Why is it even called 5th generation? Pentagon's decision not to fix supersonic speed issue with F-35C defeats jet's very purpose

A US decision to limit the F-35C's supersonic flight capabilities instead of fixing an issue that increases the risk of tail damage will put a strain on pilots and deal a huge blow to the fighter's combat power, analysts warn.

The F-35 Joint Program Office (JPO) – a Pentagon agency responsible for developing and acquiring the F-35 fighter jets – recently revealed that a specific construction issue could cause damage to the Navy F-35C jet's tail section if it flies at supersonic speed for a long time. However, it said that this was "not worth fixing," mostly due to the high projected costs of a revamp.

Instead, the JPO said the jet's very ability to fly at such speeds would be reduced to short bursts. The US media already noted that such changes would severely limit the F-35C's ability to intercept airborne targets – something for which a fighter jet is specifically designed. In addition, it is also expected to negatively affect its maneuverability in the event that it needs to a avoid a missile or survive a dogfight.

Not up to standard?

The decision appears to be less than optimal, particularly because it defeats the purpose of the much-hyped '5th generation' aircraft in general. Although Lockheed Martin – a company that developed and produced F-35 jets – tends to focus on stealth and electronics when defining its idea of such an aircraft, it still says that it should be capable of "extreme performance." That is what the Navy version of the F-35 will now apparently be lacking.

Russian Air Force Major Andrey Krasnoperov, a flight instructor and a jet aerobatics specialist, sees the limited supersonic flight capability as the most serious deficiency for a 5th generation aircraft. "Why do they even say it is a 5th generation jet? It should fly two or three times faster than the speed of sound," he told RT.

Apart from that, the decision not to fix the tail issue would only put additional psychological strain on the pilots, Krasnoperov warned. In a real combat situation, a pilot should not have to think about risk of damage to his jet's tail if he somehow flies with an afterburner on for too long, he said. "Such construction deficiency would still seriously affect pilots' safety."

Fabrizio Poli, an independent aviation consultant and CEO of the Orville Aviation, an aircraft sales, private jet management & aviation consultancy company, also believes that the limitation of supersonic flight would eventually make the jet "less versatile," affecting its combat capabilities. He also compared the fallout from the decision with the Boeing 737 MAX scandal that rocked the US civil aviation industry in 2019 and early 2020.

A particular issue arising from the decision to tie F-35C supersonic flight to an afterburner is that it might hurt the jet’s stealth capabilities – another much-hyped feature of the aircraft, said Vladimir Karnozov, an aviation expert with avia.ru. Even a short supersonic afterburner burst makes it an easy target due to a powerful jet exhaust, Karnozov explained. He also noted, though, that even fighter jets capable of moving at supersonic speed without engaging the afterburners are still much easier to detect than aircraft moving at subsonic velocity.

In fact, limiting the F-35C's supersonic flight capabilities to short bursts brings it closer to the so-called 'four-plus' generation jets such as Russia's Su-35, which also have similar capacity, Vadim Lukashevich, who worked as an aircraft engineer for Sukhoi between 1985 and 1992 and later became an independent aviation expert, told RT.

Lukashevich doubted, however, that these limitations could seriously affect F-35C's battle performance since "a short afterburner burst is enough for closing-in or breaking off the dogfight." The decision appears to be more of a blow to the F-35 program's image since the fighter jet was declared to be a 5th generation aircraft but can't now really live up to standards set by the US military themselves, he added.

Jack-of-all-trades?

Kasnoperov also questioned the very fact that such a serious flaw was not fixed during the jet development stages, adding that it might have been a result of the developers' desire to get things done ahead of time. "They might have been chasing the deadline and have not paid enough attention to it."

The cost of such haste could well be the F-35C falling far behind other nations' 5th generation jets in terms of operational capabilities. Russia's Su-57 multirole fighter is capable of flying at twice the speed of sound without even engaging its afterburners. Since the aircraft also has a high fuel load, its supersonic flight range could exceed 1,500km. China's Chengdu J-20 is also said to be capable of flying at supersonic speeds.

Another problem with the F-35 program might well lie in the fact that the US military wanted a flexible aircraft allowing various types of the jet to act as a conventional fighter, a deck-based one and a vertical take-off and landing plane.

"Any special purpose-designed aircraft would be better in its field than a multipurpose one," Lukashvich said, adding that the Pentagon apparently wanted to reduce the jet's costs but ended up with exactly the opposite outcome.

The F-35 program has experienced a dizzying array of technical issues – not to mention a ballooning price tag. A government estimate from March put the price tag at $1.2 trillion. The former aviation engineer also said that the F-35 planes are likely to be "difficult and expensive to maintain."

Whether or not supersonic flight ability would prove crucial in the future of aerial warfare is still an open question. After all, no 5th generation fighters have actually faced each other in a real battle. Yet, the constant technical flaws experienced by the F-35 program together with the increasing cost of its acquisition and upkeep would hardly boost its image either in the eyes of pilots or potential arms importers. 

"While the F35 does do well in certain areas, the amount of flaws found in the aircraft will not play in its favor. The Americans tend to be very good at sales and marketing but not necessarily produce the best aircraft," Poli said.

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