A319
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 120; Flight Crew Total 11300; Flight Crew Type 9100
Other / Unknown
Aircraft Equipment Problem Critical
Air Traffic Control Issued New Clearance; General Declared Emergency
Aircraft; Human Factors
During descent; I completed my routine system check via ECAM. The crew oxygen level was 270 PSI. During preflight; it was 1;280 PSI. The minimum is 550 PSI with no jump seaters. We had not used oxygen during the flight. We used the QRH which directed us to descend to 10;000 feet or the MSA if higher. We declared an emergency with ATC and Center descended us to 15;000 feet which was the MSA at that point. Once clear of the mountains; Approach Control descended us to 10;000 feet. Once I had declared the emergency; I informed Dispatch. He asked if he wanted to get Maintenance on the line and I said we were already close so it was not necessary. We elected to continue because it was so close and we were over the mountains as it was. I informed the lead Flight Attendant about our situation and briefed the passengers that there would be emergency equipment by the runway as a matter of standard routine but no need to worry. The rest of the approach was uneventful. We elected not to bring up emergency O2 bottles because we were already close to landing and the QRH said it was optional.
Just prior to top of descent after the briefings were completed; the Captain noticed the crew oxygen was 270 PSI. The QRH was completed and a descent to MSA was completed. Further descent was completed to 10;000 feet. The Captain declared an emergency and the flight landed without incident. I do not recall any deviations or errors from FAR's and SOP. During the preflight the oxygen was 1;260 PSI.
A319 Captain discovers low crew oxygen pressure during descent and elects to declare an emergency with ATC to expedite the descent. A normal landing ensues. Pressure had been normal during preflight.