JMSDF unveils JS Izumo’s upgraded flight deck for F-35B operations

JMSDF unveils JS Izumo’s upgraded flight deck for F-35B operations

The JMSDF has released the first images of JS Izumo’s new rectangular flight deck as Phase 2 modifications progress to its conversion to the F-35B “Lightning Carrier”.

A photo of the new rectangular deck of the JS Izumo helicopter carrier, the first ship in its class, released by the Japan Maritime Self-Defense Force (JMSDF) on April 20, 2026. This is part of an extensive two-year modification to transform the ship into a “Lightning Carrier” capable of operating the F-35B Lightning II STOVL (Short Takeoff Vertical Landing) fighter jet.

The Maritime Self-Defense Force’s

This Izumo is in the second phase of an ongoing conversion program at the Japan Marine Union (JMU) Isogo shipyard in Yokohama City. The JMSDF previously said the new modifications, which include a complete redesign and extension of the bow, forward section and flight deck, will support reliable short takeoff and landing operations for the new fighter aircraft.

Izumo’s sister ship, JS Kaga, received a new rectangular flight deck, replacing the previous trapezoidal flight deck that tapered towards the bow. The service first unveiled the modifications in April 2024, which will allow the ship to operate with both U.S. Marine Corps and British F-35Bs.

traffic news JS Izumo’s renovation is expected to be completed by 2027. Although the F-35B belongs to the Japan Air Self-Defense Force (JASDF), it will operate from the JMSDF’s JS Izumo and JS Kaga. The two services are working to deploy both warships and secure a full fleet of 42 STOVL fighters.

Edits for JS Kaga and JS Izumo

To accommodate the F-35B, the Izumo-class Landing Helicopter Dock (LHD) amphibious assault ships JS Izumo and JS Kaga are undergoing extensive modifications to both their upper flight decks, main hull sections, and interior compartments.

Work on Kaga began at the Kure shipyard in Hiroshima in March 2022. JMSDF then released images after the rework on April 6, 2024, showing a new rectangular flight deck replacing the original trapezoidal flight deck.

In the first phase of the modification, heat-resistant materials were applied to Kaga’s flight deck to help it withstand the heat from the F-35B’s vector thrust engines. new lighting for night work; Centerline markings (tramlines) along the flight deck; Internal compartments and infrastructure that support F-35B operations, such as the magazines that store the jet’s ammunition.

Izumo will receive the same type of modification, the first phase of which will be completed at the same JMU shipyard in June 2021, aligning it with the ship’s periodic refit, refit and overhaul cycle. The second phase of reconstruction is broadly on schedule to begin between late 2024 and early 2025.

Images released by independent photographers on April 17 show the JS Izumo leaving dry dock before berthing along the dock before official images were released. Japan’s report also states that Ministry of Defense (MoD) Defense Directive No. 28 October 2024 A new designation was introduced for the converted former helicopter carrier, citing 317. “CVM” stands for Cruiser Voler Multi Purpose.

Department of Defense and JMSDF officials also clarified that “CVM” is not related to the U.S. Navy’s aircraft carrier designation “CVN” and does not mean that JZ Izumo and JS Kaga are aircraft carriers themselves. Both ships still carry the designation DDH (Destroyer Helicopter). These are JZ Izumo (DDH-183) and JS Kaga (DDH-184).

JMSDF Kaga F 35BJMSDF Kaga F 35B
A British F-35B lands at JS Kaga during Operation Highmast in 2025. (Image source: Royal Navy)

Both ships may be assigned a new CVM classification after reaching Initial Operational Capability (IOC) with the F-35B Lightning II.

Maritime Self-Defense Force preparing for F-35B operation

As mentioned, Izumo, along with her sister ship Kaga, was preparing for a major change in role and began operating as a “lightning carrier”, the conversion of which is currently in its final stages. The concept envisions using the massive helicopter carrier as a vessel to carry only the F-35B Lightning II stealth fighter, taking into account STOVL capabilities.

In 2021, Izumo conducted initial F-35B STOVL tests with the help of the USMC, which deployed its base to Japan to conduct flight operations from the ship. Prior to that test, JS Kaga received a new bow as part of the modifications.

Another major incident involving the F-35B occurred on October 20, 2024. At that time, a specially equipped Lightning II from Air Test and Evaluation Squadron Two Three (VX-23) landed at JS Kaga on the southern coast of California. In addition to VX-23’s F-35Bs, the F-35 Pax ITF (Pax River Integrated Test Force) team also boarded the San Diego ship to support testing, similar to testing on British and Italian aircraft carriers.

The JMSDF has also been working with the British Royal Navy to learn and prepare for F-35B operations in support of the “Lightning Carrier” concept. This led to the first British F-35B landing at JS Kaga in August 2025 during the Royal Navy’s CSG25 deployment.

The overall collaborative effort lays the foundation for a high-tech, sixth-generation Global Combat Air Program (GCAP) pursued by Tokyo, London and Rome.

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