Personnel airdrop simulation

We develop an object-oriented simulation that models the airdrop mission of a U.S. transport aircraft, the C-17 Globemaster III. The simulation, writt en in MODSIM III, is based on three basic object types: an aircraft, a wake vortex, and a paratrooper. The aircraft object provides the required aerod ynamic constants for simulating the wake vortices generated off each wingti p; the vortex object includes velocity field and decay models as well as a position algorithm; and the paratrooper object implements a 6-degree-of-fre edom trajectory model. Using the simulation, we generate vortex encounter i nformation for various formations and wind conditions, and quantify the ass ociated risk of paratrooper/vortex encounters in a potential encounter rate . Time over the drop zone is a primary concern in any airdrop operation, an d the results of this analysis form a tool that allows the ground commander to assess the risk involved in decreasing that time.