PL-15 export version data officially released by China

[MH.Yang]

10 years ago this might be the truth due to slower speed. But with Ramjet, Scramjet and then Hypersonic missile systems, 300 KM is not that big of a deal in the next ten years. These missiles will become essentially drones or hunter-killer vehicles.

I follow this site a lot. They post great military news. Boeing is revealing a concept of such hunter-killer vehicles soon. It may blow our mind when the true range is disclosed to the media.

Boeing unveils Long-Range Air-to-Air Missile concept – Western Media

westernmedia.org

You're too optimistic. China's domestic public opinion generally believes that PL2x is used to hunt and kill early warning aircraft, and it is unlikely to shoot down flexible and high-speed fighters.

BTW: Moreover, Pakistan may not have a platform that can use PL2x. For the time being, there is only evidence of J16 mounting PL2x in China. And there is no official data on PL2x, domestic rumors in China are not uniform. Some say the range is 400km, and some even say the range is 600km. It is likely that the PLA is deliberately disturbing public opinion, so I suggest not to discuss this kind of missile.

 

[Thorough Pro]

you forgot two more zeroes at the end

Don't worry Khan saheb. India's SFDR missile with 340 km range is under testing.

 

[DJ_Viper]

You're too optimistic. China's domestic public opinion generally believes that PL2x is used to hunt and kill early warning aircraft, and it is unlikely to shoot down flexible and high-speed fighters.

BTW: Moreover, Pakistan may not have a platform that can use PL2x. For the time being, there is only evidence of J16 mounting PL2x in China. And there is no official data on PL2x, domestic rumors in China are not uniform. Some say the range is 400km, and some even say the range is 600km. It is likely that the PLA is deliberately disturbing public opinion, so I suggest not to discuss this kind of missile.

My post had nothing to do with any audience. I was speaking of technology advancement in the military field. Thanks

 

[Pak Nationalist]

Thanks, quite informative.

Extremely. I am glad I finally joined the forum as a permanent member to ask these questions I always had. Thanks to the patience shown by all the senior members and professionals for answering the queries so meticulously.

 

[MH.Yang]

So question:
How is the PL-15 achieving significantly greater kinematic performance than the PL-12 while basically being the same size?

	PL-12	PL-15	Difference
Length	3934 mm	3996 mm	+62 mm
Weight	199 kg	210 kg	+11 kg
Diameter	203 mm	203 mm	Nil
Max Range	70 km	145 km	+75 km

This has to be some revolutionary progress in rocket motors. Or PL-12 was undersold or the PL-15 is being oversold.

Using this for data:
View attachment 780497

SD10 is an export version of PL12, so the range is only 70km. PLA original PL12 has a range of 120km, original PL10 has a range of 60km and original PL15 has a range of 200km.

 

[Song Hong]

I have a question. From how far can radar or other sensors detect incoming AAM?

 

[Pak Nationalist]

COPIED:

NEZ is the distance where missiles will reach and over take target no matter what the aspect angle of it . It doesnt mean missiles will hit , it just mean the aircraft will have to defeat missiles by maneuver rather than turning and run away . NEZ depending alot on type of target , altitude ,missiles launching speed , however NEZ is about kinematics so it have nothing to do with target RCS
There is a very simple formula that can be used for estimating the performance of a missile. It goes like this :
Change in Velocity (Delta V) = 10 x Specific Impulse x LN (initial weight / final weight) m/s

This assumes that all the fuel is used to get the missile as fast as possible and
none is used to provide just enough thrust to sustain a given velocity.
In otherwords, it assumes an all-boost motor not a boost sustain motor.

For example, let'a take a look at the AIM-120A AMRAAM which we have some decent info on...

Launch weight = 335 lbs (Published stats)
Motor weight = 156 lbs (WPU-6/B HTPB rocket motor weight as per Raytheon)
Approximate specific impulse = 245 seconds (typical of HTPB solid motors)
Approximate fuel fraction of motor = 85% (typical of robust aluminum cased aerospace rocket motors)

OK... if 85% of the motor's mass is the fuel, we have about 132 lbs of fuel in the AMRAAM-A
-- roughly a 39.4% fuel fraction (sounds about right). So let's run the numbers...

Delta V = 10 x 245 x LN(335/(335-132)) = 1227 m/s

The formula predicts that the AMRAAM will go about 1227 m/s (~Mach 3.7) faster than it started.
If it is launched at say Mach 1.5 it'll be going Mach 5.2.
In reality the AMRAAM doesn't go that fast.
The reason is that not all the fuel is used to get it as fast as possible.
The AMRAAM's motor is a boost-sustain design.
It is probably grained to take the weapon to abut Mach 2.5~2.8 faster than it started at
(Mach 4+ in a typical Mach 1.5 release).
The rest of the fuel is shaped to burn much more slowly to keep it's velocity at
or near the achieved maximum out to a longer range before the motor burns out.


Well, for any given fuel fraction and specific impulse,
a designer can decide how fast he wants to go and how long he wants to stay at
or near the peak velocity achieved. For instance, if a missile carries 40% of its launch weight
as fuel and uses the typical a modern HTPB propellant motor, it can:-

(1) Spend 25% to get an approximate Mach 2.1 delta V and 15% on sustaining that speed for a relatively long while.
(2) Spend 30% to get an approximate Mach 2.7 delta V and 10% on sustaining that speed for a shorter while.
(3) Spend 40% to get an approximate Mach 3.8 delta V have no sustain burn time at all.

BTW, on deceleration :

If a missle starts at Mach 4 at burn out and decelerates 25% to Mach 3 after 10~15 seconds,
it WILL NOT decelerate to Mach 2 (another 33% from Mach 3) after 20~30 seconds.
This is impossible because aerodynamic drag (Fd = Cd x A x 0.5 x P x V^2) is a function of
the square of velocity.
As velocity decreases, drag force decreases exponentially in relation to it.
Hence, if the drag for at Mach 4 causes a 25% loss in velocity in 10~15 seconds,
there is no way a much lower drag force at Mach 3 will cause a 33% loss in velocity after
another 10~15 seconds.
What happens is that deceleration is non-linear;
you start off steep and the slope flattens out over time as velocity and hence drag drops.
It'll take a missile a heck of a lot longer to decelerate from Mach 4 to Mach 2 compared to
say Mach 2 to Mach 1 for instance.



Actually it also depends a a lot on altitude (air density)...
Let's put some numbers in:
Question: How much thrust is needed to sustain Mach 3.0 in an AAM like the AMRAAM?

Drag force (Newtons) = 0.5 x P x V^2 x Cd x A

P = Density of Air (kg/m^3) ; ~1.29 kg/m^3 @ sea level; ~0.232 kg/m^3 @ 12,000 m
V = Velocity (m/s) ; Mach 1 = 340 m/s @ sea level; ~295 m/s @ 12,000 m
Cd = Co-efficient of Drag ; ~ 0.6 to 0.95 for rockets depending mostly on finnage,
nose and tail profile
A = Sectional Area (m^2) ; ~ 0.025 m^2 for a 7" diameter missile.

For an AMRAAM like AAM going at high altitudes (40,000 ft)...

Drag Force @ Mach 3 = 0.5 x 0.232 x (295x3)^2 x 0.70 x 0.025 = 1590 Newtons = 357 lbs
Drag Force @ Mach 2 = 0.5 x 0.232 x (295x2)^2 x 0.70 x 0.025 = 707 Newtons = 159 lbs
Drag Force @ Mach 1 = 0.5 x 0.232 x 295^2 x 0.70 x 0.025 = 177 Newtons = 39.8 lbs

The same missile going Mach 3 at Sea Level...

Drag Force @ Mach 3 = 0.5 x 1.29 x (340x3)^2 x 0.70 x 0.025 = 11,744 Newtons = 2640 lbs
Drag Force @ Mach 2 = 0.5 x 1.29 x (340x2)^2 x 0.70 x 0.025 = 5,219 Newtons = 1173 lbs
Drag Force @ Mach 1 = 0.5 x 1.29 x 340^2 x 0.70 x 0.025 = 1,305 Newtons = 293 lbs

Assuming that there is no sustainer,
the deceleration experienced at Mach 3 by the 203 lbs (empty) missile is

Deceleration @ Mach 3 = -F / mass = -1590 / (203 x 0.454) = -17.3 m/s^2 = - Mach 0.059/sec @ 40,000 ft
Deceleration @ Mach 2 = -F / mass = -707 / (203 x 0.454) = -7.67 m/s^2 = - Mach 0.026/sec @ 40,000 ft
Deceleration @ Mach 1 = -F / mass = -177 / (203 x 0.454) = -1.92 m/s^2 = - Mach 0.0065/sec @ 40,000 ft

Deceleration @ Mach 3 = -F / mass = -11744 / (203 x 0.454) = -127 m/s^2 = - Mach 0.39/sec @ sea level
Deceleration @ Mach 2 = -F / mass = -5219 / (203 x 0.454) = -56.6 m/s^2 = - Mach 0.17/sec @ sea level
Deceleration @ Mach 1 = -F / mass = -1305 / (203 x 0.454) = -14.2 m/s^2 = - Mach 0.042/sec @ sea level

OK... enough of the math and the formulas... what does all these mean?
Well, it means that while coasting at Mach 3 an AAM is going to lose about less than 2% of
its velocity a second at high altitudes while it stands to lose about 13% of its velocity at
sea level! Huge difference isn't it?
Remember though that the rate of deceleration actually DECREASES as the
missile's velocity decreases.
It is easy to see that one can claim that a missile can burn out burn out its booster
and sustainer and be effective out to over 100 km at high altitudes or be useful only
against helos after 10km on the deck!

Also, we can make a pretty educated guess as to how much thrust the sustainer has to make.
An AMRAAM class missile with a 400 lbs sustain thrust will be able to stay
above Mach 3 at high altitudes and stay about Mach 1.2 at sea level.
An AMRAAM class missile carrying about 10% of its launch weight as sustainer
grained propellant will be able to keep this level of thrust lit for 20.5 seconds
in addition to whatever the boost time was using the 30% of its fuel to get a
roughly Mach 2.7 Delta V after launch.
A missile like this when fired at Mach 1.5 will reach Mach 4+ and keep
above Mach 3 for the duration of the sustainer at high altitudes.
It will also reach about Mach 2.5 and keep above about Mach 1.2 at sea level.
A motor grained for this thrust profile can have a 10 second boost at ~ 2460 lbs thrust and
a 20 second sustain burn at 400 lbs thrust -- this is a 5:1 boost sustain ratio.
This is also about right for thrust profiles of star grain vs
core burn solid propellant burn rate profiles.




Another rough rule of thumb:-

The time it takes for a missile to lose 25% of its velocity after burn out at supersonic speeds.

Never @ > 100,000 m (~300,000 ft) ; in space
~150 seconds @ 24,000 m (~80,000 ft)
~70 seconds @ 18,000 m (~ 60,000 ft)
~25 seconds @ 12,000 m (~ 40,000 ft)
~10 seconds @ 6,000 ft (~20,000 ft)
~5 seconds @ Sea Level

Remember, fractions over time are not additive.
In otherwords, if a missile loses about 25% of its velocity in 10 seconds,
in the 10 subsequent seconds (t =20s) the missile loses approximately another 25% of
the remaining 75% not a 100%. Total velocity loss is ~43.75% not 50%.

This is highly collated to the fall in air density.
Drag = 0.5 x P x V^2 x Cd x A.
Holding everything else constant Drag falls proportionally to density.
Drag also falls exponentially with Velocity which accounts for the loss in velocity
in the given time slices being about 25% instead of closer to 40%.
So based on the formula above you can estimated NEZ for yourself

SOURCE: https://www.f-16.net/forum/viewtopic.php?f=38&t=27373

 

[redtom]

Will this figure be like those 290KM rockets that China exports? You can simply remove some of the weight and increase the fuel tank for a range of far more than 290KM. After all, the cheapest way to reduce the range is to carry less fuel.

 

[siegecrossbow]

I have a question. From how far can radar or other sensors detect incoming AAM?

It’s hard for radar. Head on the RCS of AA missiles is lower than 1 meter squared. Luckily, most modern aircraft have radar warning receivers that detect radar locks from fire control radars and could provide warning about the distance and direction of the threat from a long distance. With the advent of LPI radars, however, they are less effective.

 

[FuturePAF]

If I was Pakistan, I'd use PL-15's obviously. But, I'd get ToT based SD-10 "ER" close to PL-15 range and either license manufacture it, or, get involved with the project similar to the JFT. The same 125-145 km (let's pretend the future "ER" range for upgraded SD-10) should also be mass produced as future SAMS.

Why not get ToT for the PL-15E (an export variant anyway) and work with the manufacturer to create a Meteor style ducted rocket motor variant for Pakistan and the export customers of the JF-17. First stage burns upon launch, then it coasts like a air breathing missile, the Meteor, and finally engages the second stage rocket motor as it originally does. That would give it the range for possibly a slightly larger or longer design. Similar to the new boring design, but the first stage is similar to the meteor.

Boeing Unveils New Two-Stage Long-Range Air-To-Air Missile Concept

The new missile offering from Boeing uses two stages instead of one to increase range and lethality.

www.thedrive.com

 

[DJ_Viper]

Why not get ToT for the PL-15E (an export variant anyway) and work with the manufacturer to create a Meteor style ducted rocket motor variant for Pakistan and the export customers of the JF-17. First stage burns upon launch, then it coasts like a air breathing missile, the Meteor, and finally engages the second stage rocket motor as it originally does. That would give it the range for possibly a slightly larger or longer design. Similar to the new boring design, but the first stage is similar to the meteor.

Boeing Unveils New Two-Stage Long-Range Air-To-Air Missile Concept

The new missile offering from Boeing uses two stages instead of one to increase range and lethality.

www.thedrive.com

PL-15 would be very expensive. Which is why I said to use SD-10 and build an ER version yourself. There is the Boeing's LR missile being in the pipes and the US today tested a Hypersonic airbreathing missile too at Mach 5+.

Boeing unveils Long-Range Air-to-Air Missile concept – Western Media

westernmedia.org

I like this site above, it publishes great military tech news.

 

[Bilal.]

NEZ is the distance where missiles will reach and over take target no matter what the aspect angle of it . It doesnt mean missiles will hit , it just means the aircraft will have to defeat missiles by maneuver rather than turning and run away.

There really cannot be said for the PL-15 since we dont know the specific impulse of the motor and the altitude at which one is guessing it.
The aim-120A has a NEZ of 25km at altitude and 10km at sea level.
Lets compare to a known chest thumper on NEZ superiority known as meteor.
The meteor’s advantage comes in at maintaining range at low to medium altitudes where its oxygen needing Ramjets give it more powered flight time which allows it to “guarantee” NEZ. Once its motor runs out the inherent drag of intakes and added weight will basically make it fall like a rock compared to a more aerodynamically refined Amraam or PL-15 but the intelligence in engine and fuel management are worked into the meteor to allow it to keep energy for end game maneuvering.

At high altitudes where the air is thin it can even be outranged by the aim-120C5 depending upon launch platform speed and target aspect angle. That is because the meteor doesn’t loft as quickly like the AIM-120 as its ramjet cannot provide the necessary acceleration to push it into a loft trajectory as fast without seriously compromising range. Also, the Aim-120 or PL-15 will be a very light missile once its booster runs out and capable of much tighter maneuvers compared to the meteor which has to do fuel management as well over the course of its flight. Where the meteor does have advantages is its lifting body design that allows good maneuvering at high altitudes.

When an Amraam C+ or Pl-12 or 15 comes down its carrying with it all the potential and kinetic energy so that NEZ is now also being converted to Pk even after the motor runs out.

Two different NEZ philosophies but so far only the Amraam has been battle tested and proven.

There are advantages to each approach but it all depends on the advances in efficient propellant for rockets and weight of ramjets.

What the Pl-15 does is outstick the meteor and keeps the PAF with first look, first shoot unlike the still in development Indian indigenous projects.

And if they do manage to outstick the PL-15, what the Chinese have in development next will push them back again. Why? Because the Chinese are targeting the Americans as an enemy that is on a much much higher technological plane than the Indians will ever be in the next 40 years.

Finally, regarding the Meteor and certain odd scenarios. In case a PAF fighter encounters a meteor equipped fighter at very close range and all they have is MRAAMs and is asked to engage.. it can shoot off either the SD-10, Aim-120 and PL-15 if need be off boresight and they will maneuver at very high G’s to get that target. The meteor however is pretty useless at close range as its booster works to get it up to speed.

Thank you for explaining! No wonder both the Chinese and the American are adopting other approach rather than Ramjet like meteor. Also, can multi-stage rocket be the next big thing? Like, discarding the previous stage to shed dead mass not and not just dual/multi pulse?

 

[iLION12345_1]

SD10 is an export version of PL12, so the range is only 70km. PLA original PL12 has a range of 120km, original PL10 has a range of 60km and original PL15 has a range of 200km.

View attachment 780552
View attachment 780553

Hows Does PL-10, a short range AAM have a range of 60 KM? Also where are these sources from? I doubt any of them are too accurate. That’s just now how BVR range works, “120 KM” and “60 KM” etc

 

[arjunk]

I am thinking the future of bvr combat may be suicide slave drone under the command of master fighter

That's an air to air missile with extra steps

 

[Song Hong]

That's an air to air missile with extra steps

In the POV of aerodynamic I doubt if missile can change trajectory easily. Not much degree of freedom and hence easy to miss.

Missile take advantage of low RCX and element of surprise. But this is good enough for long range BVR missile to take down tanker, AWAC and Bomber.

I am not sure if my hypothesis is correct. This is what I gather from doing work in radar. I have limited system level experience. The military guy will know better.