Narrative:

Arriving at the aircraft; the incoming crew was waiting on the ramp for the bus we arrived in. We spoke to the captain and one of the first officer. They told us of the MEL (27-25-02) which was on the aircraft. They stated they had received the warning associated with the discrepancy on final. In hindsight; this should have been written up as the requirement of the MEL: 'condition a may be inoperative provided before each flight; and for each inoperative caution; rudder deflection is checked operative using only the servo control associated with each inoperative caution.' [this] cannot be complied with in such a case. Additionally; this MEL is as setup for serious unintended consequences. We performed the required check at the gate before leaving. I really felt uncomfortable with this MEL because of the seriousness of the rudder jamming in flight with no recourse. Upon taxi out; we were just going straight on the taxiway and the warning occurred. So; we performed the check. When you turn off the green and yellow hydraulic systems to check the B; you get a number of bells and chimes; the aircraft goes into alternate law. After restoring the systems everything appeared to return to normal. Being uncomfortable; we returned to the gate only to be told by maintenance control the condition was as expect there was only a bad switch; etc. This is an unacceptable MEL because the crew cannot comply with the 'condition a' requirement in flight as happened to the crew of another aircraft. Also; putting the aircraft in alternate law by de-powering the other two systems is; at least; a bad idea as it quite possibly could have unintended consequences. Additionally; there is no specific guidance on which exact switches to utilize to properly de-power the hydraulic systems could easily have been a problem. We were fortunate to have a check airman on the international reserve officer seat so that was less challenging. By the way; this was something like the eleventh day of the MEL! So; probably twenty something crews took it across the ocean; including us!

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Original NASA ASRS Text

Title: First Officer reported an A330-300 Rudder Servo was MEL'ed; but a malfunction in flight would require turning off the Yellow and Green Hydraulic Systems which would put the aircraft in Alternate Law with potential unintended consequences.

Narrative: Arriving at the aircraft; the incoming crew was waiting on the ramp for the bus we arrived in. We spoke to the Captain and one of the First Officer. They told us of the MEL (27-25-02) which was on the aircraft. They stated they had received the warning associated with the discrepancy on final. In hindsight; this should have been written up as the requirement of the MEL: 'Condition A May be inoperative provided before each flight; and for each inoperative caution; rudder deflection is checked operative using only the servo control associated with each inoperative caution.' [This] cannot be complied with in such a case. Additionally; this MEL is as setup for serious unintended consequences. We performed the required check at the gate before leaving. I really felt uncomfortable with this MEL because of the seriousness of the rudder jamming in flight with no recourse. Upon taxi out; we were just going straight on the taxiway and the warning occurred. So; we performed the check. When you turn off the Green and Yellow Hydraulic Systems to check the B; you get a number of bells and chimes; the aircraft goes into Alternate Law. After restoring the systems everything appeared to return to normal. Being uncomfortable; we returned to the gate only to be told by Maintenance Control the condition was as expect there was only a bad switch; etc. This is an unacceptable MEL because the crew cannot comply with the 'Condition A' requirement in flight as happened to the crew of another aircraft. Also; putting the aircraft in Alternate Law by de-powering the other two systems is; at least; a bad idea as it quite possibly could have unintended consequences. Additionally; there is no specific guidance on which exact switches to utilize to properly de-power the hydraulic systems could easily have been a problem. We were fortunate to have a check airman on the International Reserve Officer seat so that was less challenging. By the way; this was something like the eleventh day of the MEL! So; probably twenty something crews took it across the ocean; including us!

Data retrieved from NASA's ASRS site as of April 2012 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.