Japan Maritime Self-Defense Force (JMSDF) unveiled the newly modified multi-role helicopter carrier Kaga to the press on April 8 at its Kure Base in Kure, Hiroshima Prefecture—much to China’s discomfiture—after completing the first phase of the transformation process. 

After undergoing two years of extensive modification, Japan’s multi-role helicopter carrier is now capable of accommodating fixed-wing fighter jets. The modifications, aimed at transforming Kaga into a seagoing base for F-35Bs, involved substantial alterations to the vessel’s structure and capabilities. 

One of the notable changes is the conversion of the ship’s flat deck to withstand the exhaust heat generated by vertical takeoff and landing fighters. The deck is now coated with heat-resistant paint, and markings for takeoffs, including a distinctive yellow line, were added to guide aircraft during operations. 

Further, the shape of the Kaga’s bow was transformed from a trapezoid to a rectangle to address turbulence issues during aircraft takeoff and ensure a safe distance for operations. This modification aligns the Kaga’s design more closely with that of full-scale aircraft carriers.

The F-35B fifth-generation fighter jets can direct their jet engine nozzles downward, enabling short takeoff and vertical landing operations. 

Captain Ichiro Kokubu, the Kaga’s commander, emphasized the significance of the vessel’s transformation, stating, “It is the first time for the MSDF to undertake such big (modification) work.” 

He expressed the JMSDF’s commitment to leveraging the Kaga’s enhanced capabilities to contribute to national security effectively. 

The unveiling follows the Japan Maritime Self-Defense Force’s release of photos via X (formerly Twitter) last week, confirming the completion of the first stage of special modification work on the destroyer “Kaga” on March 29.

The Kaga, Japan’s second Izumo-class helicopter carrier, now resembles the US Navy’s America-class amphibious assault ships. 

The Kaga has been serving as the nation’s second vessel of this class. The Izumo-class ships hold the distinction of being the largest surface combat vessels within the Japan Maritime Self-Defense Force, boasting an impressive overall length of 248 meters. 

The first vessel of its class, the Izumo, has already undergone its initial modification stage. However, this work primarily entailed the application of heat-resistant paint to its flight deck. Kaga is the first vessel in the Japan MSDF fleet to have its flight deck redesigned into a rectangular shape.

Second Phase Of Modification To Be Completed By 2027

The end of the initial modification phase of the Kaga reflects the outcome of the government’s 2018 choice to enable the Izumo-class destroyers to accommodate F-35B fighter jets.

The Kaga’s modification work commenced in March 2022 and was finalized on March 29 of the current year. Plans are now in place for the Kaga to undergo second-stage modifications starting in fiscal 2026, with alterations expected within the ship’s body.

Similarly, the first vessel of the class, Izumo, is slated to undergo its second-stage modification within the ongoing fiscal year. The JMSDF anticipates that both vessels will complete all necessary upgrades to operate as light aircraft carriers, supporting F-35B fighters, by around fiscal year 2027.

This development heralds a significant shift for the MSDF, which has not possessed aircraft carriers since the Second World War. With the conversion of the Izumo-class destroyers, Japan is poised to have two vessels to support its incoming fleet of 42 F-35B jets.

Despite these modifications, the Japanese government has been cautious in its terminology, refraining from explicitly labeling the modified Izumo-class vessels as aircraft carriers. This decision aligns with the nation’s long-standing defensive security policies under its pacifist Constitution.

According to government statements, the Kaga and Izumo are regarded as multi-functional ships capable of various roles, including transportation and medical care facilities, in addition to their aircraft-handling capabilities. 

The government argues that these vessels fulfill the minimum equipment necessary for self-defense and pose no violation.

Beijing, on the other hand, has opposed the modification of these vessels and has characterized Japan’s Izumo-class helicopter destroyers as “aircraft carriers in disguise.” 

Nonetheless, the Kaga, with its enhanced flight deck, is projected to support up to 14 Lockheed F-35B fighter jets, which possess Short Take-Off and Vertical Landing (STOVL) capability.

In its defense budget disclosed in August 2023, Japan unveiled plans to acquire 42 F-35B jets, with the first six expected to arrive in late 2024. These jets will be stationed at Nyutabaru Air Base on Kyushu Island.