The airport’s navigational grid system that conked out Saturday morning has been repaired, resuming Sunday flights at the Ninoy Aquino International Airport (NAIA) that had been suspended Saturday night.

However, the Civil Aviation Authority of the Philippines (CAAP) extended the Notice to Airmen about the limited operations of the Manila runways until 8 a.m. Monday as the system still needs to undergo reconfiguring and recalibration.

In Malacañang, Deputy Presidential Spokesman Gary Olivar said the Palace was pleased with the news that flights had resumed at the country’s premier airport but admitted that President Arroyo was initially “alarmed” by the faulty pilotguidance system.

The airport’s Very High Frequency Omni Radio Range (VOR) station, which is used to guide pilots land their aircraft during low visibility and bad weather, conked out last Saturday forcing aviation authorities to limit night time operations at the Manila runways.

In a press conference held Sunday noon by Ninoy Aquino International Airport general manager Melvin Matibag, he said that a replacement part was borrowed from the Subic airport and that it arrived in Manila around 3 a.m. Sunday (June 20).

The installation of the power supply took a couple of hours and by dawn, technicians from the CAAP started to power-up the navigation system.

But even with the replacement part installed, the CAAP extended the ‘limited operations’ of the Manila airport up to 6 a.m. Monday (June 21) as technicians still had to reconfigure the entire system.

CAAP technical assistant Lito Casaul explained that the power supply came from a similar but different navigation placement part was borrowed from the Subic airport and that it arrived in Manila around 3 a.m. Sunday (June 20).

The installation of the power supply took a couple of hours and by dawn, technicians from the CAAP started to power-up the navigation system.

But even with the replacement part installed, the CAAP extended the ‘limited operations’ of the Manila airport up to 6 a.m. Monday (June 21) as technicians still had to reconfigure the entire system.

CAAP technical assistant Lito Casaul explained that the power supply came from a similar but different navigation system.

“The technicians cannot just power up the system and go. They have to slowly power up each of the system’s component to check if everything is working properly. If and when the system proves to be ok, they can then begin to reconfigure the unit,” Casaul said.

He said they have extended the Notice to Airmen (NOTAM) they issued Saturday morning to last until 8 a.m. Monday (June 21).

“We extended the NOTAM until Monday to give our technicians enough time to get the system up and running.”

“Hopefully, we can have the system up before sundown so we can resume with normal operations at the two runways,” Casaul said.

With the VOR inoperable, pilots have to rely on Visual Flight Rules (VFR) to land – meaning pilots would have to rely on the radar and other visual aids such as the runway lights in order to see the where to land.

The pilots could have done easily even without VOR and rely on the airport’s Instrument Landing System (ILS) for guidance but unfortunately, the ILS at the NAIA is currently being replaced.

With both the VOR and ILS navigational systems down, the CAAP was forced to implement stricter rules on night landing and made the separations between airplanes much longer apart.

During normal operations--with all the systems running, flight separation between aircrafts are less than one minute. However, with the limited operations Saturday night, airplanes had to be separated by a minimum of five minutes to assure their safety.

At the same time, the CAAP gave the airline companies the discretion if they would allow their pilots to proceed to land at the airport even with the limited navigational aids. Matibag however said that should bad weather come into play, the Manila Control Tower will be forced to deny pilots permission to land.

Matibag said that should zero visibility blanket the airport vicinity, pilots can easily divert to either the Cebu, Clark or Subic airports.

As of 2 p.m. Sunday, a total of 65 flights had already been cancelled.

The affected flights were mostly from Cebu Pacific. A Hawaiian Airlines flight from Honolulu and a Philippine Airlines flight from Fukuoka were diverted to Clark while two PAL flights from Cagayan and Tacloban had to be diverted to Cebu.

Olivar said President Arroyo will have to leave to the next administration the maintenance of the airport safety operations.

“Of course, the President was alarmed as all of us should have been. It was a good thing that the problem was solved immediately. The equipment was fixed to facilitate the night flights,” Olivar said in his weekly media briefing aired over state-run radio Sunday.

Olivar said they expect airport authorities to address any problem in the navigational equipment to ensure smooth operations at the international airport.

“We expect that under former airport general manager Al Cusi, now head of the CAAP (Civil Aviation Authority of the Philippines), will be able to give quick appropriate solution to this problem,” he said.