In nocturnal flight planning, which type of turbulence would remote PICs most likely encounter?

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

Answer: (B)

Mechanical turbulence is the most likely in nocturnal flight planning because wind flowing over terrain, hills, trees, and man-made structures near the ground creates eddies and gusts at low altitude. At night, surface heating is minimal, so convection-driven thermal turbulence is greatly reduced, making clear air turbulence less common for small UAS that stay near the ground. There’s almost always some motion due to terrain and obstacles, so assuming no turbulence isn’t realistic. Focus on stabilizing winds and gusts near surface features and be prepared for wind shear when planning nocturnal operations.