Accident
A seaplane departed Sangley Point Air Force Base during the day for a maritime patrol flight. En route, an engine failure occurred. The crew contacted their base, canceled the mission, and elected to return to Sangley Point AFB. While flying back with one engine inoperative in poor weather conditions, the aircraft struck the slope of Mount Mariveles, located 53 kilometers west of Manila. All 13 crew members on board were killed.
Cause
The official investigation determined the probable cause of the accident to be engine failure and low visibility caused by poor weather conditions.