Can Sweden develop stealth aircraft

Radar system exposes the Americans' stealth jet

Switzerland is testing these fighter jets

One of the two Lockheed Martin F-35 "Lightning II" machines on April 25, 2018 at the International Aerospace Exhibition ILA in Berlin. (Archive)

Image: Getty Images

A Lockheed Martin F-35 fighter jet being evaluated in Payerne.

Image: Keystone

F-35A in flight: Lockheed Martin accompanied the evaluation in Switzerland with an advertising campaign on Twitter. (Archive image)

Image: Keystone / EPA / Yonhap

He was the first to take off in the candidate tests of possible future Swiss fighter jets in Payerne VD: The Eurofighter Typhoon - here a copy of the German Air Force during a test flight at Emmen LU airfield. (Archive image)

Image: Keystone

The F / A-18 Super Hornet fighter jet is also in the selection for the new Swiss fighter aircraft. (Archive image)

Image: Keystone / EPA / Andy Rain

A Rafale fighter jet at an air show in Sion in September 2017. (Archive image)

Image: Keystone / Christian Merz

Sweden is taking the Gripen E out of the race with the decision not to take part in the tests. Now there are only four models left to be evaluated. (Archive)

Image: Keystone / EPA / Anders Wiklund / TT

Switzerland is testing these fighter jets

One of the two Lockheed Martin F-35 "Lightning II" machines on April 25, 2018 at the International Aerospace Exhibition ILA in Berlin. (Archive)

Image: Getty Images

A Lockheed Martin F-35 fighter jet being evaluated in Payerne.

Image: Keystone

F-35A in flight: Lockheed Martin accompanied the evaluation in Switzerland with an advertising campaign on Twitter. (Archive image)

Image: Keystone / EPA / Yonhap

He was the first to take off in the candidate tests of possible future Swiss fighter jets in Payerne VD: The Eurofighter Typhoon - here a copy of the German Air Force during a test flight at Emmen LU airfield. (Archive image)

Image: Keystone

The F / A-18 Super Hornet fighter jet is also in the selection for the new Swiss fighter aircraft. (Archive image)

Image: Keystone / EPA / Andy Rain

A Rafale fighter jet at an air show in Sion in September 2017. (Archive image)

Image: Keystone / Christian Merz

Sweden takes the Gripen E out of the race with the decision not to take part in the tests. Now there are only four models left to be evaluated. (Archive)

Image: Keystone / EPA / Anders Wiklund / TT

Switzerland wants to buy fighter jets for six billion francs. The stealth plane F-35 is also in the running for the major order. It is possible that the aircraft is nowhere near as invisible as is often claimed.

The F-35 stealth fighter jet is extremely expensive. The US military alone plans to purchase 2,700 of the machines at a cost of $ 1.5 trillion. Manufacturer Lockheed Martin presents the aircraft as a high-tech weapon of the future. The stealth function of the F-35 is of particular importance: This is intended to make the multi-purpose combat aircraft virtually invisible to enemy air defense.

There have long been doubts about the camouflage capabilities of the fighter jet. In the meantime, a German arms company has apparently even managed to locate an F-35 over a distance of 150 kilometers. From a special vehicle that was parked on a horse farm in front of Berlin.

In April 2018, the US armaments company Lockheed Martin presented two of its stealth jets of the type F-35 at the International Aerospace Exhibition ILA in Berlin. Last but not least, the armaments company wanted to provide powerful sales arguments for the aircraft at the time, because the German Bundeswehr was considering new machines to replace the aging “tornado” jets. Several other countries have already had their eyes on the US plane. For example, the F-35 is still in the running for the evaluation process for new combat aircraft for Switzerland.



Located on the return flight from Berlin

Although the two F-35s were transferred to the German capital in an eleven-hour mammoth flight, they surprisingly remained on the ground at the ILA. As the "Spiegel" writes, the rumor was already circulating at the fair that the planes did not take off because the German armaments technology manufacturer Hensoldt was also present at the ILA with its new "Twinvis" air surveillance system. And with «Twinvis» it should be possible to follow the stealth jet in the sky.

According to a report in the Defense News journal, Hensoldt managed to locate the American jets. On her return flight home. According to this, employees of the company that emerged from the Airbus Group had positioned themselves in good time on a horse farm outside Berlin with the passive radar system "Twinvis".

As Hensoldt confirmed to the «Spiegel», the stealth jets were subsequently able to be followed over 150 kilometers in the sky. To do this, “Twinvis” uses a different technology than conventional radar systems, which send out a powerful search beam that is reflected by aircraft in the air.

The stealth feature of the F-35 is based on this conventional radar technology. Due to the design and the nature of the surface of the aircraft, the electromagnetic waves from the radar are reflected in such a way that almost no echo arrives at the receiving antenna.

Different radar technology

The “Twinvis” system, on the other hand, works with a different technology. It uses the electromagnetic waves from numerous civilian sources - such as radio waves from radio and television stations, but also cell phone signals - to locate objects in flight. As soon as these waves bounce in the air in an unnatural way, they are detected by «Twinvis».

As the Federal Association of the German Aerospace Industry explains, this is how passive radar processes "signal echoes that are billions of times weaker than the original signals." Therefore, with a single “Twinvis”, “up to 200 aircraft within a radius of 250 kilometers can be monitored in 3D.”

On the other hand, the “Twinvis” system has the disadvantage that it only works poorly in regions with little population and correspondingly few signal echoes, since there are only a few civil signals here. Of course, this does not apply to the airspace in Berlin, where it is teeming with relevant signals.

A spokesman for Lockheed told Defense News that the two stealth planes were only located because they had special reflectors for the return flight, with which they were made visible to radar for safety reasons. Hensoldt counters this, however, by stating that their own system works very differently. It covers the entire aircraft and does not react at all to individual features such as reflectors.