Learjet 55
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict
General None Reported / Taken
Human Factors
I was providing OJT to a Trainee on the Arrival Position. Tower had told us about a (Medevac) helicopter departure off the hospital 1/2 mile west of [the Class D] departing westbound climbing to 2;000. A LJ55 was direct to [the Class D] for a visual approach descending to 2;600 (the MVA). The LJ55 reported the field in sight; and the Trainee cleared [the LJ55] for the visual approach to Runway 18 with no restriction; and made a traffic call informing the LJ55 of the helicopter's position. I prompted the Trainee to also advise [the helicopter] of the approaching LJ55. As the aircraft neared; I observed that [the helicopter] was descending; eventually as low as 1;600 as the LJ55 descended toward the airport to 2;000. While I am the primary Instructor for this Trainee; he has completed over 60% of his OJT hours and other instructors and a Supervisor had told me they foresaw certification soon. I saw the potential for a conflict early; and was awaiting the Trainee's traffic management technique. Since traffic was light I could closely monitor the situation and see that the conflict was resolved; although more by pilot action than controller actions. However; what I observed and thought was a preemptive descent by the helicopter the pilot informed us was an evasive maneuver as he observed the LJ55 descending toward him. Do not rely on the pilot or the trainee to do what I know is the right thing. While there are different techniques; not doing anything is no technique at all; and the situation is better managed applying some restriction. During debrief with the Trainee we discussed simply vectoring the LJ55 or applying an altitude restriction to 'maintain 2;500 until advised'.
TRACON Controller providing OJT described a TCAS RA event involving a Corporate Jet arrival on a visual approach and a Medevac helicopter departing a near by hospital.