Definition

1. Noun:
   • The speed of an aircraft relative to the ground: This is the aircraft's actual speed over the earth's surface. It differs from airspeed, which is the speed relative to the surrounding air. Groundspeed is calculated by combining the aircraft's airspeed with the effects of wind.

Usage

• Groundspeed is a technical term used primarily in aviation, navigation, and meteorology. It is a critical measurement for flight planning, calculating fuel requirements, and estimating arrival times.
• It is typically measured in knots, miles per hour, or kilometers per hour.

Examples

• The pilot reported a groundspeed of 450 knots due to a strong tailwind.
• Despite a healthy airspeed, our groundspeed was low because we were flying into a headwind.
• Air traffic control advised the aircraft to reduce its groundspeed for sequencing into the airport.

Advanced Usage

• Groundspeed check: A procedure where a pilot measures groundspeed by timing the aircraft's passage between two known points on the ground.
  • We performed a groundspeed check over the coastline to verify our navigation calculations.

Variants and Related Words

• Airspeed (n): The speed of an aircraft relative to the surrounding air.
• True airspeed (TAS) (n): The airspeed corrected for altitude and non-standard temperature.
• Indicated airspeed (IAS) (n): The speed shown directly on the aircraft's airspeed indicator.

Synonyms

• Speed over ground: A more general nautical and aeronautical term with the same meaning.

Related Phrases

• To make good a groundspeed of...: To achieve or maintain a specific groundspeed.
  • We need to make good a groundspeed of at least 300 knots to arrive on schedule.

Noun

1. the speed of an aircraft relative to the ground