Thai Airways International Flight 311 was a scheduled service from Bangkok, Thailand to Kathmandu, Nepal, which tragically ended in disaster. On its final approach to Tribhuvan International Airport, the flight encountered the challenging mountain terrain of the Himalayas coupled with adverse weather conditions, including low visibility and heavy rain. The Boeing 767 aircraft was carrying 99 passengers and 14 crew members. As it attempted to land in the difficult mountainous region, the flight deviated from its approach path, ultimately crashing into a mountain located just four miles from the airport. The aircraft disintegrated upon impact, resulting in the death of all individuals on board.

Investigations following the disaster revealed that the crew had not adequately prepared for the specific challenges posed by the airport's location. The steep mountains surrounding Kathmandu require pilots to possess unique skills and insights into the weather conditions. Safety improvements in procedures and aircraft requirements were among the recommendations made after the investigation was concluded. This incident raised significant concerns regarding airline safety in Nepal, a country known for its challenging flying conditions due to its topography.

The grounding of Thai Airways flights to Kathmandu followed the crash, as the airline sought to reevaluate its operations in the region. The incident became a stark reminder of the potential dangers associated with air travel in mountainous areas, leading to enhanced regulatory scrutiny and improved pilot training in similar environments. Over the years, it catalyzed discussions about flight safety protocols and risk factors associated with flying in challenging geographical locales.