A320 captain reports aileron servo ECAM during taxi out. After consulting fom; ECAM is cleared and f...

Attributes
ACN	802153
Time
Date	200808
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	cruise : level ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 150 flight time total : 29900
ASRS Report	802153
Events
Anomaly	aircraft equipment problem : less severe non adherence : company policies
Independent Detector	aircraft equipment other aircraft equipment : ecam other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

On taxi out -- received ECAM message; 'aileron servo inoperative.' after reviewing cockpit operating manual -- message was deleted. Prior to departure; 'status page' was called up and nothing was indicated as inoperative systems. In cruise -- a random check of the flight control page indicated the aileron servo was still inoperative -- but never illuminated as an inoperative system; so I believe the servo was probably inoperative during takeoff also. The airbus system seems to have a 'hidden threat' in its monitoring system. You can actually have an inoperative system and not having it shown on the 'inoperative status' page. I don't know how the boeing monitoring system works -- but I doubt it would 'hide' an inoperative system like the 'airbus' system seems to do.callback conversation with reporter revealed the following information: the reporter believed that the servo fault had corrected itself prior to takeoff due to its absence from the status page. Elac 1 had faulted at the gate and was reset by maintenance prior to push back. It is likely that the aileron servo fault caused the elac fault and was intermittent in nature.

Original NASA ASRS Text

Title: A320 CAPT REPORTS AILERON SERVO ECAM DURING TAXI OUT. AFTER CONSULTING FOM; ECAM IS CLEARED AND FLT DEPARTS. ENROUTE FLIGHT CONTROL PAGE SHOWS AILERON FAULT PRESENT; ALTHOUGH STATUS PAGE SHOWS NOTHING.

Narrative: ON TAXI OUT -- RECEIVED ECAM MESSAGE; 'AILERON SERVO INOP.' AFTER REVIEWING COCKPIT OPERATING MANUAL -- MESSAGE WAS DELETED. PRIOR TO DEP; 'STATUS PAGE' WAS CALLED UP AND NOTHING WAS INDICATED AS INOP SYSTEMS. IN CRUISE -- A RANDOM CHK OF THE FLT CONTROL PAGE INDICATED THE AILERON SERVO WAS STILL INOP -- BUT NEVER ILLUMINATED AS AN INOP SYSTEM; SO I BELIEVE THE SERVO WAS PROBABLY INOP DURING TKOF ALSO. THE AIRBUS SYSTEM SEEMS TO HAVE A 'HIDDEN THREAT' IN ITS MONITORING SYSTEM. YOU CAN ACTUALLY HAVE AN INOP SYSTEM AND NOT HAVING IT SHOWN ON THE 'INOP STATUS' PAGE. I DON'T KNOW HOW THE BOEING MONITORING SYSTEM WORKS -- BUT I DOUBT IT WOULD 'HIDE' AN INOP SYSTEM LIKE THE 'AIRBUS' SYSTEM SEEMS TO DO.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE REPORTER BELIEVED THAT THE SERVO FAULT HAD CORRECTED ITSELF PRIOR TO TKOF DUE TO ITS ABSENCE FROM THE STATUS PAGE. ELAC 1 HAD FAULTED AT THE GATE AND WAS RESET BY MAINTENANCE PRIOR TO PUSH BACK. IT IS LIKELY THAT THE AILERON SERVO FAULT CAUSED THE ELAC FAULT AND WAS INTERMITTENT IN NATURE.

Data retrieved from NASA's ASRS site as of May 2009 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.

A320 captain reports aileron servo ECAM during taxi out. After consulting fom; ECAM is cleared and flight departs. Enroute flight control page shows aileron fault present; although status page shows nothing.