What happened
During a scheduled route check flight for a captain, a Boeing 737 was performing an ILS approach to runway 05. While the en route portion of the flight proceeded without incident, complications arose during the approach phase. As the aircraft emerged from the cloud layer, the controller noted that the flight was following an Airbus A319.
Conflicting instructions were issued to air traffic control regarding the flight path. While the pilot flying indicated an intention to execute a 360-degree maneuver, the pilot monitoring communicated a different plan, stating the aircraft would turn right rather than following the prescribed missed approach procedure, which required a left turn to a heading of 020 degrees.
Following this maneuver, the aircraft entered the clouds again. Instead of climbing to the required altitude of 4,000 feet, the crew attempted to maintain visual flight at a lower altitude despite being in instrument meteorological conditions. The flight then requested and received permission to perform a VOR/DME approach to runway 23, the opposite direction.
During this subsequent approach, the aircraft descended significantly below the established glide path. At a location where the altitude should have been 1,500 feet, the aircraft had descended to 570 feet. The Boeing 737 subsequently struck a hillside within a coconut plantation in Barangay San Isidro. The impact caused the aircraft to disintegrate and ignite, resulting in 131 fatalities.