Core housings for gas turbine engines are described. The core housings include a housing surface defining an exterior surface of the core housing, a housing aperture arranged on the housing surface, the housing aperture configured to enable fluid communication between an external environment and an interior of the core housing, a drainage hole arranged upstream relative to the housing aperture, the drainage hole configured to enable draining of a fluid from an interior of the core housing to the external environment, and a redirection device arranged to receive a fluid from the drainage hole and direct such fluid away from the housing aperture.