|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||airport : dfw.airport|
|Altitude||agl single value : 0|
|Operator||common carrier : air carrier|
|Make Model Name||Saab-Scania Undifferentiated or Other Model|
|Operating Under FAR Part||Part 121|
|Flight Phase||ground : preflight|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Qualification||pilot : atp|
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Anomaly||aircraft equipment problem : critical|
non adherence : company policies
non adherence : published procedure
|Independent Detector||aircraft equipment other aircraft equipment : rudder limiter|
other flight crewa
other flight crewb
|Resolutory Action||none taken : anomaly accepted|
Flight Crew Human Performance
Rudder limiter on aircraft was MEL'ed. MEL procedures called for visual and functional check of rudder prior to departure. We did not do this at gate. During pre-takeoff check, limited movement of rudder was noted. Returned to gate for maintenance action. Recommendation: the MEL book lists the pre-departure check as a maintenance action that may be performed by flight crew. Since this check will almost always be done by the flight crew, it should probably be listed as an item under the 'O' section of the MEL for flight crew procedure. Callback conversation with reporter revealed the following information: reporter stated that the aircraft automatically switches from 'low speed' rudder limiter throw to 'high speed' limiter during flight. Often the rudder limiter will remain (stuck) in the high speed setting and this limits the amount of rudder movement available for engine out requirements. Maintenance personnel will reset the rudder limiter to the low speed setting and defer (MEL) the limiter. After the maintenance is complete, the flight crew is authority/authorized to perform the check on the rudder. However, there is no place where the flight crew is notified regarding the required check. The reporter indicated that the requirement for the check should be on the flight plan or release, or the flight crew notified by a note in the aircraft's logbook. This is a safety of flight item and should have a positive check by either maintenance or the flight crew.
Original NASA ASRS Text
Title: SAAB 340 FLT CREW NEGLECTS TO PERFORM A REQUIRED PREFLT CHK ON THE ACFT'S RUDDER PRIOR TO DEP AND DISCOVERS LIMITED MOVEMENT OF THE RUDDER DURING THE PRE-TKOF CHK.
Narrative: RUDDER LIMITER ON ACFT WAS MEL'ED. MEL PROCS CALLED FOR VISUAL AND FUNCTIONAL CHK OF RUDDER PRIOR TO DEP. WE DID NOT DO THIS AT GATE. DURING PRE-TKOF CHK, LIMITED MOVEMENT OF RUDDER WAS NOTED. RETURNED TO GATE FOR MAINT ACTION. RECOMMENDATION: THE MEL BOOK LISTS THE PRE-DEP CHK AS A MAINT ACTION THAT MAY BE PERFORMED BY FLT CREW. SINCE THIS CHK WILL ALMOST ALWAYS BE DONE BY THE FLT CREW, IT SHOULD PROBABLY BE LISTED AS AN ITEM UNDER THE 'O' SECTION OF THE MEL FOR FLT CREW PROC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE ACFT AUTOMATICALLY SWITCHES FROM 'LOW SPD' RUDDER LIMITER THROW TO 'HIGH SPD' LIMITER DURING FLT. OFTEN THE RUDDER LIMITER WILL REMAIN (STUCK) IN THE HIGH SPD SETTING AND THIS LIMITS THE AMOUNT OF RUDDER MOVEMENT AVAILABLE FOR ENG OUT REQUIREMENTS. MAINT PERSONNEL WILL RESET THE RUDDER LIMITER TO THE LOW SPD SETTING AND DEFER (MEL) THE LIMITER. AFTER THE MAINT IS COMPLETE, THE FLT CREW IS AUTH TO PERFORM THE CHK ON THE RUDDER. HOWEVER, THERE IS NO PLACE WHERE THE FLT CREW IS NOTIFIED REGARDING THE REQUIRED CHK. THE RPTR INDICATED THAT THE REQUIREMENT FOR THE CHK SHOULD BE ON THE FLT PLAN OR RELEASE, OR THE FLT CREW NOTIFIED BY A NOTE IN THE ACFT'S LOGBOOK. THIS IS A SAFETY OF FLT ITEM AND SHOULD HAVE A POSITIVE CHK BY EITHER MAINT OR THE FLT CREW.
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.