Which wind direction is indicated by the term "headwind"?

The term "headwind" refers to winds that blow directly opposite to the direction of an aircraft's travel. When an aircraft encounters a headwind, it faces increased resistance, which can affect speed and fuel efficiency. For pilots and flight operations, understanding headwinds is crucial as they can impact takeoff, landing, and overall flight performance by potentially increasing the required runway length for takeoffs and landings and affecting time en route.

In aviation terminology, using "headwind" is an essential part of flight planning, as it allows for better calculations of flight path adjustments and fuel consumption estimations. Recognizing headwinds as opposing forces helps pilots to make informed decisions regarding altitude, speed adjustments, and route planning to enhance safety and efficiency during flight operations.