Narrative:

Once level at FL370 I noticed a slight pitch oscillation and the aircraft struggled to hold altitude. After about 10 minutes it got worse and ECAM F/control elac (elevator and aileron computer) 2 fault [was displayed]. We followed procedure and selected 'off' then 'on' per ECAM. The fault cleared and we continued. The oscillation started again and same ECAM resulted. We followed and reset again per the ECAM. After the second reset I decided that even though the computer was resetting correctly the problem with the pitch oscillation was the elac 2 computer. After the 2nd reset much more aggressive pitch up oscillation occurred and I selected elac 2 off and the problem went away. Problem solved; I considered options. The only operational consideration was loss of CAT III dual. I consulted the QRH and confirmed elac 1 had picked up the load. Not concerned about safely continuing to [destination] I consulted the MEL and confirmed that elac 2 was not allowed to be deferred. I called dispatch for consult with maintenance. Maintenance and dispatch confirmed that they wanted the aircraft to return to [departure airport]. Having no operational/safety concerns with the aircraft and weather cavu at ZZZ; a joint decision was made to return without incident.

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Original NASA ASRS Text

Title: A320 Captain reported returning to departure airport after experiencing an Elevator and Aileron Computer (ELAC) anomaly.

Narrative: Once level at FL370 I noticed a slight pitch oscillation and the aircraft struggled to hold altitude. After about 10 minutes it got worse and ECAM F/CTL ELAC (Elevator and Aileron Computer) 2 FAULT [was displayed]. We followed procedure and selected 'off' then 'on' per ECAM. The fault cleared and we continued. The oscillation started again and same ECAM resulted. We followed and reset again per the ECAM. After the second reset I decided that even though the computer was resetting correctly the problem with the pitch oscillation was the ELAC 2 computer. After the 2nd reset much more aggressive pitch up oscillation occurred and I selected ELAC 2 OFF and the problem went away. Problem solved; I considered options. The only operational consideration was loss of CAT III dual. I consulted the QRH and confirmed ELAC 1 had picked up the load. Not concerned about safely continuing to [destination] I consulted the MEL and confirmed that ELAC 2 was not allowed to be deferred. I called Dispatch for consult with Maintenance. Maintenance and Dispatch confirmed that they wanted the aircraft to return to [departure airport]. Having no operational/safety concerns with the aircraft and weather CAVU at ZZZ; a joint decision was made to return without incident.

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.