Almost by accident, the first images of Israeli Air Force F-35I Adir jets flying over Lebanon have been posted online today.
Israeli F-35I jets were flying over Lebanon earlier today, Jan. 25, 2021. The photographs of at least two “Adir” aircraft were posted online by a correspondent of Al-Manar TV and Al-Nour radio, the Lebanese satellite television station and radio owned and operated by the Iranian-backed political party Hezbollah, who initially believed the two jets were Israeli F-15s.
— علي شعيب 🇱🇧 2️⃣ (@alishaib1970) January 25, 2021
Although they were taken from significant distance, the shots are interesting for a series of things. First and foremost, they are the first images showing Israeli F-35 flying over Lebanon. In May 2018, the Israeli Air Force Commander, Maj. Gen. Amikam Norkin, announced that the Israeli Air Force F-35 stealth aircraft had had their baptism of fire taking part in air strike in the Middle East (Syria and another unspecified “front”) during an IAF conference attended by 20 commander of air forces from around the world. “The Adir planes are already operational and flying in operational missions. We are the first in the world to use the F-35 in operational activity” he said. Remarkably, Norkin also presented an image showing an IAF F-35I over Beirut, Lebanon.
As we commented back then, the blurry image showed the aircraft flying at high altitude off (rather than “over”) Beirut with radar reflectors, hence not in “stealthy mode”.
Here’s what radar reflectors, also known as RCS (Radar Cross Section) enhancers, are as explained in a previous article this Author posted here at The Aviationist:
Stealth aircraft, such as the F-22 Raptor or the F-35 Lightning II 5th generation jets are equipped with Luneburg (or Luneberg) lenses: radar reflectors used to make the LO (Low Observable) aircraft (consciously) visible to radars. These devices are installed on the aircraft on the ground are used whenever the aircraft don’t need to evade the radars: during ferry flights when the aircraft use also the transponder in a cooperative way with the ATC (Air Traffic Control) agencies; during training or operative missions that do not require stealthiness; or, more importantly, when the aircraft operate close to the enemy whose ground or flying radars, intelligence gathering sensors.
[…] the Russians are currently able to identify takeoffs from Israeli bases in real-time and might use collected data to “characterize” the F-35’s signature at specific wavelengths as reportedly done with the U.S. F-22s.
In fact, tactical fighter-sized stealth aircraft are built to defeat radar operating at specific frequencies; usually high-frequency bands as C, X, Ku and S band where the radar accuracy is higher (in fact, the higher the frequency, the better is the accuracy of the radar system).
However, once the frequency wavelength exceeds a certain threshold and causes a resonant effect, LO aircraft become increasingly detectable. For instance, ATC radars, that operate at lower-frequency bands are theoretically able to detect a tactical fighter-sized stealth plane whose shape features parts that can cause resonance. Radars that operate at bands below 300 MHz (lower UHF, VHF and HF radars), such as the so-called Over The Horizon (OTH) radars, are believed to be particularly dangerous for stealth planes: although they are not much accurate (because lower frequency implies very large antenna and lower angle accuracy and angle resolution) they can spot stealth planes and be used to guide fighters equipped with IRST towards the direction the LO planes might be.
F-35s deployed abroad usually feature their typical four radar reflectors: to exaggerate their real RCS (Radar Cross Section) and negate the enemy the ability to collect any detail about their LO “signature”. As happened during the short mission to Estonia and then Bulgaria, carried out by the USAF F-35As involved in the type’s first overseas training deployment to Europe or when, on Aug. 30, 2017, four U.S. Marine Corps F-35B Lightning II joined two USAF B-1B Lancers for the JSF’s first show of force against North Korea: the F-35Bs flew with the radar reflectors, a sign they didn’t want their actual radar signature to be exposed to any intelligence gathering sensor in the area
Since they almost always fly with the radar reflectors, photographs of the aircraft without the four notches (two on the upper side and two on the lower side of the fuselage) are particularly interesting: for instance, some shots taken on Jan. 24, 2018 and just released by the U.S. Air Force show F-35As deployed to Kadena AB, Japan, in October as a part of the U.S. Pacific Command’s Theater Security Package program, preparing to launch without their Luneberg reflectors.
Back to today’s images, considered the distance and quality of the images, it’s impossible to say whether the Israeli F-35s were flying with RCS enhancers or not. However, the shots are detailed enough to see the external AIM-9X missile rails. While we can’t assess the overall RCS penalty the rails induce but it’s certain that they have an impact on the LO (Low Observability) of the aircraft.
With AIM-9X missile rails, hence not in stealth mode (just for the records). https://t.co/5w0GldcXGD
— David Cenciotti (@cencio4) January 25, 2021
Therefore, it’s safe to say that, the Israeli F-35s caught on camera over Lebanon today for the first time, were not flying in stealth mode.