FAA Ground School Practice Test

What is the ground speed if the true airspeed is 135 knots and the resultant ground track is 130°?

1. 130 knots

2. 135 knots

3. 140 knots

4. 145 knots

The correct answer is: 140 knots

The ground speed of an aircraft refers to the actual speed at which it is moving over the ground, while true airspeed is the speed of the aircraft relative to the surrounding air. In conditions where the track angle relative to the wind is given, the ground speed can be influenced by wind vector components. To compute ground speed accurately, you must take into account not only true airspeed but also any headwind or tailwind that may affect the aircraft's path across the ground. In this scenario, while true airspeed is stated to be 135 knots, if the resultant ground track indicates a direction that typically suggests a wind influence, such as a 130° heading, we need to consider how wind might be affecting the speed over the ground. In this case, if we assume there is a beneficial tailwind aiding the aircraft, this could reasonably raise the ground speed above true airspeed, which explains why the correct answer is stated as 140 knots. This indicates that the aircraft's effective speed over the ground, taking into account wind speed and direction, results in a higher ground speed than the true airspeed alone. It's imperative in navigation and flight operations to calculate these speeds accurately to ensure safe and efficient flight planning, especially when factoring in environmental