Combat Aircraft technology and Evolution

[ersakthivel]

Re: ADA LCA Tejas - IV

@ersakhivel, I am still waiting for the reply to the pointed questions I asked. Regarding F-22, I had clearly stated that I have not found anything which states that it is RSS ac. I had asked you to post such data if you have it. Posting the reference data for making an aircraft does not mean the ac is RSS. The wiki which you seem to rely on very clearly states the RSS for every ac which has it but even that is silent on this aspect for F-22 & F-35.
have a look at trapezoidal wing form, it overcomes the problem of backward movement of CP with mach number. RSS allows the CP to move both sides of CG and its movement depends only on airspeed(AOA). Infact even the CG moves with fuel burn and load release. So no RSS ac is always RSS in flight.

just click the wing below


https://www.google.co.in/?source=se...BrQe4s4CQAg#q=f-22+relaxed+stability&start=20

you will get the following links.

Wings That Stay on - Page 223 - Google Books Result
books.google.co.in/books?isbn=1563115689
Edward V. Coggins, "ŽEd Coggins - 2000 - "ŽHistory
The F-22 has a number of new and outstanding features: "¢ State-of-the-art, ... relaxed stability design controlled by computers and combined with vectored thrust.
[PDF]


Introduction to Stability & Control
soliton.ae.gatech.edu/people/ejohnson/ae1350-Fall2007/10.stabcon.pdf"Ž
Outline. "¢ What do we mean by aircraft stability and control? "¢ Static and Dynamic Stability ... Stability Margin. "¢ Relaxed Stability Margin .... Page 22 ... From vertical tail. "¢ Anhedral can be used to get desired level of dihedral effect. AV-8B. F-104 ...
[PDF]



F-22 « Defense Issues
defenseissues.wordpress.com/tag/f-22/"Ž
Apr 13, 2013 - F-22 and F-16 have two major things in common: both are relaxed-stability designs and both have LEX. As such, similar wing loading figures ...
Mar Vista Stable - Daly City, CA - Yelp

Assessing the Sukhoi PAK-FA - Air Power Australia
www.ausairpower.net/APA-2010-01.html"Ž
by C Kopp - "Ž2010
Designed to compete against the F-22 in traditional Beyond Visual Range (BVR) ...... by providing the PAK-FA with relaxed static stability in the directional axis.
Previous


If you say all these links are not enough I can't help it.

The following link clearly says how important the low wing loading and relaxed static stability are for agility in close combat. Tejas had a loading as well.Even though mk-1 has a bit lower TWR(still higher than the Mirage-2000) In mk-2 it will have a comparable TWR as well.

http://defenseissues.wordpress.com/tag/f-22/

F-22 is comparable to F-15C (claim made by Pierre Sprey)

Comparing it to the F-15C, we see two things: wing loading and thrust-to-weight ratio that are very similar, with F-15C having slight advantage. While F-22 is larger and heavier aircraft, it is also unstable, improving its response time and removing resustance of aircraft towards the continued turn. It also has LEX, which improves lift at high angle of attack.

Are you satisfied?

Got any proof that F-22 is a stable fighter? give the source.
http://en.wikipedia.org/wiki/Lockheed_Martin_F-22_Raptor

Former Lockheed chief test pilot Paul Metz stated that the Raptor has a fixed inlet, as opposed to variable intake ramps, and that the F-22 has a greater climb rate than the F-15, despite the F-15's higher thrust-to-weight ratio of 1.2:1 (the F-22 has a ratio closer to 1:1)

So even fixed intakes can let the fighter fly above mk-2, food for thought for some guys who were pestering me (not you) forever saying without variable intakes and DSI bumps Tejas air intake is an obsolete design.

The reason for the higher climb rate of F-22 is low wing loading and RSS flight profile, both the features are absent in F-15. Tejas too has both the features-low wing loading and RSS flight profile, so by no stretch of imagination any one can say it is an obsolete design of the 1980s. It has all the specs of any modern fighter out there.

 

[Decklander]

Re: ADA LCA Tejas - IV

Got any proof that F-22 is a stable fighter? give the source.

The same wiki very clearly mentions if an ac is RSS. It does not do so for most stable design ac. If it is silent on RSS for F-22, it means that F-22 is not RSS. It cud be anything but RSS.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

The same wiki very clearly mentions if an ac is RSS. It does not do so for most stable design ac. If it is silent on RSS for F-22, it means that F-22 is not RSS. It cud be anything but RSS.

And all other links I provided are False!!!!!!!!!!!!!!

Not really,

The Lockheed Martin/Boeing F-22 Raptor was designed as an Advanced Tactical Fighter to replace the McDonnell Douglas F-15 Eagle. In 1981, the ATF requirement called for a fighter combining low-observability or stealthy design, the ability to cruise over long ranges at supersonic speed without afterburning, a very high degree of aerial agility and STOL-capability with the aid of two-dimensional thrust vectoring, a fly-by-light control system for a relaxed-stability airframe, and an advanced nav/attack system using artificial intelligence to filter data and so reduce the pilot's workload while improving his grasp of tactical situation.

The ATF requirement under which the F-22 was built called for a fly-by-light control system for a relaxed-stability airframe.

So how come F-22 which was built as per the ATF specs becomes a non RSS fighter?

If you are still not satisfied , then words of the tedt pilot of the F-22 to Carlo Kopp in an interview will be the ultimate proof I think,

http://www.ausairpower.net/API-Metz-Interview.html

Carlo Kopp interviews F-22 Chief Test Pilot, Paul Metz

Kopp:

You are on record as describing the F-22A to be 'as easy to fly as a Cessna 150'. Knowing how over-damped the 150 is in all axes, the tempting question here is what is the damping like in the various modes of the F-22A's fly-by-wire control system? Can you comment on FBW behaviour in different flight regimes, and how this appears to the pilot?

Metz:

Some days I wish I had never made that comment about the Cessna 150 and the ease of flying the F-22. I've had about a million applications since then so I need to get the word out through your publication. Here it is: "sorry folks, we're all sold out."

Seriously, the handling qualities are actually better than a light aircraft since we have an active control system that damps out unwanted disturbances to the flight path. Where a Cessna bounces in turbulence the Raptor rides smoothly. The sensation in the cockpit is of a more direct connection to the airplane - a very solid link between man and machine. Quantitatively, the F-22 is well damped in all axes (the technical term is 'heavily damped'). Since the Raptor is also an unstable airplane it requires very little control deflection to start it moving in a new direction. The combination of unstable airframe with a digital, fly-by-wire flight control system gives a cat-like quickness but very predictable and pleasant flying qualities.

I think now you know how obsolete are the non- RSS fighters are.

you can find these as new fighter platforms, like JF-17 only in bankrupt PAF!!!!!!!!!!

 

[Decklander]

Re: ADA LCA Tejas - IV

I hope you know the diff between an Unstable and RSS ac. Do you know it? I am still waiting for the replies to my questions reproduced below.

1. Why has cranked delta design not been applied to anyother fighter tilldate including the latest stealth designs?
2. I have searched the net and cud not find any mention of RSS for F-22 & F-35, can you post the true picture?
3. What do you have to say about F-20 which had two crashes due to very high onset of G resulting in G-LOC of pilots.
4. 42* sweepback gives a particular point of MAC which is generally about 25% chord, the look at F-22 & F-35 airframe clearly shows that they are most likely stable designs. Pls compare the position of F-16 wing w.r.t to these fighters and also of highly swept designs like F-16XL, M2K & Tejas and pls tell me in which flight conditions will they be stable and in which they will be unstable?
5. Does an RSS ac remain RSS thruout its flight envelope?

 

[happy]

Re: ADA LCA Tejas - IV

All fighters have to go through wind tunnels, their aerodynamics designs are important ..

In that sense most are aero dynamic stable, The question is how much efficient is one design over other and what is the role that they intended for ..

==============

IAF presently use MIG-23 as drones for EW and other purposes, They dont use PTA so much ..

Sir, is it possible to use these drones in strike roles also? What would be the potential risks involved?

 

[Decklander]

Re: ADA LCA Tejas - IV

@ersakthivel, As you may know that CP is related to MAC which in turn is related to wing shape which means sweepback or lack of it has big effect on location and movement of CP. So I wrote about 42* sweepback. Regarding cranked delta design, It has been hailed as best design for supersonic cruise & F-16XL was called a cruiser but not the best design for combat and just for this reason this wingform has not found favour with designers of multirole ac. If you may recall, F-16XL was also offered as a bomber and not a multirole ac.
We have basically four kinds of stability, positive(stable), Negative (Unstable), Neutral and Relaxed. As I had written to you, Relaxed stability is when the CP moves on both sides of the CG and that creates a nightmare for pilots in controlability. A stable, unstable or Neutral design is very easy to fly as the behaviour of the ac is along one particular line only. F-22 can afford to be unstable as its controls are augmented by its 2D TVC. So You do agree that F-22 is unstable and not RSS. An unstable ac behaves in similar manner in pitch up as a stable design will in pitch down. A stable design in pitch down and an unstable design in pitch up is more agile than a RSS design at all stages of flight.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

@ersakthivel, As you may know that CP is related to MAC which in turn is related to wing shape which means sweepback or lack of it has big effect on location and movement of CP. So I wrote about 42* sweepback. Regarding cranked delta design, It has been hailed as best design for supersonic cruise & F-16XL was called a cruiser but not the best design for combat and just for this reason this wingform has not found favour with designers of multirole ac. If you may recall, F-16XL was also offered as a bomber and not a multirole ac.
We have basically four kinds of stability, positive(stable), Negative (Unstable), Neutral and Relaxed. As I had written to you, Relaxed stability is when the CP moves on both sides of the CG and that creates a nightmare for pilots in controlability. A stable, unstable or Neutral design is very easy to fly as the behaviour of the ac is along one particular line only. F-22 can afford to be unstable as its controls are augmented by its 2D TVC. So You do agree that F-22 is unstable and not RSS. An unstable ac behaves in similar manner in pitch up as a stable design will in pitch down. A stable design in pitch down and an unstable design in pitch up is more agile than a RSS design at all stages of flight.

F-16 XL improves over the stable F-16s (after blk-30 ) in all flight profiles. So Why can't it be a multi role fighter?

The reason the F-15 won over F-16 XL was ,more power for all avionic systems and radars , with their twin engines and the higher TWR possible with the twin engines .

Unstable is what I call RSS. F-22 is RSS air frame.

All RSS fighters become stable once they cross sound barrier as CP moved back is what I wrote. It is true for F-22,or Tejas or any other RSS fighter.

TVC has nothing to do with RSS airframe

No nightmares with Fly by wire always keeping the fighter in flyable aerodynamic config regardless of the pilots inputs. . Noway the pilot can crash the plane unless he overrides the Fly by wire software.

The lesser swept angle at the front on Tejas is designed to perform the job of canards,with out the drag penalty ,rcs reflections,., and canard wash disadvantages, so that wings can always get the fresh airstrean at any angle of attack without turbulence from canards.

This frees tejas from ,force coupling issues resulting in uncontorallable flat spin ,and loss of control of the fighter, if certain parameters are exceeded, capping the agility of canard-deltas at some portions of flight envelopes.

Lower stall speed, tighter turns (in general). Usually wings will stall at the same angle of attack however planes with low wingloading will reach this angle of attack at a lower speed.SO their stall speeds are lower than high wing loading fighters.It is very important to have lower stall speeds in high Angle of attack.That's why low wing loading fighters like TEJAS have this design.Low wing loading delats are associated with high altitude, high alpha charecter that is so important in modern fighters.

Think of wingloading as the whole weight of the aircraft dived by the area of the total wing(s).

This tells you that if you have huge wing and a low weight aircraft you will get a very very low stallspeed for example and probably a pretty good turner. BUT, there wil be big drag as well.Lift=drag.So what is important in low wing loading dltas is the all important Lift to drag ratio,matching TWR ratio.as they have natural high AOA charecteristics, the combination of these 3 is vital in design

SO an a/c will a small wing will be very fast but poor turners(fw190, p47, p51 etc) and a/c with big wings will usually be slow and good turners(any biplane, spitfire etc etc) in close combat with high ITR, and better nose pointing authority vital in high off boresight WVR missile combat.As no high wing loading fighter can out turn the 60 G turning WVR missiles and get another chance to fight against a low wing loading fighter, good pilots in low wing loading fighters finish the issue then and there.

Nowadays compound deltas and delata canards make a third of the wing behave like a high wingloading wing and narrows the fight further.

For example the canards delay the on set of stall ,by producing energising vortices that cling to the upper surface of wing delaying stall in high AOA ,high STR turn.

Similarly the cranked delta and compound delta in F-16 xl and tejas has different lower sweep angles allowing the same flow energizing vortices to cling to the wing longer delaying stall and giving better lift at points in flight envelope where the pure delta is generally considered weak.

In general, aircraft with higher wing loadings tend to be faster but less manoeuvrable. Since speed is life, this has historically been a desired design . However, once top speeds become supersonic manoeuvrablity is not poaaible due to operational, aerodynamic and thermodynamic issues associated with supersonic flight.

As a result of this, current fighters are no faster than 1960s fighters, but generally have lower wing loadings, since if you can't go faster the next best thing is to turn harder (apart from which, low wing loadings are necessary for high supersonic L/D and therefore help towards supercruise). As such, wingloadings are likely to stay roughly constant or possibly even decrease in future designs until such time as the upward trend in speed reasserts itself.

You can also take off easier with higher bombloads from high altitude airfields.You can also take off easier with higher bombloads.
low wing loading fighters need less trimming because the needed lift can be generated with small AoA changes.

The lower your wingloading, the less AOA you have to pull to get the same lift vector.

The lower the wingloading, the lower the angle of attack you have to pull to carry out the same manoeuvre (other things being equal).If you have less wing area then you need more AOA or speed to regain the lost lift.

It is your lift vector that turns the plane as well as allows it to climb and fly.

For turning ,it is better to have a wing that needs less AOA than one the one that needs more AOA for the same same amount of turn.As higher AOA for the same turn changes the DIRECTION of airflow over the wing radically and brings the aircraft nearer to stall ,reducing the flying efficiency further.

 

[happy]

Re: ADA LCA Tejas - IV

I have over 2500 hrs on A-320 and that is a stable FBW pax ac. But do you know what happens when the FBW fails in that ac? It goes into direct law wherein the FBW computer cuts out of the system and it becomes Power-by-wire design. The ac becomes extremely responsive and a pilot can easily overload the airframe by his control inputs.

Sir, I have experienced similar affect in MS Flight Simulator with Bombardier CRJ700. BTW, it was a rush just flying it.

 

[Decklander]

Re: ADA LCA Tejas - IV

@ersakhivel we are once again getting to the same point where we stopped last time. can you pls tell what is the relationship between wingloading, AOA, rate of turn and radius of turn. Once you do that, re-read what you have posted above.
Lastly RSS & Unstable for you maybe same, but for people who know aerodynamics, these are two very different kind of stabilities. Read anybook on aerodynamics and you will know how diff they are. An unstable ac can be controlled by conventional controls but RSS will need FBW.

 

[p2prada]

Re: ADA LCA Tejas - IV

@Decklander

From what I know, both F-22 and F-35 are RSS designs. The basic premise of the designers was that if the aircraft is unstable, or RSS, then they don't need larger control surfaces for maneuverability thereby further reducing RCS.

PAKFA is being designed to be RSS in both the subsonic regime and the supersonic regime(highly likely or at least much more than any other fighter design even if it is stable). It is twice as unstable as the Su-27, that's over 12% for PAKFA.

 

[Decklander]

Re: ADA LCA Tejas - IV

@Decklander

From what I know, both F-22 and F-35 are RSS designs. The basic premise of the designers was that if the aircraft is unstable, or RSS, then they don't need larger control surfaces for maneuverability thereby further reducing RCS.

PAKFA is being designed to be RSS in both the subsonic regime and the supersonic regime(highly likely or at least much more than any other fighter design even if it is stable). It is twice as unstable as the Su-27, that's over 12% for PAKFA.

The RSS & Unstable designs need larger surfaces than stable designs as they need to prevent and control uncommanded pitch up.
F-22 & F-35 both are unstable designs. none of them is RSS. The huse two heavy engines plus large wing set very aft and wheels which are also set well aft makes F-22 an unstable design. If they bring the main fuel tank forward, the design might become stable design.

 

[p2prada]

Re: ADA LCA Tejas - IV

The RSS & Unstable designs need larger surfaces than stable designs as they need to prevent and control uncommanded pitch up.

Then that doesn't explain away F-35's smaller control surfaces. Fifth gen aircraft, especially if you look at the difference between PAKFA and Su-27, the control surfaces are smaller than what's on their fourth gen counterpart.

F-22 & F-35 both are unstable designs. none of them is RSS. The huse two heavy engines plus large wing set very aft and wheels which are also set well aft makes F-22 an unstable design. If they bring the main fuel tank forward, the design might become stable design.

Okay, but I don't know by how much that it qualifies as unstable.

 

[mehrotraprince]

Re: ADA LCA Tejas - IV

Then that doesn't explain away F-35's smaller control surfaces. Fifth gen aircraft, especially if you look at the difference between PAKFA and Su-27, the control surfaces are smaller than what's on their fourth gen counterpart.

If you carefully inspect the pictures of Su-27 and PAKFA then you will find,
1. Compared to Su-27, we have one more control surface in PAKFA in the form of LEVCON.
2. In PAKFA Rudder act as Vertical Stabilizer as well as air brakes while in Su-27 we have vertical stabilizers as well as small rudder.

So control surface in 5th generation aircraft as compared to 4th generation has increased(not the static area but moving surfaces area) especially in case of PAKFA, of course to increase its maneuverability.

 

[Decklander]

Re: ADA LCA Tejas - IV

Then that doesn't explain away F-35's smaller control surfaces. Fifth gen aircraft, especially if you look at the difference between PAKFA and Su-27, the control surfaces are smaller than what's on their fourth gen counterpart.

Both these ac have as big control surfaces as any conventional ac. Tail volume ratio and vertical tail volume ratios are dependent on the kind of controlability you want to have. In a stable design, tail plane adds to the weight of the ac by providing negative lift while in an unstable design it adds to the lift of the ac but also moves the CP backwards. Depending on the stability/unstability margins which an ac maintains, the tail and vertical volume ratios will be nearly equal for stable & unstable design. pls read the link below in detail. You will be able understand it better. The size of the control surface has only one criteria and that is stability margin.
http://www.google.co.in/url?sa=t&rc...9aQ&sig2=kUkAa-DdiEVzD2ntcmIpiQ&bvm=bv.535371
you can also increase the stability margin without increasing the constrol surface area by increasing the moment arm. Pls go thru those equations and you will understand it all.

 

[ersakthivel]

Re: ADA LCA Tejas - IV

@ersakhivel we are once again getting to the same point where we stopped last time. can you pls tell what is the relationship between wingloading, AOA, rate of turn and radius of turn. Once you do that, re-read what you have posted above.
Lastly RSS & Unstable for you maybe same, but for people who know aerodynamics, these are two very different kind of stabilities. Read anybook on aerodynamics and you will know how diff they are. An unstable ac can be controlled by conventional controls but RSS will need FBW.

Please explain the difference between unstable platform and RSS platform!!!!!!!!

http://tejas.gov.in/featured_articles/dr_kota_harinarayana/page02.html

Wing Commander Kothiyal was our test pilot. He was a very professionally competent person. I know that he had never flown a prototype in his life. That too an unstable aircraft. So, I thought about how to give confidence to him. We did two or three things. One was to work on the control laws. We tested on a modified F16 aircraft in USA. One of the comments of the test pilot from the Pentagon was that the F16 flies better with LCA control laws. Even the aerodynamics of the aircraft was excellent. It gave a lot of confidence to our pilot. I never wanted to side step any testing. I felt that you must test until you give confidence to the airworthiness team and to the pilots.

here in the official ADA web page the designer of the TEJAS describes it as unstable air craft.

in other sites like wiki tejas is described as RSS fly by wire fighter,

So AFAIK Tejas is both a RSS(relaxed static stability ) and unstable fighter at the same time.

So what is the difference between RSS and unstable fighter. Nothing.

so please explain how an unstable airframe can be controlled by conventional controls,

With some source ofcourse,

AFAIK RSS is same as called unstable aerodynamic lay out.

Relaxed static stability , unstable flight profile negative static stability are all exact opposites of stable flight profile old platforms like F-15,

AFAIK there is no single static stability platform is being designed or introduced in any airforce save JF-17.

Also RSS or instability has nothing to do with control surfaces, It is all related to the area of wing weight of the fighter position of the wing and where the CG and Center of lift or CP lies , nothing to do with having lesser control surfaces.

Once again some people are bent on confusing the issues.

 

[Decklander]

@ersakthivel, Bro I do not go by press reports. I go by what is called aerodynamics. I had posted the link in post #74 for the benefit of all members regarding what is called stability.
I also asked you about the relationship between wingloading, AOA, rate of turn and radius of turn. I have yet to get an answer. Once you read about these, lot of your doubts will be cleared and all the talks of wingloading will disappear.

 

[gadeshi]

Russian moderm displays and indication support systems:

1 - MFI-10-7V (11'') MFD (Su-30SM and Su-34):

2 - MFI-50 (15'') MFD (Su-35, T-50):

3 - SRPNP-1 reserve emergency MFD:

4 - LINS-100RS Inertial navigation system on laser hyroscopes:

4 - BSPI-6 transiever (TKS-3 datalink hardware codec):

5 - BGS-5 onboard graphics station - a "video adapter" for all the displays on board:

6 - BK-79 onboard signals switch (onboard network switch):

8 - IKSh-1K wide angle HUD (Su-35 and Su-34):

 

[gadeshi]

LMs 6G fighter concept:

 

[ersakthivel]

Re: ADA LCA Tejas - IV

MOD Edit: Unnecessary content truncated.

I am staying out of this one. I agree with him that tejas has got a pretty good radar but not so much on tracking and detection.


I do know that it is not frontal RCS RCS that is crucial but all round. However doesn't tejas have the same randome dia as the rafale? It won't be as effective as that of rafales radar due to less.thrust but if I.remember right the radar has a detection range of of 120 kms for.a 3 m^2 target. That means all the targets other than stealth will be seen well before this range? In your last post you haven't mentioned r77 or astra mk 2? Won't mk1 use these as it has the interface to fire 120 km range bvr? Or are these reserved for mk2? By the way why don't you think it possible to guide tejas to the target passively? Mig 31 could do so so qssume the mkis are capable of doing so too.

Tejas has almost the same radome dia as RAFALE and same detection and tracking range and same long range BVRs like Astra mk-1 and mk-2 in future.

Engine thrust has nothing to do with radar range, power for radar comes from separate generator on board, If enough power is supplied to modules on the radome , and if the radome dia is same as that of RAFALE, there can be no shortfall.

All fire control radars of IAF fighters will network with AWACS platforms and even among themselves when AWACS is not around. It is no space age tech!!!!!!!!!

All new IAF fighters will do so in future with sensor fusion nodes and can guide their long range bvrs passively using the most powerful radar among them or using the AWACS guidance to guide the BVR missiles closer to the enemy fighter till the active sensors of the missile takes over.

And with stealth external weapon pods the RCS of Tejas even with four long range BVRs will be closer to 0.5 sq meter compared to 5 sq meter for SU-30 MKI even when the Su-30 MKI carries no weapons and flying in clean configuration.

http://www.flightglobal.com/blogs/the-dewline/2013/05/fa-18f-cft-weapons-pod-mockup/

Gammon, who has worked on the Hornet since the first days of the original F/A-18A classic model jets, says that the CFTs won't add any cruise drag at high subsonic speeds, but it will have a negative impact on drag at transonic speeds–but the company has done a lot of engineering work to try mitigate that. In fact, Gammon notes, at low air speeds, sometimes overall drag with the CFTs is actually lower than a clean aircraft's. - See more at: http://www.flightglobal.com/blogs/t...aid to be substantially less than 1 sq meter

 

[ersakthivel]

Re: ADA LCA Tejas - IV

The Aviationist » Super Hornet road map

that could be retrofitted to any Block II aircraft. The most interesting change is a stealth-configured weapon pod designed to accommodate a range of weapons, including four AMRAAMs, or a mix of two Mk82-class bombs and two AIM-120 missiles. The external pod would help to reduce the Super Hornet's RCS (Radar Cross-Section) by removing missiles and bombs from external underwing pylons.

http://defense-update.com/20130830_...et-completes-first-phase-of-test-flights.html

The enclosed weapons pod is designed to allow the Super Hornet to reduce its RCS while carrying a meaningful munitions load. One pod is able to carry both six small diameter bombs and two advanced medium-range air-to-air missiles (AMRAAMs); or two 500 lb Paveways laser guided bombs and two AMRAAMs; or an equivalent load up to 2,600 lb (1,179 kg).

So the center line fuel tank can be converted to stealth weapon pod for any fighter, Tejas included