Abstract : NOVA-2 (Nuclear Overpressure Vulnerability Analysis, Version 2) is an updated version of NOVA, a FORTRAN-4 digital computer program for calculating the response of individual structural elements of aircraft, such as stringers, frames and panels, exposed to the transient pressure loading associated with the blast wave from a nuclear explosion. The updated version extends the capability of NOVA to analyze rib elements, frames with variable cross section, and offers a choice of clamped, simply supported or free edge boundary conditions. For inelastic structural response, a much improved elastic-plastic model for material behavior is provided. Also added to NOVA is the REFRA near-ground reflections model for blast waves. The program still provides the overall capability to analyze multilayered beam and panel elements exposed to a steady- state subsonic or supersonic aerodynamic preload, followed by a dynamic blast wave. A critical slant range is automatically determined in an iteration where damage criteria (specified on a probabilistic basis) are compared with the structural response.