Senator Grace Poe will hold a hearing on the incident at the Ninoy Aquino International Airport (NAIA) incident on Sunday where a malfunction of the air traffic control system halted flights for nearly seven hours.

In her social media account Monday, Poe said: ''We will conduct an inquiry to find out who is liable and how we can avoid this incident from happening again.''

''This is a national security concern. Thousands of lives depend on the efficiency and competence of CAAP (Civil Aviation Authority of the Philippines),'' added Poe, chairman of the Senate committee on public services.

However, Poe said officials will be given time to restore normal flight operations before a hearing can be scheduled.

Senators Jinggoy Estrada and JV Ejercito assailed the incident. Estrada described it as ''a double black eye.''

Ejercito added that CAAP is the agency in charge. ''They will have a lot of explaining to do,'' he said.

Senator Sherwin Gatchalian said:'' It is unfortunate to see a crisis-like situation such as this at NAIA at a time when demand for air travel in the country has been restored to normal levels.

Senator Nancy Binay said she is ''appealing to the Department of Budget and Management to help in sourcing the needed funds for CAAP so the upgrade and augmentation of the system can start.'' DMS