This Data Item demonstrates the application of an empirical model in order to calculate the decelerating forces acting at the tyre-runway interface of undercarriage tyres that belong to an aircraft operating in a braked state on a dry runway. The aircraft comprises three multiple-wheel undercarriages: one nose undercarriage and two wing undercarriages. Each type of undercarriage is initially considered in isolation. The total aircraft deceleration due to tyre-runway interaction is then calculated.

Decelerating forces are calculated for a range of operating speeds.

Step-by-step solutions, with detailed explanations, are provided for a particular operating condition for the tyres in a wing undercarriage.

The Data Item is an application of ESDU 23002, ‘Tyre braking on dry or water-covered runways – summary of ESDU tyre-runway modelling’. Familiarity with the relevant methods outlined in that Data Item is essential before ESDU 23009 is studied.

The document is one of a series of ESDU Data Items illustrating the application of the methods summarised in ESDU 23002. Further worked examples include ESDU 23010, ‘Braked tyre operating on water-covered surface – application of ESDU 23002’, and ESDU 23011, ‘Ground-test machine operating on contaminated runway surface – application of ESDU 23002’.