B737-700
Flight Crew Last 90 Days 54; Flight Crew Type 310
Distraction; Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Procedure; Human Factors
Arriving on the SEAVU 2; we had set up and briefed the ILS 24R approach. Upon checking in with SCT Approach; we were cleared for the ILS 25L. Prior to changing approaches in the FMS; the MCP was set in VNAV PATH at 10;000 FT. Once the ILS 25L was set in the FMS; I set 1;900 FT in the altitude window to allow a descent on the approach profile. Just prior to KRAIN at approximately 9;600 FT; we were attempting to brief the [Runway] 25L approach when ATC told us to level at 9;000 FT and said we were supposed to cross KRAIN at 10;000 FT. We acknowledged and were then cleared to continue the approach. We were subsequently cleared for the visual approach and landed with no further event. When last-minute runway changes are made; correct altitude and MCP settings must be verified prior to descending below any crossing restrictions and briefing the new approach.
B737 First Officer reports descending below the KRAIN crossing restriction during the ILS 25L approach at LAX after changing the FMC from an expected ILS 24R approach.