On April 19, 2019, Yemen rebels shot down a Chinese-built medium-altitude and long-endurance Wing Loong drone with a surface-to-air missile. The drone, operated by Saudi Arabia, was reportedly on a surveillance mission over Bani Muadh area in the Sahar district of Saada province and was armed with air-to-surface weapons. The Houthis later released a video that shows the drone being hit by an unidentified surface-to-air missile and falling to the ground. With the repeated SEAD (Suppression of Enemy Air Defence) missions by the Saudi led coalition and the drying up of arms supplies, the use of a surface-to-air missile against the Saudi drone raises the question – which missile was used to down the drone?
When the Saudi air operations began in 2015, it was assumed that the air defence forces of the Houthi rebels would play a critical factor and would affect the outcome of the ongoing conflict. This was based on the fact that the Houthis had been seized the weapon systems earlier operated by the Yemeni air defence forces. These included most of the ex-Soviet SA-2, SA-3, SA-6 and SA-9 SAMsas also the large inventory of the man-portable air-defence systems.
The Houthis were not able to pose a serious threat to the Saudi led air coalition air forces as most of the air defence systems had become unserviceable and non-operable due to years of poor maintenance and shortage of spares. Moreover, a large number of the fixed sites missile systems were targeted and destroyed by the coalition in the initial air strikes during early days of the war in April 2015. As a result, the coalition air forces did not face any serious opposition from the Houthis air defence systems; and the same was reflected in the low level of attrition faced by them during the year.
The Houthis manged to shoot down only four manned aircraft in 2015, the first of which was a Moroccan F-16 shot down by anti-aircraft guns over in the remote Wadi Nashour area in the north-western province of Saada, a Houthi stronghold bordering Saudi Arabia.The other ‘kills’ by Houthi air defences during the year were two Saudi AH-64 Apache helicopters and up to a dozen reconnaissance drones. The next year, Houthi air defences did not achieve much of success against the coalition air forces and managed to bring down only one helicopter and one drone ;though the Houthi claimed that they had destroyed an F-16, four helicopters, and sixteen drones.
This failure to cause any viable attrition on to the Saudi coalition spurred the Houthis to innovate and develop air defence weapons, using the Russian-made heat-seeking air-to-air missiles. Using the AA-10 Alamo-B, AA-11, AA-8 and probably the AA-7, the Houthis developedtruck mounted antiaircraft surface -to-air-missiles; the first of which was photographed in February, 2017 by a coalition drone in the al-Salif region. Though these missiles did not have radar guidance or cuing facility, the Houthis used them for carrying out SAM-ambushes and claimed to have downed two F-16s in Saudi Arabia’s Najran province on February 24, 2017.The same month, a United States MQ-9 Reaper UAV was also shot down by the Houthis with their innovative SAM. Another successful kill, of a Saudi AH-64 Apache, was claimed over the Red Sea port of Hudaydah by the rebels in March.
The use of air-to-air missiles(AAM) in an air defence role by the Houthis was not something new- the Serbs had earlier tried out the concept in 1999 during the Balkan conflict though the reasons of developing and using improvised SAMs were different.
Serbia had a reasonably well equipped air defence force with a large number of radar guided SAMS, mainly used at the strategic level. At the divisional level, air defence was provided by 113 SA-9 and 17 SA-13 SAMs. As the associated SA-9 missile was being manufactured in Yugoslavia before the war, adequate reserves of the SA-9 were available. To beef up its air defence of its air bases, Serbia had developed improvised air-defence missiles using IR guided air-to-air missiles. Pracka, the simpler of the systems, mounted an R-60 (AA-8 ‘Aphid’) missile on an improvised launcher based on the mounting of the towed M55 20 mm anti-aircraft gun. The other systems were mounted on the chassis of the Czechoslovak M53/59 30 mm self-propelled twin-barrelled anti-aircraft gun. The twin rail RL-2 used the R-60MK missile while the single rail RL-4 was based on the R-73 Air-to-Air Missile(AAM). more than 100 of which were in local service.
The use of heat-seeking missiles to develop the improvised air defences was due to two reasons. Having learnt the lessons of the Gulf War , the Serbs were well aware that use of radar guided SAMs would invite a swift and deadly retaliation. This left the IR SAMs as the only viable option to be used to ensure survivability in an intense SEAD environment. Secondly, AAMs were more readily available than others and could be used with relatively less changes.
During the Balkan conflict, the IR-SAMs, including the improvised missiles, were the most prolific air defence weapons to be used by the Serbs and brought to fore an important lesson – that for low-technology armies, the IR-guided SAMs is the most cost-effective solution for tactical air defence which gives them a tremendous capability to harass and deter even the most advanced air forces.
They were effective in countering the UAV(Unmanned Aerial Vehicle) threat also; which were used extensively in Kosovo by NATO for reconnaissance. Of the 25 to 27 UAVs lost in operations, a significant number were downed by IR-guided SAMs. The details of aircraft/ drones shot down or hit by the improvised SAMs are however not available to make a realistic assessment of their efficacy during the Balkan conflict.
Another form of improvised air defence system tried out earlier was the so called the “aerial improvised explosive devices” used by Iraqi insurgents. In 2006, faced with a shortage of anti-aircraft weapons, insurgents tried improvised explosives to target coalition helicopters. The home-made “Aerial IEDS” were placed along known flight paths and triggered when a low-flying helicopter approached- fired into the air to a height of about 50ft before a proximity fuse detonated the explosivemaking it explode close to passing aircraft and filling the air with thousands of metal shards. As these devices were based on old anti-aircraft or artillery shells, the bombs would have a devastating effect if detonated close to a thin-skinned helicopter; used on numerous occasions, they clamed ‘ more than one” helicopter.
Coming back to Yemen. A Jordanian F-16AM crashed over southern Saudi Arabia on February 24, 2017while returning from a combat sortie over Yemen. The Houthi-dominated coalition was quick to take credit for the same; claiming that it had been downed by an air defence missile that had been improvised and developed by its Missile Development & Research Command (MDRC) using abandoned Soviet era Surface-to-Air Missiles. No independent verification could be obtained to back the claim though the loss of the F-16M was duly acknowledged by Jordan.
Having achieved some success with their innovations, the Houthis warned of a “new, highly accurate air-defence system” and reportedly improved the SAMs by incorporating FLIR (Forward Looking Infra-Red) Systems with ULTRA 8500 turrets to develop fire control system for their new R-27T based SAMs. The Houthis claimed more success in shooting down coalition aircraft, including a Saudi F-15 on January 7, 2018,with the “new” weapons system though no details could be ascertained and only the firing of the R-27T could be confirmed. The new SAMs had in fact missed the F-15 though videos posted online showed a ball of fire as the missile supposedly ‘hit’ the aircraft.
The failure to bring down an aircraft by the converted SAMs was repeated in another incident on March 21 when a second Saudi F-15 suffered minimal damage only from the R-27T (AA-10) SAM fired at it. Later that month, on the 26th, two Emirati F-16s were unsuccessfully targeted in an apparent missile attack. The Houthi air defences were increasingly looking impotent against the coalition air forces, not capable of causing any serious damage. The failure was also raised doubts about the capabilities of passive target tracking systems acquired by the Houthis from Iran. The Houthis had been supplied a transponder interrogator system (a virtual radar receiver, or VRR) by Iran which could have posed a serious threat to Saudi led coalition forces though the failure to hit any aircraft raised doubts about the efficacy of the VRR and the improvised SAMS. has been confirmation of their use by the Houthis.
The improvised weapons used by the Houthis till date have been based on AAM only and the recent shooting down of a Saudi drone does suggest that the threat from improvised SAMs is far from over and cannot be considered as only of nuisance value.