Definition
Onboard systems that warn the pilot of an approaching aerodynamic stall, or in some cases automatically act to prevent one. Common examples include stall warning horns, stall warning lights, aerodynamic stall warning vanes, angle-of-attack indicators, and stick shakers. Some advanced systems also include stick pushers that physically lower the nose if the pilot does not respond to the warning.
Plain English
Equipment in the airplane that alerts the pilot before the wing stops producing enough lift to fly, and on some aircraft takes action on its own to keep the airplane from stalling.
Context Anchor
You encounter this term during slow flight, stall awareness, preflight checks, and discussions of stall warning systems.
Derivation
“Stall” originally means to stop or come to a standstill. In aviation, it does not mean the engine has stopped; it means the wing is no longer making lift normally because the airflow over it has broken down. “Avoidance” points to the purpose of these devices: helping the pilot stay out of that condition.
Why Pilots Care
They reduce the chance of an unintentional stall during critical phases such as takeoff, landing, and maneuvering at low airspeed.
Intuition Check
Do not assume stall avoidance devices prevent a stall by themselves. They warn or guide the pilot; the pilot still has to take the correct action.
Example Sentence 1
During the slow flight maneuver, the stall avoidance device sounded a steady horn as the airplane approached the critical angle of attack.
Example Sentence 2
The instructor demonstrated how the stall avoidance system automatically lowered the nose before a full stall could develop.