Narrative:

We were cleared to descend via the ivane two arrival; landing north in clt. Airplane was in managed descent; 6;000 ft set in FCU altitude window to cross esene as published. Pilot flying had selected prior to TOD 'localizer 36R;' approach in the FMS/mcdu. We could not accept the RNAV to [runway] 36R due to MEL; [runway] 36R glideslope out of service. Switching to clt approach; we were told to expect runway 36C. As the pilot flying was searching for new approach plate to review; the pilot not flying selected [runway] 36C in the FMS/mcdu. At that moment; airplane descent mode changed from managed to a V/south descent of 1;800 FPM. We were only a few miles from majic at this time; altitude approximately 13;000 ft. By the time pilot flying realized the aircraft was no longer in managed descent; we had crossed majic intersection approximately 400 ft too low. Clt approach must have seen our altitude as they canceled the ivane and cleared us to 11;000 ft. When the pilot not flying changed the runway approach selection from [runway] 36R to [runway] 36C in the FMS/mcdu; the vertical descent mode changed from a managed descent to a V/south descent. All constraints were now being ignored by the FMS. The pilot flying was temporarily out of the loop looking for the new approach plate for review. When pilot flying noticed the vertical speed descent on the FMA; the aircraft had descended below the bottom altitude of 13;000 ft at majic.pilot flying should always be alert and prepared to intervene when an uncommanded vertical descent mode change occurs. This altitude deviation took just a few seconds to happen. Also; the ivane two arrival is still a challenge so the pilot flying needs to make all the 'ATC' changes in the FMS. In our case; the pilot not flying made a runway change in the FMS/mcdu without confirming action with pilot flying. Always perform cami (confirm; activate; monitor and intervene) as good CRM. It traps errors and could have prevented this one!

Google
 

Original NASA ASRS Text

Title: An A319 First Officer flying the IVANE 2 RNAV Arrival with his ND MELed reported the FMS defaulted to V/S as the Captain; pilot not flying; change the arrival runway from 36R to 36C which then allowed the aircraft to descend below the MAJIC altitude constraint.

Narrative: We were cleared to descend via the IVANE TWO arrival; landing north in CLT. Airplane was in MANAGED descent; 6;000 FT set in FCU altitude window to cross ESENE as published. Pilot flying had selected prior to TOD 'LOC 36R;' Approach in the FMS/MCDU. We could not accept the RNAV to [Runway] 36R due to MEL; [Runway] 36R glideslope out of service. Switching to CLT Approach; we were told to expect Runway 36C. As the pilot flying was searching for new approach plate to review; the pilot not flying selected [Runway] 36C in the FMS/MCDU. At that moment; airplane descent mode changed from MANAGED to a V/S descent of 1;800 FPM. We were only a few miles from MAJIC at this time; altitude approximately 13;000 FT. By the time pilot flying realized the aircraft was no longer in MANAGED descent; we had crossed MAJIC Intersection approximately 400 FT too low. CLT Approach must have seen our altitude as they canceled the IVANE and cleared us to 11;000 FT. When the pilot not flying changed the runway approach selection from [Runway] 36R to [Runway] 36C in the FMS/MCDU; the vertical descent mode changed from a MANAGED descent to a V/S descent. All constraints were now being ignored by the FMS. The pilot flying was temporarily out of the loop looking for the new approach plate for review. When pilot flying noticed the vertical speed descent on the FMA; the aircraft had descended below the bottom altitude of 13;000 FT at MAJIC.Pilot flying should always be alert and prepared to intervene when an uncommanded vertical descent mode change occurs. This altitude deviation took just a few seconds to happen. Also; the IVANE TWO arrival is still a challenge so the pilot flying needs to make all the 'ATC' changes in the FMS. In our case; the pilot not flying made a runway change in the FMS/MCDU without confirming action with pilot flying. Always perform CAMI (Confirm; Activate; Monitor and Intervene) as good CRM. It traps errors and could have prevented this one!

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.