How 'defenceless' Iran likely took down 'unkillable' US F-35 fighter jet?

New Delhi,UPDATED: Mar 20, 2026 11:42 IST

The F-35, America's most advanced stealth fighter jet, has never been hit in combat in its entire operational history. Until March 19, when Iran did the unthinkable. Iran's air defences, which US President Donald Trump said were destroyed, detected, locked on to, and hit an F-35. The jet later made an emergency landing at a US base in the Middle East. A second F-35 jet was also reportedly hit over Iran's Bandar Abbas. It raises a pertinent question. How did Iran, with its depleted air defences, manage to hit one of the world's most advanced and costliest aircraft?

That the US F-35 was flying over central Iran when it was struck indicates a degree of confidence within America's security circles that Iranian air defences have been sufficiently weakened. "We're flying wherever we want. Nobody is even shooting at us," Trump boasted on Thursday. Defence Secretary Pete Hegseth further said Iran's air defences have been "flattened". Hours later, the F-35 jet, which has been designed to evade radar, was hit.

Even before the US could issue a statement, Iran twisted the knife by publishing footage showing the exact moment when Iranian air defences tracked and intercepted the American jet, which cost over $100 million.

Experts said it was a very significant moment in the war—one whose ripples would be felt across the world. Around 15 countries currently operate various versions of the F-35. The jet was also offered to India by Trump when Prime Minister Narendra Modi visited the White House last year. India has, however, not expressed any inclination so far.

Factor this - the F-35 is the acme of US aerospace capabilities. It is the product of a trillion-dollar program. But now, a "decimated" Iran has shown it has certain vulnerabilities.

HOW DID IRAN HIT US F-35 FIGHTER JET?

But how did a stealth aircraft, specifically designed to evade radar, get hit? Defence expert Sandeep Unnithan said the so-called stealth technology was a "misnomer".

"Company brochures may claim it is totally invisible to radar. But there are other ways to get detected. One of them is through heat. It is exactly what happened on Thursday," Unnithan told IndiaToday.in.

While it is not known what missiles the Iranians used, it was a loitering munition, specifically the 358 anti-aircraft missile, or a short-range surface-to-air missile.

The 358 missile, also known as the SA-67, is a kind of loitering drone equipped with an infrared sensor that can target slow-moving aircraft. But the F-35 is not a slow-moving jet. Previously, Iran has used the 358 missile to target American MQ-9 Reaper drones. Iran has also supplied these missiles to the Houthis in Yemen.

In fact, since the war began on February 28, the US has reportedly lost over 12 MQ-9 Reaper drones.

HOW THE EVENT MAY HAVE UNFOLDED?

So what happened on March 19? Unnithan hypothesised that the missile homed in on the F-35 using an infrared search and track (IRST) system after detecting the jet's heat signature.

This is itself very significant. It points to the fact that while the F-35 is radar invisible, it is vulnerable to the infrared spectrum.

Engines of such advanced aircraft produce a lot of heat. After all, the F-35 is a single-engine aircraft that generates an enormous amount of heat. Systems like the IRST can pick up this heat and track the aircraft without using radar.

This is what likely happened on Thursday, Unnithan said.

"One of the most sanctioned countries on Earth was able to detect, lock on to, and hit an F-35. I don't think most people understand that the world has just changed," tweeted a geopolitical expert who goes by the name Adam on X.

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