2016 Yemen Missile Attacks - My Thoughts
Because of the highly speculative nature of this post, I thought it better to upload it separately from the factual description of the events. Link to the original post on the 2016 Attacks.
The other option is that the missiles were imported after the conflict began. However, antiship missiles are large and expensive items and not the kind of weapon that would be easily found on the black market. This suggests that any missiles would have needed to be supplied by an actual state. Very few states build such weapons and a state that doesn't could only supply missiles by taking them from its own navy. Currently, only sixteen states are producing antiship missiles and ten of those are the United States and her close allies. Of the rest, India is no friend of Muslim separatists, Pakistan supports the Saudi coalition and Russia and China, the most notorious suppliers of arms, also both prefer the coalition to the Houthis. This leaves only Iran and North Korea as possible suppliers. While North Korea cannot be entirely ruled out, Iran is far more likely source, and of Iran's arsenal, the Noor is the most common missile.
The reason that I believe the weapon in question was C-801 rather than Noor is because of the details of the first attack. In this attack the first missile was intercepted 12 miles away, the American ships put distance between themselves and the shore, and then the second missile crashed 9 miles away. According to one report, one of the Houthi missiles traveled over 24 miles in this attack. Given how the ships maneuvered and how close the two missiles came, it is almost certain that the second missile was the one that traveled this distance. This is relevant because C-801 has a published range of 42 kilometers (23 nautical miles). While it is possible that the second missile crashed because of jamming or a malfunction, I suspect that it was a C-801 that was fired from out of range and simply ran out of fuel.
So why the ESSM? Well, the second Houthi missile crashed at a much closer distance than the first was intercepted at. When this is coupled with the fact that ESSM was intended as a Phalanx replacement, it leads me to believe that SM-2 missed the second missile (or at least inflicted only minor damage) and the ESSM was fired as a second layer of defense. However, the incoming missile crashed before the ESSM could reach it.
Some quick math supports this hypothesis. ESSM has an estimated speed of over Mach 4 which would allow it to cover nine nautical miles in around 10 seconds. Adding a bit to account for the crew's reaction time and for the tip over from vertical launch, we could be looking at total system time of around 15 seconds. In that time the attacking missile (both the C-801 and Noor are high subsonic weapons) could cover around 2.5 nautical miles which means the ESSM was likely launched when the threat was around 12 nautical miles away (the 9 miles it crashed at plus 2.5) - which is the same distance at which the first incoming missile was intercepted, supporting the theory that ESSM was launched after SM-2 missed.
Applying similar math we can get some more information. SM-2MR has an estimated speed of Mach 3.5. Thus, it can cover 12 nautical miles in around 25 seconds. During the same time, the attacking missile can fly around 4 nautical miles. Given the intercept distance of 12 miles, this suggests SM-2 was fired when the target was about 16 nautical miles away. Both C-801 and Noor have terminal altitudes as low as 5 meters while the AN/SPY-1 radar on an Arleigh Burke is about 20 meters above the surface. Plugging these figures into a horizon calculator tells us that the missile will cross the destroyer's radar horizon at 15 nautical miles - well within the margin of error for our calculated 16 nautical miles.
While all of these figures are purely speculative, they combine to produce a very believable account of the attack.
#2 - The US Navy has almost certainly adopted a "Shoot - Look - Shoot" doctrine, firing missiles one at a time, rather than the often-quoted "Shoot - Shoot - Look" where two missiles are fired at each target. This has significant implications when considering the number of missiles needed for a saturation attack or the combat endurance of warships in an A2/AD environment.
#3 - SM-2 had exactly a 75% hit rate during the attacks. While eight missiles is a small sample size, we don't have any better information available in the unclassified world. Although 75% is far short of the 90% plus often touted by manufacturers, it is believable - especially against very low altitude targets. If accurate, this number means that having a multi-layer defense is vital and the Navy should possibly consider replacing Phalanx with RAM on destroyers and cruisers to add a third layer after SM-2 and ESSM.
What Missiles Did the Houthis Use?
As far as I have been able to determine, the only antiship missiles present in Yemen before the civil war were the twelve C-801 missiles on the three Type 021 missile boats and the SS-N-2 Styx missiles on the Tarantul I and Osa II missile boats. However, the Styx missile uses a corrosive liquid fuel and cannot be kept in a ready state, while the C-801 uses a far simpler solid rocket. Given the chaos in Yemen, I find it difficult to believe that Styx could remain operational. Further, C-801 weighs only a quarter as much as Styx, making it far easier transport the missiles and devise a ground launch system.The other option is that the missiles were imported after the conflict began. However, antiship missiles are large and expensive items and not the kind of weapon that would be easily found on the black market. This suggests that any missiles would have needed to be supplied by an actual state. Very few states build such weapons and a state that doesn't could only supply missiles by taking them from its own navy. Currently, only sixteen states are producing antiship missiles and ten of those are the United States and her close allies. Of the rest, India is no friend of Muslim separatists, Pakistan supports the Saudi coalition and Russia and China, the most notorious suppliers of arms, also both prefer the coalition to the Houthis. This leaves only Iran and North Korea as possible suppliers. While North Korea cannot be entirely ruled out, Iran is far more likely source, and of Iran's arsenal, the Noor is the most common missile.
The reason that I believe the weapon in question was C-801 rather than Noor is because of the details of the first attack. In this attack the first missile was intercepted 12 miles away, the American ships put distance between themselves and the shore, and then the second missile crashed 9 miles away. According to one report, one of the Houthi missiles traveled over 24 miles in this attack. Given how the ships maneuvered and how close the two missiles came, it is almost certain that the second missile was the one that traveled this distance. This is relevant because C-801 has a published range of 42 kilometers (23 nautical miles). While it is possible that the second missile crashed because of jamming or a malfunction, I suspect that it was a C-801 that was fired from out of range and simply ran out of fuel.
What Were the American Tactics?
Over the course of the first action, Mason fired two SM-2 missiles (almost certainly the far more common RIM-66 medium range variant), one Evolved Sea Sparrow Missile, and two decoys (including at least one Nulka). Attempting to reconstruct the action from this limited information is difficult, but I think we can make some educated guesses. With two incoming missiles, two SM-2 fired, and two decoys launched, I believe that the initial response to each threat was one SM-2 and one Nulka (remember, the two attacking missiles were fired an hour apart, so the first Nulka likely ran out fuel before the second missile was detected).So why the ESSM? Well, the second Houthi missile crashed at a much closer distance than the first was intercepted at. When this is coupled with the fact that ESSM was intended as a Phalanx replacement, it leads me to believe that SM-2 missed the second missile (or at least inflicted only minor damage) and the ESSM was fired as a second layer of defense. However, the incoming missile crashed before the ESSM could reach it.
Some quick math supports this hypothesis. ESSM has an estimated speed of over Mach 4 which would allow it to cover nine nautical miles in around 10 seconds. Adding a bit to account for the crew's reaction time and for the tip over from vertical launch, we could be looking at total system time of around 15 seconds. In that time the attacking missile (both the C-801 and Noor are high subsonic weapons) could cover around 2.5 nautical miles which means the ESSM was likely launched when the threat was around 12 nautical miles away (the 9 miles it crashed at plus 2.5) - which is the same distance at which the first incoming missile was intercepted, supporting the theory that ESSM was launched after SM-2 missed.
Applying similar math we can get some more information. SM-2MR has an estimated speed of Mach 3.5. Thus, it can cover 12 nautical miles in around 25 seconds. During the same time, the attacking missile can fly around 4 nautical miles. Given the intercept distance of 12 miles, this suggests SM-2 was fired when the target was about 16 nautical miles away. Both C-801 and Noor have terminal altitudes as low as 5 meters while the AN/SPY-1 radar on an Arleigh Burke is about 20 meters above the surface. Plugging these figures into a horizon calculator tells us that the missile will cross the destroyer's radar horizon at 15 nautical miles - well within the margin of error for our calculated 16 nautical miles.
While all of these figures are purely speculative, they combine to produce a very believable account of the attack.
Key Takeaways?
#1 - Modern warships can reliably defeat antiship missiles. This really calls into question the value of such weapons and may help explain the US Navy's relative lack of interest in antiship missiles after Aegis reached the fleet.#2 - The US Navy has almost certainly adopted a "Shoot - Look - Shoot" doctrine, firing missiles one at a time, rather than the often-quoted "Shoot - Shoot - Look" where two missiles are fired at each target. This has significant implications when considering the number of missiles needed for a saturation attack or the combat endurance of warships in an A2/AD environment.
#3 - SM-2 had exactly a 75% hit rate during the attacks. While eight missiles is a small sample size, we don't have any better information available in the unclassified world. Although 75% is far short of the 90% plus often touted by manufacturers, it is believable - especially against very low altitude targets. If accurate, this number means that having a multi-layer defense is vital and the Navy should possibly consider replacing Phalanx with RAM on destroyers and cruisers to add a third layer after SM-2 and ESSM.
