Maritime helicopters have the ability to greatly increase the range of influence and utility of naval vessels. For smaller ships in rough seas, flight deck motion becomes considerable and additional infrastructure is required for securing and traversing helicopters while on-deck. The current state-of-the-art in dynamic modelling of the on-deck helicopter/ship dynamic interface includes a fully spacial securing simulation and one capable of modelling planar manoeuvring operations. A fully spacial securing and manoeuvring simulation named SSMASH (Spacial Securing and Manoeuvring Analysis for
Shipboard Helicopters) has been developed to provide complete analysis capability of the on-deck helicopter/ship dynamic interface. A new capability to model helicopter response to manoeuvring events in the presence of flight deck motion is realized. The SSMASH simulation is modeled with twelve degrees-of-freedom and mass coupling between the helicopter body and wheel carriages. The model has been validated against another simulation and experimental data from land-based manoeuvring trials.