The phrase comes from the ground proximity warning system fitted to commercial airliners such as the Boeing 737, which monitors height above terrain and issues an urgent aural command when a collision risk is detected. Cockpit recordings and flight simulator footage helped the warning move beyond aviation circles, and editors began lifting the short, unmistakable command for dramatic effect. It remains popular because listeners instantly understand the danger without needing any explanation, making it a compact shorthand for a near miss, a bad decision or a moment that is about to go wrong.