ESDU 15009 is an application of the methods for determing the hydrodynamic forces acting on@ and planing characteristics of@ an aircraft tyre which are described in ESDU 15003@ Planing of rib-tread aircraft tyres. The planing speeds of different types of tyres from an aircraft operating on a water-covered runway surface are determined for a wide range of conditions. The influence on planing speed of parameters such as water depth@ runway surface macro-texture depth@ tyre inflation pressure@ tyre width and tyre diameter are analysed. Additionally@ the hydrodynamic forces acting on each type of tyre during various aircraft operations are also investigated Step-by-step solutions@ with detailed explanations@ are provided for each case