Rising Sun, Rising Capabilities: a guide to Japan's electronic warfare aircraft
The Japan Air Self-Defence Force operates two one-of-a-kind aircraft and is replacing its ageing fleet of electronic warfare aircraft with new platforms
As the older Japanese YS-11 and US-made EP-3C Orion electronic warfare and signal intelligence aircraft are being phased out, several of Japan’s C-2 transport aircraft are being modified into electronic warfare platforms. These new aircraft will significantly increase Japan’s electronic warfare capabilities in an increasingly important region. In addition to the electronic warfare aircraft of Japan, the country also houses a wide range of U.S. military signals intelligence aircraft as well as several contractor-owned, contractor-operated aircraft:
While the American aircraft are primarily based at Kadena Air Base in southern Japan, the electronic warfare aircraft of the Japan Air Self-Defense Force are stationed at Iruma Air Base near Tokyo. The aircraft are operated by the Denshisen Shientai (Electronic Warfare Support Squadron) and the Denshi Hiko Sokuteitai (Electronic Intelligence Squadron), which operate the YS-11EB, EC-1, and RC-2 aircraft. Electronic warfare refers to engaging in the electromagnetic spectrum, which includes radio, infrared and radar signals, to sense, protect, and communicate. At the same time, the adversaries’ signals can also be disrupted, denied or degraded through, for example, jamming. Electronic warfare is generally divided into three components: electronic attack, which includes jamming or deceiving, electronic protection, which prevents a receiver from being jammed or deceived, and electronic support, which is primarily surveillance of, and intelligence-gathering in the electromagnetic spectrum.
Note: more photos of each aircraft can be found at the bottom of the post
NAMC YS-11
Japan’s Nihon Aircraft Manufacturing Corporation (NAMC) YS-11 was the first domestically produced aircraft after the Second World War and first flew in 1962. Initially designed as a passenger and cargo aircraft, the Japan Air Self-Defense Force (JASDF) and the Japan Maritime Self-Defense Force (JMSDF) used it for military purposes as well. In addition to transport roles, for which it is being replaced with the C-130, these include electronic warfare roles. For this role, the transport aircraft were modified into the YS-11EA and the YS-11EB. The YS-11EA is used for electronic warfare training, while the YS-11EB is modified to conduct signals intelligence (SIGINT) missions. There are likely three modified YS-11 electronic warfare aircraft still active, but the official number of active-duty aircraft is classified.
All three aircraft that are confirmed to be still active were manufactured as cargo aircraft and delivered to the JASDF in 1971. The first electronic warfare variant of the YS-11 first flew in 1976 and entered service a year later. The second aircraft entered service in 1979. An upgrade program started in 1991, during which the YS-11E received more powerful engines with four-blade propellors. In addition, the electronic warfare suite was upgraded to the J/ALQ-7 system and the radome fairings were replaced by blade antennas. After the program was completed, the YS-11E was redesignated as the YS-11EA. For SIGINT missions, four YS-11C aircraft were transferred to a new squadron in 1991. The transport aircraft were modified into YS-11EL aircraft with the J/ALR-1 SIGINT sensor suite. Less than 10 years later, the four signals intelligence aircraft were upgraded to the J/ALR-2 sensor suite. The YS-11EB SIGINT aircraft still have the radomes, which is a clear visual difference from the YS-11EA aircraft. The relatively old YS-11 electronic warfare aircraft are still in active service, but details remain limited. However, the YS-11EA has been joined by the EC-1 and, after decades of active service, the YS-11EB SIGINT aircraft are being phased out and replaced by several RC-2 aircraft.
Kawasaki EC-1
As the name already suggests, the Kawasaki EC-1 is based on the C-1 military transport aircraft. Entering service in the Japan Air Self-Defence Force (JASDF) in 1974, a total of thirty-one airframes were built for Japan’s air force. However, the number of operational C-1 aircraft in the JASDF has been shrinking as the service is preparing to retire the type. The only squadron currently operating the transport aircraft is located at Iruma Air Base, approximately 55 kilometres (35 mi) northwest of Tokyo. The same base also hosts the only Kawasaki EC-1 aircraft. This heavily modified C-1 aircraft first flew in December 1984 and, after a series of test flights, the electronic warfare aircraft was delivered to the JASDF's Electronic Warfare Training Unit in 1986.
The EC-1 (78-1021) is a modified electronic warfare variant of the C-1 and is used to detect, locate and jam radar and communications signals. Its mission is to conduct electronic warfare training and radar (validation) tests, but the EC-1 can likely be used for operational electronic warfare missions as well. The EC-1 is equipped with Mitsubishi Electric’s XJ/ALQ-5 electronic countermeasures (ECM) system, electronic intelligence (ELINT) systems from Toshiba as well as some American ECM and ELINT sensor suites. Between the late 1990s and 2015, the aircraft was spotted flying with the AN/ALE-41K chaff countermeasure pod, showcasing its ability to fly with external pods. While the pods have not been spotted in recent years, the heavily modified Kawasaki EC-1 aircraft is still flying missions out of Iruma Air Base and serves as the basis for a future stand-off jamming aircraft (more on that later).
Kawasaki RC-2
In the early 2000s, Japan’s Ministry of Defense requested design proposals to replace its ageing fleet of Kawasaki C-1 and US-made C-130 transport aircraft. The result of this request, the Kawasaki C-2, first flew in 2010. The C-2’s official development program was completed in 2017 when the first three transport aircraft were delivered to Miho Air Base. While the new C-2 looks similar to its predecessor, it’s good to keep in mind that there is a huge size difference between the C-1 and the C-2, and thus the EC-1 and the RC-2 as well, which can be seen in this photo. Compared with the C-1, the larger C-2 can carry payloads up to four times heavier and has six times the operational range.
The signals intelligence (SIGINT) variant of the C-2 transport aircraft, designated as the RC-2, has been in development since at least 2015 to replace the NAMC YS-11EB, and possibly the YS-11EA as well. A total of three C-2s are planned to be modified into RC-2 aircraft and the program has been designated as a high-priority project. After modifications and a test program, the first (and currently only) Kawasaki RC-2 went into service at Iruma Air Base in 2020. Compared to the YS-11EB, the RC-2 has more than double the operational range and flies at higher altitudes. This enables longer duration and/or missions at higher altitudes. The higher altitude is critical as it allows the onboard sensor suites to sense significantly deeper into contested territory. Additionally, the onboard sensor suite developed by Toshiba, NEC and Mitsubishi Electric has an expanded reception frequency band, is capable of collecting digitally modulated waves, and has improved multi-target simultaneous collection capabilities. While the RC-2 is capable of jamming operations, its primary mission is to conduct signals intelligence missions. The new fleet of RC-2 electronic warfare aircraft will significantly upgrade Japan’s SIGINT capabilities in the region of increasing strategic importance.
Conclusion
Japan operates a fleet of NAMC YS-11EA electronic warfare and YS-11EB signals intelligence aircraft. In the 1980s, the YS-11EA aircraft was joined by the Kawasaki EC-1. This one-of-a-kind aircraft is still actively flying electronic warfare missions out of Iruma Air Base near Tokyo, where the modified YS-11 aircraft are also based. However, as these ageing aircraft become increasingly redundant in the complex strategic region, Japan is developing the Kawasaki RC-2 for signals intelligence missions. This aircraft is based on the larger and modern C-2 transport aircraft and is equipped with an advanced sensor suite. The (currently) only RC-2 aircraft entered service in 2020 and is set to be joined by two other RC-2 airframes. However, details are still limited and many of the technical specifications are classified.
As Japan continues to look into strategies to further expand its electronic warfare capabilities, research is underway to make an electronic intelligence variant of the domestic P-1 maritime patrol aircraft. In addition, there is a development program for a stand-off jammer aircraft based on the C-2 with similar fairings compared to the ageing EC-1 (see last photo in the gallery below). The program, which is scheduled to be completed in 2026, is still in the early stages and public details are very limited. Still, Japan’s investments in advancing its electronic warfare aircraft highlight the importance of these capabilities in modern conflict, especially in the Indo-Pacific region, where Japan’s allies as well as China are also expanding their electronic warfare and intelligence capabilities.
Thank you
Thanks to ryo-a for the help with Japanese sources, and thank you for reading this post! As always, feel free to reach out with your thoughts, questions and/or suggestions for future posts.
Gallery
