Aviation Wind Hazard Maps of Tribhuvan International Airport Terminal Maneuvering Area in the Mid-Hills of Nepal Himalaya

Tribhuvan International Airport (TIA), Nepal's principal airport, remained a location of a series of aircraft accidents. The complexity of the topological floor of the Kathmandu Valley and its surroundings, the mid-hills of central Nepal Himalaya, and the associated atmospheric dynamics over the TIA-Terminal Maneuvering Area (TIA-TMA) are difficult for aircraft to negotiate. Indeed, the airport and its immediate surroundings have witnessed 14 aircraft accidents/incidences, eight of which claimed 413 lives. It has raised serious concerns about civil aviation and passenger safety. Early knowledge of wind adversities like low-level wind patterns over the TIA-TMA appears to be a critical component for safe landing and takeoffs. In this study, aviation wind hazard maps for TIA-TMA have been developed, adopting an integrated research approach comprising field observations, pilot surveys, and high-resolution numerical meteorological modeling. The wind hazard maps show the areas over the immediate atmosphere that can be potentially unstable and hence hazardous for aircraft operations concerning head/tail- and cross-winds, wind shear, turbulence, mountain wave excitations, and hydraulic jumps. The improved understanding of wind hazards prevailing over the TIA-TMA can be of significant help in planning as well as in negotiating the possible atmospheric instabilities in and around the airfield.