Citation Excel (Model 560XL), utilized a shortened Citation X fuselage combined with the V Ultra's straight wing and the V's tail; used new PW545A engines.[22][23] Includes a stand-up cabin. Citation XLS, evolved from the Excel Citation XLS+ which includes FADEC (Full Authority Digital Engine Control) and a redesigned avionics system.[24] Citation Sovereign (Model 680), utilizes a stretched version of the Excel's fuselage with an all-new moderately swept wing.[25][26] Stand-up cabin is 24 feet (7.3 m) long.[27]