Cumulonimbus and aviation at this altitude, updraughts with speeds that can exceed . Such an updraught speed corresponds to the wind speed of a small hurricane. The speed can even exceed . The maximum number in the Beaufort scale is 12 ("hurricane force" wind) and is assigned to wind speeds of 64 knots or greater. If the Beaufort scale were extended, these updraughts would have a Beaufort number of 14 "in the vertical direction". The turbulence is then "extreme" at this altitude. Moreover, the diameters of the updraught columns vary between 2 km (air mass thunderstorm) and 10 km (supercell thunderstorm). The height
Full-Scale Wind Tunnel Full-Scale Wind Tunnel The Full-Scale Tunnel (abbreviated FST, also known as the 30-by 60-Foot Tunnel) was a wind tunnel at NASA's Langley Research Center. It was a National Historic Landmark. In 1929, National Advisory Committee for Aeronautics began construction of the world's first full-scale wind tunnel. The design team was led by Smith J. DeFrance. The tunnel was completed in 1931 (dedicated 27 May) at a cost just under $900,000. It was a double-return tunnel capable of moving air at speeds up to 118 miles/hour (190 km/h) through its circuit. It had a 30 ft by 60 ft (9.1 m