ground speed
Definition
- Noun:
- Speed relative to the ground: "ground speed" is the speed of an aircraft relative to the surface of the Earth, as opposed to its speed through the air (airspeed). It is calculated by combining airspeed with wind speed and direction.
Usage Examples
- (The aircraft's speed over the Earth's surface was 500 nautical miles per hour.)
- (The wind blowing against the aircraft slowed its progress over the ground.)
Advanced Usage
"to have good ground speed": to maintain a high speed relative to the ground, often due to favourable winds.
- The flight had excellent ground speed thanks to a strong tailwind. (The aircraft moved quickly over the Earth because the wind was pushing it from behind.)
"ground speed check": a verification of the aircraft's speed over the ground, often using GPS or navigation instruments.
- The navigator performed a ground speed check to confirm the estimated time of arrival. (The navigator measured the speed relative to the ground to update the schedule.)
Variants and Related Words
Ground (n): the solid surface of the Earth.
- The plane touched the ground smoothly. (The aircraft landed on the Earth's surface.)
Speed (n): the rate at which something moves.
- The car reached a high speed on the highway. (The vehicle moved quickly.)
Synonyms
- Over-the-ground velocity: a technical term for the speed of a moving object relative to the Earth's surface.
- True ground speed: a precise term often used in navigation to distinguish from indicated or calibrated airspeed.
Antonyms
- Airspeed: the speed of an aircraft relative to the air around it.
- The airspeed was 450 knots, but the ground speed was only 400 knots due to a headwind. (The speed through the air was higher than the speed over the ground.)
Related Idioms
- "to make good ground speed": to travel quickly relative to the Earth, often used in aviation or sailing.
- With the current behind us, we made good ground speed. (We moved fast over the ground because the water or wind was pushing us.)