Private Pilot License (PPL) Aerodynamics Practice Exam

Which phenomenon directly affects the approach path when landing behind a large aircraft?

1. Wind shear

2. Wake turbulence

3. Thermal currents

4. Cloud cover

The correct answer is: Wake turbulence

Wake turbulence is the correct answer because it refers to the disturbing air that is generated by a large aircraft as it passes through the atmosphere. This turbulence is a byproduct of the lift generated during flight and is particularly significant behind heavy aircraft. When a large airplane takes off or lands, it produces two vortices that descend at a rate of about 300 to 500 feet per minute and can last for a considerable time. For smaller aircraft landing behind a large one, wake turbulence can create hazardous flight conditions. It can induce unexpected changes in airflow, which could lead to loss of control if not properly managed. Pilots are trained to maintain a safe distance and to be aware of the potential for wake turbulence when landing after larger aircraft to ensure that their approach path remains stable and controlled. While wind shear, thermal currents, and cloud cover can also influence flight dynamics and safety, they do not specifically relate to the physical phenomena caused by a preceding large aircraft, making wake turbulence the most pertinent consideration in this scenario.