Aircraft have horns, although they may seem unusual for vehicles that don’t encounter traffic. These horns are not used during flight but serve a purpose on the ground, especially during maintenance or while in a hangar.
The main use of an aircraft’s horn is to get the attention of ground engineers. It allows them to communicate with the ground crew via a headset and intercom system when they are working in the cockpit.
The sound produced by an airplane’s horn is different from a car horn; it’s more like an alarm. KLM Airlines once described it as resembling the passing of three steamboats under the plane when the button is pressed.
Unlike car horns, which are mainly used as warnings, aircraft horns have practical functions. They can signal engineers about system issues or the presence of a fire.
Importantly, during flight, the aircraft horn is turned off to avoid distractions and unnecessary noise in the cockpit.