WeatherQuestion 72 of 100
The surface wind is 18 knots and you must launch from a ramp immediately downwind of a large metal hangar. What should you expect there?
a.Smooth, steady air because the hangar blocks the wind completely
b.Mechanical turbulence and rolling eddies on the lee side of the hangar
c.A dependable updraft off the roof that improves your climb performance
d.A wind gradient that reverses the wind direction above the roofline
Explanation
Wind flowing over and around a building breaks into rolling eddies and downdrafts on the downwind, or lee, side, and this mechanical turbulence can flip or slam a light sUAS during launch and landing. The stronger the wind and the larger the obstruction, the more violent and further downwind the turbulence extends. An obstruction does not create a wind shadow of truly calm air, and there is no reliable updraft or reversal you could count on for performance.
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