B737-300 flight crew refused aircraft for APU which had been inoperative for days. Shortly thereafte...

Narrative:

On arrival; we noticed aircraft had APU inoperative for about 6-7 days. We opted to refuse aircraft. Line maintenance called and tried to 'talk' me into taking this aircraft with APU inoperative. Said will be fixed within 10 day requirement. Said; 'we will have to leave 25 passenger behind if you refuse aircraft' (trying to guilt me into taking broken aircraft). Again I refused. As aircraft assigned for our flight arrived (approximately XA30...XA55 departure) we met aircraft and discovered the same aircraft. Called operations and fodm and explained not taking aircraft. While sitting in boarding area waiting to discover where we were going; the departure screen above csr's changed from 'delayed' to 'now boarding.' stunned I approached csr's to discover what changed. Ramp control said maintenance called and aircraft fixed. We went down and mrd was still old/no maintenance personnel onboard/no paperwork explaining fix. Called again; told 'paperwork all there.' I stated; 'no it isn't;' and further I directed that no boarding until I know what is going on here (this aircraft magically fixed at XA45 when maintenance said no parts and 10-12 hour fix). A mechanic arrived to explain his discovery. 1) the APU is fine. Clean; no leaks and working perfectly. 2) the hydraulic leak preview written up was valid (residue fluid) but the leak was either fixed (and no paperwork generated) or self-sealed? My copilot and I verified no continued or new hydraulic leaks so we believed this mechanic. This mechanic said there is a distinctive odor difference between hydraulic fluid and engine oil. Said he cannot begin to explain how this error ever occurred. To state that it is possible that maintenance 'missed' this fluid source is absolutely inconceivable as if the APU had been checked it would've been noted as clean and not the source. The issue here is not an inoperative APU for 6+ days nor even the hydraulic leak. Nor even the fact that someone screwed this up either intentionally or not. The issue is that the true source of this errant hydraulic fluid was never discovered (at least not on paper). Whether self-induced pressure or pressured from 'above' (which can create self-induced) the bottom line is our safety of flight has been compromised.

Original NASA ASRS Text

Title: B737-300 FLT CREW REFUSED ACFT FOR APU WHICH HAD BEEN INOP FOR DAYS. SHORTLY THEREAFTER; THE ACFT WAS RELEASED BY MAINT. THE APU WAS INSPECTED AND NO DEFECT WAS FOUND.

Narrative: ON ARR; WE NOTICED ACFT HAD APU INOP FOR ABOUT 6-7 DAYS. WE OPTED TO REFUSE ACFT. LINE MAINT CALLED AND TRIED TO 'TALK' ME INTO TAKING THIS ACFT WITH APU INOP. SAID WILL BE FIXED WITHIN 10 DAY REQUIREMENT. SAID; 'WE WILL HAVE TO LEAVE 25 PAX BEHIND IF YOU REFUSE ACFT' (TRYING TO GUILT ME INTO TAKING BROKEN ACFT). AGAIN I REFUSED. AS ACFT ASSIGNED FOR OUR FLT ARRIVED (APPROX XA30...XA55 DEP) WE MET ACFT AND DISCOVERED THE SAME ACFT. CALLED OPS AND FODM AND EXPLAINED NOT TAKING ACFT. WHILE SITTING IN BOARDING AREA WAITING TO DISCOVER WHERE WE WERE GOING; THE DEP SCREEN ABOVE CSR'S CHANGED FROM 'DELAYED' TO 'NOW BOARDING.' STUNNED I APCHED CSR'S TO DISCOVER WHAT CHANGED. RAMP CTL SAID MAINT CALLED AND ACFT FIXED. WE WENT DOWN AND MRD WAS STILL OLD/NO MAINT PERSONNEL ONBOARD/NO PAPERWORK EXPLAINING FIX. CALLED AGAIN; TOLD 'PAPERWORK ALL THERE.' I STATED; 'NO IT ISN'T;' AND FURTHER I DIRECTED THAT NO BOARDING UNTIL I KNOW WHAT IS GOING ON HERE (THIS ACFT MAGICALLY FIXED AT XA45 WHEN MAINT SAID NO PARTS AND 10-12 HR FIX). A MECH ARRIVED TO EXPLAIN HIS DISCOVERY. 1) THE APU IS FINE. CLEAN; NO LEAKS AND WORKING PERFECTLY. 2) THE HYD LEAK PREVIEW WRITTEN UP WAS VALID (RESIDUE FLUID) BUT THE LEAK WAS EITHER FIXED (AND NO PAPERWORK GENERATED) OR SELF-SEALED? MY COPLT AND I VERIFIED NO CONTINUED OR NEW HYD LEAKS SO WE BELIEVED THIS MECH. THIS MECH SAID THERE IS A DISTINCTIVE ODOR DIFFERENCE BTWN HYD FLUID AND ENG OIL. SAID HE CANNOT BEGIN TO EXPLAIN HOW THIS ERROR EVER OCCURRED. TO STATE THAT IT IS POSSIBLE THAT MAINT 'MISSED' THIS FLUID SOURCE IS ABSOLUTELY INCONCEIVABLE AS IF THE APU HAD BEEN CHKED IT WOULD'VE BEEN NOTED AS CLEAN AND NOT THE SOURCE. THE ISSUE HERE IS NOT AN INOP APU FOR 6+ DAYS NOR EVEN THE HYD LEAK. NOR EVEN THE FACT THAT SOMEONE SCREWED THIS UP EITHER INTENTIONALLY OR NOT. THE ISSUE IS THAT THE TRUE SOURCE OF THIS ERRANT HYD FLUID WAS NEVER DISCOVERED (AT LEAST NOT ON PAPER). WHETHER SELF-INDUCED PRESSURE OR PRESSURED FROM 'ABOVE' (WHICH CAN CREATE SELF-INDUCED) THE BOTTOM LINE IS OUR SAFETY OF FLT HAS BEEN COMPROMISED.

Data retrieved from NASA's ASRS site as of January 2009 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.

Attributes
ACN	753164
Time
Date	200709
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 250 flight time total : 13000 flight time type : 2200
ASRS Report	753164
Events
Anomaly	non adherence : company policies other anomaly other
Independent Detector	other flight crewa other other : 2
Resolutory Action	aircraft : equipment problem dissipated
Supplementary
Problem Areas	Company Maintenance Human Performance
Primary Problem	Maintenance Human Performance

B737-300 flight crew refused aircraft for APU which had been inoperative for days. Shortly thereafter; the aircraft was released by maintenance. The APU was inspected and no defect was found.