Definition
Small external sensors mounted on the outside of an aircraft that measure local airflow properties — such as air pressure, airflow direction, or angle relative to the oncoming air — and send that data to cockpit instruments or flight computers. In the context of an Angle of Attack (AOA) indicator, probes detect the angle at which air is meeting the wing or fuselage and feed that information to the AOA display.
Plain English
Probes are little sensors sticking out of the aircraft that 'feel' the air as it flows past, and pass what they sense to the instruments inside the cockpit.
Context Anchor
Seen in angle-of-attack indicator discussions and during preflight inspections of exterior sensors.
Derivation
From the Latin 'probare', meaning 'to test' or 'to examine'. A probe is literally something that examines or samples its surroundings — in this case, the airflow around the aircraft.
Why Pilots Care
Reliable probe data lets the pilot know how close the wing is to stalling and supports safe speed and attitude decisions.
Analogy
A probe is like the outdoor sensor for a weather station: it has to be out in the air to measure what is happening there.
Intuition Check
Do not think of a probe as just a pointed object. In this context, a probe is a sensor that measures or samples outside air for an aircraft system.
Example Sentence 1
During preflight, the pilot checked that the AOA probes on the wing were clean, undamaged, and free of obstructions.
Example Sentence 2
Ice forming on the probes gave false angle of attack readings during the climb.