Justin Bronk, airpower research fellow at London’s Royal United Services Institute, explains why Russian air defence systems may have failed to shoot down any of the cruise missiles the US Navy launched at targets in Syria on 7th April.
The 7th April strikes against the Syrian regime’s Shayrat airbase in the west of the country, have generated much comment and speculation. One question which has not been asked much outside Russia is why that country’s much vaunted Almaz-Antey S-400, S-300 and KBP Pantsir-S1 ground-based air defence systems apparently failed to engage any of the 59 Raytheon BGM-109C Tomahawk satellite-guided/terrain contour matching surface-to-surface missiles on their subsonic flight from the US Navy’s USS Porter and USS Ross ‘Arleigh Burke’ class destroyers in the eastern Mediterranean to their targets.
Sources have stated that the Russian forces deployed in Syria in support of the regime were given significant early warning of the strike since they have used Shayrat airbase as a forward operating location for Russian Air Force Mil Mi-35 and Mi-24 helicopter gunships in the past, and had to be given time to evacuate any personnel and equipment that was present to avoid an international incident. This should have allowed them to place their missile defences on high alert. However, as far as we know, no BGM-109Cs were shot down despite Russian claims that a significant proportion failed to hit their targets. There are a couple of potential explanations for this.
Firstly the S-300 system at Russia’s Tartus naval base, and the S-400 system at Khmeimim airbase, both on Syria’s Mediterranean coast are theoretically capable of engaging cruise missiles in flight. Nevertheless, since BGM-109Cs follow a very low-altitude flight path and will vary their route to take best advantage of terrain masking, and ground clutter between themselves and the surface-to-air missile batteries, such tactics might well have prevented an engagement window.
Secondly, even if there had been a brief window for the S-300 or S-400 batteries to engage some of the BGM-109Cs, Russian commanders may have decided to hold fire since the likely damage to Shayrat airbase was not of strategic significance and the number of SAMs in Syria is limited. There would also be a significant risk of international humiliation if the much-touted, but not combat tested, S-400 failed to successfully intercept the subsonic, non-manoeuvrable BGM-109Cs.
The point defence Pantsir-S1 system, by contrast, is designed to intercept cruise missiles and other precision-guided munitions in their terminal phase of flight, but only has an engagement range of between circa eight nautical miles/nm and 10.7nm (15 kilometres/km to 20km) depending on target altitude and bearing. Therefore, the Pantsir-S1s in Syria would only have been effective if the cruise missiles had flown very close to an active site. Given the huge ISR (Intelligence, Surveillance and Reconnaissance) capabilities which the US-led coalition has in Syria, such as the routine deployment of United States Air Force’ Boeing/Northrop Grumman E-8C JSTARS (Joint Surveillance Target and Attack Radar System) aircraft which gathers imagery of the ground using their AN/APY-7 Ku-band (13.4-14/15.7-17.7GHz) airborne surveillance radar, it is likely that the US Navy was able to plan the BGM-109C’s flight paths to avoid known Pantsir-S1 sites. Therefore, since there are not known to have been any Pantsir-S1 batteries deployed at Shayrat airbase, they would not have been able to engage the US Navy missiles.