The pull up and sink rate calls are standard Mode 1 alerts from the Ground Proximity Warning System fitted to commercial aircraft since the 1970s to warn crews of an excessive descent rate close to the ground. Recordings and simulator recreations of the synthetic voice spread through flight simulator videos, cockpit footage and avgeek communities online. The clip became a reusable shorthand beyond aviation because the wording is self-explanatory and instantly urgent, so creators borrow it for virtual crashes, near misses and any uncontrolled fall.