Commercial Fixed Wing
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1
Situational Awareness; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance
Environment - Non Weather Related; Human Factors; Airspace Structure
Working in a north flow; with arrivals coming in on the downwind; spacing not really an issue; and I had just been in a rhythm bringing the arrivals in for visual approaches. My general method is to give a descent to 9;000 feet which is the downwind Minimum Vectoring Altitude (MVA) when clear of traffic; then slow to 180 knots 2 miles from the base turn; then turn to a 070 heading; then when the first turn is observed and they are now crossing the 9;000 foot MVA line into the 8;000 foot MVA; give a descent to 7;000 feet; then call the airport; then clear them for an approach with a turn to final. This sequence requires 5 or 6 transmissions per plane; but I feel like it is an expeditious way to safely get aircraft in with such a high MVA on the downwind. After having worked many aircraft in without issue and rather monotonously; Aircraft X checked on and was one of the last aircraft in the bank. I descended them to 9;000 feet; slowed to 180 knots at the normal place; then got distracted by something going on with another sector; I can't remember what; but I returned my focus to Aircraft X; incorrectly thinking that I had already given the base turn; and I was watching for the target to start a turn to the east. I saw the target move and started the transmission to descend. The pilot read it back; but I soon could tell that they were not in the turn and were not leaving the higher MVA for lower terrain. I asked the pilot if they were in the right turn heading 070 yet; and they responded that they were turning to 070 degrees; but in reality I had not yet issued it and didn't realize that until reviewing it afterward. The aircraft was soon in the base turn leaving the higher MVA; I called the airport and the pilot responded in sight; and I issued a visual approach clearance. It was my mistake that I did not catch it earlier. I will practice more vigilance in ensuring a complete turn out of the MVA before issuing the descent.
S56 TRACON Controller reported they forgot to issue a heading to an aircraft for the base leg and the aircraft flew below the Minimum Vectoring Altitude.