Narrative:

After verifying the fixes and associated altitudes on the IVANE5 arrival in to clt; we were cleared to 'descend via the IVANE5 landing south.' as the pilot flying I set the altitude in the FCU to 6000 feet and confirmed the altitude as the bottom of the IVANE5 with my first officer. We initiated a managed descent just prior to TOD. During our descent; in order to maintain profile I extended 1/2 speed brakes when 'more drag' was displayed. The mcdu displayed 'too steep path' between the following three fixes on the arrival (which to me made no sense). My awareness was up with the anticipation of intervening later in the arrival yet every indication was that the FMS would comply with magenta starts next to each fix. We were to cross mayos between 240 and 260. The aircraft appeared to be on a proper profile with the only magenta altitude constraint being displayed as 6000 (the bottom of the arrival) indicating to me that the aircraft would comply without issue with all prior constraints. Nearing the mayos fix I allowed myself to get distracted coordinating passenger service issues [while the] aircraft descended below the floor of FL240 at mayos and we crossed the fix about 1300 feet low. My first officer appropriately questioned the altitude and I immediately stopped the descent leveling at FL224; thus the aircraft did not appear as if it was going to respect the following constraint of kiyen at or above FL220. I manually complied with kiyen at or above FL220 and during that period noticed that the aircraft programmed path indicated we were over 1500 feet high as we approached the constraint at kiyen at the proscribed altitude. I manually crossed all of the following constraints to insure compliance prior to being cleared direct to atell with a descent to 6000 to join the LOC23. The remainder of the flight was uneventful ending with a normal landing in clt. There was no mention whatsoever of the deviation by ATC.aside from the obvious reason of allowing myself to get distracted nearing a crossing restriction; I do not know or understand why the system behaved the way it did and completely disregarded programmed crossing restrictions and windows; all the while indicating compliance. Even as we approached the mayos intersection below the proper altitude the aircraft indicated compliance with magent on the pfd; constraints properly depicted on the nd; and magenta asterisks in the mcdu. As I intervened by leveling off and manually complying with the following altitude constraint at kiyen the path indicated high leading me to believe that without intervention and with the mcdu properly programmed the aircraft would have continued to descend disregarding this constraint also.please check the navigation data programming for this arrival specifically on this tail number. I will work on avoiding distraction in the future.

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Original NASA ASRS Text

Title: An A321 flight crew inbound to CLT on the IVANE RNAV STAR in managed descent mode received multiple improper FMGC commands regarding the need for drag and improper warnings with respect to prognosticated compliance with future crossing restrictions. The flight crew overrode the automation and complied manually with the restrictions.

Narrative: After verifying the fixes and associated altitudes on the IVANE5 arrival in to CLT; we were cleared to 'Descend Via the IVANE5 landing south.' As the pilot flying I set the altitude in the FCU to 6000 feet and confirmed the altitude as the bottom of the IVANE5 with my First Officer. We initiated a managed descent just prior to TOD. During our descent; in order to maintain profile I extended 1/2 speed brakes when 'More Drag' was displayed. The MCDU displayed 'Too Steep Path' between the following three fixes on the arrival (which to me made no sense). My awareness was up with the anticipation of intervening later in the arrival yet every indication was that the FMS would comply with magenta starts next to each fix. We were to cross MAYOS between 240 and 260. The aircraft appeared to be on a proper profile with the only magenta altitude constraint being displayed as 6000 (the bottom of the arrival) indicating to me that the aircraft would comply without issue with all prior constraints. Nearing the MAYOS fix I allowed myself to get distracted coordinating passenger service issues [while the] aircraft descended below the floor of FL240 at MAYOS and we crossed the fix about 1300 feet low. My First Officer appropriately questioned the altitude and I immediately stopped the descent leveling at FL224; thus the aircraft did not appear as if it was going to respect the following constraint of KIYEN at or above FL220. I manually complied with KIYEN at or above FL220 and during that period noticed that the aircraft programmed path indicated we were over 1500 feet high as we approached the constraint at KIYEN at the proscribed altitude. I manually crossed all of the following constraints to insure compliance prior to being cleared direct to ATELL with a descent to 6000 to join the LOC23. The remainder of the flight was uneventful ending with a normal landing in CLT. There was no mention whatsoever of the deviation by ATC.Aside from the obvious reason of allowing myself to get distracted nearing a crossing restriction; I do not know or understand why the system behaved the way it did and completely disregarded programmed crossing restrictions and windows; all the while indicating compliance. Even as we approached the MAYOS intersection below the proper altitude the aircraft indicated compliance with magent on the PFD; constraints properly depicted on the ND; and magenta asterisks in the MCDU. As I intervened by leveling off and manually complying with the following altitude constraint at KIYEN the path indicated high leading me to believe that without intervention and with the MCDU properly programmed the aircraft would have continued to descend disregarding this constraint also.Please check the navigation data programming for this arrival specifically on this tail number. I will work on avoiding distraction in the future.

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.