EMB-175 flight crew reported ATC climbed them for terrain avoidance after they descended below a crossing restriction on a STAR.
Synopsis
EMB-175 flight crew reported ATC climbed them for terrain avoidance after they descended below a crossing restriction on a STAR.
Narrative
While coming into ZZZ; we received the ATIS and they were using Runway XXL/R. We had briefed the fixes and altitudes throughout and also had our performance numbers. We were about less than 30 minutes out when we were given our clearance to descent via the ZZZZZ Runway XX configuration. We noted the final altitude set; which was 6;000 ft. and proceeded to descend. A few minutes later while descending; ATC informed us that they had just switched runway configurations and were now landing on Runways XYR/L. So; it caught us by surprise and so I was going into the FMS to get the new landing data numbers as well as putting the new runway with the corresponding arrival. We verified the fixes and read out the altitudes while descending. So; the final altitude on the ZZZZZ arrival with the Runway XY configuration is now 8;000 ft. However; we failed to remember that we had the altitude set for 6;000 ft. As we got to the last fix; ZZZZZ1; we were told to expect Runway XYR. I also heard a company aircraft was coming in on approach as well; coming from the southeast; so I was anticipating that traffic. The aircraft continued its descent past 8;000 ft. since it was set for 6;000 ft. in the altitude alerter. ATC queried us and told us to climb back up to 8;000 ft. for terrain separation. They also gave us a vector. We stopped our descent around 7;400 ft. and continued to climb to 8;000 ft. We got back to 8;000 ft. and proceeded with vectors to the airport and landed safely. The biggest factor was the sudden change in runway configuration while descending. We didn't plan for that and when it occurred; it became rushed trying to configure the FMS to the new runway and to get all the performance data; as well as doing the checklists. If given a new runway; perhaps check the altitude alerter to make sure that the altitude were descending for matches the new arrival procedure. Maybe incorporate the read back of our fixes and check the last point and the altitude and then give a look at the altitude alerter.
Second reporter narrative
Received runway change at lower altitude. Prior ATIS lacked wind reports causing confusion and distraction. Clearance granted to prior assigned runway for STAR bottom Altitude was 6;000 ft. After runway change; crew failed to correlate change in published bottom altitude during brief with the altitude previously set for XXL. Diligence when confirming fixes below 18;000 ft. during runway change. Request for delay vector during time of confusion and heavy workload. Make time when needed.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.