Flight Crew Air Transport Pilot (ATP)
Confusion; Workload; Time Pressure; Situational Awareness; Fatigue
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Weather / Turbulence
Flight Crew Became Reoriented
Chart Or Publication; Human Factors; Weather
Cleared for the ILS 16R at SEA and established on the LOC; prior to Bugne; SEA Approach Control advised new cleared for the LOC 16R. [GPS] was set-up 'Vectors-to-Final' and #2 Nav set-up to the LOC. I started flipping thru approaches to bring-up the fixes; the weather was bad; faster traffic behind me; using the #2 Nav/DME; I had the field in sight; and continuing to flip thru the approaches to bring-up the fixes. My altitude was then 2;700 feet prior to Bugne (3;200 ft) and then Approach Control advised me to 'Cross Bugne at 2;700 feet.' Then halfway between Bugne and Finka (1;900 feet); the Gilde Slope came alive and I continued to landing.After landing and waiting for clearance to cross 16L; I flipped thru the approaches again; pressed Agane fix and there was what I was trying to get. I can only explain that I had a brain-lock at the worst possible time.
Air taxi pilot reported his confusion during an SEA ILS Runway 16R Approach.