air-speed indicator

The pilot checks the air-speed indicator during the flight.

Definition

Noun: An instrument in an aircraft that measures and displays the speed of the aircraft relative to the air through which it is moving.

Usage Examples

Advanced Usage

"airspeed" vs. "ground speed": The air-speed indicator shows speed relative to the air, not the ground. Wind can cause a difference.
- The air-speed indicator read 150 knots, but the ground speed was only 130 knots due to a headwind. (The instrument shows airspeed, not ground speed.)
Pitot-static system: The air-speed indicator relies on the pitot tube and static ports to measure dynamic and static air pressure.
- If the pitot tube is blocked, the air-speed indicator will give an incorrect reading. (The instrument's accuracy depends on the pitot-static system.)

Variants and Related Words

Airspeed (n): The speed of an aircraft relative to the air.
- The airspeed was 200 knots. (The speed through the air.)
Indicator (n): A device that shows information.
- The fuel indicator showed half a tank. (A gauge displaying data.)

Synonyms

Airspeed gauge: Another term for the same instrument.
Airspeed meter: A less common synonym, especially in older aviation contexts.

Related Idioms

"Needle on the air-speed indicator": A phrase used metaphorically to mean a critical measurement or gauge.
- In business, keeping an eye on the needle on the air-speed indicator means monitoring key performance metrics. (A figurative use of the instrument as a symbol of essential data.)

Phrasal Verbs

"Read off": To take a reading from the air-speed indicator.
- The co-pilot read off the air-speed indicator and reported 180 knots. (To obtain and state the measurement.)

Additional Notes

The air-speed indicator is a critical flight instrument, typically part of the "six-pack" of basic flight instruments in an aircraft cockpit. It is essential for safe flight operations, especially during takeoff, landing, and maneuvering.