The most common practical way to simplify the structural analysis of airfie
ld pavements is the use of equivalent single wheel load models instead of t
he actual gear of the aircrafts. As the accuracy and reliability of these m
odels strongly affects the design and evaluation of airfield pavements, the
re is considerable need to investigate both system approaches. The first on
e, which uses a constant value for the pressure while the radius is variabl
e, is currently under use by the aircraft classification number-pavement cl
assification number method of the International Civil Aviation Organization
, but despite this fact it proved to be inadequate to express the aircraft
loading in many situations. On the contrary, according to this study, the s
econd model, which has a constant value for the radius while the pressure v
aries, is more reliable, and it can be an interesting alternative. Thus, ba
sed on this model, an aircraft loading index is introduced, which aims to b
e a simple and reliable factor for expressing the severity of the loading o
f the aircrafts and a utility for several matters related to the airfield p
avement applications.