Aircraft Knowledge and Flight Performance
What the controller needs
You do not fly the aircraft, but you must understand its performance. Know aircraft categories by wake turbulence (Super, Heavy, Medium, Light) and by approach speed (A–E). Understand take-off and landing performance, climb and descent rates, and how weight, temperature, altitude and wind affect performance. Know V-speeds at a conceptual level: V1 (decision), Vr (rotation), V2 (take-off safety), Vref (reference landing).
Wake turbulence
Wake turbulence is generated by wingtip vortices and is strongest when the aircraft is heavy, clean and slow. Know the separation intervals by weight category and the rules for following and crossing aircraft. Understand ground effect and wind shear effects.
Traps and a rule of thumb
Traps: assuming a Light aircraft needs no wake separation behind a Heavy; confusing aircraft category (wake) with approach category (speed); and forgetting that vortices sink and drift with wind. Rule of thumb: the heavier and slower the leader, the greater the wake hazard - apply the interval and consider the wind. Worked example: a Medium following a Heavy on approach needs the prescribed time/distance interval; if the wind is light and the Heavy is slow, the hazard persists longer.