Aircraft Classification Numbers (ACN) for runway pavement
Aircraft Classification Numbers (ACN) for runway pavement
(OP)
Where can I find the formula for computing the Aircraft Classification Number (ACN) for flexible and rigid pavements? It involves tire pressure, gross weight, tire footprint area, etc.





RE: Aircraft Classification Numbers (ACN) for runway pavement
For rigid pavements the aircraft landing gear flotation requirements are determined by the Westergaard solution for a loaded elastic plate on a Winkler foundation (the interior load case) assuming a concrete working stress of 399 psi. The standard single wheel load is computed at a tire pressure of 181 psi and is expressed in kilograms divided by 500. The use of the 500 as a divisor is a rounding off process to make the numbers smaller.
The reporting format for the ACN and the PCN can be found in the FAA Advisory Circular AC 150/5335-5, Standardized Method of Reporting Airport Pavement Strength.