Revealed: China's Radars Can Track America's Stealthy F-22 Raptor
Dave Majumdar
Security, Asia
Contrary to popular belief, the F-22 is not invisible to enemy radar contrary.
State-run Chinese media is claiming that the People’s Liberation Army has been able to track the U.S. Air Force’s Lockheed Martin F-22 Raptor stealth fighters over the East China Sea. While the Chinese report might be easily dismissed as propaganda—it is not beyond the realm of possibility. In fact—it’s very possible that China can track the Raptor. Stealth is not a cloak of invisibility, after all. Stealth technology simply delays detection and tracking.
First off, if a Raptor is carrying external fuel tanks—as it often does during “ferry missions”—it is not in a stealth configuration. Moreover, the aircraft is often fitted with a Luneburg lens device on its ventral side during peacetime operations that enhances its cross section on radar.
That being said, even combat-configured F-22s are not invisible to enemy radar, contrary to popular belief. Neither is any other tactical fighter-sized stealth aircraft with empennage surfaces such as tailfins—the F-35, PAK-FA, J-20 or J-31. That’s just basic physics.
The laws of physics essentially dictate that a tactical fighter-sized stealth aircraft must be optimized to defeat higher-frequency bands such the C, X, Ku and the top part of the S bands. There is a “step change” in a Low Observable (LO) aircraft’s signature once the frequency wavelength exceeds a certain threshold and causes a resonant effect. Typically, that resonance occurs when a feature on an aircraft—such as a tail-fin — is less than eight times the size of a particular frequency wavelength. Effectively, small stealth aircraft that do not have the size or weight allowances for two feet or more of radar absorbent material coatings on every surface are forced to make trades as to which frequency bands they are optimized for.
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