Aircraft radii

The "radius" parameter is used internally by FlightGear's AI Traffic system to determine whether an AI aircraft will fit at a parking location. The rule is that aircraft will prefer to park at the smallest possible parkings, but only at those that have a radius value (in metres) that is slightly larger than the radius value of the aircraft itself.

When designing Groudnets, data developers should assign ICAO Standardized values to their Parking Positions radii to ensure AI aircraft can coexist peacefully and not park over each other :

Category	Wingspan	Groundnet ParkPos Radii	Example Aircraft
A	< 15 meters	NA	General Aviation Piper PA31, Cessna 404
B	15m but < 24m	14	Regional Jets CRJ, ERJ, Dash
C	24m but < 36m	18	Narrow Body Boeing 737, Airbus A318/319/320
D	36m but < 52m	26	Boeing 767, Airbus A310
E	52m but < 65m	33	Wide Body Boeing 777/787, Airbus 330/350
F	65m but < 80m	40	Boeing 747-8, Airbus A380

Source : CS ADR-DSN.A.005 Aerodrome reference code (ARC)