Flight crew of an medium large transport aborted takeoff due to hydraulic fluid loss.

Attributes
ACN	291601
Time
Date	199412
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Aircraft 1
Controlling Facilities	artcc : rktt
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	291601
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : rejected takeoff other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On dec/xx/94 aircraft, an A-320, arrived at ord for overnight maintenance. A maintenance call was assigned to change a parking brake dual shuttle valve. The valve installed on the aircraft was on loan from air carrier Y. I removed and replaced the valves as per A-320 maintenance manuals. The system was operational checked and gear checked with no problems found. My shift ended before the aircraft departed. On takeoff roll an o-ring failed on the installed valve. Yellow system hydraulic fluid drained from the aircraft and the takeoff was aborted. The aircraft returned to the gate, at which time dayshift mechanics replaced the failed o- ring. The system was tested, found normal and the aircraft continued on revenue service. Very little could be done to avoid the situation. The valve installed was installed in the condition as delivered. No o-rings were disturbed at ord that night. All maintenance manuals were followed. I feel this incident was out of the control of the person/persons involved. I feel there were no other actions available to stop this from happening.

Original NASA ASRS Text

Title: FLC OF AN MLG ABORTED TKOF DUE TO HYD FLUID LOSS.

Narrative: ON DEC/XX/94 ACFT, AN A-320, ARRIVED AT ORD FOR OVERNIGHT MAINT. A MAINT CALL WAS ASSIGNED TO CHANGE A PARKING BRAKE DUAL SHUTTLE VALVE. THE VALVE INSTALLED ON THE ACFT WAS ON LOAN FROM ACR Y. I REMOVED AND REPLACED THE VALVES AS PER A-320 MAINT MANUALS. THE SYS WAS OPERATIONAL CHKED AND GEAR CHKED WITH NO PROBS FOUND. MY SHIFT ENDED BEFORE THE ACFT DEPARTED. ON TKOF ROLL AN O-RING FAILED ON THE INSTALLED VALVE. YELLOW SYS HYD FLUID DRAINED FROM THE ACFT AND THE TKOF WAS ABORTED. THE ACFT RETURNED TO THE GATE, AT WHICH TIME DAYSHIFT MECHS REPLACED THE FAILED O- RING. THE SYS WAS TESTED, FOUND NORMAL AND THE ACFT CONTINUED ON REVENUE SVC. VERY LITTLE COULD BE DONE TO AVOID THE SIT. THE VALVE INSTALLED WAS INSTALLED IN THE CONDITION AS DELIVERED. NO O-RINGS WERE DISTURBED AT ORD THAT NIGHT. ALL MAINT MANUALS WERE FOLLOWED. I FEEL THIS INCIDENT WAS OUT OF THE CTL OF THE PERSON/PERSONS INVOLVED. I FEEL THERE WERE NO OTHER ACTIONS AVAILABLE TO STOP THIS FROM HAPPENING.

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.