In 2009 there were reports that Internet based hackers had made off with the manufacturer database for the new F-35 stealth fighter. The data theft was believed to be for China, which had two stealth fighters, the 37-ton J-20 and 28-ton FC-31, which is still in development. The J-20 made its first flight in 2011 and entered service in 2917. There were problems that delayed mass production until 2022. As of early 2023 only about 200 J-20s were in service. The J20 was the first Chinese designed and built modern jet fighter. China saw the J-20 as similar to the American F-22 while the FC-31 would be similar to the American F-35. It did not turn out as China had hoped and until 2015 there were few details revealed about the FC-31.
In 2015 someone in China anonymously posted performance data for the new 18 ton FC-31/J-31 stealth fighter. This was in the form of a sales brochure (for trade shows) that had not been distributed to the public. Up to 2015 the manufacturer has been vague about J-31 performance data. This despite the fact that the J-31 had been showing up at Chinese weapons shows. The 2015 promotion was all about looking at the impressive appearance of the J-31, not crunching any numbers.
It gets more interesting when you realize that the recently posted data ascribes better engine performance than actual engines the Chinese have in service or access to. There were also descriptions of J-31 electronics that sounded more like a Chinese wish list rather than anything the Chinese have or are known to be developing. Many in the industry see this as some kind of desperate publicity stunt. Efforts to sell the J-31 to export customers have failed.
It was later revealed that in late 2014 China quietly approached some potential customers about buying J-31s. For export customers the J-31 would be called the FC-31 and it was understood that this version would not have all the best equipment the Chinese J-31 had. Pakistan expressed some interest, but then Pakistan is the largest export customer for Chinese weapons. Pakistan apparently thought it best to wait a bit because it was unclear how ready the J-31 was for active service. Since 2012 China has been testing the J-31 “Falcon Eagle” (from an inscription on the tail). While it looks like the American F-22, it’s also smaller than China’s other stealth fighter, the J-20, which has been around longer. The J-31 was built by the Shenyang Aircraft Corporation, which also makes the J-11, an illegal Chinese copy of the Russian Su-27. The J-31 has some characteristics of the F-35 as well and appears to be something of an “F-35” to the earlier J-20s effort to match the American F-22. The J-31 flew for the first time in October 2012 and at that point there were at least two prototypes. The designer talked of the J-31 being able to operate off an aircraft carrier, like the U.S. F-35 and the Chinese J-15, a J-11 variant. A carrier version is in development.
One advantage of the J-31 is that it has two engines, compared to one for the 31 ton F-35. In theory this means the J-31 could carry more weapons, but this is less crucial with all the guided weapons available. Another problem is that the J-31 was using Chinese engines, which are less powerful and reliable, even when two are used, compared to the single engine in the F-35C.
The J-31 is further evidence that China is determined to develop its own high tech military gear. While China is eager to develop advanced military technology locally, it recognizes that this takes time and more effort than nations new to this expect. Thus, China is trying to avoid the mistakes Russia made in this area. That means having competing designs and developing necessary supporting industries as part of that. All this takes a lot of time and involves lots of little (and some major) failures. The Chinese are doing it right and are willing to wait until they get military tech that is truly world class. Originally the J-31 was supposed to be ready for service by 2019 and have ground attack as well as air-to-air capabilities. As of 2023 the J-31 is still stuck in the prototype stage.
Meanwhile, the F-35 has been very successful and the Chinese pay close attention to that. New or prospective customers for the F-35 are attracted by the enthusiasm of those who have flown the F-35. There are only about 1,200 F-35 pilots, and about ten times as many maintainers who keep F-35s ready to fly. The U.S. Air Force, the largest F-35 user, has a shortage of trainers and is having problems keeping up with total demand for pilots. Most F-35 pilots are transitions, that is experienced fighter pilots transitioning to the F-35. These require much less training time and the Americans are concentrating on expanding their transition program. F-35 pilots all confirm that the F-35 is not just a modern stealth aircraft, but incorporates software and a degree of built-in automation that produces a spectacular, easy to use and very effective pilot experience. The F-35 has a large number of sensors, including 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 is impressive. This fusion 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 forces. Put simply, it's all about taking real-time video camera, radar and sensor data plus other information about the battlefield situation from databases and current reports, and combining it to provide commanders 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’s superior capabilities is its software along with digital communications with ships, 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 ground, 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-35s' stealth, maneuverability and sensor/data fusion, most pilots quickly become enthusiastic proponents of the aircraft. China won’t discuss its plans to incorporate these F-35 data management capabilities into their stealth fighters. The Chinese do like to talk about their research into AI (Artificial Intelligence) systems.
The F-35 software is more complex and omnipresent throughout the aircraft than in any previous warplane. Because of that, it requires a major effort to implement and test any software 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 vulnerable aircraft would be grounded when needed most.
As of 2023 over 900 F-35s have been delivered, mostly to the U.S. Air Force and Marine Corps. In 2018 alone 133 were delivered and that rose to 141 in 2020 with additional slight increases in annual deliveries until 2023. By the end of 2020 about 650 F-35s were in service, a status that takes place months after delivery. 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 F-35A is a 31-ton, single engine fighter that is 15.7 meters (51.4 feet) long with a 10.7-meter (35 foot) wingspan. The F-35A can carry 8.1 tons of weapons in addition to an internal 20mm four-barrel autocannon. 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 could be carried. 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 internal weapons.
In 2001 the U.S. believed 5,100 F-35s would be sold but the rising costs and increasing delays drove that down to 3,100 by 2013 and 2,500 by 2018. Now that some F-35s are actually in service and getting good reviews from users, sales are increasing. The aircraft carrier F-35C was supposed to enter service in 2018 but that didn’t happen until January 2020. That has no impact on foreign sales because few, if any, export orders were ever expected for the F-35C.