What indicates that the Protective Breathing Equipment (PBE) oxygen is flowing correctly?

The indication that the Protective Breathing Equipment (PBE) oxygen is flowing correctly is represented by a blinking green light. This signal is crucial for crew members to ensure that the PBE system is functioning as intended and that the oxygen supply is active and available for use in emergencies.

The blinking green light serves as a visual assurance that the equipment is operational, providing confidence for the flight crew in high-stress situations where clear communication and effective use of emergency equipment are vital. This readiness is a fundamental part of maintaining safety protocols on board, as proper functioning of the PBE can be critical for crew members in toxic smoke conditions or other hazardous environments.