The inefficiency of F35's stealth technology

04/05/14

In February 2013, the pentagon spread the news that China had intercepted the F-35 telemetry, but previously several terabytes related to the design and electronic systems of the fighter had been stolen.

A new anomaly seems to afflict the Lightning, which does not seem to possess a very advanced stealth technology in the contrast of air defense systems. The density of the electromagnetic spectrum is increasingly complex and difficult, therefore it requires specific skills to evade opposing defenses in attack and reconnaissance missions.

Russia and China, perhaps facilitated by the F-35 telemetry observations, have developed contrast systems that put the stealth technology of the US aircraft to the test. And if these features were to be implemented, the Lightning development program could have limitations especially in offensive missions. Furthermore, even the disruptive radar abilities would not have reached the state of the art, this means that the F-35 will need the aid of electronic war planes in order to penetrate areas of high conflict density.

The US aircraft appears to be detectable by research radars operating in the VHF band and the hunting disturbance system would be limited to the X band. Electromagnetic radiation is diffused by objects smaller than its wavelength, this is true for the stabilizers and the wing surfaces of aircraft, which are about the same order of magnitude as the VHF metric waves. To design an aircraft with stealth features at VHF, the engineers scored a major success by removing the vertical fletching, as in the B-2 bombers. But this solution is not simple to apply for an agile supersonic fighter.

When the JSF specifications were defined, this was compounded by the difficulty of equipping it with an active broadband jammer. Basically, to use the radar disturbance system, you need to be sure that the opposing air defense has locked onto the aircraft, otherwise the disturbance would reveal the presence of an aircraft with stealth characteristics, in fact the target acquisition radars can detect the signal, but not the reflection. It seems certain that the disturbing electronics have not yet been added to the F-35.

Ultimately, the JSF will have to be equipped with a radar disturbance device known as EA, "electronic attack". The technicians who developed the Lightning project had set themselves the goal of obtaining a low radar signature combined with passive electronic surveillance, in order to allow the pilot to have a full awareness of the external environment, but this happened over the years 90, when China did not yet possess adequate technological capacity.

The threats of the 2010 years are qualitatively different: The VHF radars with electronic scanning active in AESA, at high power and with decimetrical and centimetric waves, are the greatest dangers for an aircraft incursor, in fact they return a reverberation quite net compared to the previous ones and have a greater tracking and tracking capability.

Russia has developed a new highly mobile anti-stealth radar system. Its core is a VHF antenna of 30 meters of the fully digital AESA type and also incorporates powerful radar at a higher frequency, allowing even small targets to be monitored. A similar system is also supplied on the new Chinese warships, it would be a VHF research radar type 517M, classifiable in the AESA type.

Of course, it is not conceivable that the technological implementation in the field of target detection and evasion techniques in aerial combat has gone down.

EA and stealth still do not coexist with simplicity on the same platform, but they are synergistic: the smaller the target, the less disturbing power is needed to mask it.

Giovanni Caprara

(photo: Lockheed Martin)