Is Russia's Lethal Su-35 Fighter Better than the American F-15?
I have been asked to compare the venerable American F-15 Eagle fighter to Russia’s new competitor for the crown of best Fourth Generation fighter, the Su-35S “Flanker E.”
The former is the airplane that in many ways defined what a Fourth Generation fighter can do. Introduced in the 1970s, it has been extensively updated to keep with the times—and hundreds will remain in service for decades to come.
The latter is an upgraded Su-27 Flanker—the Soviet-era counterpart to the F-15—now sporting modernized avionics and munitions, fancy vector-thrust engines and a fresh coat of radar-absorbent paint.
I’ve written in detail about the Su-35S before, and the National Interest’s Dave Majumdar has written an excellent analysis of how the two aircraft would fare in aerial clash. He concluded that regardless of their differences, the two aircraft were more or less closely matched. As a result, supporting assets and pilot skill are more likely to determine the outcomes of an engagement between the two rather than any technological gap.
Here, I’d like to break down the strengths and weaknesses of the two aircraft, and how those will inform their ability to perform various mission.
Sensors and Stealth
The Su-35S has a powerful Irbis-E passive electronically scanned array radar with a range of up to 400 kilometers; it is also effective against ground targets. However, the F-15’s APG-63 V3 Active Electronically Scanned Array radar is superior—harder to jam, higher resolution and harder to track.
The Su-35 boasts an infrared search and track system (IRST), which allows it to determine the general position of aircraft within a fifty kilometer radius—potentially quite useful for detecting stealth aircraft at shorter ranges. The F-15 doesn’t have an IRST.
However, a new add-on pod that is entering service, Talon HATE, will not only add an IRST to the F-15 but provide data fusion with other air and surface sensors, even allowing it to network with F-22 Raptor stealth fighters, which use a nonstandard datalink. Using this system, Raptors could fly ahead and identify hostile targets and send the targeting data to missile-firing F-15s a safer distance to the rear.
The F-15 wasn’t designed to be stealthy—and it isn’t, with an average radar cross section of five meters squared. The Su-35 has been designed for stealth, and reportedly can achieve a radar cross section ranging between one to three meters squared. So the Su-35 will show up on radars less quickly—but a radar cross-section of one meter squared can still be detected at fairly long ranges by good modern radars, and will not protect it from being targeted by long-range missiles.
Beyond Visual Range Combat
The latest air to air missiles can be launched at targets well over 100 kilometers away. While the United States Air Force is convinced that beyond visual range (BVR) combat will dominate air warfare in the twenty-first century, with missiles fired over vast distances, the Russian aviation establishment is more skeptical. It holds that electronic counter measures and evasive maneuvers will lower the hit probability against maneuverable fighter aircraft considerably below the projected fifty to seventy percent hit rate. Russian aircraft are still designed to engage in BVR warfare, but with the belief that short-range combat is likely to ensue after BVR volleys are exchanged.
In terms of weapons load, the Su-35 has twelve or more hardpoints for carrying missiles compared to just eight on the F-15C. This is a clear advantage for the Su-35, which will likely fire multiple missiles at a time to increase hit probability; however, this edge may prove temporary. Boeing is offering to upgrade F-15s with quad-rail racks that will double the F-15’s loadout to sixteen. This would enable rear-deployed F-15s to serve as “missile boats” firing at targets painted by a vanguard of F-22 stealth fighters. For the time being, however, the F-15 is out-missiled.
Both the F-15 and Su-35 carry long-range, radar-guided air-to-air missiles: the AIM-120D (160 kilometer range) and the K-77M (200 kilometers range). These missiles are basically in the same class—though the comparative effectiveness of their seekers has yet to be established—and would likely be fired under their maximum range when used against fighter-type aircraft to increase the likelihood of a kill.
The Su-35 can also fire the super-long range (300-400 kilometer) R-37M missile, designed to take out ungainly tanker and AWACS support aircraft.
Another advantage of the Su-35 is its L175M Khibiny radar jamming system. While American AESA radars are believed to be resistant to jamming, the same is not believed to be true of the radars in AIM-120 missiles; the air-to-air missiles may have a high failure rate against aircraft protected by the Khibiny. In contrast, the Eagle’s Tactical Electronic Warfare Set countermeasure system dates back to the 1970s—a new system is being proposed as part of the Eagle 2040 upgrade package.
Within Visual Range Combat