Cessna Citation modifier Sierra Industries is expanding its product line by offering extended-range upgrades for the Citation I, II and S-II. The Uvalde, Texas company recently introduced for these older Citations a new aft fuel tank modification that adds 120 gallons of fuel capacity, extending range by as much as 400 nm. The FAA-approved “XR” modification entails installing a double-walled aluminum fuel cell in front of the aft cabin bulkhead, which Sierra claims makes the modified Citation I cabin virtually identical in size to a CJ1 while still allowing ample room to retain an aft toilet. The installation also includes a new pressure bulkhead, fuel lines and venting equipment and aft cabin reupholstering to match the original interior. The XR upgrade, which costs $199,000, is available for Citation Is and II/S-IIs with or without Sierra’s FJ44 engine upgrade. When combined with FJ44 re-engining, the XR upgrade adds approximately two weeks of installation time.