A driveshaft vessel assembly for a gas turbine engine is disclosed. The driveshaft vessel assembly comprises a driveshaft vessel and an outlet guide vane. The driveshaft vessel includes a forward face, an aft face, and opposing side faces and is configured to house at least a portion of a radial driveshaft. The outlet guide vane includes a leading edge and a trailing edge. The length of the trailing edge is substantially equal to a length of the forward face of the driveshaft vessel such that the trailing edge of the outlet guide vane is faired into the forward face of the driveshaft vessel.