F9 Systems Practice Test

Testing the oxygen system without removing the mask is how preflight checks are typically done. The mask remains in its container so there’s no risk of accidental deployment or damage, and you can verify the system’s readiness using built-in indicators or a designated test switch that confirms oxygen flow. This approach ensures the mask is available and functioning while staying properly stowed for passenger use. Only if the manual or specific procedures explicitly say to remove the mask would you do so; otherwise, standard practice is to keep it in place.