A DC10 lost #2 hydraulic system quantity on taxi out. Hydraulic reservoir was previously replaced at...

Attributes
ACN	356963
Time
Date	199612
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	DC-10 10
Operating Under FAR Part	Part 121
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	356963
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	other flight crewa other other : unspecified cockpit
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On dec/xx/96, I changed #2 hydraulic system reservoir because of no head pressure in the reservoir. I replaced #2 hydraulic reservoir per maintenance manual. I leak checked the reservoir and found no leaks, since the pressure at the tank is only 45 psi the leak would take a long time to show. The cause of the leak was the relief and sampling valve that XXX mechanics found leaking. This valve is installed at the shop and is installed completely at the shop. I saw no leaks at the time when I made my check. Also it was raining that night and rain was dripping into the tail cone compartment making a leak very hard to find. Callback conversation with reporter revealed the following information: reporter stated that after changing the #2 hydraulic reservoir in YYY the airplane was flown to XXX with no loss of #2 hydraulic quantity. But on departure from XXX on taxi out the #2 system lost its fluid. Leak was from the relief and sampling valve. This component is not line replaceable and is installed on the reservoir in the overhaul shop. The FAA has not contacted the reporter.

Original NASA ASRS Text

Title: A DC10 LOST #2 HYD SYS QUANTITY ON TAXI OUT. HYD RESERVOIR WAS PREVIOUSLY REPLACED AT SEA.

Narrative: ON DEC/XX/96, I CHANGED #2 HYD SYS RESERVOIR BECAUSE OF NO HEAD PRESSURE IN THE RESERVOIR. I REPLACED #2 HYD RESERVOIR PER MAINT MANUAL. I LEAK CHKED THE RESERVOIR AND FOUND NO LEAKS, SINCE THE PRESSURE AT THE TANK IS ONLY 45 PSI THE LEAK WOULD TAKE A LONG TIME TO SHOW. THE CAUSE OF THE LEAK WAS THE RELIEF AND SAMPLING VALVE THAT XXX MECHS FOUND LEAKING. THIS VALVE IS INSTALLED AT THE SHOP AND IS INSTALLED COMPLETELY AT THE SHOP. I SAW NO LEAKS AT THE TIME WHEN I MADE MY CHK. ALSO IT WAS RAINING THAT NIGHT AND RAIN WAS DRIPPING INTO THE TAIL CONE COMPARTMENT MAKING A LEAK VERY HARD TO FIND. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT AFTER CHANGING THE #2 HYD RESERVOIR IN YYY THE AIRPLANE WAS FLOWN TO XXX WITH NO LOSS OF #2 HYD QUANTITY. BUT ON DEP FROM XXX ON TAXI OUT THE #2 SYS LOST ITS FLUID. LEAK WAS FROM THE RELIEF AND SAMPLING VALVE. THIS COMPONENT IS NOT LINE REPLACEABLE AND IS INSTALLED ON THE RESERVOIR IN THE OVERHAUL SHOP. THE FAA HAS NOT CONTACTED THE RPTR.

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.

A DC10 lost #2 hydraulic system quantity on taxi out. Hydraulic reservoir was previously replaced at sea.