ICAO-ACN calculates ICAO aircraft classification numbers (ACN) for aircraft operating on flexible and rigid airport pavements. The flexible pavement ACNs are calculated using the CBR method of thickness design at standard CBR values of 15, 10, 6 and 3.  Alpha factors follow the revised schedule of alpha factors adopted by ICAO in a State Letter dated October 16, 2007. The rigid pavement ACNs are calculated using the PCA method thickness design at standard k-values of 150.0, 80.0, 40.0 and 20.0 MN/m3.  ICAO-ACN 1.0 is based on the computer program COMFAA 3.0 that accompanies AC 150/5335-5C, “Standardized Method of Reporting Pavement Strength – PCN.” However, ICAO-ACN 1.0 is not an official FAA or ICAO standard at this time.

For further information, please contact Dr. David R Brill