July 31, 2020: Japan has ordered another 105 F-35 stealth fighters. This will cost $23 billion and include spare parts, including 110 engines and additional electronic and other accessories. With earlier purchases this new order will give Japan 147 F-35s. That large force of stealth fighters won’t be in service until the mid-2020s because of growing demand for F-35s and limited production capability. Japan will help by manufacturing some components and assembling their F-35s in Japan.

All this Japanese F-35 news was not welcome in China. Combined with South Korean F-35s, China now has to deal with over 300 F-35’s operating near its northern borders. In the 1990s Chinese support for an aggressive and unpredictable North Korea prompted South Korea to become a major developer, manufacturer and exporter of modern weapons. Now Japan, with a larger population and industrial base than South Korea has followed South Korean in an arms race with China.

Most (63) of the new fighters will be the land-based F-35A model but 42 will be F-35Bs, the VTOL (vertical takeoff and landing) version that can operate from carriers. Japan already had 42 F-35As on order to replace 73 F-4 interceptors. The new F-35As on order are to replace a hundred older F-15J fighter-bombers. At this point Japan is the largest export customer for the F-35.

Japan also asked to have its status as a F-35 upgraded from buyer to partner. That will mean Japan will build more components for F-35s, not just its own but for other customers as well. Japan can and has built modern jet fighters. Before Japan increased its F-35 orders it decided to cancel its plans to build a locally designed F-2 maritime attack aircraft. This move was in recognition of the high production costs and uncertain performance of the maritime F-2. Japan also sought to design and build a stealthy replacement for the 1990s era F-2 fighters but concluded it would be too expensive for just a hundred aircraft and such an “X-2” aircraft could not compete against the American F-35 in export markets, assuming Japan changed its constitution to allow weapons exports. The F-2 was an enlarged Japanese version of the American F-16. Now Japan seeks to eventually replace the F-2 with F-35s. Japan imports a lot of foreign warplanes but usually assembles them locally under license, which it will do with the F-35s.

For most of the last two decades Japan has been undecided about how to proceed with updating its many warplanes. At the end of the Cold War (1991) Japan had a small but well equipped and trained air force. But since 1991 there was not a lot of enthusiasm in parliament or among voters to spend what was needed to keep the air force up to date. After 2000 it became obvious that China was building a modern, and threatening, air force. Russia was becoming more hostile as well and North Korea remained a problem. Gradually Japan accepted the fact, and cost, of upgrading its air force.

A recent example of this was the 2019 decision to act on long-delayed plans to upgrade 98 of its heavily used F-15J interceptors. The parliament was reluctant to spend the billions of dollars this would cost. For some legislatures it was an economic decision, for others it was feared upgrading would anger China and Russia. But as incursions by Chinese and Russia military aircraft increased fivefold over the last decade, to over a thousand a year, parliament changed its mind. The upgrades will cost $4.5 billion and be carried out in Japan using American made electronics. This includes an AESA radar, new computers and EW (Electronic Warfare) equipment. This includes a jam-resistant GPS device. There will also be new communications including jam-resistant digital data links.

The growing presence of Russian and (mostly) Chinese military aircraft has also persuaded legislators to spend a lot of money replacing older aircraft. The Japanese Air Force has about 50,000 personnel and 775 aircraft, 39 percent of them fighters. The air force is usually the first responder when any potentially hostile ships or aircraft come near any of the islands. Most of the 302 fighters need upgrades or replacement. The 73 F-4s were built in Japan during the 1970s and are very much in need of replacement despite light use, some upgrades and careful maintenance. The new F-35s were initially replacements for retiring F-4s.

The 155 F-15Js were also built in Japan during the 1980s and 90s. These are the most heavily used warplanes as most serve as interceptors. There have already been some upgrades, but the newly ordered upgrades are the most extensive in a while. The 62 F-2s were developed and built in Japan between 1995 and 2011. There are currently 12 F-35s in service.

Ordering some F-35Bs makes it clear that Japan is going to experiment with some of these aircraft aboard the existing Japanese “helicopter carriers”. Since 2017 Japan has had operational two 27,000 ton “destroyers” (DDH type ships) that look exactly like an aircraft carrier. These Izumo class ships can carry up to 28 helicopters or up to ten vertical takeoff aircraft. The carriers are armed only and two 20mm Phalanx anti-missile cannon and sixteen ESSM missiles for anti-missile and aircraft defense. The DDH have powerful engines capable of destroyer-like speeds of over fifty-four kilometers an hour. There are also more medical facilities than one would expect for a ship of this size. Izumo does have considerable cargo capacity for moving disaster relief supplies quickly to where they are needed. Apparently some of these cargo spaces can be converted to berthing spaces for troops, disaster relief personnel, or people rescued from disasters, as well as additional weapons and equipment needed to support F-35B fighter-bombers. Izumo could carry and operate at least ten of the F-35Bs once modifications were made to the flight deck to handle the extremely high temperatures the F-35B generates when taking off or landing vertically (like a helicopter).

When the first DDH entered service in 2015 Japan made no mention of buying F-35Bs or modifying the LPH flight decks to handle the very high temperatures generated by the F-35B. The Izumos already have an elevator (to the hanger deck under the flight deck) large and powerful enough to handle an F-35B.

These new Japanese F-35 plans make it clear that Japan agrees with pilots who have many F-35 flight hours. The F-35 software and the degree of automation built in is spectacular, easy to use and very effective. The F-35 has many sensors (receivers for electronic signals, six cameras and a very capable radar) and the fusion of all that data and presentation to the pilot based on the current situation makes the F-35 much easier to fly, despite all the additional capabilities it has. This sort of thing is not a new idea. By the 1990s it was recognized that this new technology (called data fusion) would be a key capability for combat aircraft, as well as ships and ground combat vehicles. Put simply, it's all about taking real-time vidcam, radar and other sensor data (sensor fusion) along with non-sensor information about the battlefield situation (all sorts of databases and reports), and combining them to provide commanders or pilots with a better understanding of current operations, preferably in real time if you are a fighter pilot. Pilots agree that the heart of the F-35 superior capabilities is its software and digital communications with other aircraft and troops on the ground.

The F-35 is apparently the best working example of this so far and what is learned from the F-35 software has become the basis for updated software for older aircraft. But beyond the data fusion (and automatic sharing with other aircraft or systems on the surface), the pilots were impressed about how effective the “pilot assistant” software was. This is another concept that has been around for decades and more frequently installed in new aircraft. These minor advances get reported but never make headlines. But given the F-35's stealth, maneuverability and sensor/data fusion, most pilots quickly become enthusiastic proponents of the aircraft.

F-35 software is more complex and omnipresent throughout the aircraft than in any previous warplane. It’s a major effort to carry out and test any changes. Some major upgrades are needed in how F-35 software changes are made and how quickly. In wartime this would be essential as otherwise servicable aircraft would be grounded when needed most.

As of early 2020 500 F-35s had been delivered, mostly to the U.S. Air Force and Marine Corps. Over 4,000 F-35s are expected to be delivered by the mid-2030s with more than 70 percent going to the United States. The 31-ton F-35 is armed with an internal 25mm cannon and, before the SDB (GPS guided Small Diameter Bomb) arrived, four internal air-to-air missiles (or two missiles and two smart bombs) plus four external smart bombs and two missiles. A new bomb rack allows the F-35 to carry eight SDBs internally. All sensors are carried internally, and max weapon load is 6.8 tons. The aircraft is very stealthy when just carrying only internal weapons.