Small Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 5
Distraction; Training / Qualification; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors
This was my first OJTI session on the arrival sector. The developmental issued Aircraft X a heading toward the final; but did not instruct the aircraft to join (vector angle too large). The aircraft began slowing as Aircraft Y was coming up behind. The developmental recognized the blow through of the final and issued a LA (low altitude) alert and a turn back west. We were focusing on Aircraft X and getting him out of the MVA that we didn't notice right away Aircraft Y overtaking; but still with vertical separation. I eventually had Aircraft Y maintain Visual Separation with Aircraft X; but I don't know exactly at what point that occurred. There were other IFR conflicts that we were focusing on and traffic was getting busier. I failed to listen actively and assumed Aircraft X was going to join the final. I should have stopped Aircraft Y at 4;000; but was too concerned about Aircraft X and the MVA. I realize that in this sector; control from the OJTI must be maintained constantly or things get out of hand quickly - not like other sectors where there's room to correct actions.
SCT Controller reported a loss of separation and a MVA violation.