Large Transport; Low Wing; 2 Turbojet Eng
Flight Crew Last 90 Days 295; Flight Crew Type 10000
Confusion; Situational Awareness; Communication Breakdown
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
While flying the TMBRS2 Arrival; I did not comply with the speed restriction of 280 knots noted in a box on the chart. I was flying our Cost 40 index and was at 285 knots when ATC asked about our speed. He then informed us of this speed restriction. I briefed the arrival fixes and their speeds and altitudes but failed to notice this box on the left side of the page.
An air carrier captain reported noncompliance with a published speed restriction on the PDX TMBRS2 STAR due to a low cost index profile programmed in the FMC computer with automation engaged.