A300
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Workload; Confusion; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Chart Or Publication; Aircraft; Human Factors; Procedure
We were descending on the Tammy Four RNAV arrival; LIT transition; landing south. In between LIT and JESSC; Center told us to expect to land north. The Captain was PM and deleted all waypoints between JESSC and the runway in an attempt to delete the landing south arrival and switching it to a landing north arrival. While approaching JESSC; and aware that no waypoints remained after JESSC; the Captain tried several times to reload the arrival from JESSC without avail. The Captain did not select the LIT transition on the TAMMY 4; thus not loading the waypoints after JESSC. The Captain then quickly loaded waypoints manually after JESSC; as we descended through FL180. As pilot flying; I set my altimeter to the field altimeter setting of 30.21 passing FL180; and leveled at 16;000 feet before JESSC; as per the STAR. When level; we heard the altitude alerter sound. I looked cross cockpit and noted that the Captain's altimeter was set to QNE; thus displaying 15;700 feet. He reset his altimeter to QNH and flight progressed normally. First; we could have avoided the problem by not deleting all the waypoints down track of the TO [active] waypoint on an arrival and by; instead; selecting the correct transition when inputting a STAR. These would have reduced the workload in a critical phase of flight. Third; remind the other crew member to set QNH when passing FL180; even if he is task saturated.
When the Captain/PNF became task saturated programming a runway change while descending via the TAMMY RNAV STAR to MEM; he failed to reset his altimeter passing FL180. The altitude alert warning sounded when the PF leveled at 16;000 feet while the Captain's altimeter read 15;700 feet.