Japan’s Nikkei Asian Review reported on 2 January that a requirement for a new airborne Electronic Warfare (EW) platform has been included in the country’s 2018 defence budget.

Press speculation has focused on the possible acquisition of Boeing EA-18G GROWLER EW aircraft, although no further details regarding the number of aircraft were provided. Nonetheless, the report did specify that Japan could acquire “several jets” between 2019 and 2023. A final governmental decision on their purchase could be made by the end of the year and, should the acquisition go ahead, these aircraft could equip the Japanese Air Self Defence Force (JASDF).

The procurement of the EA-18G could herald a step change for Japanese air power. The country does not maintain a dedicated Suppression of Enemy Air Defence (SEAD) platform capable of performing both the kinetic and Electronic Attack (EA) of hostile radars, and the collection of Electronic Intelligence (ELINT). The procurement of such a capability would place Japan in an exclusive club which comprises a handful of nations including Australia and the US, both of which are equipped with the EA-18G. A SEAD capability is traditionally associated with the Offensive Counter-Air (OCA) mission. According to current US Air Force doctrine, OCA is defined as the destruction, disruption or degradation, “of enemy air capabilities by engaging them as close to their source as possible, ideally before they are launched against friendly forces.”

While the adoption of such an OCA-focused platform is arguable unremarkable vis-à-vis the United States or the Royal Australian Air Force (RAAF), both of which have performed expeditionary air operations as part of multinational coalitions relatively frequently over the past two decades, it reflects a changed posture for the Japanese armed forces writ large. Article 9 of Japan’s Constitution outlawed the country’s use of war as a means of settling international disputes. Nevertheless, in July 2014 the Japanese government approved a reinterpretation of this clause which allows the country to perform offensive military action if one of her allies was threatened under the principle of collective self defence. The subtext of this reinterpretation is that Japan could in the future perform offensive operations to protect her neighbours and allies. Such operations could include the use of offensive air power, and thus operational endeavours, such as OCA.

Moreover, the EA-18G could offer the JASDF a potent suite of capabilities, particularly if the aircraft is delivered with the Raytheon AN/ALQ-249 Next Generation Jammer pod which is outfitting the US Navy’s (USN) and RAAF’s EA-18Gs. The AN/ALQ-249 will be deployed with the USN via a series of blocks offering ever-increasing levels of capability. Block-1, providing mid-band jamming, will debut from 2020/21 with Block-2 providing jamming for low-band frequencies being spun onto the AN/ALQ-249 from 2022, and Block-3, jamming undisclosed high-band frequencies following in 2024.

Reports add that an open architecture design philosophy will allow the AN/ALQ-249 to relatively easily integration of new software and hardware to detect and jam emerging Radio Frequency (RF) threats in the future as and when these are determined. The EA-18G’s communications jamming functions will be assumed by Raytheon’s AN/ALQ-227 system. This latter capability could ease enable future participation of the JASDF in coalition counter-insurgency operations where the jamming of insurgent communications, and their use of the radio segment of the electromagnetic spectrum for the activation of improvised explosive devices could be required.

Regarding the aircraft’s potential kinetic capabilities, the EA-18G acquisition could pave the way for the possible purchase of Orbital ATK’s AGM-88E High Speed Anti-Radiation Missile (HARM) which can equip the aircraft. This air-to-ground weapon adds a number of improvements to the legacy Raytheon AGM-88C HARM variant including an improved RF homing seeker and the addition of a millimetric wave radar sensor.

The new RF homing seeker improves the field-of-view of the seeker used in the AGM-88C and sharpens its detection capabilities for hostile ground-based air surveillance radars. The millimetric wave radar sensor, meanwhile, provides high resolution imagery of the missile’s end game which will provide a useful analytical tool for post-sortie analysis of the accuracy of the attack. This weapon is being acquired by the USN and the Aeronautica Militaire (Italian Air Force). In addition to the AGM-88E, the aircraft could deploy Raytheon’s AGM-88F HARM which too confers a number of improvements on the legacy AGM-88 missile, including the so-called HARM Control Section Modification (HCSM) which adds a Global Positioning System/Inertial Navigation System (GPS/INS) to the missile to counter the so-called ‘switch off’ tactic by which radar operators deactivate their ground-based air surveillance radar in the hope of breaking an anti-radiation missile’s lock on its RF transmissions. The addition of the GPS/INS will allow the missile to be programmed with the radar’s geographical location rendering the switch off tactic void.

Moreover the GPS/INS allows the missile to be pre-programmed with zones of exclusion where the missile is not permitted to fly, reducing the possibility of the missile inadvertently hitting a civilian target and causing collateral damage. This latter issue is an important consideration: Media reports stated that during NATO's ALLIED FORCE air campaign over Serbia and Kosovo a rogue AGM-88B accidentally hit a suburb of the Bulgarian capital Sofia on 29 April 1990, destroying a house, hitting a car and causing damage to other houses.

The potential EA-18G acquisition will have two important impacts for future Japanese air operations: Firstly it provides an electronic attack capability to supplement the JASDF’s existing NAMC YS-11EA/EB EW and ELINT gathering aircraft. Secondly the EA-18G will provide a robust tactical EW capability to help protect and escort the JASDF’s forthcoming fleet of Lockheed Martin F-35A LIGHTNING II fighters which the force has an order, as well as providing an operational level EA capability to support coalition high-intensity and counter-insurgency air operations. Thus, the advent of the EA-18G in JASDF could represent a subtle, but nonetheless important, step change in the country’s air power posture.

Thomas Withington




Japan has expressed interest in acquiring the EA-18G which could represent an important enhancement in its airpower. (Photo: US Navy)

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