Date: 201602
Local time of day: 0001-0600
Location: S56.TRACON, UT
Light: Night
Aircraft: Light Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B SLC
ATC / advisory: TRACON S56
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Confusion; Distraction; Situational Awareness
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Procedure; Human Factors
Primary problem: Human Factors

Narrative: Aircraft X was issued a base turn vector 15 south of SLC to set up for the approach to RWY 35. I descended the aircraft to 080 in an area where the MVA was 080. I then remember thinking a 060 heading would work better to tighten the turn up. At that moment; I got some verbal coordination from the supervisor about how we would handle the simul procedures between this aircraft and another. Immediately after that coordination; I told the aircraft to 'descend and maintain 060' when my head was thinking 'fly heading 060'. The aircraft was still in the 080 MVA and I didn't catch my mistake even from the good read back Aircraft X provided. I then turned the aircraft to a dogleg and cleared them to cross ZEPOG at 080. At this exact moment; the aircraft was descending through 080. The pilot started to question the 080 restriction and I immediately issued a low altitude alert with a climb immediately to 080. I observed the aircraft as low as 073 before they climbed back to 080. No other traffic was involved.Prior to this session which was late into my shift; I trained a CPC-IT (Certified Professional Controller In Training) for a two hour session on extremely busy traffic. I then completed a 20 minute debrief followed by a 30 minute break. After this 30 minute break was the time this event occurred. I remember feeling some level of stress about the long session and the debrief but didn't let it concern me too much. I don't know if the stress I was feeling had anything to do with the situation; but I wanted it to be clear that I made this personal observation prior to sitting for this final session. The 30 minute break I received might have not been enough to fully recuperate my 'racing mind' from the previous session. I would say most supervisors already do what I am about to recommend; however; I feel it would have been a benefit to let me work a sector that had less traffic and complexity than Final during a stagger to wide simul configuration. This configuration requires a great deal of coordination and the ability to exercise extreme dynamics among all the rules involved. I understand that going to 060 in an 080 is never allowed and it's very black and white.




Synopsis: S56 Controller reported of descending an aircraft to the MVA of 8;000 feet. Aircraft was on approach to SLC.  Controller then intended to turn the aircraft to a heading of 060 but became distracted and told the aircraft to descend and maintain 6;000 ft while thinking he was instructing the aircraft to turn to a 060 heading. Aircraft then was given an 8;000 foot crossing restriction after the aircraft had started the descent. Realizing the error the reporter climbed the aircraft back to 8;000 feet but not before the aircraft descended as low as 7;300 feet.