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.
Plain English
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.
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 speed of flowing water in rivers. The same principle — a tube facing into a moving fluid — was later applied to measuring an aircraft's speed through the air.
Why Pilots Care
A blocked or iced-over pitot tube makes the airspeed indicator unreliable or inoperative, which can lead to loss of control in instrument conditions or during critical phases of flight.
Analogy
Think of holding your hand out of a car window. The faster the car moves, the harder the air pushes against your palm. A pitot tube does the same thing, but it measures that push and turns it into an airspeed reading.
Intuition Check
Do not think of pitot tubes as general air vents. They are pressure-sensing openings that must face the airflow to help measure airspeed.
Example Sentence 1
During preflight, the pilot removed the cover from the pitot tube and checked that the opening was clear of insects and debris.
Example Sentence 2
A blocked pitot tube caused the airspeed indicator to remain at zero after takeoff until the pilot applied alternate static and pitot heat.