A swivel base assembly for an aircraft seat, comprising: a swivel center beam; a swivel plate pivotally coupled to the swivel center beam, the swivel plate configured to rotate with respect to the swivel center beam about a first centerline axis, the swivel plate comprising at least one attachment feature for attaching to a base member of said seat; a first side rail coupled to the swivel center beam; and a second side rail coupled to the swivel center beam, the swivel center beam being located between the first side rail and the second side rail, wherein a track lug is pivotally coupled to the first side rail, the track lug configured to retain the first side rail in a track and translate along the track, wherein the swivel center beam comprises: a center body; a first member extending from the center body having a first aperture; a second member extending from the center body having a second aperture; a third member extending from the center body having a third aperture in which a first fastener for attaching the third member to the second side rail is received; and a fourth member extending from the center body having a fourth aperture in which a second fastener for attaching the fourth member to the second side rail is received, characterised in that: a first sliding bar for coupling the first member to the first side rail is received in the first aperture; and a second sliding bar for coupling the second member to the first side rail is received in the second aperture; wherein the first aperture comprises a second centerline axis, the second centerline axis being perpendicular with the first centerline axis, the swivel base assembly further comprising a pin for retaining the first sliding bar at least partially within the first aperture, wherein the pin extends in a direction being perpendicular with the second centerline axis, wherein the first member is configured to receive the pin. a swivel center beam; a swivel plate pivotally coupled to the swivel center beam, the swivel plate configured to rotate with respect to the swivel center beam about a first centerline axis, the swivel plate comprising at least one attachment feature for attaching to a base member of said seat; a first side rail coupled to the swivel center beam; and a second side rail coupled to the swivel center beam, the swivel center beam being located between the first side rail and the second side rail, wherein a track lug is pivotally coupled to the first side rail, the track lug configured to retain the first side rail in a track and translate along the track, wherein the swivel center beam comprises: a center body; a first member extending from the center body having a first aperture; a second member extending from the center body having a second aperture; a third member extending from the center body having a third aperture in which a first fastener for attaching the third member to the second side rail is received; and a fourth member extending from the center body having a fourth aperture in which a second fastener for attaching the fourth member to the second side rail is received, characterised in that: a first sliding bar for coupling the first member to the first side rail is received in the first aperture; and a second sliding bar for coupling the second member to the first side rail is received in the second aperture; wherein the first aperture comprises a second centerline axis, the second centerline axis being perpendicular with the first centerline axis, the swivel base assembly further comprising a pin for retaining the first sliding bar at least partially within the first aperture, wherein the pin extends in a direction being perpendicular with the second centerline axis, wherein the first member is configured to receive the pin. a center body; a first member extending from the center body having a first aperture; a second member extending from the center body having a second aperture; a third member extending from the center body having a third aperture in which a first fastener for attaching the third member to the second side rail is received; and a fourth member extending from the center body having a fourth aperture in which a second fastener for attaching the fourth member to the second side rail is received, characterised in that: a first sliding bar for coupling the first member to the first side rail is received in the first aperture; and a second sliding bar for coupling the second member to the first side rail is received in the second aperture; wherein the first aperture comprises a second centerline axis, the second centerline axis being perpendicular with the first centerline axis, a first sliding bar for coupling the first member to the first side rail is received in the first aperture; and a second sliding bar for coupling the second member to the first side rail is received in the second aperture; wherein the first aperture comprises a second centerline axis, the second centerline axis being perpendicular with the first centerline axis, the swivel base assembly further comprising a pin for retaining the first sliding bar at least partially within the first aperture, wherein the pin extends in a direction being perpendicular with the second centerline axis, wherein the first member is configured to receive the pin.