Flight crew reported incorrect FMS data and a GPWS alert due to late runway change and high workload task saturation.
Synopsis
Flight crew reported incorrect FMS data and a GPWS alert due to late runway change and high workload task saturation.
Narrative
We were inbound to ZZZ on the ZZZZZ arrival and were initially expecting to transition to the X Runways but were later changed to the YY Runways. At the last minute they switched us over to plan the RNAV visual for ZZR. This lead to the task saturation that ultimately lead us to the snowball effect that was about to ensue. ZZZZZ1 was our last fix on the arrival which is also the first fix on the visual approach. So when we were in a hurry to get this entered last minute; and dual verify our fixes; we failed to notice that just above what we had just entered still showed Manual Sequence. Our first indication that something was wrong was when my Captain noticed we were really high in reference to the airport since the VNAV was not stepping down due to the fact we were still on Manual Sequence which we didn't notice in our flight plan sequence since we were busy manually going to vertical speed to reach the altitudes at each fix. While I was dealing with getting us down; my Captain was trying to work on what caused this all to break down. Meanwhile; I was still expecting the FMS to sequence to the next fix; but instead it kept heading in Manual Sequence towards a hotel. Once I noticed something didn't seem right as we shouldn't keep heading in that direction and I couldn't see the airport at this point; we made a sharp turn (this all happened in a matter of seconds) and the GPWS sounded off. We got the aircraft stabilized and proceeded to land safely with no further issues. I didn't even realize what had happened until after we landed I asked my Captain if there was a Manual Sequence that hadn't allowed us to sequence through to our next fix and sure enough; as we were debriefing; we noticed this was the case. With task saturation being the culprit; I know human error is ultimately the issue. There was just a lot going on at once. Usually when there aren't so many changes to a flight plan; it's easy to check and re-check how you have everything setup. In this situation we just didn't get a lot of time to see our mistake. I definitely take responsibility for that.
Second reporter narrative
Our destination was ZZZ. Initially we were cleared as filed after the addition of a couple of departure fixes. The filed flight plan route included the Runway X transition. Very near where the transitions split for various runways we were cleared the Runway YY transition. Later we were cleared the ZZR transition. Just prior to ZZZZZ1 intersection we were cleared the ZZR RNAV Visual approach. As pilot monitoring I failed to notice that on the arrival after ZZZZZ1 there was a Manual Sequence leg and after that was the ZZZZZ1 intersection as the first IAF. Soon after crossing ZZZZZ1 I noticed we seemed high and suggested we initiate a descent. I was trying to understand why the FMS was not sequencing when the flying pilot advised me to look up. We were heading for a hotel and we were way to close. We made an immediate left turn. The GPWS alarm sounded as we were turning away from the obstacle. Once headed toward the runway we increased our descent rate and we were able to stabilize the approach and land normally.I was flying with a pilot new to the Company and obviously I devoted too much effort attempting to orient them to the procedure and the area. I have to ask why we are using a complex procedure to complete a task that used to be as simple as 'turn final at the hotel 3500 ft'. You are directed to set the Maximum Authorized Altitude (MAA); no MAA altitude is listed on the approach plate or on the Attention All Users Page. All the points on this approach are so close together it makes it difficult to analyze where you are; where you should be and if necessary; how to get to where you should be. All this happens at a time when you are configuring the aircraft; communicating with your flying partner and communicating with ATC.Suggestions: Eliminate or simplify this procedure.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.