ACN-PCN method

The Aircraft Classification Number (ACN) – Pavement Classification Number (PCN) method is a standardized international airport pavement rating system promulgated by the ICAO in 1981. The method has been the official ICAO pavement rating system for pavements intended for aircraft of apron (ramp) mass greater than 5700 kg from 1981 to 2020. The method is scheduled to be replaced by the ACR-PCR method by November 28, 2024.

For the safe and efficient use of pavements, the method has been designed to:

1. enable aircraft operators to determine the permissible operating weights for their aircraft;
2. assist aircraft manufacturers to ensure compatibility between airfield pavements and the aircraft under development;
3. permit airport authorities to report on the aircraft they can accept and allow them to use any evaluation procedure of their choice to ascertain the loading the pavements can accept.

The method relies on the plain comparison of two numbers:

• The ACN, a number that expresses the relative effect on an airplane of a given weight on a pavement structure for a specified standard subgrade strength;
• The PCN, a number (and series of letters) representing the pavement bearing strength (on the same scale as ACN) of a given pavement section (runway, taxiway, apron) for unrestricted operations.