Transport Canada Private Pilot License Practice Exam

During descent, winds at higher altitudes are often influenced by the atmospheric conditions, which can lead to variations that cause them to back and decrease in speed. As an aircraft descends, it typically transitions through different layers of the atmosphere, where various factors such as terrain, thermal activity, and the jet stream can affect wind characteristics.

The phenomenon of backing winds — where the wind shifts direction counterclockwise in the Northern Hemisphere, for instance — can occur due to terrain interaction or changes in temperature and pressure as the aircraft approaches lower altitudes. Additionally, winds at higher altitudes tend to be stronger due to less friction with the ground, resulting in a decrease in speed as the aircraft descends to areas with more surface friction. This transition from faster winds at altitude to slower winds near the surface exemplifies the variations that can occur during a descent.

Understanding how wind behavior changes with altitude is crucial for pilots, influencing flight planning, approach strategies, and overall safety.