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.
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.
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.
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.