Ever Watched a missile chase scene in movies, where it aggressively chases aircraft, even after several misses, it continues chasing! Fascinating but far from the truth. Let’s do some myth-busting of this Highly maneuverable Ever-following Missiles.
Lets start by this small clip from a famous movie “Behind Enemy lines“
In recent times, many such movies have come out showing very high-end graphics with precise aircraft simulations and flight missions. While watching this it feels so realistic, each and every moment in a very precise manner, the radio chatter, the pilot flying at supersonic speeds doing aggressive maneuvers just to dodge a missile fired by the enemy. Multiple aerial rolls, flares all of that seems very fascinating. But in the end, the missile misses but comes back again like a Wounded lion who will attack with a double punch and kill the pilot. Really Breathtaking.
But among all these there are many things which we have made perception about missiles, first and foremost is they are angry monsters, once fired will hunt you down till the end. The SAM, the Air to Air missile, etc once have a target lock on you, will chase you even after they miss you several times. But what if said that till all is just a drama to attract your attention and get your hopes high so that you would not even like to blink an eye for enjoying that dog fight.
Let’s Start A Little Myth-Busting Of This Myth
Here I won’t go in many details of a missile but will cover the most important ones that will let you know what actually happens when a missile is fired to hit the target.
The starting from the base, let’s consider an Aircraft is in our territory, and our Radars have detected it hostile (there are waves which identify an aircraft is friendly or foe by certain frequencies and codes). Now, the Radar and Processing unit traces the path and does the required calculation in a way that missiles can intercept that particular target. And as soon the calculations get completed, the launch command is either given manually or in most cases automatically by the ADS (Air Defence System). Here, the platform will get ready to launch the missile and after the command, the cover pops off and the missile is fired.
Here, the missile has an amount of fuel, which stars combustion and generated thrust through the rocket motors, now these motors make this missile to gain momentum as soon possible and its job along with the hold propulsion system is to guide the missile at a height, angle and required speed according to the calculations. This phase lasts for a short period of time( around 20 sec to 1 min depending on the type of missile).
Thinking what happens the rest of the time, well here comes the magic of engineering, such missiles normally travel at speed of a minimum 2.5 Mach (it’s normally more). Now from 0 to reaching this speed whole fuel is combusted to again this level of kinetic energy. Here the guidance system who is constantly in contact with ground radar traces the hostile aircraft and guides accordingly.
Now missile is fired but gaining other variables’ inner system i.e. control and guidance system comes into the picture. It controls dorsal fins, Control Surfaces. All of this is operated by mainly a battery embedded in the missile. Dorsal fins and control surfaces are parts of a missile handled by steering control which helps in gaining the particular variables and maintaining them.
In front of all this, there is a seeker, which either uses infrared waves(IR seeker) or electromagnetic waves(Radar Seeker). IR seeker locks the missile on the heating surface of the target( we can say heat-seeking) while the Radar seeker locks the target by the principle of radar. And missile hits or detonates in 2 ways either by hitting or by proximity sensor distance set on that missile.
Here, the pilot gets a notification by its Aircraft systems as soon as the missile gets locked on it. In order to save himself, the pilot has to apply the countermeasure. here main 2 countermeasures are used widely breaking the lock, by using flares ( for IR missile) or chaff ( for Radar Seeker one) or jamming signals, or the other way of Out maneuvering the missile
Naturally, both of these countermeasures are done simultaneously and depending on the type of missile, its distance, and direction. Now here where I come to point of this Drama, what we see in the movie is flares only because they are easy to show and outmaneuvering.
Here, as I mentioned that the Propulsion is for very little time, rest time the missile glides over the trajectory. So see it in a way that missile has a packet of Kinetic energy and it gets lessen every second of travel, there is enough to hit the target, but what is target doesn’t stay on the calculated path.
Means, as soon the missile is getting near, the aircraft change their trajectory and maneuver since the missile also has surfaced, it will also try to maneuver but it cannot directly do it due to 2 reasons large inertia and momentum( a higher force is required to change direction) and unable to pull high G turns due to its structure.
Doing this, the missile will spend much of its Kinetic energy in maneuvering leaving it very small packet but it will still try to follow. But since now the energy for maneuvering is less, a sharp turn, dive or sudden height gain or some other tactics, will outmaneuver the missile which leads to failure of interception and missing of the target.
Now here, assume pilot to a very sharp turn or a big dive and then sudden height gain then, the missile will miss the aircraft, in drama as soon this happens, it is seen that missile re-traces the target and again tries to attack it.
Here is the mistake, once the missile missed the target, it cannot retrace the path and again attack aircraft, the missile is now a failure so it either detonates or falls on a ground where the safety lock doesn’t let it detonate.
You would be probably thinking why isn’t it possible, lets it see this way, the missile changes the path after the aircraft changes the path so a little delay over there, and this delay is what the pilot takes advantage of. Also think of a sharp turn, of 90 degrees or more by aircraft. Think about how much momentum will have to be changed in that case, and think about energy to be used in it, and most probably after this maneuver either the missile will have 0 energy or some energy it could easily be detonated by other countermeasures like flares or chaff.
Now imagine this whole not in 2D but in 3D. Sounds easy but its really hard to implement. It takes many months to properly perform it and years to master it, as result lies in spans of a second.
This dog chase doesn’t happen in SAM, however, if its an Air to Air Missile and the Aircraft is in the no-escape zone of that missile, there would be very very less chance that the fighter pilots would be able to outmaneuver the missile. But at the same time, other countermeasures( Chaff/ Flares / Drop tanks or Missile Jamming) might work out.
So in real life, a missile dodged(Outmaneuvered from its zone) the same won’t come back to hit again by taking a turn which is normally shown in movies where missile chases the aircraft like it has nothing to do with the physics of loads applied during the maneuvering. They either hit you quickly on one pass, or they miss you forever. There is no “chasing”. And that’s why never only single SAM is fired on aircraft, there are done in a bunch of 2 and if the aircraft doesn’t come down, the third is fired in almost immediately in the next 20 seconds.
Now, one can understand how Sukhoi 30 MKI was able to dodge about 4 to 5 AMRAAM during the Day after the BALAKOT strike, main reasons are SUKHOI is one most maneuverable aircraft with thrust vectoring nozzles allowing it to perform more complex maneuvers, the Israeli Elta EL/L-8222 Airborne Self Protection Jammer (ASPJ) pods and the flares of the Aircraft. The AMRAAM debris was also shown to the media by the Air Force showing that really SUKHOI was able to outmaneuver many AMRAAM at a time. Here Sukhoi actually had the advantage of being at more distance from AMRAAM.
Scientists are now trying to overcome the same by making missiles which will stop propulsion in mid and can restart again in between the trajectory, saving fuel and making missiles more maneuverable.