Narrative:

I was part of an originating (first flight of the day) crew for this aircraft. During preflight cockpit flows; placing either of the guarded hydraulic switches to standby failed to activate the standby hydraulic/rudder system. This test of the standby hydraulic system by means of a standby rudder check was a part of an originating preflight procedure at our company from at least the time I was hired in until approximately six months ago when it was removed from our aom; (flight deck prep). On this particular originating preflight; my old habit pattern resulted in testing and subsequently discovering a complete failure of the standby hydraulic system. All the normal protocols involving dispatch/maintenance control/contract maintenance and maintenance documentation were followed. When I left the aircraft; contract maintenance was still troubleshooting and had already determined that the electric powered standby hydraulic pump did not appear to be receiving power. Although I was not required to perform a standby rudder check; my concern is how long was this particular aircraft flying without a properly operating standby hydraulic system? How long would it be before a routine maintenance inspection would reveal the failure? Why was this check removed? What was the rational? Is it the feeling that we would have to lose both hydraulic a and B systems to need the standby? As a high time captain in the B737; it makes me uncomfortable knowing that I could have been flying this aircraft without standby rudder/hydraulics. Did we do the right thing by removing this check from our originating aircraft procedures?

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Original NASA ASRS Text

Title: A B737-300 Captain discovered the Standby Hydraulic/Rudder System inoperative after inadvertantly performing the system preflight check which had been removed as a preflight requirement about six months prior.

Narrative: I was part of an originating (first flight of the day) crew for this aircraft. During preflight cockpit flows; placing either of the guarded hydraulic switches to standby failed to activate the Standby Hydraulic/Rudder System. This test of the Standby Hydraulic System by means of a Standby Rudder Check was a part of an originating preflight procedure at our Company from at least the time I was hired in until approximately six months ago when it was removed from our AOM; (Flight Deck Prep). On this particular originating preflight; my old habit pattern resulted in testing and subsequently discovering a complete failure of the Standby Hydraulic System. All the normal protocols involving Dispatch/Maintenance Control/Contract Maintenance and maintenance documentation were followed. When I left the aircraft; Contract Maintenance was still troubleshooting and had already determined that the electric powered standby hydraulic pump did not appear to be receiving power. Although I was not required to perform a standby rudder check; my concern is how long was this particular aircraft flying without a properly operating Standby Hydraulic System? How long would it be before a routine maintenance inspection would reveal the failure? Why was this check removed? What was the rational? Is it the feeling that we would have to lose both Hydraulic A and B systems to need the standby? As a high time Captain in the B737; it makes me uncomfortable knowing that I could have been flying this aircraft without standby rudder/hydraulics. Did we do the right thing by removing this check from our originating aircraft procedures?

Data retrieved from NASA's ASRS site as of July 2013 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.