CAPT OF B727 ASKS FOR FL330 AS OXYGEN PRESSURE DECREASES TO ZERO NEAR LAS.

Narrative

DURING AFTER TKOF FLOW; FE NOTICED OXYGEN PRESSURE DECREASING FROM 900 PSI. CAPT WAS INFORMED AT THIS TIME. AFTER COMPLETING AFTER TKOF FLOW AND CHKLIST OXYGEN PRESSURE CONTINUED TO DECREASE. A SHORT TIME LATER; OXYGEN PRESSURE WAS 100 PSI. CAPT WAS INFORMED IN BOTH CASES. CIRCUIT BREAKER WAS CYCLED AND WENT TO 'O PSI.' CIRCUIT BREAKER WAS PUSHED BACK IN AND GAUGE WENT BACK TO 100 PSI. CAPT ELECTED TO CONTINUE FLT AND CLBED TO FL330. FLT WAS CONTINUED AT FL330 FOR APPROX 1 HR. WX; TSTM ENRTE. FE INFORMED CAPT THAT INSUFFICIENT OXYGEN EXISTED IF SMOKE OR RAPID DEPRESSURIZATION WERE TO OCCUR. IF A LEAK EXISTED; THERE COULD BE ZERO OXYGEN. CAPT ELECTED TO CONTINUE FLT AND LATER REQUESTED FL250 FOR DURATION OF FLT. LEAK WAS FOUND IN OXYGEN SYS UPON REACHING DEST. FACTORS AFFECTING HUMAN PERFORMANCE: POOR CRM SKILLS; CAPT APPEARED TO BE MORE CONCERNED ABOUT EVENTS (PERSONAL) TAKING PLACE IN HIS LIFE. HAD ALREADY FLOWN 4 PLUS HRS IN SAME ACFT. WANTED TO GET HOME. DID NOT WANT TO DELAY FLT AND FIX OXYGEN. CAPT TRIED TO EXPLAIN IT AWAY AS GAUGE ERROR. HUMAN FACTORS: AFTER FE EXPRESSED CONCERN OVER LOW OXYGEN PRESSURE; CAPT ADVISED HIM HE WOULD BE THE SACRIFICIAL LAMB IF THERE WAS NOT ENOUGH OXYGEN TO GO AROUND.