ACN-PCN method

The FAA also developed COMFAA, a software enabling the calculation of ACNs for different aircraft depending on the input parameters.

The PCNs are determined by airports for their runways, taxiways and aprons and published in the Aeronautical Information Publication (AIP).

With the exception of massive overloading, pavements in their structural behaviour are not subject to particular limiting load above which they suddenly or catastrophically fail.

As a result, minor or medium overload operations may be allowed by the airport authority depending on the corresponding loss in pavement life expectancy.

The method is also failing to consider accurately the effect of modern landing gear configurations (with multi-wheels arrangements) and the improved characteristics of new-generation pavement materials.