Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 222; Flight Crew Type 1106
Time Pressure; Workload; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Human Factors; Procedure
We were on the SITEE3 arrival into LAS. The ATIS was advertising ILS 26L and RNAV Visual 19R approaches. Because of our direction of arrival we had set up for and briefed the ILS 26R. Just prior to WYYNN; Approach advised us we would be doing the RNAV visual 19R. This required changing runways very quickly as the arrival also changes shortly after WYYNN. We were able to do this; but Approach Control then refused to clear us for the approach until we called the airport in sight. We had been very busy setting up for the new approach and had not had time to visually acquire the airport. This caused a delay in beginning our descent. Compounding this; LAS is only visible at night as a dark spot near lights and while it is possible to see the airport; Runway 19R does not come into view until short final.We were able to successfully fly the approach and make a safe landing; but this practice is far from safe.
B737 Captain reported receiving a late runway/arrival change and increased workload associated with making the necessary FMS changes resulting in a late descent.