Iran’s Top Air Defence System: How Capable is the Bavar 373 Credited with Israeli F-35 Shootdowns?

Following reports on July 15 that Iranian air defences had <a href="https://militarywatchmagazine.com/article/two-israeli-f35-shot-down-iran-pilot-captured" target="_blank">successfully shot down</a> two Iranian F-35 fighters, and a subsequent report that a third F-35 had <a href="https://militarywatchmagazine.com/article/iran-shoots-down-third-f35-captures-second-pilot" target="_blank">also been downed</a>, Iranian government sources provided details of the engagements, and reported that Bavar 373 air defence systems had been responsible for all three kills. The reported shootdowns, which Iranian state media claims resulted in the capture of two Israeli F-35 pilots, will if confirmed be the first ever achieved against fifth generation fighters, reflecting the fact that penetration of Iranian airspace is by far the highest risk mission ever flown by such advanced aircraft. An evaluation of the Bavar 373’s capabilities provides important insight into the performance attributes which may have allowed it to shoot down Israel’s very low observable aircraft, and the likelihood that their deployment to protect key sites in Iran could deter Israel from launching future penetration strikes. Although the Bavar 373 operates as part of a much larger air defence network, which includes long range <a href="https://militarywatchmagazine.com/article/iran-used-russian-radar-system-to-successfully-track-american-f-35-stealth-fighters-reports" >Rezonans-NE radar systems</a>, and longer ranged but less advanced <a href="https://militarywatchmagazine.com/article/upgrades-s200-iran-modernising-a2ad" target="_blank">S-200 surface-to-air missile systems</a>, among many other complementary assets, the system is seen to form the backbone of this network.<img src="https://militarywatchmagazine.com/m/articles/2025/06/15/article_684ed62d48c4c2_67635967.jpg" title="Israeli Air Force F-35 Stealth Fighter">The Bavar 373 began development in the early 2010s, with Iranian sources reporting that this was stimulated by Russia’s <a href="https://militarywatchmagazine.com/article/iran-trust-russia-fighter-no-deals" target="_blank">termination of a deal </a>in 2010 to supply S-300PMU-1 air defence systems to the country due to Western pressure. The first variant of the indigenous system was unveiled in 2016, which had a reported engagement range of 200 kilometres, although serious questions remained regarding its maturity. The Iranian Defence Ministry’s subsequent decision to proceed with the procurement of S-300PMU-2 air defence systems in 2016 provided an indication that the Bavar 373 could not be fully depended on for long range air defence roles, despite the Russian system being close to two decades old and dating back to the late 1990s. The Iranian system would subsequently be modernised considerably, with significant speculation that it benefitted from <a href="https://militarywatchmagazine.com/article/north-korea-test-firing-s400-similar-air-defence" target="_blank">North Korean technology transfers</a> for its initial development, and in the late 2010s from Russian technology transfers to support incremental modernisation as part of the S-300PMU-2 deal. This culminated in the unveiling of a new variant of the system in August 2021, which Iranian sources claimed had surpassed the capabilities of the Russian <a href="https://militarywatchmagazine.com/article/russia-compromised-legally-resell-s400" target="_blank">S-400 long range system</a>.&nbsp;<img src="https://militarywatchmagazine.com/m/articles/2025/06/15/article_684ed537d80d08_47785707.jpg" title="Surface-to-Air Missile Launcher From Initial 2016 Variant of the Bavar 373">Commenting on the new Bavar 373 variant unveiled in 2021, Iranian Deputy Defence Minister Brigadier General Mahdi Farahi, who formerly served as the head of the country’s Aerospace Industries Organization, claimed in August that year: “New editions of the Bavar-373 are coming and soon, a new edition that may be at the same or higher level than S400 will be unveiled.” Much like the S-400, the new Bavar 373 variant employed multiple radars operating in complementary wavebands, and could reportedly detect up to 300 targets simultaneously while tracking up to 60. Although little was known regarding the system’s actual standing against the S-400, the Iranian Defence Ministry’s decision not to proceed with the procurement of modern Russian systems, which had long been expected, indicated a high degree of confidence in its standing. Although Iran had no close counterpart to the Russian Rezonans-NE radar system procured in 2019, which provided a near unique capability to detect stealth fighters at long ranges, it appeared the country’s indigenous long range surface-to-air missile system was seen to be a sufficiently capable substitute for its Russian-built analogue.&nbsp;<img src="https://militarywatchmagazine.com/m/articles/2025/06/15/article_684ed73a0800d5_77196382.png" title="Surface-to-Air Missile Battery From Modernised Bavar 373 Variant in 2024">On April 17, 2024, the Iranian Air Defence Forces<a href="https://militarywatchmagazine.com/article/iran-next-generation-bavar-373-threat" target="_blank"> unveiled a new variant </a>of the Bavar 373 that had undergone significant further modernisation, including integrating a new class of solid fuelled surface-to-air missile, the Sayyad 4B, which had a reported 300 kilometre engagement range. Bavar 373 systems of the 2021 variant had a detection range of 260 kilometres against large aircraft, which was significantly shorter than the 600 kilometre detection range of the S-400’s 91N6E Big Bird radar. This raised questions regarding whether the 2024 variant had integrated a much longer ranged radar, or whether the Sayyad 4B was designed to rely on targeting data from other assets to engage targets near its maximum range. Considerable speculation emerged in October 2024 that the Bavar 373 may have seen its first employment in combat, when an indigenous Iranian air defence system was reported to have intercepted one or more incoming Israeli missiles at <a href="https://militarywatchmagazine.com/article/iran-antiair-range-repel-israel">ranges exceeding 100 kilometres</a>.&nbsp;Although much remains uncertain regarding the Bavar 373’s capabilities, the considerable confidence which the Iranian Defence Ministry has placed in the system, and the significant <a href="https://militarywatchmagazine.com/article/india-reconsidering-6-billion-contract-for-elite-u-s-drones-after-poor-performance-against-iranian-defences" target="_blank">confirmed successes</a> of other shorter ranged Iranian air defence systems during major engagements, has raised the possibility that the system is indeed highly capable. Although the limitations of Iran’s technological base mean it is unlikely to be competitive with the most advanced Chinese, North Korean and Russian systems, there is a significant possibility that the system can outperform the S-300PM-2 and early variants of the S-400, and pose a serious threat to advanced stealth fighters when operating as part of a wider network.