ESPROP was developed to fit the requirements of a propeller manufacturer using third party blades in custom constant speed hubs. The problem was to select the optimum blade for a particular airframe, engine and operating points. The system consists of two components: ESPARA: a subroutine within CROTOR that sets up parameters and gathers and saves parametric data for multiple propellers. ESPROP: a standalone utility that reads the resulting data file and presents the data in a variety of ways. The system has two chief applications: 1. The propeller designer seeking to directly compare competing designs over a wide range of operating conditions. 2. The propeller manufacturer (or buyer) seeking to select the optimum existing blade for a specific application. ESPROP databases can be built from any blade geometry that has been loaded into XROTOR, over any range of operating parameters for which XROTOR will converge solutions.