Anatomy of the Hatf-VIII Ra’ad Air Launched Cruise Missile

[Nigel Farrage]

How quickly this thread changed from Anatomy of Raad missile to Anatomy of Mastaan Khan.

 

[Blue Marlin]

I understand that the PAF defined the JF-17's SOW capacity to conventional warfare, fair, the question I and some others have is, why not strategic? Yes, the Mirage ROSE can do it ... for now. The Mirage is a much older platform and it will not be long before it is retired. Granted the PAF could maintain a small number for strategic usage into the 2020s, but isn't that a bit of a limitation? Isn't one of the main advantages of having tactical warheads the ability to potentially distribute those warheads across a wider deployment net? Configuring the JF-17 for the strategic role gives the PAF its widest deployment net possible.

the mirages will be around for a few years after their replacement is here (post 2020)
and distributing nukes is a bad idea

 

[ghazi768]

Introduction
The Ra’ad Air Launched Cruise Missile (ALCM) is a peculiar system. It has long been rumored that it is too big to be carried by anything but the Mirage aircraft of the PAF. The purpose of this article is twofold: understand the design decisions made while designing the Ra’ad and what can be done to evolve the design. Hopefully, by the end we will appreciate why the Ra’ad is the way it is and try to think of ways to evolve it.

Even though vertical clearances are taken care of but the Ra’ad is so wide that it will interfere with the landing gear/ventral fin of the JF-17 and possibly any weapon system mounted on the hardpoint next to it.

A very good effort and I mean it. Thanks You

Can you help me out with a few calculations via your 'pixel counting' skills?

can you let me know the distance from vertical stabiliser fin to fin, also clearance of the aircraft, thanks.

Also as you look to be knowledgable about air-craft/cruise missile design, may I ask why JF-17 designer chose to place stabiliser fins so wide, logically as much as I know it is better to place them closer to centre of gravity horizontally to achieve better results. like in this image of a jet, a portion of whose fuselage design may have been an inspiration as well.

here another view of JF-17

May I suggest that if you really want to see if Raad will fit or not than try developing 3d models to scale according to your 'pixel counting' exercise and than draw whatever conclusions you want to draw.

For those who look at images of JF-17 with central drop tank and than start worrying about if it has the "clearance", a few images to enjoy and kill some free time..

First, the 'benchmark' of poor follow through resulting in 'clearance' issues.. @JamD can you please help in pixel counting how many inches high is drop tank. It could be the best proof of sheer unprofessionalism..

How much high it is? These IDF guys must be as negligent and un-professional as PAF guys @MastanKhan

and a MIRAGE TOO, and why the hell they always cant them nose down for drop tanks, poor regard to flight safety and therefore professionalism.. if off-course may have fuel left and worse vapours when landing. It after all is considered an EPITOME of clearance on PDF by some guys. Has some one tough that a longer gear may be have to do with a wing welded at bottom of fuselage. Nope that could not be true.. epitome of 'clearance'..no..NO

 

[JamD]

A very good effort and I mean it. Thanks You

Can you help me out with a few calculations via your 'pixel counting' skills?

can you let me know the distance from vertical stabiliser fin to fin, also clearance of the aircraft, thanks.

Also as you look to be knowledgable about air-craft/cruise missile design, may I ask why JF-17 designer chose to place stabiliser fins so wide, logically as much as I know it is better to place them closer to centre of gravity horizontally to achieve better results. like in this image of a jet, a portion of whose fuselage design may have been an inspiration as well.

here another view of JF-17

May I suggest that if you really want to see if Raad will fit or not than try developing 3d models to scale according to your 'pixel counting' exercise and than draw whatever conclusions you want to draw.

Thanks for the appreciation.

I don't quite understand what you mean by " distance from vertical stabiliser fin to fin". Perhaps mark it on the picture.

It is actually desirable to place them as far as possible from the center of gravity if you are limited by how large you can make them. The size of the surface dictates how much force it can generate. The distance from the center of gravity dictates how much moment that force will generate, just like a longer spanner allows you to loosen a bolt more easily. Ideally you want the surface to be as small as possible as structure adds weight and drag. By placing it further from CG you get more bang for the buck. Unless of course you're adding more weight by putting it farther away than you are saving by reducing the size of the surface.

And yes you are right 3d models would be better but I have a busy schedule and don't have enough time to dedicate to these endeavors. Nevertheless, I believe the calculations I have done are quite representative of the actual situation. Aircraft were designed with pen and paper for a long while afterall.

When the word 'clearance' is used it is with regards to everything not just ground clearance. As you might have noticed Ra'ad has more ground clearance than the fuel tank. It is its rear end that is problematic. Notice in the pictures you have posted the belly mounted fuel tanks point down slightly. This is to maximize permissible rotation angle on landing and takeoff which one of the most crucial issues with clearance.

 

[ghazi768]

Thanks for the appreciation.

I don't quite understand what you mean by " distance from vertical stabiliser fin to fin". Perhaps mark it on the picture.

It is actually desirable to place them as far as possible from the center of gravity if you are limited by how large you can make them. The size of the surface dictates how much force it can generate. The distance from the center of gravity dictates how much moment that force will generate, just like a longer spanner allows you to loosen a bolt more easily. Ideally you want the surface to be as small as possible as structure adds weight and drag. By placing it further from CG you get more bang for the buck. Unless of course you're adding more weight by putting it farther away than you are saving by reducing the size of the surface.

Yes, I think you have guessed them correctly, I was mentioning ventral fins.

My apologies, you are not correct. In jet fighters their main job is to keep directional stability because in high AOA vertical tale gets 'shadowed' by fuselage. In some earlier aircrafts a single fin at bottom of fuselage below the tail was used for this purpose that is why it/they are sometimes called extended tail as well or stabiliser fins too. Now in normal aircraft or 'others' their purpose may be different such as inducing a bit of lateral instability as vertical tails may be large or too stable, in such situations ventral fins can be used to induce lateral instability which can be useful in turning and capturing bigger yaw moments. But I think you will get the point. Now can you please provide info about what you think is the distance between both ventral fins, also about 'over-all' clearance.

Thanks for the appreciation.

And yes you are right 3d models would be better but I have a busy schedule and don't have enough time to dedicate to these endeavors. Nevertheless, I believe the calculations I have done are quite representative of the actual situation. Aircraft were designed with pen and paper for a long while afterall.

When the word 'clearance' is used it is with regards to everything not just ground clearance. As you might have noticed Ra'ad has more ground clearance than the fuel tank. It is its rear end that is problematic. Notice in the pictures you have posted the belly mounted fuel tanks point down slightly. This is to maximize permissible rotation angle on landing and takeoff which one of the most crucial issues with clearance.

I mentioned 3d models as they make it quite easy to simulate clearances from different structures in even inches. They help you simulate whether a straight or 'canted' payload will clear fuselage or not . Or in case of under wing, you can model where to 'put up' a payload so that it clears all structures and any moving parts and also whether a present pylon will handle it or you will need another one.. etc. etc.

what you called 'permissible rotation angle' may be an issue in landing not necessarily in take-off, you do not need to pitch up to be air-borne, at most just a slight pressure on stick just to be sure about when lift starts working. Again some accurate 3d modelling can do wonders with 'held' opinions.

 

[JamD]

Yes, I think you have guessed them correctly, I was mentioning ventral fins.

My apologies, you are not correct. In jet fighters their main job is to keep directional stability because in high AOA vertical tale gets 'shadowed' by fuselage. In some earlier aircrafts a single fin at bottom of fuselage below the tail was used for this purpose that is why it/they are sometimes called extended tail as well or stabiliser fins too. Now in normal aircraft or 'others' their purpose may be different such as inducing a bit of lateral instability as vertical tails may be large or too stable, in such situations ventral fins can be used to induce lateral instability which can be useful in turning and capturing bigger yaw moments. But I think you will get the point. Now can you please provide info about what you think is the distance between both ventral fins, also about 'over-all' clearance.



I mentioned 3d models as they make it quite easy to simulate clearances from different structures in even inches. They help you simulate whether a straight or 'canted' payload will clear fuselage or not . Or in case of under wing, you can model where to 'put up' a payload so that it clears all structures and any moving parts and also whether a present pylon will handle it or you will need another one.. etc. etc.

what you called 'permissible rotation angle' may be an issue in landing not necessarily in take-off, you do not need to pitch up to be air-borne, at most just a slight pressure on stick just to be sure about when lift starts working. Again some accurate 3d modelling can do wonders with 'held' opinions.

Sorry I misread your post and I thought you were asking about the Ra'ad. Regardless you want the most moment arm possible to get the most moment from the least amount of surface.

I must admit I don't quite know why they would put them that far apart. It is not changing the effective moment arm by much. I believe it is to make the mount higher rather than lower like the f16. There might be interfering flows from the fuselage/intake area as well. But all this is speculation.

I'll see what I can do about your image when I sign in from my computer.

EDIT:
I have scaled it so that each pixel is a cm. Have fun.

 

[amardeep mishra]

As one would imagine the heavier the aircraft the more tail and wing area is required for “enough” positive stability. The Ra’ad is a heavy aircraft with very small wings so roll damping is small. This would mean for enough roll damping the designers have to compensate with more tail area in the form of ventral fins. The farther away they are from the center of mass of the missile the better they will perform as they produce more moment for the same area. It is for this reason they extend below the fuselage (in contrast to the vertical tail that are in line with the fuselage).

Hi dear @JamD
I wanted to add my comments to your wonderfully written piece of article-why wonderful-because unlike me you have avoided rigorous mathematics! Now,the reason why I am writing this is to correct certain mis-conceptions about the possible usage of ventral fins in raad missile. The reason why raad requires a ventral fins is not for roll stability but for directional-stability. As you know,Ra'ad is a sub-sonic cruise missile that is designed to fly low and slow. Lets say we want to trim our ra'ad missile to a lesser IAS(indicated air speed),for that we would require to increase the alpha to effective increase the Cl(here Cl means lift coeff and not roll coeff)-kindly note that Cl here is a strong function of both alpha and de(elevator deflection). But at higher alpha the wake from the wings start getting into contact with the vertical fins thereby reducing itz effectiveness.This effectively results in reduced directional stability.

Picture Courtesy- youtube
TO by-pass this problem,we can install another lifting surface(vis-a-vis side-slip air) to the keel surface aft of CG that is not in the wake of the wings.And that lifting surface is usually mounted below the fuselage.This is done because at higher AoA,the ventral fins mounted below the fuselage will still be able to see clean air(clean in this sense means without wake!) and hence provide adequate directional stability that might be lost due to increased AoA.

As you can see in my explanation above,to trim the vehicle at lesser speed,one would have to increase alpha to generate same amount of lift L.

 

[JamD]

Hi dear @JamD
I wanted to add my comments to your wonderfully written piece of article-why wonderful-because unlike me you have avoided rigorous mathematics! Now,the reason why I am writing this is to correct certain mis-conceptions about the possible usage of ventral fins in raad missile. The reason why raad requires a ventral fins is not for roll stability but for directional-stability. As you know,Ra'ad is a sub-sonic cruise missile that is designed to fly low and slow. Lets say we want to trim our ra'ad missile to a lesser IAS(indicated air speed),for that we would require to increase the alpha to effective increase the Cl(here Cl means lift coeff and not roll coeff)-kindly note that Cl here is a strong function of both alpha and de(elevator deflection). But at higher alpha the wake from the wings start getting into contact with the vertical fins thereby reducing itz effectiveness.This effectively results in reduced directional stability.
View attachment 314566
Picture Courtesy- youtube
TO by-pass this problem,we can install another lifting surface(vis-a-vis side-slip air) to the keel surface aft of CG that is not in the wake of the wings.And that lifting surface is usually mounted below the fuselage.This is done because at higher AoA,the ventral fins mounted below the fuselage will still be able to see clean air(clean in this sense means without wake!) and hence provide adequate directional stability that might be lost due to increased AoA.
View attachment 314567
As you can see in my explanation above,to trim the vehicle at lesser speed,one would have to increase alpha to generate same amount of lift L.

Let me clarify something that I did not write well enough I admit.

Yes I understand the common logic of why ventral fins are used, to avoid loss of lateral stability at high alphas.

I don't think that is the purpose they serve here. I strongly suspect because of the missiles mass and moment of inertia it requires large surfaces for directional stability. This required area is so large that not even the two vertical tails can make up for it. They couldn't make the tail any taller as it is already pretty tall. There is also precedent for this use of ventral fins. F-7 has a single ventral fin while the FT-7, a heavier aircraft, has two. The wing wake for the F-7 and FT-7 will be virtually the same at high alphas but the weight and inertia is different.

Also roll damping is also achieved by any surface you mount on a craft. It might not be a primary purpose of it but it will surely be helpful for a slender missile with small wings that has very little roll damping. Almost every flight surface you add, adds to some coupled effect you're not adding it for. In this case it is helpful.

 

[amardeep mishra]

Again the heavy weight of the Ra’ad means rather large horizontal tails are needed which make the missile 1.25 meters wide.

Hmm,thats correct, But the large horizontal tails effectively mean a larger volume ratio(Vh) that helps in increasing the control effectiveness of the control surface.

I strongly suspect because of the missiles mass and moment of inertia it requires large surfaces for directional stability.

Hi @JamD
Yes there is no doubt that moment of inertial of the missile about the z axis is appreciably higher than the moment of inertial about lets say longitudinal axis.Hence they might use ventral as you suggest.I was merely un-convinced as to how ventral fins might add up to the lateral stability or in other words enhance roll stability. Thats all

 

[The SC]

I'm more interested to see a Babur or Raad based ASM ...

Is there any work being done on that ? Can we expect a homegrown ASM ?


Also any info on the "Zarb" ASM coastal battery?



Raad or any missile with a range of over 300 km can't be marketed or sold... So now PAF officials aren't joking or even offering RAAD to potential customers.


Your posts are pathetic and usually claims full of shyt debunked a billion times .. From JF not being able to carry ASMs like C series or CM-400 to other undiluted crap.


As for JF.. If the reports are true .. That's 2 customers for JF... That's 3 nations operating our machine !

View attachment 313973 View attachment 313974 View attachment 313975

So the JF-17 can lunch the Ra'ad, that what I have thought, and there came all these calculations saying it can not, but now we have an image better than a thousand words..Oops That is a Mirage!

 

[Bilal Khan 777]

haters gonna hate. but what i find strange is that "other" think thereaare right against someone whos actually been in the airforce. i dont like sh!t stiring but i have a weird feeling he got rejected by the airforce. i have never seen a pakistani been so negative against the airfore of his own country. sure its good to be critical but when one compares cars to planes as an arguement in a smooth tone then theres a problem. personally put him in your ignore list and move on. no need to lose your sleep over it, just ignore them and share what you want where necessary and its happy days. and if they quote you wont know they they are being ignored and you wont se their messages. end of really.

You are right. We don't need to prove anything, or rake anyone through coals. Being called traitor is always interesting. Shows you the mind of others. I guess one finds their own faults in others? There is just too many of you nice gentlemen here for me to leave the forum for anyone being a pest. These are just opinions.

@Blue Marlin I look at it from the standpoint that the JF-17 is going to be the most pervasive fighter in the PAF. Why wouldn't you want to draw the maximum flexibility of such an arrangement, i.e. be able to position theoretically any JF-17 squadron for any role within what is capable of the fighter? For example, if Southern Air Command required more anti-ship capable fighters, the other areas could provide JF-17s, and SAC would have no trouble absorbing them. Why wouldn't you want to extend this advantage to strategic munitions?

Sir with all due respect. You signed onto waking up at 4AM and reaching a flight line, and the nation gave you not just a wage, but an actual life and career as compensation. You serve the nation sir, and the nation can demand you be held accountable. Don't be offended, I apply this very same rule to every single public servant and official, and I am much harsher on this front with our politicians (who have fundamentally failed the country).

I don't say this as an outsider. My father is a retired PAF officer, and there is no doubt that this fact gave me a huge advantage in life in many areas, and despite all the problems or issues, I owe the people of Pakistan for being a meaningful contributor to my successful life.

We can continue discussing this based on facts and with the aim of examining arguments for what they are, or we can continue reminding one another who owes what and why.

Quwa, for your consumption, lets just say that the strategic chapter of JF17 is Not to be Disclosed.

With all due respect to your father for raising a fine young man, no amount of compensation can be given for service. Service is a choice, and we are proud of it. We are not offended. Over our lives and careers we have seen many naysayers. However, as I have repeated many times, what i say is my opinion, and I respect everyone else's. I can at times disagree with people's opinion based on my experience (bias you can also call it), and in that case we can only agree to disagree. However, I refuse to undertake childish arguments with anyone who just are pushing some arm chair agenda without having any knowledge of air war and our world.

BR

For this topic only, weapon integration has also some serious issues such as:

Flutter
SSS (Safe Stores Separation)
Aerodynamics
Kinematics
Drag
Clearence (overall)
Hardpoint Stress
Wing Root Stress
Aircraft Safety of Flight
SMS Integration
Mission Computer Integration

All of these and many more need to be thought through prior to physically putting anything on the A/C. First this is all done by technical people on computers, and then when in safe limit put on mock ups, aircraft etc etc.

I love the enthusiasm about Ra'ad and JF17, but really, JF17 in the current form is well equipped for its role, and we already have a Ra'ad trucks to be in operation 2025.

BR

 

[ghazi768]

Sorry I misread your post and I thought you were asking about the Ra'ad. Regardless you want the most moment arm possible to get the most moment from the least amount of surface.

I must admit I don't quite know why they would put them that far apart. It is not changing the effective moment arm by much. I believe it is to make the mount higher rather than lower like the f16. There might be interfering flows from the fuselage/intake area as well. But all this is speculation.

I'll see what I can do about your image when I sign in from my computer.

EDIT:
I have scaled it so that each pixel is a cm. Have fun.
View attachment 314565

ha, ha,ha.. 6-7 inches away from heaven or hell.. what a vocational hazard..

A nice effort again, brought some memories back, thanks again.

 

[Tipu7]

Snaps from recent Ra'ad test.
Intake is re traceable, fins too ?

 

[Bratva]

Snaps from recent Ra'ad test.
Intake is re traceable, fins too ?

View attachment 314604 View attachment 314605 View attachment 314606

Not the first time, but second time.

 

[Nigel Farrage]

Not the first time, but second time.

When was the first time? I guess there was no pod video in Jan 2015 test?