Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness; Communication Breakdown
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
Flight Crew Returned To Clearance
Human Factors; Procedure
While on a left dogleg to final we were set up for a visual approach to XXL. We had selected the ILS as a backup. We were set up to come down to the glideslope from the dogleg and intercept the localizer at approximately the FAF; with a aircraft intercepting the north runway (XYR) from the other direction and approximately abeam our position. The Controller initially incorrectly cleared us for a visual to XYR at the same time the PF set the MCP altitude to what we thought was the FAF altitude. In the task saturated moment of looking for traffic; verifying and correcting the clearance; and a configuration change we failed to select the approach mode on the MCP and flew down below the glideslope toward an incorrectly set MCP altitude. As it was a visual approach we elected to level off and re-intercept the glideslope at approximately 1;300-1;400 AGL. The approach was stable after glideslope intercept. Task saturation and communications errors; along with a focus outside for traffic; led to a slow response as PM. I should have paid more attention to the setup for the approach and suggested earlier configuration changes to be more stable during the turn to final. After several months of little flight time I need to pay more attention to slowing down and controlling the pace better than I did today.
We were setup for visual Runway XXL. On base leg with airport in sight. Controller accidentally cleared us for visual Runway XYR. We queried and he corrected it to Runway XXL. The CA said 'set 2;300' in the MCP since we are cleared visual.  I did not verify that on the chart because I was saturated with getting the speed back and configured. We should have set 2;800 until crossing ZZZZZ.  We ended up descending below glideslope and leveled off once we noticed. We intercepted glideslope about 1;400 AGL. We were stable and never heard anything from ATC about it.We were task saturated in a busy traffic environment on approach to parallel runways. I failed to double check the altitude on the approach chart once we were cleared for the visual. A contributing factor was the ATC clearance for visual approach to a runway other than what we had been previously told to expect.If I had double checked the altitude on the chart when the Captain said set 2;300; the event would not have happened.
Air carrier flight crew reported being high on the approach due to task saturation; communications errors and focusing outside for traffic.