Airbus A320 exterior oxygen discharge indicator disc (Green Blowout Disc) -
Green frangible disc of crew oxygen
The Airbus A320 exterior oxygen discharge indicator disc / green frangible disc of crew oxygen is a small round disc located on the exterior of the aircraft, typically on Lift side of the fuselage near the front of the plane. The purpose of this disc is to indicate whether the oxygen supply in the aircraft's emergency oxygen system has been discharged or not.
If the oxygen supply in the emergency system is activated, the exterior oxygen discharge indicator disk will blowout, providing a visual indication to the ground crew that the system has been used. This is an important safety feature, as it helps maintenance personnel ensure that the oxygen system has been properly restored after an emergency situation.
It's important to note that the exterior oxygen discharge indicator disc is just one part of the overall emergency oxygen system on an Airbus A320 aircraft.
The crew oxygen system consists of two separated subsystems. The first system supplies oxygen to the Captain (CAPT) and third Occupant (OCCPNT) stations, and the second system supplies oxygen to the First Officer (F/ O) and fourth OCCPNT stations.The equipment with the inlet of each Low Pressure (LP) oxygen-supply solenoid-valve is a part of each of the two oxygen storage sub-systems. For each oxygen storage sub-system, a fully isolated source supply line receives the LP oxygen from the pressure regulator/ transmitter and supplies it to the LP oxygen-supply solenoid-valve.
The LP oxygen-supply solenoid-valve has an electrical shutoff function between the oxygen supply sub-system and the downstream crew distribution sub-system. Each system is mechanically isolated from the other system. Thus, if there is a malfunction in one of the systems, this will not have an effect on the other system.
