The Iranian state media said to show fragments of a downed US jet in this picture, which was said to be taken in central Iran and released on April 3, 2026. (REUTERS)

Here’s a breakdown of how the US aircraft were downed:

A degraded, but still dangerous, air defence network

Despite early US strikes targeting hundreds of Iranian air-defence assets, Iran has retained enough capability to continue engaging American aircraft, according to data compiled by conflict monitoring organisations, reported Palestine Chronicle.

The key reason lies in Iran’s architecture. Rather than relying on a single, centralised system, Iran operates a layered air defence network designed for survivability and redundancy.

Bavar-373: At the top tier is the Bavar-373, a domestically developed long-range system using phased-array radar and Sayyad-series interceptors capable of engaging targets beyond 200 km.

Khordad-15: The middle layer includes systems such as Khordad-15, which can track multiple targets simultaneously. These systems are supported by mobile launchers and distributed radar units, making them harder to neutralise through follow-up strikes, Palestine Chronicle reported. It added that mobility and redundancy, including older Soviet-era systems, help maintain defensive density even after heavy strikes.

MANPADS: Low-altitude threat

The most significant vulnerability for US aircraft has emerged from MANPADS (man-portable air defence systems), shoulder-fired missiles that are difficult to detect and neutralise.

A retired US Army colonel told Al Jazeera that while Iran’s primary air defence systems were degraded early in the war, these portable missiles likely remained operational and may have been responsible for downing a US F-15.

These systems typically have a range of 3 to 6 miles and are effective below 15,000 feet, according to The National Interest. They use infrared heat-seeking guidance to lock onto aircraft engines and operate in “fire-and-forget” mode, requiring minimal training. Because they rely on infrared rather than radar, they are harder to preempt or jam.

The National Interest reported that the missile used in a near-miss against a US Navy F/A-18 Super Hornet on March 25 was likely a Misagh missile, an Iranian version of the Chinese QW-1 system.

Short-range systems still active

Iran’s short-range systems have also remained operational.

On March 31, Iranian forces shot down two US MQ-9 Reaper drones over Isfahan using the AD-08 Majid short-range air defence system, according to reports.

Analysts also suggested a Raad air defence system may have damaged an F-35, forcing what was described as the aircraft’s first combat-related emergency landing, according to assessments reported by Ukrainian and Chinese analysts.

April 3 F-15 shot down

Iran’s Islamic Revolutionary Guard Corps (IRGC) released a video claiming to show the shootdown of a US F-15 near Qeshm Island in the Strait of Hormuz.

The footage reportedly showed a ground-based infrared tracking system following the aircraft as it manoeuvred and deployed flares before going down.

Fragments of a downed US jet in this picture said to be taken in central Iran and released on April 3, 2026. (Reuters)

The aircraft was flying at low altitude, a profile often used during close air support and rescue missions. However, this tactic increases exposure to short-range air defences and MANPADS.

According to Defence Security Asia, mountainous terrain in Iranian border provinces such as Khuzestan creates ideal ambush conditions for low-flying aircraft moving along predictable flight corridors.

Rescue mission turns into ambush

What followed the shootdown further highlights the risks facing US aircraft.

The rescue operation reportedly included HH-60W Jolly Green II helicopters and at least one A-10C+ aircraft assigned to rescue combat air patrol duties.

Mehr News Agency reports: an Iranian projectile struck a U.S. #helicopter during an operation to search for a downed pilot.#BreakingNews #Iran #US #War pic.twitter.com/IHspdc64RZ

— Consulate General of the I.R. Iran in Mumbai (@IRANinMumbai) April 3, 2026

During the rescue attempt, one A-10C+ was engaged by a MANPADS and reportedly sustained minor damage to its vertical stabiliser and rudder.

Two search-and-rescue helicopters were also hit, injuring crew members before they safely returned to base, reported the Washington Post.

Images of the US CH-47 helicopter in Kuwait, which was targeted by Iran.

Follow https://t.co/B3zXG74hnU pic.twitter.com/oPrEnJ9Tfg

— Press TV 🔻 (@PressTV) April 4, 2026

Why US countermeasures are struggling

US aircraft are being forced into lower altitudes partly due to the depletion of standoff weapon stocks and the need to preserve precision munitions, according to The National Interest.

Low-altitude strikes are cheaper but expose aircraft to portable missiles. A retired lieutenant general and dean of the Mitchell Institute for Aerospace Studies acknowledged the risks, telling Air & Space Forces Magazine: “High-end combat against a capable, integrated air defence system is never risk-free… Air superiority does not mean zero risk.”

(With inputs from AP)