Why Tejas Mk2 (MWF) Will Be Important

[IndianHawk]

Clearlly, you know something about this plane that American designer of F35 doesn't know.

Even if not today that specification is a requirement of a proper Stealth fighter and American are developing powerful engine for it.

 

[IndianHawk]

You clearly didnt get what i said, knowing first gives more tactical time to perform based on your strengths and opponents weakness....

He is not wrong though. If you don't have a weapon to match your tracking range than your tactical advantage is gone. As you will close in to bring enemy within your strike range you might light up his irst/ passive sensors. Most bvr kill happen within envelope of 20-40 km anyway and irst ranges are starting to surpass them.

 

[Armand2REP]

Clearlly, you know something about this plane that American designer of F35 doesn't know.

It can go Mach 1.2 for 150 miles without afterburner. The friction of going supersonic will damage the RAM coat as it is poorly made.

 

[ersakthivel]

Remind me of students who complains on the day of exam that they had only one day to complete the syllabus . When they had an entire year to do so.

When a project is sanctioned it means it is sanctioned . One can play around the dates if it soothes them .

https://pib.gov.in › PrintRelease
Schedule for Induction of Tejas Mark Ii Aircraft Into Service - PIB

around 2500 crore were earmarked for it . What they do with it how they proceed was their problem.

Similarly AMCA was sanctioned in 2016 now how long you will hear about is not anyone's concern .

https://www.livefistdefence.com/201...-to-marshal-its-full-muscle-for-the-amca.html


"The technologies and learnings from the LCA Mk1 and the LCA Mk1A will help the DRDO, HAL, ADA and the private sector companies involved to make the AMCA. This was also stated by the HAL CMD R Madhavan. Interestingly, this was in December 2018 when the LCA MkII had not changed into the bigger MWF.



"Earlier In April 2018, the then Defence Minister Nirmala Sitharaman in a written reply to a question in Lok Sabha stated that the feasibility study for the programme has been already completed So clearly, the making of the MWF has no bearing on the future manufacturing of the AMCA"


So by April 2018, only feasibility studies fr AMCA were completed.

AND


Till December 2018 "the 2500 crore ear marked" tejas mk2 ,"sanctioned project as per PIB ", was essentially a SOUNDING BOARD , between IAF & ADA discussing "possible configuration of mk2",

Which has resulted in the MWF.

So actual design process fr MWF has started only in 2019.

Of course students hv to study throughout the semester fr exams

But before that they hv to enroll in a college.

So AMCA has completed ONLy its feasibility course in 2018 April

& Tejas MK2 MWF is entering the college campus only in 2019

 

[ersakthivel]

This is not to say I agree with Yusuf's analogy that we don't need MWF before development of AMCA.

ADA has stated TEJAS MK1,MK1A, MK2, STEALTH AMCA will all hv the same wing loading SPEC i.e ,"wing area/ take off clean".

They hv already mastered , the
control laws CLAWS &Relaxed Static Stability 4 channel all digital fly by wire software fr this wing loading spec.

It's this Flyby wire validation process, that took several years & 1000s of calibrated test flights over decades across so many Tejas TDs, PVs, LSPs,

In Tejas mk1 this wing design was validated around 8G

Mach 1.6at service ceiling , supersonic at sea levels,

Hot weather trials cold weather trials at Leh,


AOA of 26 deg

& respective CLOSE COMBAT SPECS LIKE


Sustained Turn Rates (STR),

Instantaneous Turn Rate(ITR),


G onset rate,

Etc, etc

In MWF or TejasMK2 (which will also hv same wing loading as tejas mk1 & canards)they will expand this envelope further to extreme limits demanded by IAF.

ADA has explicitly stated that AMCA too will hv the same loading of Tejas mk1 & MK2,

So development of MK2 OR MWF gives ADA a chance to refine this wing shape & finetune the Fly by wire software , Which will form.the bedrock of AMCA.

And the needed subtle changes in wing shape in area of Tejas mk2 will hold many important consideration fr AMCA stealth design.

Agreed MWF has canards,AMCA is twin engined, but wing loading is a spec independent of these config changes

THIS CRUCIAL POINT IS MISSED BY ALL PUNDITS WHO THINK ADA CAN JUMP STRAIGHT TO AMCA frm tejas mk1,

Just like Daniel craig jumps across so many iron grinders & buildings in CAsino Royal opening sequence.

ADA is no james bond & these ,"jump through" to AMCA from Tejas mk1 , will hv no reshoots with body doubles & safety nets as in film

 

[ersakthivel]

Other than those specifications it's nothing like Gripen. It has more the 10m² extra wing area, compound delta wings, 110+KN class co-developed engine (or maybe GE414 EPE).
Looks completely different too... Mirage-Tejas difference.

With the 6G-restriction Tejas Mark1's manoeuvres are already at par with Gripen A/B/C/D's... 16-20sec loop, 18-21sec minimum radius turn.

Tejas mk1 is already above 8G,
Please quote any source fr your 6G Claim

 

[ersakthivel]

In its testing in Himalayas , Tejas easily carried 2.5 ton payload which its designers thought it may carry at Max . Surpasing all the expectation of its designers, Tejas carried that weight very easily in Himalayas. I remember the statement of a scientist saying that there is a great possibility off putting greater weiwht on Tejas for Himalayan region operations

Thats due to specific IAF demand , which resulted in the lowest wing loading of Tejas mk1, which no other modern fighter has.

So it's pertinent to note that hiw useful Tejas will be in kashmir valley & Exercise HIMVIJAY type situations in future.

 

[ersakthivel]

...But that article does not say that Tejas has achieved angle of attack of 35°. It just states the design requirements are to achieve it.
You'll notice that it's also written +9 G limit, but it's a known fact that's not true yet.

And link I shared is also very reliable, if not THE most reliable.

AOA expansion is a process that continues well after FOC in all fighters

I hv already posted a ADA CFD Study which showed that Tejas pilot will still retain aerodynamic control of wings well up to 32 deg, in the closed ADA tejas thread.



What FOC did is to validate it up to 26deg.so if the wing performance was as per the design calculation till 26 , then mostly it will hold good fr 30 plus deg also , in a restricted flight envelope, like all other fighters

 

[ersakthivel]

Tejas Mk2 is a testimony of Progress we made in the area of Aerodynamics. 6.3 ton payload is not a joke. Even mighty MKI carries some 8 tons and Rafale a bit more. A single engine fighter carrying a 6.3 ton load is a great achievement in itself. Even if I consider Dry thrust 64 Kn, it easily surpasses the thumb rule of Dry thrust X2.5/10= MTOW. It is not possible for any fighter to achieve such a high T/MTOW ratio. Look at the Tejas Mk1. It has Just ideal ratio of 2.5 i.e 54X2.5/10= 13.5 tons which is the MTOW of tejas Mk1.

This very high MTOW will provide great flexibility to Mk2 to be used in many roles. It can substitute MKI in many roles and missions which is simply great and highly cost effective.

Earlier IAF insisted thT Tejas mk1 should hv the same foot print of mig21, to fit into the existing infra in bases
So ADA has to factor that into design.

MWF is the unleashing of the full potential of Tejas tech & design capabilities.

It vancbe easily evolved in to twin engined stealth like mirage2000 to mirage4000 evolution, with some modifications like stealth airframe& internal bay,
if we face any delays in the demanding AMCA project


That's why itsita crucial project tTfr IAF

Also we may produce a indigenous 100kn engine in ten yrs or so, an easy upgrade from kaveri, two of these engines r more than enough fr any future twin engined stealth AMCA,

On the other hand local development of AMCA 110 KN plus Engine,
is a very difficult task , that will take more time.And if we end up with a thrust shortfall of 100 Kn engine, it can be used in stealth MWF config.

Even if we refine kaveri with just 70KN peak thrust, we can evolve a rafale sized stealth bird by incorporating twin engines & stealth airframe into MWF design

 

[piKacHHu]

AOA expansion is a process that continues well after FOC in all fighters

I hv already posted a ADA CFD Study which showed that Tejas pilot will still retain aerodynamic control of wings well up to 32 deg, in the closed ADA tejas thread.



What FOC did is to validate it up to 26deg.so if the wing performance was as per the design calculation till 26 , then mostly it will hold good fr 30 plus deg also , in a restricted flight envelope, like all other fighters

Your thoughts on incorporating Diverterless intakes (DSI) in MWF and AMCA? Is there any program working on its development?

 

[Bleh]

Tejas mk1 is already above 8G,
Please quote any source fr your 6G Claim

Literally any single one out there on the internet... now let's see your source for claim it to be 8G capable.

https://www.flightglobal.com/news/a...ima-deployment-marked-new-high-for-in-457001/

http://ajaishukla.blogspot.com/2013/07/a-bird-in-hand-induct-tejas-mark-i-into.html

https://www.business-standard.com/a...as-performance-at-bahrain-116022200321_1.html

https://www.google.com/url?sa=t&sou...FjAPegQIBhAB&usg=AOvVaw01_48UbwPnXt5i616h_Xle

https://www.google.com/url?sa=t&sou...FjAGegQICBAB&usg=AOvVaw2EXadMSddoyXJnEPlA0fsL

http://www.defencenews.in/article/How-LIMA-deployment-marked-new-high-for-Indias-Tejas-584025

 

[Aashk]

Literally any single one out there on the internet... now let's see your source for claim it to be 8G capable.

https://www.flightglobal.com/news/a...ima-deployment-marked-new-high-for-in-457001/

http://ajaishukla.blogspot.com/2013/07/a-bird-in-hand-induct-tejas-mark-i-into.html

https://www.business-standard.com/a...as-performance-at-bahrain-116022200321_1.html

https://www.google.com/url?sa=t&sou...FjAPegQIBhAB&usg=AOvVaw01_48UbwPnXt5i616h_Xle

https://www.google.com/url?sa=t&sou...FjAGegQICBAB&usg=AOvVaw2EXadMSddoyXJnEPlA0fsL

http://www.defencenews.in/article/How-LIMA-deployment-marked-new-high-for-Indias-Tejas-584025

https://www.ada.gov.in/#
ADA says Tejas mk1 capable of sustaining 9g
...........

 

[nongaddarliberal]

countering the the fraudulent narrative being built up fr scrapping TejasMK2 & buying 100 odd f16s or f18,

which r a generation behind in RSS fly by wire aerodynamic planform

Or Gripen NG which is same as #ejasMK2 , but costly.

comparing the delayed timelines of Tejas_LCA mk1 ,

which had zero infra,

Noready LRU ,

IAF apathy,

FSED ph-2 delay,

Trickle funding,

US Sanctions delay,

US confiscating software equipments after pokhran test sanctions,

forcing redevelopment of RSS fly by ware frm scratch?

.pitiful dribble of funding by devil may care govts


No ready fly by wire tech fr RelaxedStaticStability fighter,(takes decades to master) To Tejas_LCA mk2 is unfair TejasMK2

Due to differences of opinion btn IAF,

MOD, ADA, Tejas_LCA mk1 followed the tortured ,

Tech development TD (just to prove flight) to Prototype PV, to limited series production LSP model,

IAF specified R73e only in 2008 or so leading to long FSED Phase2 of wing redesigning,


TejasMK2 is the much needed insurance against delays in StealthAMCA,

greenfield Tejas Mk1 Took tedious TD - PV-LSP route ,

needing 20 yrs fr FOC .

Tejas_LCA Mk2 -direct Limited Series Production from 1st fighter, fr quick FOC .

Fly by wire CLWAS, , Composites already mastered,

Since Tejas mk2 has ready availability of Tejas_LCA mk1's completed fly by wire control laws effort,

ADA is going fr direct production of TejasMK2 , no tech demos(TD), no PVs(prototype vehicles).

Since wing loading is the same fr both mk1&mk2, Mk2 can be developed very fast.


TejasMk2 A 's low wing loading (world's lowest)design was custom built fr high altitude himalayan theatre,

with load ( Leh,other rough air fields) , which no other foreign single engine fighter design has.

Tejas_LCA mk1 spent decade mastering,

EW suit,

software defined radios,

SPJ, IRST, BVR,

ASEA radar integration,

HMDS cued off bore sight WVR missile capabilities,

all glass cockpit.

Now All of these are readily available TejasMK2 effort,

Considerably cutting down yrs needed fr FOC

What is , "entirely" new abt Tejas_MK2?,

Which won't substantially draw on , #Tejas mk1's,Composites,

Control laws of RSS fly by wire airframe,

tier 2 vendors, System integration experience frm integrating mission computer,

HMDS cued WVR DRFM equipped ASEA jamner

Air to air refuelling,

Astra, Derby , R73E, litening,

SPJ integration, Quartz radome,

SFDR, stores release simulation,

Cold start with decent loads fr a light fighter frm Leh?

CFD studies,

Cockpit ergonomics,

MFDs, Margin fr relaxed static stability, especially ,

when TejasMK2 has the same wing loading as tejas mk1.

Tejas mk2 has a world class new tech assembly line fr precise,

faster LSP production, Unlike mk1A which was cobbled together in obsolete jaguar production line.

All these long delays won't be there fr #TejasMK2

bcos weapon fit specs, proven tech are Already on the table.

Evolutionary designs don't need experimental airframes aka prototypes.

They go straight to LSP bcoz of lesser unknowns involved.

JAS-39E/F & F/A-18SH programs are examples. SAAB Test flighted systems individually on JAS-39D

before jumping straight to production standard JAS-39E.

Question remains whether the US will simply sell us 200 F414 engines.

 

[ersakthivel]

Senior Member
https://defenceforumindia.com/forum/threads/ada-tejas-lca-news-and-discussions.1/page-422

Firstly, as testified by the IAF test pilots who have flown the Tejas through more than a thousand hours of flight-testing, the current version of the fighter, i.e. the Tejas Mark I, is already a world-class fighter that has achieved most performance landmarks that the IAF had demanded.

It flies at Mach 1.6 (about 2,000 kmph), a speed that the IAF is satisfied with.

Its state-of-the-art quadruplex digital flight control system makes it a maneuverable and easy-to-fly fighter,


unlike the unforgiving MiG-21 that it is slated to replace.

The Tejas has not had a single accident so far, testifying to the stability of its design.



Another key measure of a fighter's capability is the Angle of Attack (AoA) it can achieve.

The higher the AoA, the more lift that is generated, allowing a fighter to get airborne at slower. speeds from short airstrips, e.g. aircraft carriers.

The IAF had demanded an AoA of 26 degrees for the Tejas.

The Tejas has already been tested to 24 degrees, and is on course to achieve that target.



Says Air Commodore (Retd) Parvez Khokhar, who was for years the chief test pilot of the Tejas programme:

"The Tejas Mark I is far superior to the MiG-21 fleet that the IAF would have to operate to the end of this decade.


In key respects, it is a better fighter than even the Mirage2000.

The Tejas Mark I should enter the IAF's combat fleet in larger numbers and the Tejas Mark II scaled down

 

[ersakthivel]

http://sturgeonshouse.ipbhost.com/topic/188-a-quick-explanation-of-relaxed-stability/

Delight to read

Negative stability (Relaxed Static Stability, RSS) fighter like Tejas,


Center of Lift (CP or CL) is in front of Center of Gravity(CG),

So that the fighter is UNSTABLE in pitch axis & goes with the wish of pilot trying agile manuoveres,

They need precise analog or digital flight control systems that keeps the fighter fom going out of control, by giving
inputs to control surfaces every milliseconds,


In contrast,

In the old world positive stability fighters,

CG in front of CP, so that fighter resists pilot's attempts at agile manuoveres & tries to return back to stable flight,


that are directly , physically controlled by pilots input to control surfaces.


Because sophisticated analog or digital flight control systems were not in existence that time

https://forums.bharat-rakshak.com/v...d=788e6782db9d2125e02389b40222afad&start=2080

All concerns regarding increase or decrease if weight in relation to CG, CP, margin if instability are debated there.




Before analog & digital fly by wire systems came into existence all fighters were stable in flight profiles.

With the advent of trans sonic & super sonic fighters, wing sweep angle increased ,


Because of the need to restrict air frame with in trans sonic shock cone.

So the fighter's mass began to coalesce around its fuselage, due to wing spans getting shorter in relation to fuselage length.

So fighters became more stable & increasingly hard to manoeuvre in pitch angle,

Due to the increase in Stability margins,

To obviate this RSS fly by wire deltas design became dominant,

From this point onwards weight distribution in fighters had to be precisely calculated with regards to CG, CP, margin of instability

 

[ersakthivel]

December - The PV-3 flew for the first time for 27 minutes at an altitude of 2.5 km and at a speed of Mach 0.8. The PV-3 was equipped with a more advanced pilot interface, refined avionics and higher control law capabilities compared with the previous versions.
2007

Tejas PV-1 firing an R-73 missile during weapons trials in Goa
25 April - The first Limited Series Production LCA (LSP-1) made its first flight and it reached a speed of Mach 1.1.
PV-2 and PV-3 underwentsea-level trails at INS Rajali Naval Air Station, Arakkonam to study the effects of flying at sea-level, as all earlier trials have been conducted at Bangalore which is 3,000 feet above sea-level. The reliability of the LCA systems under the hot and humid conditions, as well as low level flight characteristics was tested.[6][7] It is due to this intense flight testing schedule that the LCA was not able to fly at the Paris air show-2007, as was originally planned.
7 September - TejasPrototype Vehicle (PV-1) made a successful maiden flight with two 800 litre drop tanks.
25 October - Tejas PV-1 fired a Vympel R-73 missile for first time. The trials were conducted off the Goa coast at INS Hansa Naval Air Station.
11 December - LITENING Pod was successfully tested on Tejas PV-2.
2008
7 February - Tejas Prototype Vehicle (PV-1) made a successful flight powered by fuel from two 800 litre drop tanks. It made a one hour and 24 minute long sortie. On internal fuel LCA can perform a 40-minute sortie.


So An hour & half with two 800 litre drop tanks on February 7,2008.
This is before centerline fuel tank. & 1200 liter fuel tanks were tested.


Endurance 2 hrs 30 minutes says the HAL poster at AeroindiaAe2013

Fr MWF it will be at least double of this

 

[ersakthivel]

Some rough & ready calculation by Indranil Roy of BR will guide u to calculate ferry range of plain mk1,
Extrapolate it to MWF, to know what it can do


the ferry range is 1700 kms with 1200 ltr drop tanks. So it must at least have a 2 hour endurance under cruise condition.

Another way is to calculate it is from the SFC. But you would need to know the thrust required for the flight at the aforementioned range. I don't know that. But let us continue. For example, let us find the endurance at maximum speed without afterburner. We know that:
1. SFC for military thrust = approx. 84 (kg/kN-hr) .
2. Maximum military thrust = approx. 54 kN.
3. Therefore, the rate of fuel consumption at this speed = approx. 54 kN * 84 kg/(KN-hr) = approx. 4536 kg/hr.
4. Total fuel: 2 X 1200 ltr tanks and about 2600 kg of internal fuel = approx. 4600 kg

5. Therefore, endurance in this regime is nearly 1 hour, and you would have flown around 800-900 kms.

You can do the same thing with afterburners. It will be about half an hour (but you will most probably cook the engine before that).

 

[mayfair]

Question remains whether the US will simply sell us 200 F414 engines.

It's a matter of 200+ confirmed engines plus after sales support and follow on orders for AMCA.

Good business for GE.

 

[ersakthivel]

https://defenceforumindia.com/forum/threads/ada-lca-tejas-mark-ii.45058/page-40

Kunal"S post,

Blast from the past

Compares mig21 & tejas( at 2014 level, it has come a long way since)

 

[nongaddarliberal]

It's a matter of 200+ confirmed engines plus after sales support and follow on orders for AMCA.

Good business for GE.

We better not be getting foreign engines for AMCA.