McCavity is a software product for the modelling of whole aircraft signatures with plumes, and specialises in the accurate modelling of the complex radiative interactions that occur within aerial vehicle intake and exhaust cavities, and is commercially available. McCavity can be used to analyse the contribution of individual engine components to the aircraft’s overall infrared signature, thus providing invaluable options to modify any components and minimise its signature. Both inband and line-by-line solutions are possible. Hyperspectral thermal images of an aircraft can be rendered from any given observer position, with atmospheric effects included. An overall distribution of the thermal radiation emitted from a cavity can also be generated over an exit hemisphere to identify viewing angles with high signatures.