More likely to happen is that a F-15 would run into a Su-35 operated by some Third World despot. The pilots are not likely to have the training, tactics or experience to fight against an American aviator with a realistic chance of winning. Further, Russian jets arenot exactly known for their reliability, combine that with poorly trained maintenance crews and lack of spare parts, some random Third World power is not likely to be able generate a fully operational jet much of the time. Furthermore, other than Russia and China, a potential adversary is not likely to have an AWACS or full ground controlled intercept capabilities—which further hampers the enemy.
The Boeing F-15C Eagle has been in service with the U.S. Air Force for nearly 40 years and will likely serve for decades to come . Over the years, the mighty F-15 has been upgraded to keep pace with evolving threats, but does the venerable Eagle still have what it takes to dominate the skies?
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The answer is yes—absolutely. The Eagle may be old, but it’s still one of the best air superiority fighters flying. The only operational aircraft that is definitively superior to the F-15 in most respects is the Lockheed Martin F-22 Raptor—other machines have the edge in certain aspects, but the F-15C is still competitive overall despite what the business development departments at various rival contractors might say.
Perhaps the most advanced threat the F-15 is likely to encounter is the Russian-built Sukhoi Su-35 Flanker-E. While there are more advanced threats in development, those aircraft are likely to be too expensive to ever become commonplace. The Su-35 isn’t the most common potential threat out there, but there is a good chance it will proliferate. Indonesia has reportedly decided to purchase the Su-35 , and we know that the Chinese have had discussions about a potential purchase.
(This first appeared in late 2015.)
The Su-35 is a genuinely dangerous war machine , and in many metrics, it matches or even exceeds the capabilities of the latest upgrades for the F-15. In terms of pure kinematic performance, the Su-35 is slightly slower than the F-15C in terms of max speed but it can out accelerate the Eagle with its powerful twin Saturn Izdeliye 117S engines, which put out 31,900lbs of thrust each. Further, when the jet is relatively lightly loaded, it can maintain supersonic speeds without the use of its afterburners.
While excellent acceleration at high altitude to supersonic speeds is a huge advantage, the F-15C is no slouch—and it wouldn’t be a decisive edge for the Russian jet. However, where the Su-35 does have an insurmountable edge is at low speeds. The Flanker-E has three-dimensional thrust vectoring and is unbelievably maneuverable at low speeds. However, given the advent of helmet mounted cuing systems and high off-boresight missiles like the AIM-9X and Russian R-73, more often than not, close in visual encounters tend to be “mutual kill” situations as many pilots can attest. A lot of it is going to come down to pilot skill and, frankly, luck.
At longer ranges, the F-15C and the F-15E still have the advantage over the Su-35 with their active electronically scanned array radars. The Raytheon APG-63 (v)  3 and APG-82 (v)1  on the two Eagle variants are still considerably superior to the Su-35S’ Tikhomirov IRBIS-E phased array radar. The Su-35 does hold a fleeting advantage for now for passive sensors since it has a built-in infrared search and track system (IRST), but the F-15 fleet will receive a very capable IRST in the near future—nullifying the Flanker’s edge.
One area the Flanker-E probably holds the edge is with its electronic warfare suite. The Su-35S boasts a potent digital radio frequency memory jamming suite that can wreck havoc with the AIM-120 AMRAAM missile . While American missiles are likely to eventually make it through, it will take many more missiles to achieve a kill than planners were counting on. The Su-35, meanwhile, carries a huge arsenal of air-to-air missiles versus the F-15 fleet’s obsolete defensive electronics. The U.S. Air Force is keenly aware of the problem, which is why it places such emphasis of on the $7.6 billion Eagle Passive/Active Warning and Survivability System upgrade .
The real dilemma is that the Su-35 and the current day F-15 Eagle are comparable—and that’s what is worrisome for the U.S. Air Force. The service is used to fighting adversaries where it has a huge technological advantage—against the Su-35 that deficit does not exist and the Flanker-E even has some advantages over the Eagle. Overall, if all things were equal, even a fully upgraded F-15C with the latest AESA upgrades would have its hands full versus the Su-35. But that would mean the United States would be fighting a war against Russia or some other great power—like China. That’s not likely to happen.
More likely to happen is that a F-15 would run into a Su-35 operated by some Third World despot. The pilots are not likely to have the training, tactics or experience to fight against an American aviator with a realistic chance of winning. Further, Russian jets are not exactly known for their reliability , combine that with poorly trained maintenance crews and lack of spare parts, some random Third World power is not likely to be able generate a fully operational jet much of the time. Furthermore, other than Russia and China, a potential adversary is not likely to have an AWACS or full ground controlled intercept capabilities—which further hampers the enemy.
Bottom line: unless the F-15 is fighting World War III, the Air Force is probably going to be ok keeping the Eagle in service for another two decades. It might not be the one-sided turkey-shoot the Air Force has gotten used to, but the United States isn’t in danger of losing air superiority.