SR22
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 4
ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Procedure; Airspace Structure; Human Factors
Aircraft X was being vectored for the RNAV Approach when Aircraft Y checked in for the Visual Approach. The trainee decided to make Aircraft Y number one and take Aircraft X off their approach. When he did this he gave Aircraft X a right turn; northbound toward higher terrain and the aircraft was at 2500 ft. The aircraft had to ask him if he wanted her to maintain 2500 ft; in which he agreed. I immediately advised him not to turn the aircraft northbound and to continue her turn back southbound. When he gave the aircraft a turn it was to a 100 heading and the aircraft replied with; 'Was that for me'? He did not hear her say that and at this point was entering a 3400 ft MVA (Minimum vectoring Altitude).I took over and proceeded to turn her immediately to a heading of 180 for higher terrain and attained from the pilot that they could maintain their own terrain clearance; to which they answered in the affirmative. This turn to the north has many consequences. One of which the trainee witnessed today. The aircraft can lose radio contact; not hear you; take a late or slow turn or fly into clouds or into terrain. I advised the trainee of several of the issues that can arise from turning aircraft northbound into a higher MVA. More education and experience in radar will help him learn.
[Report narrative contained no additional information.]
SBA TRACON Controller reported ATC trainee vectored an aircraft off the approach into an area with a higher Minimum Vectoring Altitude.