If an aircraft has a true airspeed of 180 knots and encounters a headwind of 30 knots, what is its ground speed?

To determine the ground speed of the aircraft when encountering a headwind, you start with the true airspeed and adjust for the effect of the wind. In this scenario, the true airspeed is 180 knots, which represents the speed of the aircraft through the air. However, when there is a headwind, it reduces the effective speed over the ground.

A headwind means that the wind is blowing against the direction of the aircraft's flight, effectively slowing it down. Therefore, to calculate the ground speed, you subtract the headwind speed from the true airspeed.

In this case, you take the true airspeed of 180 knots and subtract the headwind of 30 knots:

Ground speed = True airspeed - Headwind = 180 knots - 30 knots = 150 knots.

This calculation shows that the aircraft’s effective speed over the ground, or ground speed, is 150 knots. This understanding of how winds affect aircraft performance is crucial in air traffic control and aviation operations.