Aircraft General Knowledge
Domain 5 tests what controllers must know about aircraft performance, approach categories and wake turbulence. You are not expected to fly the aircraft, but you must know how its size, speed and configuration affect separation and runway use.
Wake turbulence categories
ICAO uses Super, Heavy, Medium and Light. The A380 is Super; aircraft of 136,000 kg or more are Heavy; aircraft above 7,000 kg up to 136,000 kg are Medium; aircraft of 7,000 kg or less are Light. Wake separation depends on the leader and follower. A Medium following a Super needs 7 NM; a Light following a Super needs 8 NM. A Medium following a Heavy needs 5 NM; a Light following a Heavy needs 6 NM. A Light following a Medium needs 5 NM.
Performance and approach categories
Approach categories are based on Vat: A below 91 kt, B 91–120 kt, C 121–140 kt, D 141–165 kt and E 166–210 kt. Category affects minima and circling areas. Speed control, climb rate and runway occupancy also shape sequencing.
Worked example: an A380 is followed by an A320 on final. The A380 is Super and the A320 is Medium, so the required spacing is 7 NM. If a Boeing 747 is followed by the same A320, the spacing is 5 NM. If a Cessna 172 follows the A320, the spacing is 5 NM because the Cessna is Light and the A320 is Medium.
Traps: mixing ICAO and FAA wake categories; applying 5 NM to every following aircraft; forgetting that Super is a separate category; confusing approach category with wake category.