The bank angle callout comes from the ground proximity and flight warning systems fitted to Boeing airliners, including the 737, where it alerts the crew when roll exceeds a safe limit during flight. The short clipped recording spread through flight simulator videos, aviation forums and meme edits, where creators isolated the voice from cockpit footage. It remains popular because the warning is instantly recognisable to aviation fans yet easy for anyone to understand, making it a reusable punchline for tilting, leaning and loss of control moments.