Date: 202012
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Aircraft: Small Aircraft
Operating under: Part 91
Flight plan: IFR
Flight phase: Cruise
Airspace: Class D RBD
ATC / advisory: TRACON D10
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Government
Reporter function: Approach
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Situational Awareness; Workload
Anomaly: ATC Issue All Types; Airspace Violation All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Result: General None Reported / Taken
Contributing factors: Airspace Structure; Procedure
Primary problem: Procedure

Narrative: Aircraft X departure ZZZ IFR enroute to ZZZ1. I released the aircraft with a heading of 130 degrees & 2;000 ft. off Runway ZZ. This is a fairly standard procedure for releasing IFR aircraft off ZZZ when the metroplex is in a north flow. This keeps the aircraft away from the ZZZ2 finals which are just a few miles to the west of ZZZ. At the time; ZZZ2 was in the middle of an arrival push. Once the aircraft became airborne & I established communication with him I called ZZZ Tower & requested control so I could turn the aircraft back to the west across the ZZZ airspace. I turned Aircraft X westbound toward ZZZ1 & pointed him out to the appropriate ZZZ2 arrival sectors & handed him off to ZZZ TRACON. My plan was to keep Aircraft X low (2;000 ft. MSL) below the ZZZ2 finals where all the arrivals would be at 3;000 ft. MSL. A couple minutes later I noticed an aircraft in very close proximity to Aircraft X on a similar course. I called traffic but Aircraft X couldn't locate the aircraft. Due to the ZZZ2 traffic I couldn't climb Aircraft X for the traffic nor could I descend him due to the MVA of 2;000 ft. I again called traffic to see if Aircraft X could acquire the target visually. He still couldn't & the courses were converging while Aircraft X was overtaking the target. I called ZZZ Tower to see if they were talking to him or see if they knew what he was doing. They told me they thought he was heading to ZZZ3 which is very close to ZZZ1. The target had just departed ZZZ. I vectored Aircraft X to the north to in an attempt to increase the distance between him & the unidentified target. I then turned Aircraft X back to the southwest to go behind & to the left of the target to try & increase the separation even more. Once I was satisfied the two targets were safely separated I transferred communications of Aircraft X to ZZZ TRACON. I believe Aircraft X was on a heading of either 250 or 260 degrees at the time. It was brought to my attention later that while Aircraft X was on the heading I gave him when I transferred communications that he clipped a 2;100 ft. MVA while still at 2;000 ft. MSL. This occurred before the ZZZ TRACON controller was able to turn the aircraft. I didn't realize the heading would allow Aircraft X to clip the MVA. The MVA is a very small area; approx. 1-2nm wide 'shelf' of a larger MVA. I would not have given the aircraft a shortcut by taking him under the ZZZ2 finals. I was attempting to be as efficient as possible. However; with the amount of traffic in the area at the time I should have just taken him to the south off ZZZ & then westbound from there. This would've added approximately 30-40nm to his route but would've prevented this from happening. In the future I would also ask ZZZ Tower if they have anyone departing to the west who would be in conflict with this aircraft when I asked for control for a westbound turn. This also would've impacted my decision making.




Synopsis: TRACON Controller reported communications transfer to late to prevent aircraft from entering a higher MVA.