A turbine engine includes an input shaft and a fan shaft rotatable about an axis. The fan shaft supports fan blades. An epicyclic gear train is connected between the input shaft and the fan shaft. The epicyclic gear train includes a plurality of star gears, a carrier supporting the plurality of star gears, a sun gear that meshes with the plurality of star gears and a ring gear surrounding and meshing with the plurality of star gears such that the sun gear is rotatable in a first direction and the ring gear is rotatable in a second, opposite direction. The ring gear includes first and second portions that each have an inner periphery with teeth. The first and second portions include respective recesses facing one another to provide an internal annular cavity.