I want to take the time to add some content for readers on the SA11 Surface to Air Missile System you’ve all been hearing about. Its proper name is the BUK and it was developed in Soviet Russia.
The system is a tracked missile battery designed to engage and defeat airborne threats. By itself, it has a detection range of about 40km. That means with its radar up and running, it has the capability of detecting a target up to 40 kilometers away. The radar is a mono-pulse system using a conical scan with a relatively narrow beam width. This is important to know because it is incapable of searching 360 degrees. The system requires a crew of 3 one to operate the radar and guidance and the other 2 to operate electrical and missile systems. The BUK can be outfitted with 1 through 4 surface to air missiles. So, don’t draw any conclusions when seeing a BUK with only 2 missiles installed. The SA11 is not new nor is it a highly sophisticated system. It has been around since 1985. However, it’s guidance, speed and altitude makes it a serious threat. I takes 5 minutes for the crew to setup and use the SA11 and 5 minutes to take it down and start to move it.
The missiles travel at 850 m/s (1900 mph) and are capable of engaging targets up to 22,000 (72,178) meters and a maximum range of 35km. The missiles are detonated by direct impact or proximity.
In the real world, successful application of the SA11 requires that they operate with a secondary radar vehicle, one equipped with a medium to long range radar that can detect a target beyond 40km and determine heading, CPA (closets point of approach) and other parameters needed to develop a fire control solution. Once a threat assessment is made, the incoming target is handed over to the SA11 which then locks on target with its fire control radar. When the missile is fired, it flies to its target by riding the radar beam from the vehicle. The 9M38M1 missile, I believe, is also equipped with its own radar that controls final phase targeting.
The Dynamics of the MH17 shoot down are interesting. So I put together a slide to illustrate the point.
The figure basically shows that at its speed and altitude MH17 would have been in range of the SA11 site for 5 minutes and 11 seconds.
Added: 21 July 2014
I want to add a small amount of detail regarding the radar used on the BUK M1 (SA11). In search mode it pulses as it scans a sector. This is the equivalent to pulsing a laser pointer while moving it across a wall. When it detects a target it goes into continuous wave or CW, so it stops pulsing and on solid. The radar can scan a sector that is 120 degrees wide and to 6 to 7 degrees high, so let’s call it 6.5 degrees, in 4 seconds.
So let’s assume that Ivan the Separatist had his SA11 site up an running, which is not generally done. Radars are allowed to transmit into dummy loads (i.e standby) or in the off position to avoid having to replace a Klystron tubes or being detected(1). Ivan would then need to know in what direction the airplane was traveling so that he can orient his fire control radar on the target. Well, maybe Ivan has good eyes and saw it coming at 33,000 feet in heavy weather conditions with overcast (2). Highly unlikely. The more probable scenario is that Ivan had knowledge of an inbound aircraft which gives him and his crew time to bring the missiles and radars online.
So what are the likely scenarios:
Ivan the Separatist got a hand off from a tracking radar, maybe from the Russian side of the border, or just a lucky shot.
It wasn’t Ivan the Separatist. It was the Ukrainian Military who tracked the flight and handed it off to one of its own SA11 sites not realizing that it was a commercial flight – the fact that in prior weeks they lost 2 military aircraft, their judgment or command and control may have been impaired.
Given the overt effort on the part of the Ukrainian government to release COMINT intercepts to CNN and the media, I’m incline to think the truth may be closer to scenario number 2. I’m still struggling with the idea of making a public disclosure that you are monitoring communications between Separatist and Russian Intelligence.
What do you think?
(1) One of the ways SA11 sites are taken out is using munitions that lock on to the SA11 launchers’ radar beam.
(2) Or they had their own version of Tatto (Fantasy Island) yelling “da plane, da plane.”