Light Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 0.5
Situational Awareness; Distraction
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Chart Or Publication; Procedure; Human Factors
Aircraft X was inbound on the Delta-5 arrival. When the pilot checked in I gave him a descend via clearance. The pilot proceeded to cross DRAPR at 14;000 feet as published. The next waypoint is SPIEK at 13;000 feet. After DRAPR the pilot descended to 11;000 feet. I caught it just as he was leaving the 12;700 foot Minimum Vectoring Altitude (MVA). I confirmed with the pilot that I gave him the descend via clearance and he said yes. I told him the restriction at SPIEK is 13;000 feet. He said something messed up with the FMS. My scan should have been better to catch that he started to descend before he was supposed to. I caught it after it was already too late. I am not sure if there is a good recommendation. Just need to be scanning to make sure that the pilot is following the instruction that was given.
[Report narrative contains no additional information.]
S56 TRACON Controller and flight crew reported the pilots descended below the MVA on a crossing restriction on the RNAV arrival.