Large Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Confusion; Situational Awareness
Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Procedure
I had base and downwind traffic for Runway 36R on both the left and right side. I turned Aircraft X behind a heavy at the same altitude and went below the required 3.5 mile RECAT separation. I did not use a memory jogger or scratch pad entry to notate the altitudes and did not recognize this until I had already turned Aircraft X to join the final approach course.I should have used my scratch pad entries to notate the altitudes assigned since I had traffic from both sides to minimize any confusion.
M03 Approach Controller reports of turning aircraft to final and losing the required separation with another aircraft on the opposite base leg.