The speed of an airplane is directly impacted by wind speed and direction. Before each flight the pilot gets forecasted wind speed and direction to determine the estimated compass heading and ground speed of the aircraft.
Airspeed is how fast the air is traveling over the airplane. Ground speed is how fast the airplane is traveling over the ground. Ground speed is used to calculate the traveling time.
Flying directly into the wind will cause the ground speed to be slower than the airspeed. If you are flying 100 mph into a 20 mph headwind, your ground speed will be 80 mph.
Flying with a wind from behind will cause the ground speed to be faster than the airspeed. If you are flying 100 mph with a 20 mph tailwind, your ground speed will be 120 mph.
A crosswind from either side of the plane requires the pilot to angle the front of the plane into the wind to keep from drifting off course causing the ground speed to be slower in a direct crosswind.
A sudden change in wind speed and direction will cause the plane to lose or gain airspeed and ground speed instantly.
