B737 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 38; Flight Crew Total 7678; Flight Crew Type 4540
Situational Awareness; Confusion
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Clearance
Human Factors
On an early evening flight to IAH we were descending via the DRLLR 5 RNAV arrival being set up and briefed for the RNAV Y 26R with our altitude set to 6000'. When checking on with the approach controller we were told to expect the runway 26L transition. We selected the new runway in the FMS but failed to reset our altitude selector to 7;000' at that time. As we neared ZOEEE Drag Required appeared on the FMS scratchpad and the Captain said; 'Careful not to be too hot at ZOEEE'. I deployed the speed brakes and slowed us to 210kts and checked the FMA and we were still in VNAV PATH. Shortly after passing ZOEEE; I noticed the FMA showed VNAV SPEED as we were leveling at 6;000' and I no longer showed SKLER as a waypoint on the screen. I then looked more closely at the DRLLR 5 chart and noticed the point we'd briefed as the lowest altitude on the arrival had (Runway 26R) beside it and thought we should've stopped at 7;000'. I brought it to the attention of the captain who then queried ATC. The ATC response was that we were ok and to now descend to 5;000'. We started the descent and shortly after were told by what sounded like a different voice on the radio to maintain 6;000'. We reversed the approximately 200' descent and returned to 6000'.The rest of the approach and landing were uneventful and the flight ended safely at the destination. I believe we should've stopped at 7;000' but am unsure since the controller didn't have a problem with us being at 6;000' so I listed the event as a possible altitude deviation.
B-737 pilot reported neglecting to change the descent altitude after receiving a change in assigned runway from ATC late in the Arrival procedure.