Narrative:

As a habit of muscle memory I will on occasion do the standby rudder test; which has been eliminated from our procedures without even thinking about it. This happened to me today on aircraft X. Interestingly the aircraft failed the standby rudder test. After making a logbook entry of the discrepancy; I called station maintenance. The mechanic found that the 'B' system standby rudder valve motor was running continuously and was so hot that it burned his hand when he touched it. While maintenance had a new valve; the new valve did not include the required packing rings; which go on behind the 'O' rings on the valve shaft. More interesting was that he showed me the old valve and said that the packing rings were not installed correctly on the old valve.I am submitting this report because I am concerned that by eliminating the standby rudder check we are compromising safety on several levels. This is the second aircraft I have had this happen on. The first one was the result of a relay failure; this one the result of the standby rudder valve failure. If we are not as a matter of procedure checking the standby rudder; how do we know it will work when we desperately need it to work? Second; how do we verify the standby hydraulic pump is operable? Finally; on this particular event where the 'B' system standby rudder valve was generating so much heat...was there a wheel-well fire hazard as the valve motor was operating continuously? As stated; this is the second aircraft I have had that failed the standby rudder test; which is no longer a procedural test. It is my belief that we are compromising safety by not doing this test as part of the originating preflight checks given the importance of standby rudder operation.

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Original NASA ASRS Text

Title: A B737 failed the preflight Standby Rudder Check which the Captain performed out of habit even though this preflight procedure was eliminated. This pilot has discovered two malfunctioning systems since the procedure was discontinued.

Narrative: As a habit of muscle memory I will on occasion do the standby rudder test; which has been eliminated from our procedures without even thinking about it. This happened to me today on Aircraft X. Interestingly the aircraft failed the standby rudder test. After making a logbook entry of the discrepancy; I called Station Maintenance. The Mechanic found that the 'B' system standby rudder valve motor was running continuously and was so hot that it burned his hand when he touched it. While Maintenance had a new valve; the new valve did not include the required packing rings; which go on behind the 'O' rings on the valve shaft. More interesting was that he showed me the old valve and said that the packing rings were not installed correctly on the old valve.I am submitting this report because I am concerned that by eliminating the Standby Rudder Check we are compromising Safety on several levels. This is the second aircraft I have had this happen on. The first one was the result of a relay failure; this one the result of the standby rudder valve failure. If we are not as a matter of procedure checking the standby rudder; how do we know it will work when we desperately need it to work? Second; how do we verify the standby hydraulic pump is operable? Finally; on this particular event where the 'B' system standby rudder valve was generating so much heat...was there a wheel-well fire hazard as the valve motor was operating continuously? As stated; this is the second aircraft I have had that failed the standby rudder test; which is no longer a procedural test. It is my belief that we are compromising safety by not doing this test as part of the originating preflight checks given the importance of standby rudder operation.

Data retrieved from NASA's ASRS site 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.