B737-300 crew had low 'a' system hydraulic fluid quantity indication.

Attributes
ACN	548607
Time
Date	200205
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : vhp.vortac
State Reference	IN
Altitude	msl single value : 28000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	548607
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe maintenance problem : improper maintenance non adherence : published procedure non adherence : company policies non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : a system hyd qty indicator other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact other
Consequence	other other
Factors
Maintenance	contributing factor : schedule pressure performance deficiency : training
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Company
Primary Problem	Maintenance Human Performance

Narrative:

Aircraft just released from contract maintenance. Walkaround did not reveal any defects. Once reaching cruise altitude, I noticed 'a' hydraulic system quantity at 1/4 full. Aircraft seemed normal, with no other indications. Talked with maintenance controller and dispatch and concluded it may be an error in the gauge. Reviewed proper checklist and continued to ord. After a non eventual landing and taxi to the gate, ord mechanic told us that the aircraft's wheel well and aft fuselage was a mess with hydraulic fluid. Our checklist for 'a' system quantity low says nothing about secondary indications, ie, hydraulic overtemp or hydraulic pressure low light. We had normal 'a' system pressure and no overtemp indications, as you would think you would have with a true low hydraulic quantity.

Original NASA ASRS Text

Title: B737-300 CREW HAD LOW 'A' SYS HYD FLUID QUANTITY INDICATION.

Narrative: ACFT JUST RELEASED FROM CONTRACT MAINT. WALKAROUND DID NOT REVEAL ANY DEFECTS. ONCE REACHING CRUISE ALT, I NOTICED 'A' HYD SYS QUANTITY AT 1/4 FULL. ACFT SEEMED NORMAL, WITH NO OTHER INDICATIONS. TALKED WITH MAINT CTLR AND DISPATCH AND CONCLUDED IT MAY BE AN ERROR IN THE GAUGE. REVIEWED PROPER CHKLIST AND CONTINUED TO ORD. AFTER A NON EVENTUAL LNDG AND TAXI TO THE GATE, ORD MECH TOLD US THAT THE ACFT'S WHEEL WELL AND AFT FUSELAGE WAS A MESS WITH HYD FLUID. OUR CHKLIST FOR 'A' SYS QUANTITY LOW SAYS NOTHING ABOUT SECONDARY INDICATIONS, IE, HYD OVERTEMP OR HYD PRESSURE LOW LIGHT. WE HAD NORMAL 'A' SYS PRESSURE AND NO OVERTEMP INDICATIONS, AS YOU WOULD THINK YOU WOULD HAVE WITH A TRUE LOW HYD QUANTITY.

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.