With its pilot believed to have been suffering from spatial disorientation, Thai Airways Flight 261 crashed in a swamp on approach to Surat Thani Airport, resulting in 101 deaths.

Spatial disorientation is the inability to determine position or relative motion, commonly occurring during periods of challenging visibility, since vision is the dominant sense for orientation. The auditory system, vestibular system, and proprioceptive system collectively work to coordinate movement with balance, and can also create illusory nonvisual sensations, resulting in spatial disorientation in the absence of strong visual cues.

Thai Airways International Flight 261 (TG261/THA261) was a scheduled domestic passenger flight from Bangkok's Don Mueang International Airport to Surat Thani International Airport in Surat Thani, Thailand. The flight was operated by Thai Airways International, the flag carrier of Thailand. On 11 December 1998, the aircraft, an Airbus A310-204 registered in Thailand as HS-TIA, stalled and crashed into a swamp during its landing attempt at Surat Thani Airport. A total of 101 people were killed in the crash.

Surat Thani International Airport is an international airport in Tambon Hua Toei, Amphoe Phunphin, Surat Thani province in Southern Thailand. It is located 21 kilometres (13 mi) west of downtown Surat Thani, and is also home to the Royal Thai Air Force (RTAF) squadrons. It has a single paved runway and is the tenth-busiest airport in Thailand in terms of passengers, handling more than two million passengers annually.