Fiscal Year 2001. This program combines major structural improvements with Command, Control, Communications, Computer and Navigation upgrades and adds 10 years to the service life, extending it to 30 years. In FY 2001, it was funded at $19.9 million and extended the service life of 1 craft. The SLEP is planned for a total of 72 craft. The near-term focus will be on the "C4N" [Command, Control, Communications, Computers, and Navigation] program, to replace the crafts' obsolete equipment. This will focus on replacement of LN-66 radars with modern, high-power P-80 radar systems. Additionally, the SLEP will include an open-architecture concept, relying on modern commercial-off-the-shelf (COTS) equipment, which will allow much easier incorporation of later technology changes, such as the precision navigation system and communications systems ¾ fully interoperable with in-service and near-term future Joint systems ¾ now planned. The C4N program is to complete by 2010. Through 2016, the Navy will look to incorporate other important service-life enhancements: Engine upgrades (ETF-40B configuration) that will provide additional power and lift particularly in hot (, and higher) environments, reduced fuel consumption, reduced maintenance needs, and reduced lift footprint; Replacement of the buoyancy box to solve corrosion problems, incorporate hull improvements, and "reset" the fatigue-limit "clock"; Incorporation of a new (deep) skirt that will reduce drag, increase performance envelope over water and land, and reduce maintenance requirements. As of September 2012, there were 80 LCACs in the U.S. Navy inventory; 39 LCACs had undergone the SLEP conversion and 7 were in progress and 4 are awaiting induction. The FY 2013 budget authorized 4 SLEP conversions per year through FY 2018. The last of the 72 SLEP conversions will be delivered to the Navy in FY 2020. After the first SLEP LCAC reached its 30 years design service age in 2015, it was to gradually be retired. In 2019, at which point the inventory of LCACs had fallen to 50, the USN began receiving the new Ship-to-Shore Connector (SSC), the LCAC-100. The USN inventory of LCACs was projected to fall until 2023 after which SSC replacements would increase it. Japanese operations Six LCAC are in use by the Japan Maritime Self-Defense Force. Approval for the sale was given by the United States Government on 8 April 1994. The craft were built by Textron Marine & Land Systems in New Orleans, Louisiana. Purchase of the first craft was included in the FY93 budget, second in