An inlet protection system for filtering air prior to entry into an air intake of an engine of an aircraft includes interchangeably a particle separator panel and a barrier filter panel. The barrier filter panel is adapted to be mounted conformal to the contour of the aircraft and to be interchangeable with the particle separator panel. The particle separator panel has an outer skin and a plurality of particle separators. The outer skin has an opening disposed along a portion of it to discharge filtered particles from within the removable panel directly outward therefrom.