Cathay Pacific A333 flight CX755 near Bangkok, smoke in cockpit and cabin

A Cathay Pacific Airbus A330-300, registration B-HLW performing flight CX-755 from Hong Kong (China) to Bangkok (Thailand), was descending towards Bangkok when smoke appeared in cockpit and cabin prompting the flight crew to don their oxygen masks and declare emergency, the crew worked the related checklists which seemed to reduce the smoke. The aircraft continued for a safe landing on Bangkok's runway 19R and stopped on the runway, as the smoke was dissipating the crew decided to not evacuate. The passengers disembarked normally. All crew were taken to a hospital for medical checks and discharged after.

The aircraft remained on the ground for 11.5 hours, then departed for the return flight CX-754 and reached Hong Kong with a delay of 10.5 hours.

Maintenance found an air conditioning pack had failed and overheated resulting in the smoke. 

The Aviation Herald