The planned delivery of the first six F-35B Lightning II fighters for Japan in FY2024 has now been pushed back to sometime during FY2025, Japan’s Defense Minister announced.
The delivery of the first six F-35Bs to the JASDF (Japan Air Self Defense Force), which was planned to happen sometime during FY (Fiscal Year) 2024 (which ends on Mar. 31, 2025), has now been postponed to sometime during FY2025. The specific dates for the delivery are still under discussion. The Defense Minister did not provide a reason for the postponement.
The manufacturer of the F-35, Lockheed Martin, resumed deliveries of the jet after the Pentagon lifted its year-long pause on the entire F-35 line in July 2024. The pause in deliveries to both its own military and foreign customers was due to the premature TR-3 (Technology Refresh 3) upgrade still being under development.
Japan intends to station the first batch of its F-35Bs at Nyutabaru Air Base, a base located in the southern part of the island of Kyushu, which is currently equipped with the F-15J/DJ interceptors. This is due to the base’s close proximity to the home port of the JS Kaga in JMSDF (Japan Maritime Self Defense Force) Kure, in Hiroshima prefecture. The set up of a temporary squadron for the F-35B in preparation for the induction continues as planned at Nyutabaru, and will take place by the end of FY2024.
“I understand that there will not be a major impact from this delivery delay, but in any case, in order to minimize the impact, we will continue to work with the U.S. side toward deployment and steadily advance the work to accept the deployment of the temporary F-35B squadron that will be established this fiscal year,” said the Japanese Defense Minister Nakatani. Future batches shouldn’t be affected by this delay, he also added.
The F-35B
The B variant of the now very popular F-35 is a STOVL (Short Take Off and Vertical Landing) platform, which allows the pilot to take off and land vertically or from very short runways. It was initially designed for the USMC (U.S. Marine Corps), who is the primary operator of the aircraft.
Other operators currently include the Italian Air Force and Navy, the UK’s Royal Air Force and Royal Navy, while Singapore’s RSAF (Republic of Singapore Air Force) is also set to receive the B model in the future, alongside the JASDF (Japan Air Self Defense Force). As currently the only actively fielded STOVL fighter aircraft besides the venerable AV-8B Harrier, the stealth F-35B allows its operators to fly the jet from almost any runway, or even from locations without a proper runway, giving them a significant advantage and flexibility.
The aircraft is designed to provide advanced multirole capabilities, leading pilots to even define it the “Swiss Army Knife of the Stealth Fighter Community.” In fact, the F-35 can “takeoff with a full combat load in around 500 feet, execute supersonic flight at upwards of 1.6 Mach, leverage its stealth capabilities” in highly contested environments and from locations inaccessible to CTOL (Conventional Take Off and Landing) fighters like the F-35A.
Central to the F-35B’s STOVL capability is its innovative propulsion system, which incorporates a swivel nozzle and a lift fan. This configuration allows the aircraft to transition between conventional flight and vertical operations seamlessly, while also offering greater payload capacity and range compared to previous STOVL aircraft like the AV-8B Harrier II. The weapons bays of the F-35B, however, are smaller than the ones of the A variant, as the lift fan limits the space available.
Similarly to the F-35A, the F-35B integrates advanced low observable technology, AN/APG-81 AESA radar, Distributed Aperture System (DAS), and Electro-Optical Targeting System (EOTS). The fusion of the data from these sensors, as well as from other F-35s connected through the Multifunction Advanced Data Link (MADL), into the cockpit’s Large Area Display (LAD) and the pilot’s Helmet-Mounted Display (HMD) ensures a greater situational awareness in highly contested environments.
The F-35B in Japanese service
Plans are in place to operate the STOVL fighter jets from the JMSDF’s two Izumo-class DDHs (Helicopter-carrying Destroyers), the JS Izumo and JS Kaga, which are currently undergoing conversion to allow F-35B operations. To better prepare for the arrival of the new aircraft, Japan is studying F-35s operations from other navies who already operate the type, such as the Italian Navy and Royal Navy.
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The F-35B has undergone tests with Japanese vessels twice, with the Izumo conducting flight ops in 2021, while the Kaga just recently had a F-35B land on its deck. Both of these tests were conducted with non-Japanese jets and pilots. The Izumo is set to start F-35B operations in 2027, while the Kaga will induct it into service a year later in 2028.
Interestingly, although the aircraft are planned to operate from these JMSDF vessels, the F-35B itself will be operated by the JASDF. The service plans to operate up to 105 F-35A CTOL (Conventional Take Off and Landing) and 42 F-35B V/STOVL fighter jets alongside their previous inventory of F-15J/DJs and F-2A/Bs.
The JMSDF also operates its own fleet of fixed-wing assets, although it does not operate any fighter aircraft. Their fixed-wing fleet comprises mainly of maritime patrol aircraft such as various variants of the venerable P-3 and its successor, the domestically produced P-1, as well as transport aircraft like the C-130 and ShinMaywa US-2 floatplane.
The Japanese carriers
Both the JS Izumo and the JS Kaga were announced to be put through modifications to their flight deck to become able to operate F-35B Lightning II STOVL (Short Take-Off Vertical-Lanning) aircraft and be employed as “Lightning Carriers.” The Izumo underwent the first phase of modifications in 2021, where its flight deck was coated with heat-resistant paint, and later saw the first landing of a F-35B in cooperation with the U.S. Marine Corps.
The work on the Kaga commenced in Mar. 2022 at Hiroshima’s Kure shipyard. The JMSDF then released images after the rework in 2024, showing a new rectangular flight deck replacing the original trapezoidal one. Work on the new flight deck of the Izumo is expected to commence by the end of FY2024.
Among the other modifications to the two vessels is a rework of the internal compartments and infrastructure to support F-35B operations, including magazines storing the jet’s munitions. Even after the end of the work, the ships will still be referred to as the “Izumo-class multi-functional destroyers,” as the Article 9 of the Japanese constitution forbids offensive weapons, including aircraft carriers.
The defensive focus of the vessels and F-35Bs is also highlighted by U.S. experts. “By operating F-35B aircraft from Izumo-class ships, the JMSDF will be able to extend its surveillance and reconnaissance and defensive weapons range by hundreds of miles,” mentioned the U.S. Naval Institute in its proceedings.
“Detecting and destroying attacking ships and aircraft before they can launch their weapons is the best means of defending the Self-Defense fleet,” further added the USNI. “In the short-term, modifying Izumo-class ships to operate STOVL tactical aircraft will provide the Self-Defense fleet, in concert with JASDF, JGSDF, and U.S. forces, an effective means to conduct the offensive tactics required for a defensive sea-control strategy.”
