CFD models are well established for aircraft aerodynamic design and analysis. However, for the analysis of aircraft aeroelastic stability, flight dynamics stability and control, and flight simulation, the size of the computational task in computing multiple conditions using time accurate calculations, the computational cost is formidable. For this reason CFD is only starting to make an impact for these applications. The reduction of cost is the focus of an intensive research effort, with reduced models and other acceleration techniques under development. The current paper reviews work which uses large scale eigenvalue solutions to develop eigenvector bases for linear and nonlinear reduced order models. the approach allows for stability calculations, and small order models to calculate dynamical response. The incorporation of uncertainty and sensitivity calculations is possible. A number of aircraft relevant examples will be used to illustrate the methodology.