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What Would War II Could Teach America's F-35 and F-22 Stealth Fighters

The U.S. military is a big proponent of networked warfare. In theory, if one airplane detects an enemy, it could pass on that data to friendly ships and aircraft—and through Cooperative Engagement Ability, even potentially allow those friendlies to shoot at that target from far away. One potential tactic is to use a vanguard of stealthy fighters to identify incoming enemy aircraft and send targeting data to ships or non-stealth fighters, which can carry heavier weapons loads. The F-35’s excellent sensors and datalinks could make it effective in this role.

In Len Deighton’s book Fighter, he describes the tactics used by the outnumbered English fighter pilots defending against German Luftwaffe bombers in the Battle of Britain:

The professional fighter pilot gained height as quickly as he was permitted, and treasured possession of that benefit. He hoped always to spot the enemy before they spotted him and hurried to the sun side of them to keep himself invisible. He needed superior speed, so he positioned himself for a diving attack, and he would choose a victim at the very rear of the enemy formation so that he did not have to fly through their gunfire. He would hope to kill on that first dive. If he failed, the dedicated professional would flee rather than face an alerted enemy.

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Deighton’s point was that the best British pilots used hit-and-run tactics emphasizing surprise and speed in order to minimize losses, rather than dogfighting at length with enemies after those advantages were spent. These tactics permitted small numbers of British fighters to tackle the aerial armadas of the German Luftwaffe.

Obviously, technology has changed dramatically since 1940. While contemporary fighters can now go more than five times as fast as the Spitfires and Messerschmitt fighters of the Battle of Britain, two new technologies promise to make hit-and-run tactics more effective: stealth technology and long-range air-to-air missiles.

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Stealth and Its Limits

While virtually any plane can be equipped to fire long-range missiles, stealth airframes are built using radar-absorbent materials and engineered precisely to minimize reflection of radar waves. This constrains their load-carrying abilities, as external weapons or drop tanks could increase their visibility on radar. The United States fields two stealth fighters, the F-22 Raptor and the F-35 Lightning II.

Stealth planes are properly described as “Low Observable” aircraft. They are not actually undetectable, but are very hard to spot on radar. Let’s review the limits on stealth technology, and how fighter doctrine may evolve around them.

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Stealth aircraft are optimized to be difficult to observe on the precise X-Band radars used on modern fighters: while some radars have better resolutions than others, most will only be able to track a stealth fighter at shorter distances. An F-22 is claimed to have the radar cross section of 0.0001 square meters in certain aspect—the same as that of a marble.

Low-bandwidth radars are more effective at detecting stealth aircraft. These are typically used by ground installations and ships, but also found on specialized aerial platforms such as the E-2D. However, they come with a major limitation: they can reveal only the general location of a stealth fighter and are too imprecise to be used to target missiles—though they can indicate to an X-Band radar where to look.

Infra-Red Search-and Track (IRST) systems offer another means of detecting stealth aircraft, but their range is generally limited. The latest IRST system on the SU-35 has extended the range up to 50 kilometers, whereas its radar has detection range of up to 200 kilometers. Just like low-band radar, IRST doesn’t give a precise track and can’t be used to lock on weapons. Stealth fighters include features designed to minimize heat signature, but they are far from completely effective.

Of course, a stealth fighter can be seen within visual range, and is vulnerable to heat-seeking missiles.

To recap: stealth technology is more effective at a distance. Although there are a number of methods to detect stealth fighters at long range, they generally don’t permit weapons to lock on to them.

In return, nothing prevents the stealth aircraft from firing at its opponents.

Enter the beyond-visual-range (BVR) missile.

Long Range Air-to-Air Missiles

Around the late 1990s, a new generation of long-range radar-guided air-to-air missiles entered service, notably the AIM-120 AMRAAM and the Russian R-77. These could hit targets over 50 kilometers away. (The earlier AIM-54 Phoenix boasted even longer range but was very expensive). In subsequent decades, the range has continued to increase to well over 100 kilometers, and new types such as the European MBDA Meteor and the Chinese PL-15 continue to push the envelope of speed and range.

The current AIM-120D has a theoretical maximum range of 160 kilometers; although in practice firing range will likely be much shorter for reasons soon discussed.

As long-range missiles are radar-guided, stealth fighters are not particularly vulnerable to them. The same cannot be said for non-stealth aircraft. An F-15 or Su-35 may attempt to avoid missiles with evasive maneuvers and counter measures—but doing so will disrupt whatever they are doing, and an opponent is likely to fire more than one missile.

One factor that is difficult to calculate is how likely long-range missiles are to hit. Extrapolating from past usage of radar-guided missiles is problematic, both because missile technology has advanced considerably since its inception (early radar-guided Sparrow missiles had a less than 10 percent kill probability in the Vietnam War), and the conflicts in which radar-guided missiles have been more successful (Arab-Israeli conflicts, the Gulf War) involved poorly trained opponents lacking effective countermeasures.

It’s safe to say that long-range missiles will have lower hit rates than short-range missiles like the AIM-9 Sidewinder and the Russian R-73—modern versions of which have chalked up a roughly seventy percent probability of kill.

Attrition and High Value Targets

Third- or fourth-generation fighters seeking to engage stealth aircraft in combat must close within short range so that their targeting systems are effective, all while dodging volleys of deadly missiles. As the stealth fighters themselves are difficult to track, they can disengage to avoid entering the short-range envelope in relative security.

It’s a difficult advantage to overcome.

But referring back to the Battle of Britain can reveal a limitation of this strategy. The British hit-and-run attacks succeeded in inflicting deadly attrition on German bombers over time until they were forced to call off the air offensive. But they rarely prevented the German formations from hitting their targets. The German simply had too many aircraft.

At first, this was a problem: the Germans relentlessly pounded British airfields, degrading the Royal Air Force’s ability to fight in the air. But then the Germans switched to bombing civilian targets in London. While this inflicted many civilian casualties, the raids did not degrade the RAF’s ability to fight back. The British fighters could sustain their advantageous rate of attrition versus the German Luftwaffe until the latter was forced to tap out.

So what happens if the other side attacks with superior numbers a target that must be defended?

An F-22 has a combat radius of some five hundred miles on internal fuel. The F-35 can fly 875 miles when loaded for air-to-air combat. Now consider the thousands of kilometers lying between U.S. bases in the Pacific and Europe and various potential conflict zones. To operate over those distances, stealth fighters would require aerial refueling from tanker aircraft. If fighting a well-equipped opponent, carrier-based aircraft would also likely be distant from the warzone, as carriers are at risk if they approach too close to ground-based anti-shipping missile batteries and aircraft.

American fighters would also likely be supported by AWACS airborne radar and command and control platforms, notably the E-2 Hawkeye and E-3 Sentry. The tankers and the AWACS aircraft are basically lumbering airliner-sized planes crammed full of fuel and electronic equipment respectively.

Let’s consider what would happen when American fighters encounter a much larger force of fighters based on the coast. The American fighters could fire their long-range AIM-120D missiles from more than one hundred kilometers away—four from each F-35 and six on the F-22. Soaring at Mach 4—twice the maximum speed of the aircraft that launched it—an AIM-120 can traverse eighty kilometers in one minute.

The radar-warning receivers on their targets would light up as they detect the incoming attack. The further away the target, the more time it has to evade the missile. Therefore, BVR missiles may be fired at well below their maximum range to ensure a higher probability of a kill, particularly when engaging maneuverable fighter aircraft.

Most opposing aircraft would not be able to shoot back at the stealth planes, though they might have a general idea of their position if they are supported by low-band radar or good infrared sensors. They could close on the American fighters, hoping to enter the envelope in which their sensors are effective.

What if the U.S. fighters close to short range after expending their long-range armaments, rather than prudently disengaging? If both sides are closing upon each other at maximum speed at high altitude, the distance between them would diminish at a rate of 60-80 kilometers a minute. Even if the AIM-120s were fired at maximum range, the opposing aircraft could close that distance in one or two minutes.

In short-range engagements, surprise, pilot training and flight performance will determine the victor.

The F-22 is a superb dogfighter. The F-35… not so much, though it has its defenders. Both aircraft can carry two Sidewinder missiles and fire shells from their onboard cannons.

However, their opponents would be able to spot the American fighters as they enter visual range thanks to the Mark One human eyeball, as well as infrared and electro-optical sensors—and even radars, which are effective against stealth aircraft at short ranges. The stealth fighters could be targeted with heat-seeking missiles, more of which could be carried by the non-stealth aircraft. If the opponents retain a significant numerical advantage, than within-visual range combat could be quite risky.

But why would stealth fighters risk engaging in short range in the first place?

Stealth Fighters Don’t Swim

The Rand Corporation’s Pacific Vision wargame simulating a conflict with China in 2008 found that even in a favorable scenario for the United States—half of U.S. missiles hit at long range and the none of their opponent’s do—a force of U.S. fighters outnumbered roughly three to one would be overwhelmed after firing off all its missiles. The less-maneuverable F-35s fared poorly in the ensuing dogfight. But in the end, nearly all of the U.S. fighters were lost.

Why? The hostile aircraft didn’t have trouble detecting the tankers supporting the U.S. forces. Unlike the F-22s and F-35s, tankers have neither the speed nor stealth to evade a determined attack.

If the tankers get shot down, it doesn’t just force the U.S. fighters to abandon the fight. It could force them to crash into the ocean, without enough fuel to make it back to base. In effect, a tanker would be a high-value target that U.S. air-superiority fighters would need to defend to the last.

A similar problem exists while defending an aircraft carrier from attack. Unlike the resilient city of London in the Battle of Britain, a carrier is a vulnerable and militarily consequential target that must be defended at all costs. A lost carrier consigns its fighters to the ocean as well.

A final consideration is that opponents may field limited number of their own stealth fighters, such as the J-20 or the Sukhoi T-50. Even a small number of stealth fighters would be effective at sneaking into the range of the tankers and AWACs aircraft and taking them out before the U.S. aircraft could evade or retaliate. Very long-range missiles such as the R-37 and the PL-13 could also assist in the anti-tanker mission.

The Psychological Factor

There are limitations to the “overwhelm with numbers” strategy.

In ground warfare, consider what would likely happen if an attacking infantry unit were to sustain 33 percent casualties attacking an objective. More often than not, the attackers would halt their advance, if not beat an outright retreat. Not only do fear and stress from incoming fire and casualties cause soldiers to abandon an attack, but disorganization and confusion set in as communication becomes frantic and links in the chain of command are eliminated.

The RAND wargame results hinged on ten surviving pilots shooting down the U.S. tankers after sixty-two of their compatriots were shot down. How coolheaded and rational would these pilots remain while their unit suffered 86 percent casualties?

Air warfare does have different psychological and physical dynamics than ground warfare. There are historical incidents in which aerial units pressed home attacks despite sustaining very heavy casualties, even up to 100 percent. However, there are also instances in which aerial attackers aborted in disorder after taking losses.

Implementing a swarm attack would also be no simple matter. Concentrating large numbers of aircraft would be a logistical challenge. They would also need to attack a target that would force American fighters to engage in such adverse circumstances.

Solutions?

How can U.S. doctrine adapt to this challenging scenario?

Already, many theorists believe that carriers would be forced to remain far away from hostile shores. The survivability of airbases in the event of a mass surface-to-surface missile attack is also open to question. One possibility is that no large-scale air battles would materialize.

The two key limitations are logistical: lack of internal fuel to operate without support, and insufficient missiles to tackle superior numbers. For the time being, there is no obvious fix to the fuel problem: the latest U.S. fighters, the F-22 and F-35, are simply going to depend on tankers. Some suggest that the Navy should deploy light-weight low-observable drones from carriers that could potentially operate further afield.

What about increasing missile capacity?

The U.S. military is a big proponent of networked warfare. In theory, if one airplane detects an enemy, it could pass on that data to friendly ships and aircraft—and through Cooperative Engagement Ability, even potentially allow those friendlies to shoot at that target from far away. One potential tactic is to use a vanguard of stealthy fighters to identify incoming enemy aircraft and send targeting data to ships or non-stealth fighters, which can carry heavier weapons loads. The F-35’s excellent sensors and datalinks could make it effective in this role.

There is even an idea being kicked around to mount large numbers of missiles on a B-1 or B-52, which would be fired off hundreds of kilometers away from the battle. Of course, such an “arsenal plane” would be vulnerable if enemy fighters broke through the accompanying line of F-22s and F-35s. The tactic would likely require even longer-range missiles than the U.S. currently employs.

Ultimately, hit-and-run tactics leaning on BVR and stealth technology may be quite effective in securing air superiority. However, they won’t suffice to overcome constraints of fuel and weapons supply in scenarios that involve distant and more numerous opponents attacking high-value targets.

Sébastien Roblin holds a Master’s Degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.

This first appeared last year. 

Image: Creative Commons.