Small Transport
Air Traffic Control Fully Certified
Distraction; Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Human Factors; Procedure
Aircraft X departed SLC on a 340 heading climbing to 100. I acknowledged his check on but did not climb him out of 100. His routing was a little strange; so I asked my hand-off to coordinate direct RKS and 150; while I checked the ASD-X to ensure that there was not conflicting traffic behind him and that the coordinated altitude would work. In the meantime I had another controlled come sit down next to me and said they were going to take the position; and several other aircraft checked on. When I returned to Aircraft X to give the new routing and altitude; I saw that he was quickly climbing out of 102; and I mistakenly assumed that I had already given him the 150 altitude; so I did not also include that in the instruction. Aircraft X quickly continued the climb to 106; and I started giving the briefing. As I began the briefing I saw that Aircraft X was descending again; and I instructed them to expedite the climb to 150 and turned them away from terrain; but they did not respond. I issued a low altitude alert and instructed them that they were about to enter a higher MVA and advised them to expedite the climb through 120. This time they read back the instruction and started the climb. They entered an 110 MVA at 102; and I again issued the heading away from higher terrain; which they did read back. The aircraft quickly climbed out of the MVA and was turned back on course. I need to make sure to reissue instructions when I'm not 100% certain they received them; just to be on the safe side.
S56 Controller reported unsure of climb clearance resulting in aircraft entering a higher MVA.