JMSDF releases first images of JS Izumo’s new rectangular flight deck as second-phase modifications progress, advancing its conversion into an F-35B “Lightning Carrier.”
The Japan Maritime Self-Defense Force (JMSDF) released on Apr. 20, 2026, new photos of the JS Izumo helicopter carrier, the lead ship of her class, with a new rectangular deck. This is part of extensive modifications underway since two years to convert the vessel into a “Lightning Carrier” capable of operating the F-35B Lightning II Short Take-Off Vertical Landing (STOVL) fighter.
The X post by the JMSDF Surface Fleet said: “The escort vessel ‘Izumo’ has reached a milestone in the modification work to alter the bow shape related to its special refit, and took a commemorative photo with those involved. Preparations are steadily progressing toward completion.”
This Izumo is in the second phase of its refurbishment program underway at the Japan Marine United’s (JMU) Isogo Shipyard in Yokohama City. The JMSDF had previously said that the new modifications, which include a complete redesign and extension of the bow, forward section and flight deck, aid stable short take-off and landing operations with the new fighter.
護衛艦「いずも」は、特別改造に係る艦首形状の改修工事の節目を迎え、関係者と記念撮影を行いました。
完工に向け着々と準備が進みます。#いずも #水上艦隊 pic.twitter.com/sDFkNDARfF
— 海上自衛隊 水上艦隊【公式】 (@JMSDF_SUF) April 19, 2026
Izumo’s sister ship, the JS Kaga, received the new rectangular flight deck replacing the previous trapezoidal one which tapered towards the bow. The service first unveiled the modification in April 2024, along with a host of other changes, which allowed the ship to operate with both U.S. Marine Corps and British F-35Bs on board.
Traffic News reports the refurbishment of the JS Izumo is expected to be concluded by 2027. The F-35Bs, although belonging to the Japan Air Self-Defense Force (JASDF), will operate off the JMSDF’s JS Izumo and JS Kaga, as the two services work on fielding the two warships and acquiring the full fleet of 42 STOVL fighters.
JS Kaga and JS Izumo modifications
To employ the F-35B, the Izumo-class Landing Helicopter Dock (LHD) amphibious assault ships JS Izumo and JS Kaga are undergoing extensive modifications both on the upper flight deck, a major part of the hull and internal compartments.
The work on the Kaga commenced in March 2022 at Hiroshima’s Kure shipyard. The JMSDF then released images after the rework on Apr. 6, 2024, showing a new rectangular flight deck replacing the original trapezoidal one.
The first special modification work on the destroyer ”KAGA” was completed as planned on March 29.
The JMSDF will continue to systematically carry out the necessary modifications to the “IZUMO” class destroyer in order to acquire the operational capability of the F-35B. pic.twitter.com/JTaLkjRWu5
— Japan Maritime Self-Defense Force (@jmsdf_pao_eng) April 6, 2024
In the first phase of its modification, the Kaga’s flight deck also received heat-resistant material on its flight deck to tolerate the heat of the F-35B’s vectored thrust engine; new lights for nighttime operations; centerline marking (tramline) along the flight deck; and internal compartments and infrastructure to support F-35B operations, like magazines storing the jet’s munitions.
The Izumo would receive the same type of modifications, with the first phase completed in June 2021 at the same JMU shipyard, aligned with the ship’s periodic refit, repair and overhaul cycles. The reconstruction’s second phase has largely stuck to the timeline, expected to commence between late 2024 and early 2025.
https://t.co/E0qye2c2So
04/17/2026 こっちはカメラで撮影した 護衛艦いずも(JMSDF Izumo DDH-183 >CVM-183)
護衛艦 かが との違いは…艤装中なのでまだわかりませんでした pic.twitter.com/XG15HNBa4t
— ( ｡･㉨･｡)ฅ (@Gov_Vessel_fan) April 17, 2026
Images published on Apr. 17 by independent photographers show that JS Izumo emerged from the dry dock, before berthing along the pier, before the official images were released. Reports from Japan have also cited an Oct. 28, 2024, Ministry of Defense (MoD) Defense Instruction No. 317 introducing a new designation for the modified former helicopter carriers, called “CVM”, which stands for Cruiser Voler Multipurpose.
MoD and JMSDF officials have also clarified that “CVM” has no relation to the U.S. Navy’s “CVN” designation for aircraft carriers, and it does not mean that the JZ Izumo and JS Kaga are aircraft carriers themselves. Both the ships still carry the designation DDH (Destroyer Helicopter) – JZ Izumo (DDH-183) and JS Kaga (DDH-184).
The new CVM classification might be assigned after both vessels reach Initial Operational Capability (IOC) with the F-35B Lightning IIs.
JMSDF preparing for F-35B operations
As mentioned, the Izumo, along with its sister ship Kaga, was being prepared for a major change of role and to begin operating as a “Lightning Carrier,” with the conversion works currently in the final stages. The concept envisages using the massive helicopter carrier ship as a vessel carrying only F-35B Lightning II stealth fighters, given their STOVL capability.
護衛艦「いずも」(JS Izumo, DDH-183)、甲板にSH60を搭載したまま、逸見岸壁に戻ってきました。
ご苦労さまでした。 pic.twitter.com/6g1ou13AzP
— MICHIYA MURATA (@MICHIYAM) June 25, 2024
In 2021, the Izumo held the initial F-35B STOVL testing with the help of the USMC, which sent its Japan-based aircraft to conduct flight operations on the ship. Prior to that test, the JS Kaga had received a new bow as a part of the modifications.
Another major event with the F-35B took place on Oct. 20, 2024, when a specially instrumented Lightning II from the Air Test and Evaluation Squadron Two Three (VX-23) landed on the JS Kaga off the coast of southern California. Along with the F-35B from the VX-23, a team from the F-35 Pax ITF (Pax River Integrated Test Force) also embarked on the ship in San Diego to support the testing, similar to the trials on the British and Italian carriers.
F-35Bが現地時間10月20日15時ごろ、初の着艦に成功！！🛩⚓ @USNavy @USMC
矩形の飛行甲板となった護衛艦「#かが」は #F35B の艦上運用に必要な諸元を収集するため、🇺🇸サンディエゴ沖にて米海軍及び米海兵隊の支援を得て所要の試験を実施中です！#自由で開かれたインド太平洋 pic.twitter.com/ar7tVYhSEc
— 防衛省 海上自衛隊 (@JMSDF_PAO) October 21, 2024
The JMSDF has also been cooperating with the UK’s Royal Navy to learn and prepare for F-35B operations in support of its “Lightning carrier” concept. This led to British F-35Bs landing on the JS Kaga for the first time in August 2025, during the Royal Navy’s CSG25 deployment.
The overall cooperation effort lays the groundwork for the high-tech sixth generation Global Combat Air Program (GCAP) being pursued by Tokyo, London and Rome.
