This was bared by Navy flag-officer-in-command Vice Admiral Robert Empedrad in an interview with reporters Tuesday afternoon.
Also, he called the acquisition of the helicopters a "big leap" in the capability of the PN, as it now has the ability to locate submarines passing through the Philippines' sea lanes.
The PN chief added that the AW-159s are considered "top-of-the line" equipment, as these are equipped with sonar for detecting submarines and weapons like torpedoes, which are capable of damaging or even sinking a submarine.
Interesting to see the pair of Philippine Navy AW159s delivered. They represent the maritime nation’s first anti-submarine capability, and will be flown from the Navy’s two new frigates due for delivery in 2021/22. I saw the first of the pair at Yeovil last November @alert5 pic.twitter.com/iA3xt1dBOI— Tom Jones (@athetommyj) May 9, 2019
He added that with the country's vast waters, more anti-submarine helicopters and sonar-equipped naval ships are needed to fully protect it.
Empedrad added that the sonar equipment of the AW-159s will give PN personnel a chance to train and use modern sonar equipment.
The PN chief said that the sonar capabilities of the AW-159 will be further augmented by the proposed upgrades of the three Del Pilar-class offshore patrol vessels, which include the installation of sonar suites.
Empedrad said the helicopters will be placed in Navy service shortly after blessing and commissioning ceremonies in Sangley Point, Cavite this coming May 27, which is also the PN's 121st founding anniversary.
The helicopters arrived in the country on Tuesday and will be based on the two missile-armed frigates Hyundai Heavy Industries is constructing in South Korea.
The two aircraft were acquired for PHP5.4 billion, including munitions, mission essential equipment and integrated logistic support.
The AW-159 can also be armed with rockets, machine guns, missiles, torpedoes and depth charges and has a top speed of 181 miles per hour and a range of 483 miles.