Japanese big deck JS Kaga (DDH-184) wrapped trials for F-35B Lightning II off the Japan Maritime Self-Defense Force said this week. Kaga had been in F-35B trials off California since Oct. 19 in preparation for Japan operating the aircraft off the Izumo class destroyer carriers.
“JS Kaga has successfully completed onboard trials for F-35B operations!” stated a social media post on X by the JMSDF which added in a follow-up post that “At the joint press conference by Vice Adm. Goka Commander Escort Fleet and Vice Adm. John Wade Commander US Third Fleet, the strong ties between Japan & U.S. were reaffirmed. We remain committed to working together for a Free And Open Indo Pacific and deepening ties with allied navies.”.
The F-35B aircraft conducting the trials on Kaga were U.S. test aircraft assigned to the “Salty Dogs” Air Test and Evaluation Squadron 23 (VX-23) with the test pilots coming from the F-35 Patuxent River Integrated Test Force (Pax ITF). The unit is responsible for testing all seagoing F-35 variants and comprised of personnel from the U.S Navy and Marine Corps, U.K. Royal Air Force, Royal Navy, Lockheed Martin, British Aerospace, Northrop Grumman and U.S. government civilian personnel. A Royal Navy pilot, Lt. Cmdr. Nick Baker, attached to PAX ITF, was one of the test pilots, announced the U.K. Defence Staff in the United States on its social media account.
Kaga’s shipboard trials are the second ones carried out by the JMSDF with F-35Bs. On Oct. 3 2021, Kaga’s sister ship JS Izumo (DDH-183) hosted two F-35Bs from the “Bats” of Marine Fighter Attack Squadron 242 (VMFA-242) based at Marine Corps Station Iwakuni, Japan.
JS KAGA has successfully completed onboard trials for F-35B operations!🌊🚢✈️ pic.twitter.com/aI5QWHb0aU
— 防衛省 海上自衛隊 (@JMSDF_PAO) November 7, 2024
Both Izumo and Kaga were originally built as helicopter carriers but are being converted to operate F-35Bs. Izumo completed its first-stage conversion in 2021, including upgrading its flight deck and landing equipment, repainting its deck lines and applying heat-resistant coating to the deck to enable it to withstand the heat generated by the F-35B’s exhausts. Kaga underwent a more extensive first-stage conversion that began in 2022 and was completed on Mar. 29 this year in which the bow flight deck was modified from a trapezoid to a rectangle shape similar to the U.S. Wasp- and America-class amphibious assault ships, along with also having the same improvement works carried out earlier on Izumo.
The second-stage conversion for Izumo, likely to begin late this year or before April next year in line with the Fiscal Year 2024 target date (Japan’s fiscal year spans from Apr.1 to Mar. 31), will involve the rectangular deck conversion along with configuring the interior compartments and components for F-35B operations, including magazines for storing F-35B munitions. The exact configuration of the interior will be based on the results of Kaga’s trials, during which the JMSDF will experience actual movements of F-35Bs on Kaga’s new deck layout. As Izumo will initially undergo the deck conversion first, there will be enough time for the results of the Kaga’s trials to be analyzed and the optimum interior configuration to be determined for the interior modifications. Izumo is expected to complete its modifications by late FY 2026 with Kaga then going in for work to reconfigure its interiors following Izumo’s return to the fleet.
Although the JMSDF has a fleet air arm, the 42 F-35Bs that Japan has ordered will be part of the Japan Air Self Defense Force which will operate a total of 105 F-35As alongside the Bs once deliveries are completed. This is in contrast to the approach taken by the U.K and Italy, the U.K, which only operates the F-35Bs has them under a command known as the Lightning Force which comprises of a mix of RAF and RN personnel with currently 3 RAF Squadrons and 1 RN Squadron though all four Squadrons comprise of personnel from both services. The Italian Air Force both operates F-35As and Bs while the Italian Navy operates F-35Bs as the Italian Air Force uses the Bs to conducted dispersed operations for ground strikes and close air support along with also augmenting the Italian Navy’s carrier embarked F-35Bs as was in the case of the Cavour Carrier Strike Group (CSG) deployment to the Indo-Pacific where two Italian Air Force F-35Bs augmented the six Italian Navy F-35Bs embarked on carrier ITS Cavour (550).
Japan has been drawing on the experiences of both the United Kingdom and Italy on F-35B operations with a joint JMSDF/JASDF team observing F-35B trials conducted by U.K. carrier HMS Prince of Wales (R09) off the U.S. East Coast in October last year, while HMS Queen Elizabeth (R08) in 2021 and Cavour this year conducted both port visits in Japan and engagements with the JMSDF and JASDF during their deployment to the Indo-Pacific along with Japan also conducting various staff and technical talks over the past years with the two countries in regard to carrier-based F-35B operations.
