Flight Crew Last 90 Days 187
Situational Awareness
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Human Factors; Procedure
Flying into LAS; we were assigned a visual approach to Runway 25L and to descend via the KEPEC3 RNAV Arrival. Flying the KEPEC3 RNAV Arrival; we passed IPUMY at 230 knots and 11;000 FT. We were told at that time to change runway to visual approach 19R. We were given a 090 degree vector and subsequent step downs in altitude until 7000 FT and then directed to slow to 170 knots. I configured to flaps 5. We were given a north vector to an intercept position between EASTR and TOWEN of the RNAV Visual 19L/R. We were directed to descend to 5000 FT. I configured with landing gear down and flaps 15. We were cleared the visual approach Runway 19R. I then continued slowing to Vt of 131 with flaps 30. I intercepted the LNAV course between TOWEN and EASTR at 4400 feet. The MCP was in LNAV; VNAV. Determining that I need to correct higher altitude; I called for 40 flaps momentarily. As I continued descent through 6000 FT; we realized that we were too high and it was better to discontinue the approach. The pilot monitoring (PM) recommended that we ask for a right 360 degree spacing maneuver to line ourselves up on final. We agreed and the PM asked for the maneuver from LAS Tower. Tower gave us a 260 vector and to maintain 4000 FT. I selected heading select 270 and the PM selected 4000 FT in the altitude window. I called for flaps 30 as we descended from 4300 FT on the way down to 4000 FT. We were given a northern heading. As the aircraft reached 4000 FT; I noticed the airspeed trend vector going below Vt of 131. I observed the autothrottles not making the adequate adjustment; so I placed them manually up to full power to stop the trend. The aircraft pitched up and started climbing above 4000 FT; the stick shaker momentarily came on. Recognizing this; I turned off the autopilot/autothrottles and reduced AOA. The airspeed recovered and I called for flaps 15. We stabilized and continued for a visual approach Runway 19R. 1. Late change in runway assignments: Recognizing that I was on short vectors for Runway 19R; I will have to configure a lot earlier to adjust for a more expeditious descent. I also will give myself space by requesting to go to points on the approach segments that will give me adequate time to slow down and go down.2. Use the appropriate level of automation for the task at hand. I will turn off autopilot and fly the jet manually. We were in a visual environment; executing a VFR spacing maneuver. I will turn off autopilot and autothrottles and target the speed bug to Vt+10 as I maneuver and keep a better crosscheck of airspeed and altitude trends while in a visual maneuvering environment.
On arrival into LAS on the KEPEC 3 Arrival; we were maneuvering to avoid weather. We finally got cleared direct IPUMY; cross at or above at 11;000 feet and then descend via the KEPEC 3 Arrival for 25L. Prior to NIPZO; we were told to maintain 9000 feet and to expect left base for Runway 19R due to traffic for 25L from the east. Prior to SUNST fix; we were given a left turn to a northerly heading and cleared to descend to 7000 feet and at 7000 feet slow to 170 knots. At this time we were heading somewhere between TOWEN and EASTR. ATC asked if we had the field; and we told them we did and we were cleared for the visual. We configured for the approach and headed for EASTR. The Pilot Flying intercepted the LNAV course towards EASTR. We realized we were high and lowered the flaps to flaps 40 to lose altitude quicker so that we could get down to the proper altitude and airspeed for a stabilized approach. Approaching 6000 feet MSL; we both realized that we were high and not going to be able to attain a stabilized approach to landing. I requested a 360 on base to lose the altitude to the Tower and instead; Tower gave us a 270 heading and maintain 4000 feet MSL. The Pilot Flying accomplished the heading and altitude maneuver fine with heading and altitude selected in the appropriate windows with autopilot engaged. I suggested going to flaps 30; as we were now going to have plenty of time to maneuver to lose the altitude for a stabilized approach. The Pilot Flying commanded flaps 30 and I reset the flaps. At this time we were given a turn to a 360; and the Pilot Flying commenced the turn. On rollout; we both noticed that the airspeed was low and decreasing and the Pilot Flying added power. Unfortunately; the aircraft pitched up and the airspeed continued to decrease and we got a stick shaker warning. Pilot Flying disconnected the autopilot; added additional power; lowered the nose of the aircraft; and we got rid of the stick shaker. We turned a right base; were cleared for the approach; and had a normal approach and landing.As Pilot Monitoring (PM); I could have been more helpful in finding out where in the sequence we were for landing. This would have helped in our awareness for altitude and configuration timing. The late change in runway assignments by Tower did makes us rushed a little bit. When we started maneuvering; we should have set our airspeed to 140 knots or at least 10 knots above target airspeed for maneuvering. As PM; I should have been much quicker to recognize that the airspeed was slowing and called for corrective action sooner.
B737-700 flight crew describes an unstabilized approach that results from a late runway change from Runway 25L to Runway 19R at LAS. The go-around is commenced above 4;000 FT but insufficient thrust is added and the stick shaker is activated. With more thrust and lowering the nose; the stick shaker is silenced and the next visual approach is successful.