B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 200
Distraction; Time Pressure
Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure; Environment - Non Weather Related
I was contacted by the Chief Pilot on Call on (date) about a possible missed preflight check item on an aircraft we flew on (date) and that was discovered by another Crew on (date). The discrepancy had to do with the oxygen system preflight check. We flew the aircraft in question for three legs on (date). I performed the oxygen preflight check each leg (as per our manual) and noticed no discrepancies. It was later discovered by the Crew on (date) that there was a drop in pressure; and they had Maintenance check the system and apparently the oxygen bottle valve was discovered to not be fully open. When I performed my checks on (date); I did not notice any discrepancies. It is possible I was distracted by events during boarding since it was just prior to XXXXXX; however I did the check each leg and noticed nothing wrong. I discussed the check with the Chief Pilot on Call and we talked about the time frame needed for a discrepancy to be seen. I do believe I tested it long enough for it to show up. I will redouble my efforts to make sure that I am testing the system for the required time and keep a closer eye on the pressure gage while performing the test.
[Report narrative contained no additional information.]
An air carrier aircrew flew three legs with an oxygen system bottle not fully opened. The discrepancy was discovered later by another aircrew.