With the growth in the size, weight and ground pressure of ever larger aircraft, and the replacement of 'all over' grass aerodromes with sealed runways, taxiways and aprons, it became necessary to be able to specify the strength of aerodrome pavements. At first this was done differently in different nations, but in 1982 Australia adopted the new ICAO standard Aircraft Classification Number-Pavement Classification Number (ACN-PCN) system.

Click on the image at left to download and read Aeronautical Information Circular (AIC) CO 22/1982 which details the ACN-PCN system. (1.2 MB .pdf file)