A U.S. Marine Corps F-35B stealth fighter has for the first time operated aboard Japan’s biggest in-service warship, the Izumo class ‘multifunctional destroyer’ Kaga. We have previously reported on the significant modifications made to this ship to ensure it can operate the short takeoff and vertical landing (STOVL) jets, which Japan is also acquiring. At the same time, there are signs that Japan may also be looking to expand the fixed-wing capabilities of this class of vessel, including drones and potentially other crewed platforms.
A Marine Corps F-35B flown by a test pilot from Air Test and Evaluation Squadron Two Three (VX-23) landed aboard Kaga for the first time on October 20, off the southern coast of California. The vessel is currently embarking an integrated test team as part of the developmental test effort to certify the modified vessel for operating F-35Bs.

Metadata provided with the U.S. Navy photos indicate that the test pilot was British, part of the F-35 Integrated Test Force (ITF) at Naval Air Station Patuxent River, Maryland.
According to the U.S. Department of Defense, “Data that testers gather during these sea trials will be analyzed and eventually inform decisions to enhance the capabilities of the [Japan] Maritime Self-Defense Force as well as contribute to improved interoperability between Japan and the U.S.”

In April last year, we published photos showing some of the modifications made to Kaga, as it left dock as the latest STOVL carrier for the Japan Maritime Self-Defense Force (JMSDF).
Modifications included reconfiguring the shape of the vessel’s bow section, making the bow significantly wider, and applying a heat-resistant coating to its deck. The Phalanx 20mm close-in weapon system (CIWS) previously mounted on the front of the warship was also removed. Subsequently, further modifications involved re-balancing and structurally reinforcing Kaga’s hull.

Kaga was originally launched in 2015 and commissioned in 2017.
Japan has previously tested the U.S. Marine Corps F-35B from the deck of a modified Izumo class warship, when the name ship of the class undertook trials in October 2021, as you can read about here. This was the time that Japan had operated fixed-wing aircraft from ships since the end of World War II. A video showing those trials is embedded below.

Izumo was commissioned in 2015 and completed its first phase of modifications in 2021. However, the second phase of modifications, including the Kaga-style squared-off flight deck, are not scheduled to begin until March next year.
Tokyo took the decision to modify its two Izumo class vessels for STOVL operations back in 2018, although there had previously been rumors that a return to fixed-wing carrier aviation was always likely, despite official statements to the contrary.
While officially described as ‘multifunctional destroyers,’ the Izumo class warships were primarily helicopter carriers, prior to the STOVL modifications.

Once modified, the two warships will be able to embark Japan’s F-35Bs. 42 are on order and they will be operated by the Japan Air Self-Defense Force (JASDF), which also has a growing fleet of conventional takeoff and landing (CTOL) F-35A versions.
As the tests with U.S. Marine Corps F-35Bs suggest, the modifications to the vessels also pave the way to interoperability with American F-35Bs. While this would help maximize the utility of these vessels, especially bearing in mind the JASDF’s relatively small F-35B fleet, there remain questions about the feasibility of longer-term Marine Corps deployments aboard Japan’s carriers. This is something that also applies to the United Kingdom, which has raised the possibility of embarking Marine Corps F-35Bs more regularly to help boost its carrier strike potential.

Still, even if embarked on a more ad-hoc basis, or during cross-deck operations, Marine Corps F-35Bs will likely go to sea aboard the Izumo class in the future.
What aircraft might join them is somewhat more intriguing.
Last week, at the Japan International Aerospace Exhibition in Tokyo, General Atomics Aeronautical Systems (GA-ASI) presented a rendering showing its carrier-capable Gambit 5 drone — which is based around a common modular core ‘chassis’ concept — operating from an Izumo class warship.

This is not the first time that we’ve seen the Gambit 5 presented on an aircraft carrier. The drone was revealed in the form of concept artwork showing it on a Queen Elizabeth class vessel for the United Kingdom at the Farnborough Airshow in July. You can read about the overarching Gambit 5 concept here.

Regarding the Gambit 5 on the Izumo class, C. Mark Brinkley, a General Atomics spokesman, explained to TWZ: “It’s meant to open the discussion with attendees on sea-based options for autonomous collaborative platforms because we see that as a very real opportunity for many nations.”
As to the drone itself, while the Gambit 5 is now also being suggested for short takeoff and landing (STOL) operations from land bases, it was originally developed for shipboard use.

“The biggest challenges for Gambit 5 are sea-basing challenges, not specifically short takeoff and landing,” Brinkley added. “The ship is moving, the deck is moving, the weather and climate play a role. We’ve invested years of research and investment on projects such as the U.S. Navy’s Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) program and Carrier-Based Aerial-Refueling System (CBARS). We understand the challenges to operating uncrewed jets at sea, and we know that Gambit 5 can be made real.”
Putting advanced drones on carriers is a growing area of interest right now, with China, Turkey, the United Kingdom, and the United States all exploring options of how best to integrate uncrewed platforms, of different sizes, on these warships. In particular, the potential for smaller aviation-capable vessels to operate drones is being explored, with Turkey notably even seeking to field a carrier that’s specifically tailored to support drones.

In the case of the Gambit 5 concept, the vessel is provided with catapults to launch the drones, as was the case with the Queen Elizabeth class concept. However, the British carrier differs from the Izumo class in being equipped with a ‘ski jump’ launch ramp, originally for STOVL operations. The British announced plans last year to integrate assisted launch systems and recovery gear onto the ships in the future.
Although there is no confirmation at this stage that Japan plans something similar for its smaller Izumo class ships, it would make them able to operate fixed-wing drones, and potentially even other fixed-wing crewed aircraft.
As well as the Gambit 5 and F-35B, the GA-ASI concept artwork shows F/A-18E Super Hornet fighters and an E-2 Hawkeye airborne early warning and control aircraft operating from the Izumo class. While Japan already operates the E-2 in a land-based capacity, it has no known plans to acquire fixed-wing carrier fighters in the Super Hornet class.

There are huge challenges in adapting carriers that are already fixed-wing-capable to accommodate even slightly larger aircraft, due to space requirements and the dimensions of existing elevators and other infrastructure. Even if Japan was in the market for carrier-based non-STOVL fighters and E-2s, whether they would be able to incorporate them in the Izumo class is another question entirely.
Also shown in the artwork is an SH-60 Seahawk series helicopter, a type used by Japan previously aboard a wide range of warships, including the Izumo class. Not shown, but another important type for the Izumo class is the MV-22 Osprey tiltrotor, of which Japan is currently the only export operator. Potentially, the tiltrotors could be configured as tankers, to support the F-35Bs, which would be a huge benefit for operations over the expanses of the Pacific.
Nevertheless, the artwork does reflect the potential that the Electromagnetic Aircraft Launch System (EMALS) and the Advanced Arresting Gear (AAG) that GA-ASI first developed for the U.S. Navy’s Ford class aircraft carriers could also bring new capabilities to the Izumo class and other aviation-capable vessels.

We have discussed in the past how EMALS and AAG are well suited to bringing drones into carrier air wings since they can be finely tuned in terms of the forces they exert on aircraft during launch and recovery. This makes them especially relevant for operators looking to utilize smaller and lighter drone designs from flattops.
For Japan, having a carrier-capable drone like the Gambit 5 would provide a powerful adjunct to the F-35B. The Gambit 5 was derived from the air-to-air-capable Gambit 2, but it could also be used for strike as well as intelligence, surveillance, and reconnaissance (ISR).
Drones such as the Gambit 5 and or the same company’s MQ-9B STOL could bring important boosts in capability and overall capacity to Japan’s carrier air wings, which are now very much in their infancy. Faced with the prospect of a potential confrontation with China, armed carrier-based drones could help Japan generate critical additional ‘mass,’ supporting F-35B missions including in more hazardous scenarios, engaging targets in the air, at sea, and on land.

Even unarmed drones would be valuable force multipliers, conducting missions such as ISR, command and control, extending targeting capabilities, and boosting situational awareness. Meanwhile, a drone like the MQ-25 Stingray, provided it could be integrated on the Izumo, would deliver aerial refueling to extend the reach of the carriers’ F-35Bs.

At this stage, it’s not clear if Japan is actively planning to add drones to the future air wings of the Izumo class and, if it does, whether they would be fixed-wing types requiring launch and recovery gear to be added.
“We are absolutely talking to potential customers at Farnborough about the concept,” Brinkley said in the summer, when the Gambit 5 was unveiled, but did not name any specific prospective buyers.
The U.S. Navy is already signaling the centrality of drones in future carrier operations, with plans to eventually have up to 60 percent uncrewed aircraft in its carrier air wings. Very likely, Japan is watching such developments closely and looking at the options for adding drones to its already very capable Izumo class vessels.
Until then, Japan will continue to work toward having crewed stealth fighters operational on these two warships, with the recent test flights by a Marine Corps F-35B the latest step toward achieving this.
Contact the author: thomas@thewarzone.com