B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 170
Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Unstabilized Approach
Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Became Reoriented
Human Factors
It was a normal flight; until flying the RNAV visual Runway 19L Approach. Prior to arriving in LAS; we had accomplished all our checklists and were still unaware of which runway; 7's or 19's; since we were arriving from the southeast gate over KADDY. Once handed off to Approach; just prior to KADDY; we were informed that we would be given the RNAV visual 19L. At that point the First Officer (FO) loaded the approach and we then briefed it.While briefing the approach; a discrepancy; first red flag; was noted in the speed at EASTR. The CDU speed had a lower case 153 when the arrival showed a hard 150. We noted that and corrected it in the CDU; but what we missed was that the altitude in the CDU was also incorrect at 3500A rather than a hard altitude of 3500. We were cleared for the approach while at 8000 feet and about 10 to 12 miles from TRROP.The FO reprogrammed the ALT; 8000 feet; in the CDU and selected LNAV and VNAV and began to slow to 170 Knots to meet the airspeed restriction at TRROP. TRROP at 170 and 6000A were properly programmed in the CDU. Second red flag; the Approach Controller ensured that we knew we had been cleared the approach; we acknowledged and stated that we would start down in approximately one mile per the CDU.At this point; the FO and I both questioned the accuracy of the VNAV profile. Having done this approach before; the picture was off. Although we were now descending; we felt high; although the CDU showed us on profile. We discussed the situation; and the FO; now inside of TRROP; disengaged VNAV; selected 3500 in the altitude window; selected V/S; and configured the aircraft to enable the steeper descent; yet maintain the published speeds on the arrival. The profile view on the CDU now showed us low; but we both agreed that we would not be able to cross EASTR at 150 knots; or make the 3500 feet altitude restriction. At this point we contacted Tower; informed them that we were too high for the approach; and requested a go-around. Tower acknowledged and asked us to continue and that we would be given go-around instructions at the runway. As we crossed over EASTR we noticed that the vertical guidance that once showed us low; was now trending in the opposite direction; and last I saw showed us over 700 feet high. We continued with LNAV engaged and a configured descent to avoid any possible conflicts with VFR departing traffic. As we approached the runway we were given a climb to 3500 feet and runway heading and then vectored to a visual approach to Runway 7R; this all was uneventful. Once on the ground we tried to figure what went wrong. As we went through the approach pages we realized that we had selected the RNVV [RNAV with vertical velocity]  rather than the RNVS [RNAV with vertical speed] for 19L. Although the points on the arrival are the same to include the first point TRROP at 170 knots and 6000A; RNVV has EASTR at 3500A with no airspeed limitation.Our errors occurred mostly because we couldn't see the 'forest for the trees.' I was talking on the radios when the FO selected the RNVV versus the RNVS for Runway 19L. Comparing the FMC title to the approach plate title; RNVS 19L; would have made this approach a non-issue. Second; when we briefed the RNAV visual we should have started over when we found the speed at EASTR incorrect; and corrected it; rather than move on to the next item. It's much simpler to catch mistakes when an item is omitted (i.e. the 150 at EASTR then hearing a correct altitude but missing the suffix such as an at or above.) After the first mistake; I heard only what I wanted to hear and that was the 3500 feet; and not the above part. We were given a few red flags and we only picked up on some; we needed to do more research earlier to see what was wrong. I do believe that the FO did a good job in assessing the situation once we had a handle on the approach. He balanced his options and attempted to fix the problem with what tools he had available to him. Even though we were unsure why the approach wasn't working even though the FMC showed us on profile; we communicated our dislikes and reduced the automation and attempted to fly the proper profile through V/S and additional drag. Prior to any ATC deviations; EASTR at 150 knots/3500 feet; we both agreed that a go-around was necessary and we coordinated with LAS Tower for further instructions. Although we had to go around; I believe that our emphasis on training that we have received; enabled us to move from the Yellow of having the wrong RNAV visual programmed in the FMC and being high; to allowing us to do a plan B; go-around; and get back into the Green rather than continue to push forward with a bad approach. My only item I have; from a safety point; is why we even have the RNVV in the FMC. The title RNVV itself; as in our case; can be deceiving when given the RNAV visual approach; although our book does say that we will [use] the RNAVS for this type of approach.
B737 Captain reported a go-around followed an unstable approach related to incorrect programming of FMC on the arrival into LAS.