This Data Item demonstrates the application of an empirical model in order to calculate the retarding forces acting on an aircraft-type tyre that operates in both braked and unbraked states on dry and contaminated runway surfaces. Retarding forces are calculated for a wide range of operating speeds and the contaminants considered are water@ slush@ loose snow and ice. Step-by-step solutions@ with detailed explanations@ are provided for a specific case from each case analysed. The Data Item forms part of a series of Data Items which outline application of the empirical model that is defined in ESDU 10015@ Model for performance of a single aircraft tyre rolling or braking on dry and precipitate contaminated runways@ and summarised in ESDU 05011@ Summary of the model for performance of an aircraft tyre rolling or braking on dry or precipitate contaminated runways. Background information relating to the application of the model is given in ESDU 10002@ Introduction to worked examples of tyres rolling or braking on dry or precipitate contaminated runways.