What happened
During a nighttime flight originating from Bangkok, the crew initiated their descent toward Phuket Airport under favorable weather conditions. Shortly after receiving clearance to descend to an altitude of 3,000 feet, the pilot notified air traffic control that the DME signal could not be received.
In response to this loss of navigation data, controllers offered the option of performing a VOR approach for runway 09. However, the captain elected to proceed with a visual approach targeting runway 27. While executing the final segment of the approach, the aircraft type impacted an 800-foot hill located roughly 18 km from the runway threshold. The impact resulted in the total destruction of the airframe and caused 11 fatalities among all occupants.
Findings
Investigations into the accident determined that the primary factor was the crew's decision to continue the approach below the minimum descent altitude before the aircraft had safely reached the runway environment.