Houthis challenge stealth: The threat to American aircraft
The Houthis threatened an American F-35 aircraft, prompting the pilot to maneuver to avoid being hit by an anti-aircraft missile. F-16 aircraft were also targeted, and the risk of these planes being shot down was assessed as high.
How is it possible that planes, which both the manufacturer and users claim are difficult to detect, do not grant American pilots full operational freedom? The Aviationist attempts to explain how the F-35 was attacked.
The explanation might lie in the Houthis' use of modern anti-aircraft missiles with thermal guidance, such as the Piorun missile. Their warheads detect heat sources—like engines, especially exhaust nozzles—toward which the missile is directed.
This guidance can be disrupted by using flares—pyrotechnic charges ejected from the aircraft that, by burning at high temperatures, can confuse the missile’s sensor.
How to detect a stealth aircraft?
A solution that reduces the effectiveness of flares, possibly used by the Houthis, includes missiles equipped with a guidance sensor similar to a thermal imaging camera.
This technology allows the missile to "see" not only point heat sources but also their shape, enabling it to identify the silhouette of an aircraft against the sky and disregard flares.
This type of solution was likely employed in the Iranian Saqr-1 missiles provided to the Houthis. However, due to their low speed, missiles of another type were likely used to attack the aircraft.
IRST – a heat-detecting sensor
Fifth-generation aircraft—including the F-35—are constructed with stealth technology, which reduces radar and thermal signatures. This is achieved by shielding engine nozzles and cooling exhaust gases, among other measures. However, it is impossible to completely eliminate heat or conceal the aircraft's hot components, allowing for the possibility of detection.
For this reason, a sensor that detects heat sources can also complement radar systems. IRST sensors (infrared search and track) are installed on many Russian and European aircraft, as well as some American models.
IRST enables passive detection—without emitting signals that reveal presence—of heat sources in the sky. Under optimal conditions, it allows for the detection of aircraft from distances of tens of kilometres.
