Definition
An audible alerting device installed in an aircraft that sounds when a specific unsafe or abnormal condition is detected, such as the landing gear not being down and locked when the throttle is retarded, an approaching stall, or excessive cabin altitude. The horn draws the pilot's attention to a condition that requires immediate action.
Plain English
A loud horn in the cockpit that goes off when something is wrong and the pilot needs to notice it right away.
Context Anchor
Pilots encounter warning horns during cockpit checks, takeoff and landing, slow flight, and any situation where the aircraft system is designed to give an audible alert.
Derivation
“Warning” comes from an old word meaning to give notice of possible danger. “Horn” originally referred to an animal horn used as a loud signaling device, and later to any device that makes a loud alerting sound. Together, “warning horn” means a sound-making device that gives notice of a possible unsafe condition.
Why Pilots Care
The horn provides an immediate, unmistakable alert that draws attention to situations that could lead to loss of control or an accident if ignored.
Intuition Check
A warning horn is not a communication horn or a general noise maker. In aviation, it is an automatic cockpit alert tied to a specific aircraft condition.
Example Sentence 1
When the pilot reduced the throttle on final approach without lowering the gear, the warning horn sounded.
Example Sentence 2
On final approach the pilot heard the warning horn and realized the landing gear had not extended.