JASDF RF-4 Phantoms of the 501st Tactical Reconnaissance Sqn

The author visited the 501st Tactical Reconnaissance Squadron in October 2019 as the squadron was preparing to disband and retire the aircraft from JASDF service. Unless stated otherwise, the content in this article reflects information correct at the time of the visit.

The F-4 Phantom II is among the most iconic aircraft in history. Arguably the definitive Western fighter of the Cold War, it has helped to define an era. Famously blooded over Vietnam and most familiar to us as a NATO mainstay in Europe it was an enormously successful aircraft that saw service around the globe. Just as most countries have now retired their Phantom fleets, the Japan Air Self Defence Force (JASDF) operated the F-4 in the twilight of its career. As well as the F-4EJ the JASDF operated the RF-4E reconnaissance version, flown by the 501st Tactical Reconnaissance Squadron (TRS), until the 9th of March 2020.

Sam Wise visited the 501st TRS at Hyakuri AB in October 2019 to discuss the RF-4 in its last few months of service with the JASDF.

The 501st TRS was formed in 1961 as Japan’s only reconnaissance unit as necessary for the self defence role fulfilled by the JASDF. The squadron was based at Matsushima AB initially and was first mounted on the RF-86F Sabre until an eventual move to Iruma AB in 1962. It flew the Sabre until 1975 when the first deliveries of the RF-4E arrived, coinciding with a move to Hyakuri base in the same year at which the squadron was based until retirement. The 501st TRS was the only aircraft squadron in the Tactical Reconnaissance Group at Hyakuri, alongside the Recon Maintenance Squadron and Recon Intelligence Processing unit.

In 1968 Japan placed an order for 140 F-4EJ Phantoms for air defence and 14 RF-4Es to replace the aging RF-86Fs, which the squadron eventually received in 1975. In 1993, to replace lost RF-4E airframes and provide a post-Cold War increase in capability the 501st also took on 17 RF-4EJs, in essence an F-4EJ with the capability to carry and operate external reconnaissance equipment. The RF-86F was finally retired in 1977.

The RF-4’s primary role with the JASDF was for combat reconnaissance. As a self-defence force the JASDF never employed the RF-4 in combat nor did it see overseas deployment but its crews nevertheless provided a vital capability to the Japan Self Defence Forces that allowed the country to keep its combat readiness to a high degree. However, the 501st also assisted in disaster relief operations throughout its existence, most recently in the earthquake of September 2018 and Typhoon Hagibis in October 2019 and perhaps most notably in the disastrous 2011 tsunami that affected the Fukushima nuclear powerplant. Employing the same techniques and skills required for combat recon the 501st were able to supply hugely accurate and detailed imagery of natural disasters within hours of them occurring, greatly aiding relief efforts on the ground.

The original RF-4Es were unarmed but were equipped with multiple wet film cameras. Three Short Range Cameras were mounted in the forward nose providing forward, vertical and slant viewpoints. A Long Range Camera could also be mounted in the side camera position. Further aft were positions for a Panoramic Camera and Infrared Camera which could provide imagery at night. The film from these would be processed immediately after landing while new films would be immediately installed ready for the next mission.

The RF-4EJ, being converted from F-4EJ airframes, had no internal space for camera or reconnaissance equipment - all recon was gathered from externally mounted centreline pods. These included the Tactical Electronic Reconnaissance (TACER) Pod for gathering and locating radar emissions, Long Range Oblique Photography (LOROP) Pod and Tactical (TAC) Pod which could carry the same cameras as the RF-4E did internally minus the Long Range Camera. In doing so, the RF-4EJ held the same and expanded capabilities as its forebear as well as retaining some combat capability in the form of the 20mm cannon and AIM-9L Sidewinder.

Speaking at the end of 2019 the last commander of the 501st TRS, Lieutenant Colonel Tomomitsu Okada, reflected on the end of the RF-4’s service in Japan as well as the disbandment of the 501st TRS: “The out of service date for the RF-4 will in be March 2020, but we will keep readiness or disasters until then. For example, if we are required to provide imagery due to Typhoon Hagibis we can do it. Keeping our readiness is important in the last few months, but so is maintaining flight safety. At the time of retirement we should have around five jets still able to fly.”

The nature of the RF-4E, with its fixed film cameras and lack of armament, means that the execution of its mission at the end of its career was more or less exactly the same as it was in 1974 when it was first bought. This has limited the JASDF’s reconnaissance capability to some extent: “It is a huge honour to still fly the last RF-4s in the JASDF. However, every other country is using UAVs now. To continue with mission success it is time to retire the RF-4 - it has reached the end of its life as it’s simply not as good as, for example, UAVs are at reconnaissance. The JASDF will continue the reconnaissance mission with the RQ-4 Global Hawk UAV, which will come to Japan in the next few years.

“The tactics are also the same. The JASDF does not take part in wars so we have not had any fight. Our abilities have been used against disasters such as typhoons, volcanoes, floods, taking pictures for relief efforts. Forty years ago SAM range was very short but now it’s much bigger, so we need to change our tactics. I don’t want to say that they are outdated but with the RF-4 they are so it’s time to change.

“We still practise combat operations as there is no difference between combat and disaster tactics. Intelligence is very important for operations. We want fast information so we will respond immediately to produce the films and develop them. Speed is the most important thing in combat or for disasters. I can’t tell you exactly how quick we can turn around reconnaissance in response to an event, but it’s pretty quick! In terms of combat, reconnaissance is most important for tactical decisions so we can analyse the results of the engagements through Battle Damage Assessment. Therefore we train with all sorts of other packages and aircraft, not just our own RF-4s.”

One of the most striking aspects of the JASDF’s RF-4s was their bright and distinctive camouflage schemes. Adorned with the world-famous Spook and film strips for their final few months the aircraft stood out from the familiar greys of even the other remaining JASDF F-4EJs. Lt. Col. Okada elaborated on the schemes the Phantoms wore: “We want to paint our jets and people want to see them in nice schemes, especially for retirement. It allows people to engage deeply with us and our aircraft and help them understand our squadron well. The blue camouflage might seem unusual but given that Japan is an island all of our enemies will come from the sea.”

It is a moving thing to be a squadron’s last commander after many decades of history. Though the crews stayed ready for the fight until the minute they were stood down it was still hugely emotional: “The 501st Tactical Reconnaissance Squadron will be disbanded for good. We’ve decided where the enlisted personnel and the officers will go to different squadrons and missions. I will be sad! But the people will still be in the JASDF with new jobs and new missions, so it’s just a little bit sad. They will keep the memory of the 501st TRS. I don’t know yet where I will go, but I’ll have an order to move and I know I will do my best in the next place.

“If I have one thing to say to the RF-4 and those that flew it, it’s this: thank you. Both the RF-4 and the F-4 have kept the peace for Japan.”

The Phantom is an old aeroplane. Compared with the hyper-bleeding-edge F-35 now in service with the JASDF it’s a positively stone age machine, especially for the maintainers and engineers on the ground who had to work with fifty year old techniques to keep the aeroplanes flying. At the end of its life the RF-4 offered challenges to keeping it airborne. An Inflight Technician (IFT) Staff Sergeant Kasuya and Aircraft Maintenance Crewman (AMC) Technical Sergeant Takeya from the Recon Maintenance Squadron explained what working on this veteran jet was like and the special techniques needed to keep it going.

“I have maintained only the Phantom in practice,” Ssgt Kasuya related, “Even though we follow the manual, it is not always repaired. Though damage is automatically detected by computer [on modern aircraft], with the Phantom we have to detect the damaged parts by hand so it requires some experience. Similar to an old television or a refrigerator, makers have already stopped supplying some old parts so if it is impossible to fix, we sometimes need to cannibalise retired aircraft for parts.”

Tsgt Takeya expanded on the problems with the age: “It requires experience and techniques. Also, it is challenging that sometimes techniques and repairs differ from aircraft to aircraft. Because the aircraft is old, serviceability is mostly bad and the number of operations which maintenance crews perform per flight is large. Many maintenance crews on the Phantom have something like a craftsman spirit.”

Given the extremely specialised equipment needed for the role and the precision demanded not only by camera equipment in general but military machinery especially the most complicated aspect of maintaining the RF-4 was, perhaps unsurprisingly, the cameras. Ssgt Kasuya explains: “If the film is exposed to light even slightly before use, it cannot be used anymore so we still load the film in a darkroom. Unlike a digital camera, the many parts of the film camera are drivable so their maintenance requires adjustment in millimeters.

“I am in charge of maintaining avionics. I don’t think the serviceability is good because the structure is old and parts are big - for example, when I try to fix one part I sometimes have to remove other parts to reach that part. Though the job is tough, it satisfies me when I have fixed it, and I think this satisfaction is only given by the Phantom. For avionics we use a tester to detect damage. The tester itself is also old, so inspecting and maintaining it as well is necessary.”

Both ground-crew spoken to were looking forward to moving onto more modern aircraft, with Ssgt Kasuya in particular hoping to switch to the aerial refueling aircraft in service with the JASDF.

The 501st TRS’ pilots and navigators were some of the last to fly the RF-4 in the world. Unlike most modern aircraft the Phantom requires a pilot and navigator crew pairing, with both operating different camera equipment. They train to fly both the RF-4E and RF-4EJ and operate both according to mission or requirements. The 501st TRS did not keep single crew pairings together and pilots and navigators would swap round with each mission. Major Takahiro “Little” Itai, pilot, and First Lieutenant Ryota “Drill” Horita, navigator, were among those who saw the aircraft to its retirement.

Maj. Itai, who flew both the F-4EJ Kai and Mitsubishi F-2 before transitioning to the RF-4E, describes the difference between flying the Phantom and more modern jets: “It’s important to recognise that the Phantom is difficult energy-wise. The F-2 is much more powerful whereas the Phantom has low energy. It’s hard to manoeuvre but it helps to improve the pilot’s skill as a result. In terms of our mission, the RF-4 is definitely limited. There are some things we can’t do with it and it’s certainly behind the digital age, but since it came to the JASDF in 1975 it has been a very successful aircraft.

“For our mission, most objectives are preplanned. We plan them in advance so that we can take the most appropriate routes and make sure that the flight is at the correct time of day to cast shadows on the target for better photography. If the target is more distant, it is possible for us to receive target information while already airborne.

“It was my dream as a child to fly the F-4 as it is so famous so to have flown it at the end of its career has been a huge honour. One of my favourite memories of being on the RF-4 has been helping to design the special scheme with the rest of the squadron. Now that I’m moving on, I’d particularly like to fly the aerial refueling aircraft as it will be the newest aircraft in the JASDF.”

It might seem archaic to still require a fast jet navigator in 2020 but according to 1LT Horita it brings its own advantages: “I will miss the two person crew. Unlike F-15 or F-2 squadrons Phantom squadrons are very close with a combination of veteran pilots and young navigators. Single pilot squadrons seem scary in comparison! Flying as a two person crew is very supportive, and as a navigator I’m always providing active commentary to the pilot.

“It feels good to fly an old, iconic aircraft like the Phantom. The maintenance crews are very experienced and skillful so you always trust the aeroplane. I think the Phantom is still relevant. We can support disasters, which we have done in the last decade, but this is still secondary to military reconnaissance.”

1LT Horita trained as a navigator on the YS-11 before moving straight to the RF-4, and described what the navigator’s work involves: “For navigation we primarily use the AN/APQ-172 ground mapping radar for choosing the vectors, correcting and using the course. This is supported by INS navigation as well. We also use TACAN. In the 501st we fly from Hyakuri, it’s very close to Tokyo which has an incredibly busy airspace.

“After disbandment I’d like to work in an embassy overseas, or possibly be a navigator on the C-130 Hercules. I will remember the Phantom for giving me my first ever jet flight - that gives me an extreme fondness for the aeroplane. The Phantom is old and so it has old fans, but it has cheered up its fans over the years. We will miss it.”

The RF-4 has now finished its service with the JASDF. It was formally retired with a “small ceremony” in March 2020 but the jet was given a bigger send off at the end of November 2019 at the annual Hyakuri Air Festival which saw fans from all over the world visit the base to pay their respects to the veteran type. While its role will now be performed by much more advanced aircraft there is no doubt that it will be missed by its crews and supporters alike.

With the JASDF’s RF-4s now grounded it leaves the Republic of Korea Air Force as the sole remaining operator of the variant.


All photography captured by the 501st TRS’s RF-4s was processed by the Reconnaissance Intelligence Squadron (RIS), the third squadron in the Tactical Reconnaissance Group structure. These specialists analysed the imagery for whatever information was required of the mission. One example is the Hokkaido Eastern Iburi earthquake on 6th September 2018 which struck the country in the early hours of the morning and killed 41 people and injured 691 more. The earthquake hit at 3:08am, and by 8am the RF-4s of the 501st TRS were airborne and on their way to the devastated area. Landing back at Hyakuri three hours later, the RIS immediately got to work.

One of the biggest quirks of the RF-4 was the use of wet-film for photography. Anachronistic in 2019 when so much had turned digital it nevertheless allowed the specialists of the RIS to accurately detail and report on required intelligence effectively. Unlike digital imagery, however, it had a very stringent yet well-oiled and practiced procedure for processing and reporting using physical originals.

As soon as the RF-4s are parked, the film units are loaded off the jets and immediately brought to the RIS. The first step after it arrives is for the film to be processed. The technician loads the film into a magazine which is fed into black and white auto film-processing machines. However, while the accompanying photos show this occuring in a lit room, for “live” film the entirety of this has to be done in the dark in order to avoid ruining the film.

Once the films are processed the best strips of the target have to be selected. Some missions will require multiple passes from multiple aircraft giving the specialists a wealth of different images to select from. For colour films they check each strip against maps to decide which has the best possible image of the target area.

After the best strips have been selected they are ready for digitisation - a step introduced about twenty years ago. Dust is removed from the strips and each film is scanned twice by a technician. They are then digitally processed on computers using Photoshop, the colours are adjusted and consecutive images are stitched together.

Finally, the digitised images are printed in large format and analysed by specialists for requested information. For this particular mission requested information was for images of the large area hit by the earthquake and details of any collapsed houses as well as landslides. These are marked by the analysts with red circles before the intelligence is passed forward.

The time taken for processing depended on the amount of photos taken and the mission. For example, processing for the Hokkaido Eastern Iburi earthquake took three and a half hours with 20 personnel involved. RIS personnel were kept on standby 24 hours a day with a response time of three hours.

Lt Colonel Hiroyasu Daimon, commander of the Reconnaissance Intelligence Squadron, talked about the circumstances of still using film for intelligence: “The advantage of film is that it is easier to take high resolution photographs because pitches of grains of analogue films are narrower than those of CCD elements of a digital camera. Even when the quality of digitized image gets worse by scanning, we can get images with high GSD (Ground Sampling Distance). On the other hand, the disadvantage is that the processing needs much time and staff. Another difficulty is that the films are fragile. We carefully handle them so that our work will not be delayed.

“The process was digitised about twenty years ago. Before that, we printed every single cut on photoprint sheet and manually cut and pasted it. About saving time, though the digital process is a little faster than the analogue one there is not much difference. However, the digital process makes it possible to transmit and reproduce the products which we make.

“After the retirement of the RF-4, we are going to do a new job in each section of the JASDF. We have to learn how to use the software in order to handle digital images which is much easier than handling analogue ones. There is no difference in interpreting and analysing the images between analogue and digital. I think the digital era is now, I personally would like to open up a new era (maybe coexistence with AI).”

UKAR would like to thank the Japanese Defence Attaché to the UK and the JASDF personnel who helped make this article possible.