It was a really good bet in the 1980s and a pretty good bet in the 1990s, but is stealth the way to go in the 2020s? After all, it has been around for some 40 years and – so far, at least – hasn’t made much of a dent in the world’s fleet of jet fighters.

Stealth is a means of making an aircraft significantly less visible to radar. It got its start, in a way, in World War II. With Britain vigorously defending its homeland, it deployed a novel coastal radar system called Chain Home that gave British fighters and anti-aircraft systems advance notice of any Nazi attack and told where it was coming from.

To find a way around Britain’s protective system, an upstart aircraft maker called Gothaer Waggonfabrik in Nazi Germany came up with an aircraft designated the Horton H-229. Basically this was a flying wing that was powered by two Junkers turbofan jet engines. While it never flew a real combat mission, many engineers thought that it was radar-evading, and Northrop made some tests using a scale model based on the frequencies of the British coastal radar. In fact the Horton had a significantly reduced radar signature.

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If, in fact, it was the Germans’ intention to penetrate Britain’s radar shield, the Horton would turn out to be the first aircraft capable of doing that. Stealth design information is a collection of closely guarded secrets, but even with special measures in place it is becoming apparent that much of that guarded information has leaked. Russia is at work on a fifth-generation fighter, the PAK -50, which incorporates stealth features in its design. And the Chinese already are flying two stealth fighters – the Chengdu J-20, a fifth generation fighter that entered into service this year; and the Shenyang J-31, which looks spookily like the F-35 JSF. The J-31 has not yet entered service.

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Stealth has two primary uses in fighter aircraft. It allows aircraft to get around air defense radars and enemy fighters because the radars can’t see the stealth aircraft. And it makes it easier for a stealth aircraft to detect and kill a non-stealth aircraft because it can strike before the other one knows it is even “there.”

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For the most part, stealth has not played a big role in military operations. The US did use the now-mostly-retired F-117 in the Yugoslav war (where one was lost and one was damaged) and in the Gulf wars. And it used the F-22 over Syria and Iraq, but mostly for show since it was not needed in either place.

Essentially, what this tells us is that stealthy aircraft are valuable in strategic scenarios, but in typical tactical environments they play a small role.

Even so, the US has invested hundreds of billions of dollars in stealth fighter aircraft, with more investment to come if it actually goes ahead and buys the full, planned fleet of F-35s – more than 1,700 aircraft. In that scenario, the F-35 program will be the costliest in modern aviation history, with a lifespan cost of around US$1.5 trillion and counting.

Does it make sense?

If one thinks in strategic terms, neither Russia nor China will have any quantity of stealth aircraft for decades. But the US thinks it “needs” large quantities of planes to replace the F-16s, F-15s and F-18s in its current fleet since many of them are worn out from continuous use in largely peripheral conflicts such as Afghanistan, Iraq and Syria.

In exchange, they will get a more capable aircraft in some respects in the F-35, but the F-35 is not so stealthy that it can evade even today’s modern air defense systems such as the Russian S-400. It will need the F-22 to make the first holes in an enemy’s air defense, which is not an easy task given that air defense systems such as those made by the Russians are extremely mobile and sophisticated.

In addition, even that important punch could be compromised as radars and other sensors are improved against stealth platforms. Here the Russians and Chinese are hard at work, exploiting different radar frequencies, techniques for triangulating multiple search radars and using novel sensors, including electro-optical sensors, that appear to be effective. Also emerging are passive systems, such as the Czech VERA system which, it is claimed, can locate stealth aircraft by using the radars and transponders of aircraft heading toward an air defense zone. The Russians are also exploiting VHF frequencies and the L-Band radar sets that are being built into the leading edge of some fighter aircraft.

Interesting, all of this has led to a shift in the aircraft game. Where previously the emphasis was on point-type engagement against targets, now the emphasis is shifting to beyond visual range (BVR) air-to-air weapons. BVR means that you can hit another aircraft some few hundred miles away, provided you can find the target. BVR missiles must be able to maneuver and fly very fast. The Russians have some advantage because their latest fighters can “supercruise” – that is they can fly supersonically without using afterburners, meaning much greater operating range and time, and the ability to launch missiles at very high speed.

Stealth always requires trade-offs in the design of an aircraft. The US decided stealth was more valuable than close-in capability, yet maneuvering may be one of the best ways to avoid being hit by a very fast-moving anti-aircraft missile. The S-400 can launch one missile that flies at over 11,000 miles an hour and can pull turns at 15 times the force of gravity, almost double what can be achieved in a manned aircraft. Assuming more progress in radars and sensors, there is a possibility US aircraft could penetrate close to a target only to be greeted by one of these missiles.

Meanwhile, stealth as an asset will continue to lose value as techniques develop to counter stealth platforms. Perhaps the US should be thinking about a potent conventional aircraft that can fight off enemy air defenses.

This first appeared in AsiaTimes here.