Captain of B727 asks for FL330 as oxygen pressure decreases to zero near las.

Attributes
ACN	445105
Time
Date	199907
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : las.airport
State Reference	NV
Altitude	msl single value : 33000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zab.artcc
Operator	common carrier : air carrier
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 90 flight time total : 5600
ASRS Report	445105
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : company policies non adherence : far non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	other other
Supplementary
Problem Areas	Environmental Factor Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During after takeoff flow, flight engineer noticed oxygen pressure decreasing from 900 psi. Captain was informed at this time. After completing after takeoff flow and checklist oxygen pressure continued to decrease. A short time later, oxygen pressure was 100 psi. Captain 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. Captain elected to continue flight and climbed to FL330. Flight was continued at FL330 for approximately 1 hour. WX, thunderstorm en route. Flight engineer informed captain that insufficient oxygen existed if smoke or rapid depressurization were to occur. If a leak existed, there could be zero oxygen. Captain elected to continue flight and later requested FL250 for duration of flight. Leak was found in oxygen system upon reaching destination. Factors affecting human performance: poor CRM skills, captain appeared to be more concerned about events (personal) taking place in his life. Had already flown 4 plus hours in same aircraft. Wanted to get home. Did not want to delay flight and fix oxygen. Captain tried to explain it away as gauge error. Human factors: after flight engineer expressed concern over low oxygen pressure, captain advised him he would be the sacrificial lamb if there was not enough oxygen to go around.

Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.