A Boeing 747 (B747), en route from Sydney to Hong Kong, was maintaining flight level 350 (FL350) and had been radar identified by Manila Air Traffic Control. The flight crew observed another aircraft maintaining the same level approximately 20 NM to the east displayed on their aircraft's traffic alert and collision avoidance system (TCAS). The B747 crew sighted the other aircraft as it crossed their track from east to west. The crossing aircraft was en route from Manila to Kuala Lumpur and had initially been assigned FL280.
On first contact with radar control that crew had been instructed to climb to FL350. The controller noted the proximity of the two aircraft and instructed the crew of the B747 to climb immediately to FL370. At the same time the B747 TCAS announced a "Climb" resolution advisory (RA) instruction. The B747 crew complied with the climb instruction. The crew of the crossing aircraft advised the B747 crew that they had received a TCAS RA instruction to descend which they had followed. There was a breakdown of separation. Following an investigation of the occurrence the Republic of the Philippines, Department of Transport and Communications air traffic services investigator reported that all area control centre controllers would undergo radar simulator training to enhance their proficiency. The training was to commence in January 1998.