standby generator. This resulted in the restoration of the system.
But at 12:18 p.m., Tamayo said CAAP personnel monitored an indication of over-voltage: "So instead of getting 220 volts, what came in was 380 volts so immediately they shut down the system to avoid further damage to the equipment."
"Unfortunately, there was already damage in the affected system and the worst was that it affected our VSAT.
VSAT stands for very small aperture terminal and is a two-way ground station that transmits and receives data from satellites.
"The VSAT is located outside of the air traffic system. This is the disc that serves as a receiver for the satellite or communication navigation and all the necessary data that we require," said Tamayo.
Gradual restoration
Troubleshooting had to be done again and at 4:18 p.m. Tamayo said they were able to restore the CNS or the Communication, Navigation and Surveillance.
It was then that the CAAP announced that the system was partially restored which led to limited operations at the NAIA.
Normal operations resumed as of 5:50 p.m. while equipment restoration is still ongoing.
At 7:45 p.m., Tamayo said the glitch was fixed and the operations at the NAIA were fully restored.