Sukhoi PAK FA

[nitesh]

our famou author:

Air Combat: Russia’s PAK-FA versus the F-22 and F-35

 

[neo29]

Defence minister A K Anthony has said that induction of PAK FA/NGFA will begin in 2017. i seriously doubt this . we have a huge waiting list of fighters yet to be producted from lca, mki and mmrca. We dont have enough production lines and government seems to do nothing about it. 12 fighters per year is too less considering how many fighter we yet to build.

induction of 5th gen fighter will begin in 2022-24 only .

 

[ppgj]

All I am concerned about is, if single seater pak-fa has better stealth than twin seater, then I think we should go for the single seater than the twin one.

how does single seater means less stealth??? can you elaborate? i did not get it?

I agree that RCS should be smaller than 0.5. But the explanation given for 4 to 5 meters can also be interpreted like this

4 m (width) X 5 m(length) = 20 sq m (area) object.

Ajai Shukla has said that Sukhoi has 20 sq m RCS and Pak Fa has 40 times lesser i.e. 0.5 sq m RCS. The point that worries me is, Ajai Shukla is no ordinary blogger. He is reputable.

RCS is the most misunderstood parameter and quoted with panache all over the net. it depends on many factors like geometry of the airframe, RAM's to reduce reflections, active cancellation by EW suites, distances at which they are measured and at what altitudes? etc.. and the RCS changes as the angle of incidence to the airframe changes!!

more than anything these are closely guarded secrets!!

 

[notinlove]

how does single seater means less stealth??? can you elaborate? i did not get it?

I think he means HAL should not screw up the airframe geometry while trying to fit in a second seat .... and if they are going to do that then they better leave the plane untouched.am i right QM?

 

[neo29]

they should reduce the RCS of pak fa . reports say that pak fa has rcs of 0.01 m2.

this is far less when f-22 has 0.0001 m2 and f-35 has 0.001 m2.

 

[ppgj]

I think he means HAL should not screw up the airframe geometry while trying to fit in a second seat

that is my question.how does geometry change because of an additional seat??

btw, even to operate single seaters you need double seater crafts for training purposes.

 

[StealthSniper]

that is my question.how does geometry change because of an additional seat??

btw, even to operate single seaters you need double seater crafts for training purposes.

The geometry could change ppgj because by the looks of the PAKFA I don't see where they are going to get the additional space for the added seat. Their might be large changes to the design of the forward part of the airframe to fit a large enough canopy to fit 2 people along with the avionics and additional controls. The canopy on the PAKFA right now barely looks large enough to fit 1 person so they might have to make drastic design changes to get the room to fit 2 people in the plane. And with drastic design changes, it might mean changes in stealth characteristics.

 

[kuku]

There is enough space to add another seat, however that will eat up the fuel space, as the electrical and electronic systems can not be removed.

Strange decision from InAF, perhaps the reason is that unlike Russia they want the plane to be a more of multi-role, unlike the air dominance requirement of Russia, with ground attack covered by more classes of stealthy bombers, UCAVs and long range cruise missiles.

I think we should wait for the FGFA agreement to be declared in the parliament.

 

[ppgj]

The geometry could change ppgj because by the looks of the PAKFA I don't see where they are going to get the additional space for the added seat. Their might be large changes to the design of the forward part of the airframe to fit a large enough canopy to fit 2 people along with the avionics and additional controls. The canopy on the PAKFA right now barely looks large enough to fit 1 person so they might have to make drastic design changes to get the room to fit 2 people in the plane. And with drastic design changes,

additional seat does not mean drastic change!! geometry when we talk for stealth is about the whole body (which is not going to change) designed with a view to reduce radar reflections.

btw, you are looking at PAKFA and not FGFA!! the designs for which may have already been frozen or is in the process of being frozen.

it might mean changes in stealth characteristics.

will hardly make a difference.

There is enough space to add another seat, however that will eat up the fuel space, as the electrical and electronic systems can not be removed.

kuku, you are right. that is the normal route taken. same would happen here. and it does not significantly reduce the range. atleast not which will affect our parameters.

Strange decision from InAF, perhaps the reason is that unlike Russia they want the plane to be a more of multi-role, unlike the air dominance requirement of Russia, with ground attack covered by more classes of stealthy bombers, UCAVs and long range cruise missiles.

i tend to go with you partly on this but feel air dominance will still be the main objective.

 

[StealthSniper]

Okay ppgj, I think I was a little confused and now realize that the PAKFA and the FGFA for India are close but will be based off different designs. So when we get our 50 PAKFA we will get something very close to what flew (frozen design) and the 200 FGFA will be a new design based VERY CLOSELY to PAKFA and will incorporate the same stealth as PAKFA with 2 seat canopy designed seamlessly into the plane.


If what I mentioned above is correct then the geometry won't change. I still hope FGFA still looks as good as PAKFA when we see it.

 

[plugwater]

from paralay

translating:

Top view: 33.22
Side view: 134.72
Front view: 11
Volume: 36.65 m^3

That way max take off mass of 37000kg is confirmed:
Normal take off mass 26000kg
Empty weight 18500kg
Fuek: 11000kg
Combat load 7500kg (over 14 total hardpoints)

Wing area 104m^2.

Air intake area 1.06m^2 wich coresponds to engine compressor diameter of 1.16m^2. Izdelie 117 has 0.932m^2. Suspect that Izdelie 129, the planned 5th gen motor is planned for 18500-19500kgf on afterburner, 11000kgs max w/o afterburner.

Bay volumes:
Main bays: 3.14 * 3.0 * 0.38 = 1.53m^3 * 4 bays = 6.12M^3.
Side bays: 0.08m^2 * 3.5m = 0.28m^3 * 2 bays = 0.56m^3(bay dimensions 0.3*0.3*3.5m)
total bay volume: 6.12+0.56=6.7m^3.
Bay to airframe ratio 6.7/36.65 = 18%.

 

[ppgj]

Okay ppgj, I think I was a little confused and now realize that the PAKFA and the FGFA for India are close but will be based off different designs. So when we get our 50 PAKFA we will get something very close to what flew (frozen design) and the 200 FGFA will be a new design based VERY CLOSELY to PAKFA and will incorporate the same stealth as PAKFA with 2 seat canopy designed seamlessly into the plane.


If what I mentioned above is correct then the geometry won't change. I still hope FGFA still looks as good as PAKFA when we see it.

i beleive, since there are no design specs available (atleast in the public domain) for FGFA, and also keeping in mind a completely new design for it is out of question considering the time and cost - it would be the same PAKFA with a 2 seater arrangement with same capabilities albeit with a minor reduction in range (does not make meaningful difference) to make space for 2nd seater as it will eat fuel earmarked space probably.

so what you posted is right according to me.

p.s: just to add, by the time FGFA comes, PAKFA will be fine tuned further and hence i assume FGFA will be more refined.

 

[Dark_Prince]

Finally-Times now reports on FGFA in a clear manner!!

[video]http://www.timesnow.tv/Indias-new-stealth-fighter-takes-flight/videoshow/4337444.cms[/video]

Times now report on 30/01/2010

 

[Quickgun Murugan]

how does single seater means less stealth??? can you elaborate? i did not get it?



RCS is the most misunderstood parameter and quoted with panache all over the net. it depends on many factors like geometry of the airframe, RAM's to reduce reflections, active cancellation by EW suites, distances at which they are measured and at what altitudes? etc.. and the RCS changes as the angle of incidence to the airframe changes!!

more than anything these are closely guarded secrets!!

You answered your own question. You said RCS is affected by geometry of the the airframe. A twin seater will affect the geometry of the airframe compared to single seater by increasing its size. Hence can potentially make it lesser in stealth compared to single seater versions.


Now all I am asking is, various sources say Pak-Fa will have artificial intelligence to pilot itself during occasion so that the pilot can concentrate on combat. So with the facility incorporated wont the concept of having a twin seater fighter be defeated?

 

[p2prada]

The PAKFA and FGFA will be the same except for the crew complement. Range will be affected as the extra fuel tank that is normally present behind the first pilot will have to be removed for a second seat. The FGFA will carry superior avionics because of its Multirole nature.

As to which of them would be a better dog fighter, it will be the PAKFA. The PAKFA will be lighter and will carry more fuel. The Russian requirement is primarily Air superiority because of the responsibility of protecting a vast continent sized country. However the FGFA will have better strike capability, navigation capability, battlefield management, threat prioritization, electronic warfare capability and the pilots will have less fatigue(one guy can sleep while the other flies the plane).

All in all both are going to be really good planes.

 

[ppgj]

You answered your own question. You said RCS is affected by geometry of the the airframe. A twin seater will affect the geometry of the airframe compared to single seater by increasing its size. Hence can potentially make it lesser in stealth compared to single seater versions.

no i did not. you misinterpreted it. geometry in a stealth sense means the whole body, its shape, angles at which edges merge, leaving no corners and making it seamless.

adding an additional seat does not change all that. it may at best reduce fuel space and hence will have a marginal range reduction. have answered this previously. you may not have checked out.

Now all I am asking is, various sources say Pak-Fa will have artificial intelligence to pilot itself during occasion so that the pilot can concentrate on combat. So with the facility incorporated wont the concept of having a twin seater fighter be defeated?

man is trusted over the machines. UCAV's are case in point. they still need to mature. automation cannot substitute human intelligence. in a long range fighter 2 men means being efficient and effective because fatigue is taken care by even distribution.

 

[p2prada]

You answered your own question. You said RCS is affected by geometry of the the airframe. A twin seater will affect the geometry of the airframe compared to single seater by increasing its size. Hence can potentially make it lesser in stealth compared to single seater versions.

The change in geometry will be for the better or for the worse. Adding 2 seats would mean making more adjustments to the cockpit. Aerodynamics and stealth are important factors. Perhaps new designs in the next 2 years will make the FGFA even more stealthy than the single seat PAKFA. We need to start working on the twin seat version first if we are to see which of them will be stealthy rather than jump to conclusions.

Now all I am asking is, various sources say Pak-Fa will have artificial intelligence to pilot itself during occasion so that the pilot can concentrate on combat. So with the facility incorporated wont the concept of having a twin seater fighter be defeated?

A second pilot is always beneficial. AI is not as advanced as a human brain. Our second pilot will be human...right??

The PAKFA will only be meant for air superiority. So, a lot of factors that are required for multirole operations on the FGFA does not come into the picture. The AI on the PAKFA will only be able to recognize and prioritize targets based on a threat library. Target prioritization will be better if there is a real person behind the controls. Mini-AWACS function is not easy if you have only 1 pilot either. And we have not touched on the EW aspect either. Even the Americans have 2 pilots on the Growler since EW cannot be left for the AI to decide.

 

[Quickgun Murugan]

no i did not. you misinterpreted it. geometry in a stealth sense means the whole body, its shape, angles at which edges merge, leaving no corners and making it seamless.

adding an additional seat does not change all that. it may at best reduce fuel space and hence will have a marginal range reduction. have answered this previously. you may not have checked out.



man is trusted over the machines. UCAV's are case in point. they still need to mature. automation cannot substitute human intelligence. in a long range fighter 2 men means being efficient and effective because fatigue is taken care by even distribution.

The change in geometry will be for the better or for the worse. Adding 2 seats would mean making more adjustments to the cockpit. Aerodynamics and stealth are important factors. Perhaps new designs in the next 2 years will make the FGFA even more stealthy than the single seat PAKFA. We need to start working on the twin seat version first if we are to see which of them will be stealthy rather than jump to conclusions.



A second pilot is always beneficial. AI is not as advanced as a human brain. Our second pilot will be human...right??

The PAKFA will only be meant for air superiority. So, a lot of factors that are required for multirole operations on the FGFA does not come into the picture. The AI on the PAKFA will only be able to recognize and prioritize targets based on a threat library. Target prioritization will be better if there is a real person behind the controls. Mini-AWACS function is not easy if you have only 1 pilot either. And we have not touched on the EW aspect either. Even the Americans have 2 pilots on the Growler since EW cannot be left for the AI to decide.

Why do we always have to define multi-role applications to every damn fighter? I think Pak-Fa should remain just an air-dominance platform and once air-superiority is achieved, we always have the MKI's to be used as a bomber.

P2P,

Thanks for the clarification on twin seats. I did not know that FGFA's seat comes at cost of fuel tanks. So does it mean lesser range for FGFA compared to Pak-Fa?

 

[Daredevil]

Why do we always have to define multi-role applications to every damn fighter? I think Pak-Fa should remain just an air-dominance platform and once air-superiority is achieved, we always have the MKI's to be used as a bomber.

Multi-role capabilities in the Air force will reduce too many variants of fighter aircraft and thus makes it easy to handle the logistics with minimum fuss. Its all about maximizing the capability without undermining the efficiency.

 

[ppgj]

The change in geometry will be for the better or for the worse.

actually p2p, my gut feeling is that the second seat may even marginally improve the stealth (though not significant) because an extended glass cockpit will replace the metal part.

it is purely my logical thought.