An aircraft system comprising: an inverted compound harmonic drive comprising: a wave generator configured to receive rotational input; a flex spline disposed radially within the wave generator that receives energy due to the rotation of the wave generator, the flex spline including a plurality of inner facing splines that include an axial center spline, a first axial end spline being adjacent to and forward of the axial center spline, and a second axial end spline adjacent to and aft of the axial center spline; an output gear meshes with the axial center spline; a first ground gear adjacent to and forward of the output gear that meshes with the first axial end spline; and a second ground gear adjacent to and aft of the output gear that meshes with the second axial end spline; wherein: the first axial end spline and the first ground gear have a first gear ratio; the second axial end spline and the second ground gear have a second gear ratio that is the same as the first gear ratio; and the axial center spline and the output gear have a third gear ratio that differs from the first and second gear ratios; wherein: the first ground gear includes a first ground shaft extending in a forward direction and connecting with aircraft ground structure; the second ground gear includes a second ground shaft extending in an aft direction and connecting with the aircraft ground structure; and the output gear includes an output shaft, the output shaft including one or more of: a first shaft portion extending in the forward direction with a first passage therethrough, the first passage being splined; and a second shaft portion extending in the aft direction with a second passage therethrough, the second passage being continuous with the first passage, the second passage being splined; wherein: the wave generator receives rotational input from a first aircraft component; and wherein the output shaft is configured to connect with a second aircraft component. an inverted compound harmonic drive comprising: a wave generator configured to receive rotational input; a flex spline disposed radially within the wave generator that receives energy due to the rotation of the wave generator, the flex spline including a plurality of inner facing splines that include an axial center spline, a first axial end spline being adjacent to and forward of the axial center spline, and a second axial end spline adjacent to and aft of the axial center spline; an output gear meshes with the axial center spline; a first ground gear adjacent to and forward of the output gear that meshes with the first axial end spline; and a second ground gear adjacent to and aft of the output gear that meshes with the second axial end spline; a wave generator configured to receive rotational input; a flex spline disposed radially within the wave generator that receives energy due to the rotation of the wave generator, the flex spline including a plurality of inner facing splines that include an axial center spline, a first axial end spline being adjacent to and forward of the axial center spline, and a second axial end spline adjacent to and aft of the axial center spline; an output gear meshes with the axial center spline; a first ground gear adjacent to and forward of the output gear that meshes with the first axial end spline; and a second ground gear adjacent to and aft of the output gear that meshes with the second axial end spline; wherein: the first axial end spline and the first ground gear have a first gear ratio; the second axial end spline and the second ground gear have a second gear ratio that is the same as the first gear ratio; and the axial center spline and the output gear have a third gear ratio that differs from the first and second gear ratios; the first axial end spline and the first ground gear have a first gear ratio; the second axial end spline and the second ground gear have a second gear ratio that is the same as the first gear ratio; and the axial center spline and the output gear have a third gear ratio that differs from the first and second gear ratios; wherein: the first ground gear includes a first ground shaft extending in a forward direction and connecting with aircraft ground structure; the second ground gear includes a second ground shaft extending in an aft direction and connecting with the aircraft ground structure; and the first ground gear includes a first ground shaft extending in a forward direction and connecting with aircraft ground structure; the second ground gear includes a second ground shaft extending in an aft direction and connecting with the aircraft ground structure; and the output gear includes an output shaft, the output shaft including one or more of: a first shaft portion extending in the forward direction with a first passage therethrough, the first passage being splined; and a second shaft portion extending in the aft direction with a second passage therethrough, the second passage being continuous with the first passage, the second passage being splined; a first shaft portion extending in the forward direction with a first passage therethrough, the first passage being splined; and a second shaft portion extending in the aft direction with a second passage therethrough, the second passage being continuous with the first passage, the second passage being splined; wherein: the wave generator receives rotational input from a first aircraft component; and wherein the output shaft is configured to connect with a second aircraft component. the wave generator receives rotational input from a first aircraft component; and wherein the output shaft is configured to connect with a second aircraft component.