Commercial Fixed Wing
Air Traffic Control Developmental
Confusion; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
Aircraft X departed Runway 18R. RNAV departure RNAV CHETO. Wake RECAT category D Aircraft. Aircraft Y next departure Runway 18L. On an ELVIS4 SID. Given a 200 heading climbing to 5;000 ft. I was the trainee; and was under impression this would not require in trail wake separation (RECAT F behind a D requires 4 miles). Aircraft Y acquired with roughly 3.5 miles of separation. Additionally; Aircraft Y took the heading much quicker than anticipated; which didn't really make a difference. Aircraft was shipped with approximately 3.8 miles of separation; thinking that in trail spacing wasn't needed; only giving 3 miles. I will be more aware and mindful to verify any types of separation needed moving forward.
Memphis Tower Developmental reported that failure to provide the correct wake turbulence standards resulted in a loss of separation.