Oxygen System [Question Bank Airbus A320]

1. What type of Oxygen system is present in Airbus A320 Aircraft?

A320 Oxygen System consists of:

Cockpit Fixed Oxygen System Cabin Fixed Oxygen System Portable Oxygen System

This is diluter demand type system where compressed oxygen is stored in cylinder/s. Oxygen flow can be controlled as per crew requirements. Pressure of oxygen cylinder/s is checked before every flight to ensure sufficient oxygen is available before flight.

This includes chemical oxygen generators for cabin crew and passengers. In chemical oxygen generators oxygen is generated by chemical reactions. Once this system is activated it can not be stopped unless complete oxygen in discharged. Chemical oxygen generator system does not need much technical knowledge so is easy for passengers’ usage. Portable Oxygen System is provided in both the cockpit and the cabin. As the name suggest it is easy to carry. Again like cabin fixed oxygen system this is also one time use type. PBE – Portable Breathing Equipment is common term for this. It can be used for protection of crew during on board emergencies and for first aid purposes.

2. What does SYS ON light on OXY panel indicate for Airbus A320 aircraft?

SYS ON light on OXY panel indicates when control for oxygen mask doors is activated.

3. What does half amber box on OXY pressure on DOOR/OXY page of Airbus A320 aircraft indicates?

On ground half amber frame appears on OXY pressure on DOOR/OXY page when oxygen pressure is below certain defined level. This level varies as per MSN numbers. This is an indication to check if the oxygen in sufficient from limitations section of Airbus A320 FCOM.

4. What is indicated by a missing green thermal plug during an exterior preflight of Airbus A320 aircraft?

Missing green thermal plug indicates oxygen system over pressure and/or thermal discharge.

5. Is it true that by switching off “CREW SUPPLY” p/b OFF, the oxy pressure is still available on DOOR/OXY Page of Airbus A320 aircraft?

When CREW SUPPLY push button is OFF on overhead panel Oxygen Pressure is displayed amber on ECAM DOOR/OXY PAGE.

6 When does passenger oxygen flow start from chemical oxygen generators for Airbus A320 aircraft?

Oxygen flow starts from chemical oxygen when passenger pulls the mask towards the seat.

7. At what cabin altitude do passenger oxygen masks drop for Airbus A320 aircraft?

Passenger Oxygen Masks automatically drop when cabin altitude exceed 14,000ft.

8. What is the main difference between the crew and passenger/cabin oxygen system of Airbus A320 Aircraft?

Crew Oxygen System is diluter demand type while passenger/cabin oxygen system is chemical reaction time. Crew Oxygen System can be refilled as and when required while passenger/cabin oxygen system is one type use system.

9. When does OXY high pressure indication pluse in green and amber for Airbus A320 aircraft?

This indication is MSN specific. Please review relevant FCOM.

10. What is reset, when you press RESET/TEST control to RESET position on cockpit crew oxygen system stowage box Airbus A320?

Pressing the RESET control slide, after the oxygen mask has been used, cuts off the oxygen, and the mask microphone.

11. What does yellow blinker on Airbus A320 aircraft cockpit crew oxygen system stowage box indicate?

Yellow blinker indicates the flow of Oxygen. Indicator flashes when when oxygen flows through the system.

12. How long do chemical oxygen generators supply oxygen for Airbus A320 aircraft?

Chemical oxygen generators supply oxygen for 13 to 22 min. depending on the installation type.

13. What is the purpose of CREW SUPPLY push button on overhead panel of Airbus A320 Aircraft?

CREW SUPPLY pb controls the solenoid valve . When in ON position, valve open to supply low pressure oxygen to mask. In off position, valve is closed and white light comes on at push button.

14. What is ECAM indication for “CREW SUPPLY” p/b OFF position for Airbus A320 aircraft?

When CREW SUPPLY push button is OFF on overhead panel Oxygen Pressure is displayed amber on ECAM DOOR/OXY PAGE.

15. What is the duration of oxygen flow in PBE of Airbus A320 aircraft?

PBE supplies oxygen for approx 15 minutes.

16. What is the use of EMERGENCY pressure selector on cockpit crew oxygen system stowage box Airbus A320?

Selection of EMERGENCY pressure selector creates over-pressure of oxygen in mask . This helps in eliminating condensation or fogging. Also over-pressure helps in protection against smoke or ashes entering the mask.

  • pressing this knob generates temporary over pressure
  • turning of knob generates permanent over pressure

This over pressure supply is available only when N/100% selector is set on 100% position.

17. What is difference between N/100% selector positions on cockpit crew oxygen system stowage box Airbus A320?

In 100% position mask delivers 100% oxygen and in N position mask provides mixture of air and oxygen.

18. What does “OXY ON” flag indicate on cockpit crew oxygen system stowage box Airbus A320?

OXY ON flag shows that oxygen supply to mask has started. First indication of OXY ON appears when left flap door opens. When after usage, stowage panel door is closed, OXY ON flag still appears until reset push button is pressed.