The Weather Hazards Associated With The Us-Bangla Aircraft Accident At The Tribhuvan International Airport, Nepal

Safe flights over the Tribhuvan International Airport (TIA), Kathmandu, Nepal, remain a considerable challenge. Since the airport opened, there have been 13 aircraft accidents during landings and takeoffs that have claimed 392 lives. A detailed understanding and dependable forecast of atmospheric conditions that may develop over the complex terrain of the midhills of central Nepal Himalaya are yet to be achieved. The present study discusses the near-surface atmospheric conditions possibly associated with the most recent fatal crash at TIA on 12 March 2018 as revealed by the Advanced Research version of the Weather Research and Forecasting (WRF-ARW) Model routine forecast. At the time of the accident, two prominent gap winds were converging in the valley, thereby, forming a crosswind and a mix of strong up- and downdrafts over the airfield. As a result, the near-surface atmosphere was significantly turbulent. Unexpected encounters with such turbulent winds are a likely contributor to the fatal crash. This indicates that the knowledge of near-surface atmospheric conditions, critically needed by pilots in advance, for safe operations over the airfield may be generated with WRF-ARW forecasts.