Narrative:

During the before taxi checklist; the flaps were extended. As the flaps extended I checked the rudder movement. After 1/3 rudder travel; the rudder jammed on the right side. I noticed the rudder manual control light flicker during the check. I released the rudder and tried the left side and the rudder again jammed after 1/3 rudder movement. I reported the event to maintenance and returned to the gate. I have had this occur three other times and maintenance has taken the aircraft out of service. After we returned to the gate; a mechanic showed up and I explained exactly what I had done. He left and checked the hydraulic levels and rudder. When he came back to the cockpit we accomplished the check as before and had the same results. After a period of time; I was informed by an unknown maintenance source that I had performed an 'inappropriate check' and to check the rudder only after the hydraulic load [from extending the flaps] had diminished. I cannot find this warning note in any of my operational manuals. The flow of the checklist calls for the flaps to be extended and shortly after the checklist calls for a flight control check. If this is a [known and appropriate] hydraulic issue; I think there should be some notation in our manual.

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Original NASA ASRS Text

Title: After encountering abnormal rudder response during their pre-takeoff checks; the flight crew returned to the gate for maintenance. During the maintenance diagnosis the flight crew was advised they were performing the check improperly while the flaps were being extended; thus loading the hydraulic system. The flight crew is unaware of any such published operational restriction. A subsequent check after the flap extension was complete was normal.

Narrative: During the Before Taxi Checklist; the flaps were extended. As the flaps extended I checked the rudder movement. After 1/3 rudder travel; the rudder jammed on the right side. I noticed the Rudder Manual Control light flicker during the check. I released the rudder and tried the left side and the rudder again jammed after 1/3 rudder movement. I reported the event to Maintenance and returned to the gate. I have had this occur three other times and Maintenance has taken the aircraft out of service. After we returned to the gate; a Mechanic showed up and I explained exactly what I had done. He left and checked the hydraulic levels and rudder. When he came back to the cockpit we accomplished the check as before and had the same results. After a period of time; I was informed by an unknown Maintenance source that I had performed an 'inappropriate check' and to check the rudder only after the hydraulic load [from extending the flaps] had diminished. I cannot find this warning note in any of my operational manuals. The flow of the checklist calls for the flaps to be extended and shortly after the checklist calls for a flight control check. If this is a [known and appropriate] hydraulic issue; I think there should be some notation in our manual.

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.