A319
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Distraction; Confusion; Time Pressure; Workload
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Aircraft Automation Overrode Flight Crew; Flight Crew FLC Overrode Automation
Aircraft; Chart Or Publication; Human Factors; Procedure
The First Officer was flying the leg and was descending on the IVANE RNAV STAR to CLT. The ATIS advised landing south; so the First Officer briefed the arrival and the south transition and I checked all the constraints in the plan mode and everything checked fine. We started out at 17;000 FT and crossed IVANE at 11;300 FT in managed mode. During this time we were handed off to Charlotte Approach and were again were cleared the IVANE but with a north transition; a speed of 250 KTS and to expect 36C; we were expecting 36L. I then pulled the 36C plate out. When I looked up at the Nav display we were below 11;000 FT (10550) about 8 NM north of GIZMO which must be crossed between 11;000 FT and 13;000 FT. I instructed the First Officer to stop the descent and climb back to 11;000 FT. At that point ATC told us to maintain 10;000 FT. We were then cleared to descend to 6;000 FT. ATC did ask what altitude we were showing for GIZMO.I believe the reasons for this are as follows. ATC cleared us for the RNAV arrival but also; however; assigned a speed. While we stayed in a managed mode for descent we were in selected mode for speed. During the hand off to Charlotte we were given another change from what we had expected; i.e. land north with the North transition. While I thought the First Officer was monitoring the Aircraft he was also looking at his arrival plates to get ready to brief the north transition. Both of us should not have been reviewing our charts at the same time; there was a lack of communication. The First Officer and I got along fine. The IVANE 1 is almost a joke. You never really fly the full arrival without ATC changes. Even though we were cleared for the arrival ATC changed it by changing our speed. Which brings up the question; were we really ever on it? Get rid of the arrival or have ATC let us fly it.
We were [cleared to descend] via the IVANE RNA STAR but to maintain 250 KTS. As we approached IVANE I commented we were crossing IVANE at 11;400 FT and proceeded to divert my attention to briefing [the approach to] 36C. When I looked back to monitor the descent we were still descending after IVANE; but the descent should have stopped [at 11;000 FT MSL] until GIZMO.If ATC clears us to descend via the IVANE arrival they should let us do the arrival as published. No headings and then rejoin; No speed changes. Just let it work the way it is designed to.
An A319 flight crew suffered an altitude deviation while descending on the IVANE RNAV STAR to CLT but with an assigned speed; forcing them to operate their autoflight systems in a non-standard manner.