Date: 202001
Local time of day: 1201-1800
Location: SBA.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Sail Plane
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Flight phase: Final Approach
Airspace: Class C SBA
ATC / advisory: Tower SBA
Second aircraft: Commercial Fixed Wing
Reporter organization: Government
Reporter function: Instructor; Local
Reporter qualification: Air Traffic Control Developmental
Human factors: Communication Breakdown; Time Pressure; Training / Qualification
Second reporter function: Local; Instructor
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; 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 Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Procedure
Primary problem: Procedure

Narrative: Aircraft X was approximately 5 Miles NW of the field when Approach Control approval-requested a right downwind entry for Runway 25; capped 2;000 and above for other VFR arrival aircraft for Runway 15L. I approved the request; as soon as traffic permitted I allowed Aircraft X his VFR descent at pilot discretion when he was approximately 2 Miles NNE of the field. Aircraft Y was 5 Miles south of the field; eastbound; on the visual approach for Runway 25. I immediately recognized the conflict. I instructed Aircraft X to turn Base; at this time he was approximately 2.5 Miles NE of the field. I informed Aircraft Y of the glider traffic and instructed him to execute a 5 Mile left base; at this time Aircraft Y was approximately 5 SE of the field. Aircraft Y asked if he needed to extend; I said affirmative; enter a 5 Mile left base. Aircraft Y immediately turned inbound for a 3 Mile left base. Aircraft X was established on a 2 Mile final and at 80 kts. I instructed Aircraft X to go around; he responded unable due to his engine being shut down. I then told Aircraft Y to go around; climb and maintain 3;000; fly heading 255. Aircraft Y read back his instructions and began to climb. I then coordinated with Approach Control; Aircraft Y was on the Standard Missed and coming back to him for re-sequence; Approach Control requested a 200 heading. I issued the 200 heading to Aircraft Y and told him to contact departure. I thought Aircraft Y had started turning and I switched him; but he was not turning. I realized he was heading into a much higher MVA. I told Aircraft Y he needed to start his turn to 200; that he was entering an MVA of 5700 feet but he had already switched frequencies. Adequate initial spacing and sequence provided by approach controller. Compliance from the Aircraft Y pilot to enter a 5 Mile left base. Compliance from Aircraft Y pilot to take assigned headings. Ensuring the pilot is physically turning to assigned heading to avoid conflict prior to frequency change.


Second narrative: We took LC (Local Control) for training; I was the trainer. It was in the middle of our training session that approach approved a right down wind arrival for RWY 25. Glider Aircraft X was told to turn a 3mile right base for RWY 25. At that time Aircraft Y was switched to us about 6 miles south of the airport on a visual approach. The trainee told Aircraft Y about glider traffic and instructed Aircraft Y to turn 5 mile left base. The trainee expected Aircraft Y to enter a 5 mile final; however; Aircraft Y turned a 5 mile left base for a 2 mile final and at that time Aircraft X was on a 2 mile going 70 kts. We realized it was not going to work with Aircraft Y going 170 kts so we tried to send Aircraft X around. Aircraft x told us they couldn't go around because their engine was off; so we made the decision to send Aircraft Y around. Initially; Aircraft Y was told to fly northerly hoping to build some space; then they were told to expect to go around. They were given a climb to 030 and a 255 heading; but they never acknowledged and continued northerly. The trainee coordinated the go around with the approach controller; which told us to give Aircraft Y a 200 heading. The trainee gave Aircraft Y that heading and switched them to approach. The aircraft continued northerly into a 5700 feet MVA for another few miles before they started their turn. After reviewing and listening to the tapes; we concluded that there was a misunderstanding between us and Aircraft Y. We gave certain instructions; but didn't get the results we expected. We should have used more control instructions such as; extend your downwind I'll call your base. We also switched Aircraft Y a bit too early; especially since he was heading in a north direction into a 5700 feet MVA. We had visual on the aircraft at all times; but should have kept the aircraft until we observed the turn.


Synopsis: SBA Tower controllers reported miscommunication with pilot resulted in entering a higher MVA.