The Nihon Koku Jietai (Japan Air Self-Defense Force, or JASDF) acquired 154 Phantoms for air defense and reconnaissance. The fighter version was designated F-4EJ, and (except for an initial few assembled by McDonnell) all were built under license in Japan by Mitsubishi Heavy Industries, Ltd. The reconnaissance version was designated RF-4EJ and was built in the USA by McDonnell.
The F-4EJ was ordered for the JASDF on November 1, 1968. Since the Japanese armed forces were forbidden by treaty from having even a hint of an offensive capability, the F-4EJ was optimized for the air defense role, the AN/AJB-7 bombing system being omitted. There was no provision for the carrying or delivery of air-to-ground weapons. As built, the Mitsubishi-built Phantoms were not fitted with inflight refuelling receptacles, but this was later retrofitted.
Two F-4EJs (JASDF serials 17-8301 and 17-8302) were built by McDonnell in St Louis and tested beginning on January 14, 1971. The next eleven (JASDF serials 27-8303/8307, 37-8307/8310, and 47-8311/8313) were built by McDonnell in kit form and were assembled in Japan by Mitsubishi Heavy Industries, Ltd. The first Japanese-assembled aircraft (27-8303) flew on May 12, 1972. Subsequently, Mitsubishi built 127 F-4EJs under license, the last example being delivered on May 20, 1981. This was the last Phantom built.
Fourteen unarmed reconnaissance versions of the F-4EJ were built by McDonnell and delivered to the JASDF between November 1974 and June 1975. They were designated RF-4EJ. They were virtually identical to the USAF RF-4C, with the only differences being the deletion of certain equipment such as the radar homing and warning suite which had not been released for export to Japan.
The F-4EJ first entered service with the JASDF in August of 1972. In service, the F-4EJ replaced the JASDF's fleet of Lockheed F-104J Starfighters. In the JASDF, six interceptor squadrons (Hikotai) have operated the F-4EJ. These were the 301st, 302nd, 303rd, 304th, 305th, and 306th. The RF-4EJ was operated by the 501st Hikotai, replacing that unit's RF-86F Sabres.
Throughout the 1980s, the force of 140 F-4EJs gradually dwindled by attrition and reached 125 in 1992. Conversions to the F-15J began in the late 1980s, and most surviving JASDF F-4EJs have been upgraded to F-4EJ Kai standards.
The F-4EJ Kai is an upgraded version of the Japanese-built F-4EJ, intended to bring the F-4EJ up to standards appropriate for the 1990s. It was fitted with a new AN/APG-66J pulse Doppler radar, an new centra computer, a Kaiser HUD, an AN/APZ-79 IFF system as well as the abilityh to carry an AN/ALQ-131 advanced multimode ECDM pod and to launch the AIM-7E/F Sparrow and the AIM-9L/P Sidewinder air to air missiles. The first F-4EJ Kai entered service with 306 Hikotai in November of 1989. It had originally been planned to upgrade 110 of the 125 surviving F-4EJs to Kai standards, but this was later changed to only 96.
In a program which paralleled that of the F-4EJ Kai, the JASDF upgraded 11 of its RF-4Es to RF-4E Kai standards. The modifications included the replacement of the AN/APQ-99 radar by an AN/APQ-172 unit with digital image processing. The J/APR-2 RWR was replaced by J/APr-5. However, because of budgetary restrictions, not all of the RF-4E Kais have actually been fitted with the AN/APQ-172 radar suite.
Seventeen of the remaining 29 F-4EJs that were not scheduled to be converted to F-4EJ Kai status were to be converted to the reconnaissance role under the designation RF-4EJ, with the remaining 12 to be retired. So far, nine F-4EJs have been converted to RF-4EJ standards. These aircraft had the undernose Vulcan cannon removed, but they differ from the RF-4E/RF-4E Kai in not having any internal reconnaissance equipment. However they can carry three types of sensor pods, depending on mission requirements. These comprise the TACER (an elecronic reconnaissance pod with datalink), the TAC (carrying KS-135A and KS-95B cameras, plus a D-500UR IR system) and the LOROP (with KS-146B camera). A total of 17 F-14EJ Kais will be converted to the reconnaissance role, all being assigned to the 501st Hikotai. This unit also uses the 12 remaining RF-4Es, ten of which are to Kai standards.
To date a total of 14 F-4EJs have been lost in accidents, while 96 have been converted to Kai standards.
Although the first F-4EJ Kai squadron was the 306 Hikotai at Komatsu, these aircraft were transferred to 8 Hikotai at Misawa AB (which had previously operated F-1s) and 306 Hikotai transitioned to the F-15J/DJ. This transition was completed in March of 1997.
By April 1994, F-4EJ/F-4EJ Kai strength was reduced to only three squadrons. 303, 304, 305, and 306 Hikotai all had converted to the F-15J/DJ in the early 1990s. The squadrons remaining were the 8 Hikotai of the 3 Kokudan based at Misawa, the 301 Hikotai of the the 5 Kokudan based at Nyutabaru, and the 302 Hikotai of the 83 Kokutai based at Naha on Okinawa. The reconnaissance Phantoms serve with the 501 Hikotai based at Hyakuri. These F-4EJ squadrons should remain with the JASDF until well after the year 2000. As of the year 2007, about 90 F-4s were still in service with the JASDF. Over time, the F-4s are being replaced by the Mitsubishi F-2, an indigenous development of the F-16. There are talks underway to replace JASDF F-4s with the Eurofighter Typhoon, since the sale of the Lockheed Martin F-22 Raptor is currently blocked by US export restrictions. In June of 2007, Lockeed Martin announced that it would equip several of the JASDF's F-15 Eagles with synthetic aperture radar pods, which would allow the RF-4EJ to be retired.
The RF-4E was retired from JASDF service in May of 2020. The JASDF retired its last F-4EJs on March 17, 2021
JASDF aircraft are assigned a four-digit serial with a two-digit prefix. The second digit in the prefix is the type number of the aircraft (7 for the Phantom), whereas the first digit in the prefix indicates the last digit of the year of delivery.
Serials of JASDF Phantoms:
McDonnell F-4EJ-45-MC Phantom 17-8301/8302 McDonnell F-4EJ-45-MC Phantom 27-8303/8306 last two assembled by Mitsubishi in kit form 8304 crashed 5/1/1973 McDonnell F-4EJ-45-MC Phantom 37-8307/8310 all assembled by Mitsubishi in kit form 8307 crashed 7/6/1979 8309 crashed 7/16/1986 8310 crashed 12/7/1978 McDonnell F-4EJ-47-MC Phantom 37-8311/8313 all assembled by Mitsubishi in kit form Mitsubishi F-4EJ Phantom 37-8314/8323 Mitsubishi F-4EJ Phantom 47-8324/8352 (8324 to 8331 later renumbered with prefix 37) 8325 crashed. Date ??? 8337 crashed 8/15/1999 8339 crashed 10/11/1997 8343 crashed 10/13/1982 8346 crashed 5/11/1998 McDonnell RF-4EJ-56-MC Phantom 47-6901/6905 McDonnell RF-4EJ-57-MC Phantom 57-6906/6914 6910 crashed. Date ??? 6911 crashed. Date ??? Mitsubishi F-4EJ Phantom 57-8353/8376 8358 crashed. Date ??? 8363 crashed. Date ??? 8364 crashed. Date ??? 8370 crashed. Date ??? Mitsubishi F-4EJ Phantom 67-8377/8391 8379 crashed 10/9/1998 8382 crashed. Date ??? 8385 crashed. Date ??? Mitsubishi F-4EJ Phantom 77-8392/8403 8396 crashed. date ??? Mitsubishi F-4EJ Phantom 87-8404/8415 8405 crashed. Date ??? 8410 crashed. Date ??? Mitsubishi F-4EJ Phantom 97-8416/8427 Mitsubishi F-4EJ Phantom 07-8428/8436 8430 crashed. Date ??? 8432 crashed. Date ??? Mitsubishi F-4EJ Phantom 17-8437/8440