B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 221
Situational Awareness; Human-Machine Interface; Communication Breakdown; Training / Qualification
Aircraft Equipment Problem Less Severe; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Aircraft; Human Factors
We were at FL400 before given a step-down to start the EAGUL 6 Arrival to PHX. At one point; we were given descent to FL370 and soon after to continue to FL360. I entered FL370 in the Cruise page and selected VNAV. FL360 was in the MCP Altitude window; but we did not descend. Checking in with ABQ Center; we gave them our current altitude; and he asked us if we were given a restriction. At this point; we got confused after seeing FL360 in the MCP Altitude window. Center again queried us and we admitted that we weren't sure exactly what altitude we were to descend to. He then gave us the 'descend via' clearance and we proceeded uneventfully to Sky Harbor.
[No substantive additional information was included in the secondary report.]
A B737-700 flight crew failed to properly program ATC descent clearances into their FMS and Altitude Alert window and; thus; stopped their descent from FL400 at FL370 vice FL360.