A319
Flight Crew Air Transport Pilot (ATP); Flight Crew Commercial
Human-Machine Interface; Situational Awareness
Deviation - Altitude Undershoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Aircraft
We were on the Ivane5 arrival into CLT and cleared to cross MAYOS at FL220. We had both previously checked all the restrictions prior to beginning of the arrival. ATL Center gave us a new crossing restriction to cross MAYOS at FL220. Pilot Flying (PF) changed the box; confirmed input and monitored change. I monitored as well. We both noted the box had accepted the input and was engaged in DES mode w/managed speed. The vertical profile 'donut' was centered and descent was stable.All was good and normal. I attended to some arrival duties with getting a new ATIS; changeover; and inputting the changes. Approximately several miles before MAYOS I again; checked the vertical profile and noticed we were a couple thousand feet high. I immediately notified the Captain (CA) and she concurred. She immediately shut off the automation and attempted to manually fly down to make the restriction.As it became apparent that we would not make the restriction; I was about to call ATL center and ask for some relief. Before I could; ATL Center called us and asked us to verify we were crossing MAYOS at FL220. Despite the CA's best effort we could not make the restriction. We crossed around 800 feet high and reported the altitude to ATL when asked.We then got the typical descend via clearance with a South landing. No number was given to call. No separation issues occurred and safety was not jeopardized. The event occurred because we did not catch the automation leaving the vertical profile in time to intervene.We are not sure why the automation lost [and] did not stay on profile. It's as if was ignoring MAYOS or something. Adding to the event was my doing Pilot Monitoring (PM) tasks at the exact same time the automation was leaving the vertical profile. The PF also did not catch the same thing. I believe she was briefing some changes as a result of the new ATIS.To avoid this happening again I would do several things. First; I would suggest at least one person always monitor the vertical profile when trying to make restrictions. Also; I could have checked the profile more frequently. Even though I felt it was frequent enough at the time. This scenario clearly points out that it was not.If the PF wants to do something that takes them away from monitoring the navigation profile; then they could clearly communicate this to the PM. This would allow the PF to exclusively monitor that portion of the flight. This would need to be positively communicated so one person is always responsible for the profile.As far as automation is concerned; this would not have happened had we had a FMS that would provide an audible warning when leaving the vertical profile. Perhaps a 'tone' could be used when off profile by more than some predetermined altitude. We have used alert tones with great success to date. The altitude alerter is a great example. Isn't that what we really could use an alert to notify us of an altitude error before it's too late to intervene? That would be nice.
The IVAN RNAV is too cluttered. Why does ATC find it necessary to deviate from a given STAR with so many altitudes? I believe the IVANE has more deviations than any other STAR in the nation. There is a reason for this. It should be cleaned up. No STAR should be so cluttered as to have a split chart as the IVANE does. If you are looking at whether you must have your range set for more than 40 miles; and you cannot see all the clutter of numbers on the arrival as they overlap.ON the IVANE 5 RNAV arrival all altitudes and speed were verified by both pilots separately. You are to cross MAYOS between FL260 & FL240 and 280K. We were given MAYOS at FL220. This was entered and selected; verified and managed. The aircraft showed on profile with magenta dot and no other changes were made. My range was at 80 miles for area build ups and weather. The fixes are closely spaced: 7.6/ 11.0/5.6 and overlap on map if not if a very small range. The copilot was on the smaller range and stated we were going to be high at MAYOS. The aircraft showed on perfect profile; not high at all; but FL220 / open descent and speed brakes were selected. I crossed MAYOS approximately 800 feet high. Why did the aircraft revert to the STAR with no input from the pilots; and FL220 hard tuned in the box the cross MAYOS at?
A319 flight crew reports missing an assigned crossing restriction of FL220 at MAYOS on the IVANE5 RNAV. The original altitude window of FL260-FL240 is changed to FL220; but the aircraft does not honor the new altitude and the deviation is detected too late to catch up.