The P-3 Orion patrol airplane has a need for an air-to-air missile system for defense against enemy aircraft on its long-range missions. In response to this need, the Naval Air Test Center was tasked in 1989 to conduct a P-3/AIM-9 (Sidewinder) integration program. In support of this program, a vibration test stand was established at NPS, and a ground vibration characterization was conducted to determine if a potential flutter problem existed. This test resulted in the development of a two degree-of-freedom lumped-mass model and experimental determination of the missile's resonance modes in pitch. With the recent termination of the P-7A, the P-3 community is now looking at the Orion II program to carry it into the 21st century. The Orion II will most likely have a beefed-up wing structure, necessitating an analysis of this wing in conjunction with the AIM-9 missile. This investigation responds to that requirement by concurrently developing a mathematical model of the AIM-9 missile using finite element methods to analytically determine its modal parameters, and setting up a modal test system to quantify the parameters of this model by experimentally determining the missile's natural frequencies, mode shapes and transient response. This fully instrumented test system and associated methodologies could then be the basis for conducting a comprehensive modal test of the AIM-9 missile system, as well as to quantify the vibration characteristics of other candidate missile systems for the P-3 and its eventual successor.