Small Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 12
Communication Breakdown; Confusion; Situational Awareness; Training / Qualification
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Procedure; Aircraft; Human Factors
I was working Local Control. Aircraft X (small transport) pulled up to the runway and I put him in the drop down list for release for departure with TRACON. Aircraft Y (B757) pulled up behind Aircraft X and since I had not gotten the release from TRACON; I moved Aircraft Y around Aircraft X and cleared him for takeoff. After Aircraft Y rolled; I received the release and put Aircraft X in position and launched him 6;000 feet and airborne. I did not wait the full two minutes needed behind a B757.I forgot about the wake turbulence rule. Since RECAT and B757 being treated differently as it pertains to wake turbulence; the rule just slipped my mind. My recommendation would be for me to remember the rule.
DFW Tower Controller reported a loss of separation attributed to forgetting the 'RECAT' rules pertaining to a departure behind a B757.