Early in December, the web site ChinaMil posted (and later took down) a dramatic photo showing a flight of 4 Chinese J-16 heavy fighters, allegedly from combat training flights on November 25. Two of the J-16 are seen bristling with at least 10 air-to-air missiles, each one in all 4 types.
The Shenyang J-16 is a Chinese derivative of the big Russian two-seat Sukhoi Su-30MKK Flanker-G strike plane, exported to China between 2000 and 2004. It’s conceptually much like the U.S. Air Force’s versatile and heavy-lifting F-15E Strike Eagle jet, so its ability to hold a lot of weapons isn’t surprising in itself.
What attracted attention were the missiles protruding like lances from under a DF-4 pylon on the jets’ left wings: a PL-17 very-long-range air-to-air missile, or VLRAAM.
The U.K.’s RUSI think tank estimated in 2020 that this six-meter-long-weapon (also generally known as the PL-X or PL-20) had a whopping 250-mile (ie. 400 kilometer) range. That’s greater than double the utmost range of the U.S. military’s longest-range air-to-air weapon, the AIM-120D.
The PL-17 was first publicly seen under the wing of a J-16 in 2016.
It was subsequently spotted in 2017, carried on a J-11B (a predecessor of the J-16, based on the Soviet Su-27), and again in 2020 on a JH-7A Flying Leopard fighter-bomber used as a test aircraft. The brand new photo—undoubtedly released for propaganda purposes—seemingly affirms that the powerful missile has entered regular service, as was claimed in an announcement from October of 2022.
The PL-17 appears comparable to Russia’s R-37M VLRAAM-class missile (codenamed AA-13 Axehead by NATO), which can also be said to achieve so far as 250 miles and has been utilized in combat with some successes over Ukraine.
The opposite three weapons mounted on the J-16 bear consideration as well—one older PL-12 missile under the inboard right wing station (max range 62 miles), 4 PL-10s missiles, and 4 PL-15s missiles could be seen on the J-16s, mounted under the fuselage. The four-meter-long PL-15s also outranges the AIM-120D, boasting a reach somewhere between 120 and 186 miles. Unlike the PL-17, the PL-15s also can fit inside the inner bay of China’s J-20 stealth fighter.
The 4 smaller PL-10s missiles are short-range (max 12 miles), with advanced infrared imaging seekers and thrust-vectoring motors.
China has also tested a PL-21 (or PL-XX) missile with a projected range of 186-250 miles. It’s distinguished by a throttle-able ramjet motor that enables for acceleration late in flight, making it an even bigger threat to agile fighters than the PL-17 and its simpler, slimmer, dual-pulse rocket motor. Whether the PL-21 stays in development is unclear.
How the PL-17 missile works
VLRAAMs are large because of the extra propellant needed to traverse long distances, and like all BVR missiles, they achieve their most impressive range when fired at high speed and altitude (where the air is thinner and generates less friction). They require elaborate technique of guidance and navigation, as they’re prone to be launched at targets that their plane’s own sensors can’t even detect.
Like a house run in baseball, the PL-17 likely maximizes range by launching upward in an arcing ballistic trajectory quite than directly towards the goal. An inertial navigation system contained in the missile (assisted by satellite navigation, if accessible) helps keep it heading in the right direction towards the projected goal area. A datalink allows friendly forces to transmit course updates to the missile—say, if the goal changes speed or bearing.
Because the missile finally begins arcing downwards, a built-in multi-mode seeker begins looking for its quarry from an elevated vantage. This enables it to potentially detect low-flying aircraft that might ordinarily be masked by terrain. The weapon’s steep vector might also serve to maintain it outside the vertical detection arc of the missile approach warning systems (MAWS) on some aircraft.
The seeker uses each an lively AESA-class radar (frequency-hopping AESA radars have notably superior resolution, stealth, and jam resistance) and an optical infrared imaging sensor—the port for which could be seen on the side nose.
Multi-mode seekers are expensive, but improve accuracy and goal detection odds while making it harder for countermeasures (like flare and chaff decoys or self-defense jammers) to reliably defeat the missile. The infrared seekers are also useful against stealth aircraft—but how well that could be leveraged continues to be debatable.
The built-in sensors also mean that the missile could be used as a ‘fire and forget’ weapon (or ‘Fox 3’ in pilot shorthand), with the attacking aircraft free to dart away after launching as a substitute of keeping its radar trained heading in the right direction.
The PL-17’s optimization for long-range attacks is observable in its 4 “cropped” rear maneuvering/stabilizing fins, designed to attenuate drag. That optimization comes on the expense of maneuverability, likely meaning that the PL-17 could also be relatively ‘dodge-able’ by agile fighter-like aircraft.
However the RUSI report notes that such a missile “represents a potentially formidable weapon for hunting vulnerable tanker and ISTAR [Intelligence, Surveillance, Targeting Acquisition and Reconaissance] aircraft at very long ranges.”
Such aircraft—just like the KC-10, KC-46 tanker, and the E-3 and E-7 airborne early warning aircraft—are typically based on subsonic Boeing or Airbus airliners. They will not be exactly built to perform hairpin turns, nor are they in a position to race away from incoming missiles at a supersonic speeds.
And losing a tanker or ISTAR plane is usually a devastating blow. ISTAR aircraft greatly improve the situational awareness of the fighters they support in combat, and likewise are likely to have large crews without ejection seats. The lack of a number of tankers on an extended range mission over the Pacific could lead to multiple fighters being ditched into the ocean without the fuel needed to return to base.
The brand new era of Very-Long Range aerial warfare
Very long-range air-to-air missiles were initially conceived as approach to do one in all two things: shoot down or drive away bombers before they may release their weapons, or snipe at vulnerable refueling tankers and early-warning planes that sometimes fly beyond the reach of most enemy anti-aircraft weapons.
But when Russia began employing R-37Ms on its MiG-31 interceptors and Su-35S fighters over Ukraine in the autumn of 2022, Ukraine’s military reported that the long-range weapons downed several of its fighters and helicopters while they were flying at low altitude—including a reported successful intercept from a record-breaking 110 miles away.
Admittedly, Ukrainian air losses have been light in 2023, suggesting that countermeasures and tactics have mitigated losses to R-37Ms. Nevertheless, the long-range weapons should be forcing Ukrainian pilots to abort their attack runs and perform evasive maneuvers.
Overall, the R-37M’s combat debut showed that VLRAAMs could possibly be useful against enemy warplanes basically, not only specialized and comparatively vulnerable aerial targets.
NATO doesn’t currently field any very-long range air-to-air missiles—a specialized subset of missiles intended to have interaction enemies from beyond-visual range (BVR). The ultimate AIM-54C model of the U.S. Navy’s Phoenix missile attained a max range of 114 miles, but these expensive fleet defense weapons were retired in 2004 when the specter of massed bombers attacking U.S. carriers seemed anachronistic.
But presently, the Pentagon is thought to be working on two longer-range AIM-120 successors. In theory, by 2026, Lockheed’s AIM-260 JATM missile should enter full production. This could attain parity with the PL-15—which has a variety exceeding 120 miles—and fit inside stealth fighter internal bays.
But Raytheon is working on a more mysterious Long Range Engagement Weapon (LREW). They’re aimed toward creating “oversized” missiles for potential external mounting on F-15EX fighters, or perhaps contained in the greater bomb bay of the brand new B-21 Raider bomber. That seems aimed toward a VLRAAM in the category of the R-37M or PL-17.
Tactics and challenges of very-long aerial warfare
The impressive maximum range of VLRAAMs is difficult to realize, nevertheless, since the radar on the launching fighter is unlikely to see targets from that far.
Yes, the APG-82 radar on an F-15E or the Irbis-E on a Su-35s officially have maximum detection ranges within the ballpark of a PL-17 or R-37M. But those ranges are for giant, non-stealth optimized aircraft (think B-52 bombers or 737s) at ideal angles. Fighters, then again—especially newer, 4.5-generation jets with slimmer radar cross sections—would only develop into visible once they get. And 5th-generation stealth fighters wouldn’t be visible until they were a number of dozen miles away at best.
Moreover, max ranges are achieved by concentrating the scan in a very narrow arc (only a number of degrees wide) on the expense of wider-area search. That’s only viable when a goal’s general position is thought or expected.
So, in practice, it’s likely that the aircraft firing a VLRAAM at near-max range will need cueing from a separate platform (ideally an airborne one, but a ship or ground-based radar could also work) to produce initial targeting data, and maybe to transmit midflight course corrections. For instance, it’s speculated that Russia’s A-50 ‘Mainstay’ radar planes can have transmitted targeting data to R-37M missiles in over Ukraine.
A Chinese paper on missile guidance also shows a PLA KJ-2000 early warning radar plane (based on the Russian Il-76 jet) and ground-based, over-the-horizon radars feeding targeting data to a fighter launching a VLRAAM missile. Intriguingly, it suggests that the VLRAAM wax targeting not only the expected E-3 AWACs plane, but a B-21 stealth bomber and F-35 stealth fighter as well.
Ordinarily, stealth aircraft only develop into detectable to radar or infrared/optical sensors at short ranges. Nevertheless, some large, low-band radars sometimes faintly pickup stealth aircraft with low accuracy. The diagram implies a belief that long-range stealth intercepts could possibly be orchestrated by meshing together distributed sensors and ‘shooters,’ in theory delivering a missile to a position where its seeker can detect a stealth aircraft at short range.
Rapidly forming kill chains over tons of of miles could be very technically and procedurally difficult. Attempting to cue a missile against stealth targets based on non-weapons-grade tracking data can be much more so.
Nevertheless, China’s military industrial sector (though behind in areas like fighter propulsion) is powerful in missiles, sensors, and communications systems. Thus, the potential for China’s military to form such kill chains that leverage the long reach of weapons just like the PL-17 shouldn’t be dismissed out of hand—no less than, not any greater than it ought to be taken without any consideration.