Plain English Meaning

Small open-ended tubes pointing into the airflow that catch the air rushing at the aircraft. The faster the aircraft flies, the harder that air pushes into the tube, and the airspeed indicator uses that push to show how fast you are going.

Full Definition

Forward-facing tubes mounted on the exterior of an aircraft that capture ram air pressure (the pressure of air being forced into the opening as the aircraft moves forward). This captured pressure is fed to the airspeed indicator, where it is compared with static (still) air pressure to produce an airspeed reading.

Context Anchor

Seen during preflight inspection and in pitot-static system malfunction discussions, especially when checking whether the airspeed indication can be trusted.

Derivation

Named after Henri Pitot, an 18th-century French engineer who invented the device to measure the of flowing in rivers. The same principle — a tube facing into a moving — was later applied to measuring an aircraft's speed through the air.