Dismiss Notice
Welcome to IDF- Indian Defence Forum , register for free to join this friendly community of defence enthusiastic from around the world. Make your opinion heard and appreciated.

PAK-FA vs F/A-22 - Analysis

Discussion in 'Indian Air Force' started by jagjitnatt, Jul 11, 2010.

Thread Status:
Not open for further replies.
  1. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    There have been various analysis done by various so called experts on different forums and defense sites. While I agree with some, I do tend to disagree with a lot of those. So here I present my analysis of the two aircraft, and the differences between them.

    [​IMG]

    THE AIRFRAME
    The airframe is what provides the basic stealth characteristic to both the aircraft. To apply stealth to an airframe, the first thing that needs to be taken into account is the shape of the airframe. A stealth aircraft must have as much as possible paralleled edge of the airframe to reflect the radar wave away from its source. Both the aircraft, PakFa as well as the F-22 employ optimum shapes required to keep them stealthy in air at least from the front.

    [​IMG]

    [​IMG]

    But what about the sides? Is F-22 just as effective from the sides. The answer to that may surprise some. But it is just as effective from the sides too.

    [​IMG]

    The sides of the aircraft have been shaped in such a way that there are no surfaces which could possibly reflect back radar waves. The minimum edges that do exist have been coated with multiple layers of RAM.

    Unfortunately the story is not so rosy for PakFa.

    [​IMG]

    The side of the aircraft is just not what was expected from a stealth aircraft. The engines are a party spoiler here and will take away all the stealth advantage in an engagement. The rcs from the side may be as high as 1 square meter from certain angles. The engines are supposed to be replaced in the future, but there are no plans to alter the shape of the engine ducts. So I'd assume this is the final shape and this is a cause of worry for us Indians.

    The rear of an aircraft is where the fun lies. That's because these days aircraft are equipped with IR search and tracking systems and it is just not possible to hide the IR signature of jet fuel being burnt at such high rates. A stealth aircraft might be invisible to the radar at long distances, but it can not escape the IR seeker.

    And the Americans have thought about it already. The F-22's engine nozzles are shaped in such a way that not only does it reduce the chances of radar detection but also allow mixing of cold air from the surroundings, which cools the exhaust air. This nozzle design is so effective that it reduces the IR signature by as much as 30-40%.

    [​IMG]

    The Russians unfortunately haven't thought about the IR signature AT ALL. The nozzles are the same nozzles used on the AL-31F engines. This is rather surprising since the PakFa will be housing an IRST system, whereas F-22 lacks the same. The Russians intend to detect the F-22 from its IR signature but they haven't done anything AT ALL about their own IR signature.

    [​IMG]

    I can only hope the final engines don't end up with a nozzle design like this.

    ENGINES

    The F-22 uses 2 Pratt & Whitney F119 engines that produces a dry thrust of 104 KN each and 156 KN of wet thrust. The engines are a generation ahead of the conventional engines in the sense that they have 22% less moving parts, and still deliver thrust that allow the aircraft to supercruise at a velocity of 1.8 Mach without the use of its afterburner.

    The engines also have Thrust Vectoring Control, but it is a 2 directional thrust vectoring system. The nozzles can vector up to 20 degrees in the pitch axis. This would allow the aircraft to maneuver at much faster rates. The pitch axis maneuverability is greatly enhanced due to this form of thrust vectoring.

    The PakFa on the other hand are supposed to be fitted with a derivative of AL-41 engines which are supposed to produce thrust in the 170 KN range. The dry thrust too would be more than enough to enable PakFa to supercruise. It is expected that PakFa would be capable of supercruising at velocities around 1.5-1.8 Mach, which is on par with the F-22.

    The engines are supposed to be fitted with 3 directional Thrust Vectoring Control system, which would improve the maneuverability of the already super maneuverable airframe. There are a lot of people who believe that 3D TVC is way better than 2D TVC. Disappointingly for them it is not true.

    The aircraft is highly maneuverable in its pitch axis due to the huge control surfaces on its wings, and the lift generated by the fuselage. The TVC system acts as another control element. In the aircraft the yaw control surfaces are very small and ineffective. The only yaw control surface are the vertical stabilizers. The addition of TVS doesn't make a huge difference to the maneuverability in yaw axis.

    To turn left or right, TVS or vertical stabilizers are not used, rather the aircraft is rolled in left or right direction and then its pitch control surfaces are used to direct it in the direction in which the pilot intends to go. So the advantage of 3D TVC is minimal when compared to 2D TVC.

    Also one thing I wanted to say here that I didn't mention in the Airframe part is that the engine blades of the PakFa are not hidden. The engine ducts are linear and there are no curved ducts to hide the engine compressor blades. The engine compressor blades act as surfaces which reflect back radar waves, and since the blades face the front of the aircraft, its a BIG thing to worry about. There have been talks of a radar blocker, but the aerodynamics of a radar blocker are horrible to say the least. There are also talks that the landing gear would act as a radar blocker, but it would also reflect back radar waves and hamper the stealth characteristics of the aircraft. The engines leave a lot to be desired. I just hope the final engines take care of all the problems.

    INTERNAL WEAPONS BAY

    The F-22 has four internal weapons bays for its main armaments. Two at the bottom of the mid-fuselage and two on the air intake sides. There are also four hardpoints on the wings which are mainly meant for fuel tanks on ferry flights, but can also carry a weapon load.

    [​IMG]
    [​IMG]

    The F-22 can carry 6 AMRAAMs in its 2 main weapons bays, and 2 sidewinders in its secondary weapons bay. The weapons bay are more than enough for an aircraft of this size, and 8 missiles are the standard configuration for all the aircraft in the world. Many believe that internal weapons bay can not hold as many weapons as a conventional aircraft, but F-22 can hold just as many weapons and even more if you take into account the hardpoints on the wings, which is remarkable.

    The internal weapons bay on the PakFa are a different approach. The IWB on the PakFa are placed between the engines and act as a lifting body for the aircraft.

    [​IMG]

    The straight forward placement of the IWB on the PakFa allows it to carry 8 full sized RVV-AE missiles in its internal bays. Also just like the F-22, PakFa too can carry missiles on its external hardpoints.

    But its this simple placement of the IWB which doesn't allow curved ducts for the engine. In order to reduce radar reflection of the engine blades, IWB placement will need to be changed, which doesn't seem to be a possibility now in the final stages of development of the aircraft. This is very disappointing.

    AVIONICS

    The radar used in the F-22 is the APG-77 radar. It is a solid-state, active electronically scanned array (AESA) radar operating in the X-band(8 to 12.5 GHz). The radar is composed of 2000 transmit\receive modules, which is the highest achieved till date. The APG-77 provides 120° field of view in azimuth and elevation.

    ALR-94 Electronic Support Measures system and AAR-56 Missile Approach Warning System are the backbone of the countermeasure systems. An ALE-52 dispenser for expendable countermeasures is located under doors, forward of the main wheel wells. Optical fibre links are used to significantly increase data transfer rates between the radar's high frequency components and the CIPs.

    Back to the radar, it is the most advanced radar operational. The range of the radar is remarkable.

    [​IMG]

    Not only does it have a huge range, but since its an AESA, it is also resistant to blocking and jamming electronically. It is believed that the APG-77 has a 'typical' operating range of 190 km and is specified to achieve an 86 per cent probability of intercept against a 1 square meter target at its maximum detection range using a single radar paint. In Ultra High-Resolution (UHR) modes, it can offer 31 cm resolution at ranges in excess of 161 km.The Low Probability of Intercept (LPI) capability of the radar defeats conventional RWR/ESM systems. The APG-77 radar is capable of performing an active radar search on RWR/ESM equipped fighter aircraft without the target knowing he is being illuminated.

    Along with the main radar, F-22 is also equipped with several passive sensors. I won't go in detail explaining every sensor and antenna, so this pic should get you an idea of what some of the major sensors installed on the F-22.

    [​IMG]

    [​IMG]

    On the other hand PakFa is going to be equipped with an AESA radar based on the Irbis-E radar. Tikhomirov NIIP will build the radar and very few details are available till date, but it is expected to have a range 20-30% more than the Irbis-E PESA radar. Here I have the ranges compared between APG-77, Irbis-E and the N050 radar.

    [​IMG]

    As seen from the graph, the radar in the PakFa will outrange the APG-77 and also the Irbis-E radar making it the most powerful radar in a jet fighter. This is the ultimate weapon of the aircraft and PakFa would exploit the radar to compensate for the losses in stealth.

    PakFa is also believed to use several passive sensors just like the F-22, but the approach differs, where PakFa uses multiple powerful radars to increase awareness, F-22 uses less powerful, efficient sensors to keep itself hidden from its opponent.

    The PakFa has another X-band radar in its tail and two L-Band radars on its wings to aid in detecting stealth aircraft. As previously mentioned, it also has an IRST sensor to track an aircraft from its IR signature.

    STEALTH

    What gives F-22 the superior stealth that makes it the best fighter aircraft on earth?
    I bet 80% of the people would say, its the stealth shape of the airframe. It is. But that is not what makes it the best. It can make it a low observable body in the sky but can not hide it to an extent that we call it a stealth aircraft. A plain sheet of metal would be detectable even when radar waves are passed parallel to the plane of the sheet.

    The secret of the F-22's superior stealth are the following features:

    - Shape (canted vertical stabilizers, identical sweep angles of trailing and leading edges of wings and horizontal stabilizers)
    - RAM coating
    - Saw-toothed joints
    - Complex ray tracing calculation of multiple radar wave returns
    - Efficient radar, which does not compromise stealth

    I am sure everyone has noticed some saw toothed joints and panels on the F-22. Shapes like these help tremendously in reducing the frontal radar cross section. Here's how.

    [​IMG]

    What these W shaped do is that they reflect the radar waves off these W edges and because these W shaped will never be perpendicular to the front of the aircraft, they won't reflect back in the incident direction. If instead, straight edges were used, the edges would be facing the front and any radar signal coming from the front of the aircraft would have bounced back and compromised the stealth.
    Unfortunately, we haven't seen anything like this on the PakFa.

    About the RAM coating, the RAM coats are what turn the LO aircraft into a stealth aircraft. The F-22 is not painted with RAM on the entire surface. The RAM paint is just applied to parts that demand the use.

    The RAM coating on PakFa is unknown till now and has to be bloody good to beat what F-22 has in its arsenal. Also several missiles are under development for both the aircraft and judging them now wouldn't be possible.

    So its a no brainer now. The F-22 beats the Russian stealth plane hands down. But since its in development stages, I wouldn't announce a winner yet and let the final plane surface. It is only then that I would conclude. Till then, Sayonara!
     
    9 people like this.
  2. booo

    booo Lieutenant FULL MEMBER

    Joined:
    Apr 14, 2010
    Messages:
    545
    Likes Received:
    175
    This has been discussed already:rolleyes:
    [​IMG]
     
    Last edited by a moderator: Mar 12, 2014
    1 person likes this.
  3. Naren1987

    Naren1987 Captain SENIOR MEMBER

    Joined:
    May 30, 2010
    Messages:
    1,647
    Likes Received:
    273
    Jagjit, buddy, you should start your own show on Times Now,:D:D
     
    5 people like this.
  4. AVADI

    AVADI Lieutenant FULL MEMBER

    Joined:
    Apr 14, 2010
    Messages:
    604
    Likes Received:
    117
    very nice analysis but one thing i find fundamentally wrong here you are comparing a prototype aircraft with an aircraft which is in service.
     
    2 people like this.
  5. prototype

    prototype Major SENIOR MEMBER

    Joined:
    May 31, 2010
    Messages:
    2,050
    Likes Received:
    300
    but according to the statement by NPO saturn the engine which engine which pak-fa used was not AL-41F1A,they said it was something new,and no specifications was released

    and some more conflicting statements
    Russian Vice Premier Sergei Ivanov said the aircraft flew with engines from an earlier “4++” generation fighter which was conformed by media and that is AL41F
     
    Last edited: Jul 12, 2010
  6. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    I know its fundamentally wrong, but what in life is fundamentally right?
    Life is just not fair. If we attack Pak now, would they say "hey, we don't have the J-10s yet, and we just inducted the JF-17, we are not ready, this is not fair."??

    PakFa is in its final development stages. Don't expect major changes now. In fact don't expect any changes now except for the engines, installation of radar and RAM coatings now.

    It has been made clear by Putin that they are happy with the current prototypes and this will be the final design. They expect to induct in before 2015. It wouldn't have been possible if it still had to undergo major changes.

    Yes, the engines weren't 117s. They were a new engine derived from the AL-41. But even they are not the final engines.

    Actually the AL-41F1A is not a derivative of AL-41 engine, rather it was derived from the AL-31 engine. It was named AL-41F1A because its wet thrust approached the thrust generated by the original AL-41 engines.
     
    1 person likes this.
  7. Naren1987

    Naren1987 Captain SENIOR MEMBER

    Joined:
    May 30, 2010
    Messages:
    1,647
    Likes Received:
    273
    Jagjit , I've been wondering.
    Russia said it plans to make a 1000 of these aircraft,
    200-250 which will be operated by us, while the rest could most likely be operated by countries which are not allied to the US.
    Would they really field 180-190 F-22s, while the other Air forces operate more T-50s?
    And I don't think the JSF can fare against these aircraft.
    What are the Americans doing, one would expect a revival of the F-22 program.
    I say this bcoz, the only country other than Russia and India, most likely to buy these birds is none other than China.
    Our pilots could go up against Chinese PAK FAs.
     
  8. booo

    booo Lieutenant FULL MEMBER

    Joined:
    Apr 14, 2010
    Messages:
    545
    Likes Received:
    175
    letting pak-fa sale to china would be a diplomatic "failure" for india.
     
  9. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    Your question is valid.

    Russia does plan a 1000 of these birds, but, a huge BUT, who are the possible potential customers for such aircraft??

    The european countries wn't go for Russian planes, they are all in with the JSF. China won't be sold these planes because of India's concerns. Pak is a no go.

    The only potential customers are Brazil, SA, Malaysia, and Iran. Now will these countries be able to buy these aircraft in good numbers? I don't think so.

    Except for Iran, the other countries don't even have an enemy.

    So Russian estimates of 500 exports are very very optimistic. Its not 90s when everyone was in for Russian hardware. Several firms have come up and offer serious competition.

    The Americans have a great plane at hand - F22. The F-35 too wouldn't be bad. It would be on par with PakFa in terms of stealth. PakFa would have an upper hand in terms of maneuverability though.

    According to me, there's something the US is hiding from the world. They can't be all F-35. I bet they are working on much advanced aircraft. They have always been working on projects 20 years ahead of time. Till the time PakFa rolls out and we get them in good enough numbers(150-200), it would be 2025 already and till then US would have come up with its 6th gen aircraft.

    YF-22 (early prototype of F22) is already 2 decades old. Its still the best platform. They haven't been idle these past two decades. There is something going on but unfortunately no one knows about it.
     
    1 person likes this.
  10. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    India would never allow China to get their hands on PakFa. Also China knows now that Russia won't sell them any more hardware, because of China's dirty copying strategy.

    So its, started its own development and is already developing an alternative to PakFa.
     
  11. prototype

    prototype Major SENIOR MEMBER

    Joined:
    May 31, 2010
    Messages:
    2,050
    Likes Received:
    300
    china was the first choice of Russia in this programme rather than India,but after Chinese pulling out now we r paying half of the money for the programme in this joint venture, Russia even if it wants cannot go against Indian wishes
     
  12. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    The image you've shown can not be used as a radar blocker because of the following reasons:

    - it has a huge rcs of its own.
    - it would act as a nozzle for the air going into the aircraft and its not good for the engine. The engine need air to be at sub sonic levels to sustain burning of fuel.
    - It is just not aerodynamic.

    I've seen the image and several of these surfaced a few months back when PakFa first took flight. They are not feasible and most of these were photoshopped, even the pic with the compressor blades was a photoshop.
     
    1 person likes this.
  13. Naren1987

    Naren1987 Captain SENIOR MEMBER

    Joined:
    May 30, 2010
    Messages:
    1,647
    Likes Received:
    273
    But the later engines will be different, right?
     
  14. jagjitnatt

    jagjitnatt Major ELITE MEMBER

    Joined:
    Apr 30, 2010
    Messages:
    3,352
    Likes Received:
    1,563
    Yes, the later engines would be a further advancement on the engines tested on first flight.
     
    1 person likes this.
  15. Naren1987

    Naren1987 Captain SENIOR MEMBER

    Joined:
    May 30, 2010
    Messages:
    1,647
    Likes Received:
    273
    But u missed the missiles and also the fact that, the F-22 has NO Infra red sensor.
     
Thread Status:
Not open for further replies.

Share This Page