The Japan Maritime Self-Defense Force (JMSDF) has announced that it has completed the first of a two-stage modification for its helicopter carrier JS Kaga to operate the Lockheed Martin F-35B fighter aircraft.
“We had carried out the first special modification work on the destroyer Kaga in conjunction with a regular inspection for about two years starting at the end of fiscal year 2021, and the modification was completed as planned on March 29 of this year.”
Admiral Ryo Sakai, Chief of staff of the JMSDF
“The destroyer Kaga is scheduled to undergo various tests (such as sea trials) during this fiscal year after the first modification, and the results of those tests will be reflected in the second special modification of Izumo, which will begin this fiscal year,” Sakai said.
“The Japan Maritime Self-Defense Force will continue to steadily advance the necessary modifications to acquire the operational capability of the F-35B on Izumo-class destroyers,” the top officer of the JMSDF added.
The service also announced the completion of JS Kaga’s first-stage modification on X on April 6.
According to the JMSDF, the modifications to its two Izumo-class helicopter carriers – JS Izumo (DDH 183) and JS Kaga (DDH 184) –are underway in two main stages to coincide with the vessels’ periodic refit and overhaul programs, which take place every five years.
The JMSDF expects both ships to complete all of the upgrades to become a light aircraft carrier operating F-35B fighters around fiscal year 2027.
As for Kaga, Japan Marine United (JMU) started refit work on at the company’s Kure shipyard in Hiroshima in March 2022. Its initial modifications include the modifications of the bow section of its flight deck into a square shape from a trapezoid, similar to that found on the US Navy’s Wasp-class and America-class amphibious assault ships. The first-stage modifications also include reinforcing the flight deck to support additional weight, placing additional guidance lights, drawing the yellow lines on the flight deck necessary for launching and landing F-35Bs, and fitting the ship with heat-resistant deck spots for vertical landings.
The second and final modifications, which are expected to be made during Kaga‘s next overhaul starting from the end of fiscal year 2026, include changes to the ship’s interior compartments and crew waiting areas.
Kaga was initially scheduled to undergo only a one-time large-scale renovation in conjunction with a large-scale regular inspection that takes place once every five years starting at the end of fiscal 2021.
However, regarding the retrofit improvement of its internal compartments and crew waiting areas, the JMSDF conducted it was necessary to finalize the details of the interior modification only after conducting verification experiments and tests with the cooperation of the U.S. military, and carefully considering the movements and flow lines of crews and goods during actual operations.
For this reason, the remodelling of the ship’s internal compartments was scheduled to be carried out not in conjunction with the regular inspection starting in fiscal 2021, but in conjunction with the regular inspection from the end of fiscal 2026.
Meanwhile, the service has begun the process of converting Izumo into a carrier capable of supporting F-35B operations in Yokohama City of Kanagawa in the first half of 2020, and its first-stage modifications were completed in June 2021 by upgrading the carrier’s fight deck and fitting heat-resistant deck spots for vertical take-offs and landings. A single yellow marking line (tramline) was also drawn on the flight deck from bow to stern. This line is provided on the flight deck of carrier-based aircraft to guide pilots during takeoff and landing. On October 5, 2021, when the U.S. Marine Corps F-35B conducted a takeoff and landing test on Izumo, the pilot landed with the centre of the aircraft aligned with this yellow marking line.
The second refurbishment of Izumo will begin in this fiscal year 2024. Just like the current Kaga, its bow is planned to be modified to a square shape during this second phase. The Japan Ministry of Defense (MoD) expects the modifications of the Izumo to be completed by the end of fiscal year 2026.
The MoD plans to deploy the F-35Bs to the Japan Air Self-Defense Force’s (JASDF’s) Nyutabaru Air Base on Kyushu Island from fiscal year 2024. By deploying F-35Bs to Nyutabaru, Tokyo intends to enhance Japan’s ability to defend its remote southern islands, including those near the disputed Senkaku/Diaoyu Islands. These islands are controlled by Japan but claimed by China and Taiwan.
The MoD plans to procure a total of 42 F-35Bs, along with 105 F-35As.
