At night, remote PICs should expect:

At night, remote PICs should expect:

• A. Clear air turbulence
• B. Thermal turbulence
• C. Mechanical turbulence
• D. No turbulence

Answer: (C)

At night the surface cools and convection diminishes, so thermal turbulence from daytime heating is greatly reduced. Clear air turbulence is something you typically encounter at higher altitudes and near jet streams, not as a routine nighttime condition near the surface. The turbulence you’re most likely to face during nighttime operations is mechanical turbulence, produced by wind interacting with the Earth's surface and obstacles like hills, trees, and buildings. So, even with a stable nocturnal atmosphere, wind shear and friction over terrain create fluctuating air movements that affect small UAS, making mechanical turbulence the expected condition.

At night the surface cools and convection diminishes, so thermal turbulence from daytime heating is greatly reduced. Clear air turbulence is something you typically encounter at higher altitudes and near jet streams, not as a routine nighttime condition near the surface. The turbulence you’re most likely to face during nighttime operations is mechanical turbulence, produced by wind interacting with the Earth's surface and obstacles like hills, trees, and buildings. So, even with a stable nocturnal atmosphere, wind shear and friction over terrain create fluctuating air movements that affect small UAS, making mechanical turbulence the expected condition.