Tejas Mk.2: News & Discussions - 25 February 2018

[Cybaru]

Hope they are not reaching for pie in the sky.

Keep the requirements realistic so the project does not spend years trying to achieve a bar set too high.

All hopes are being pinned on top level performance of the engine in the airframe with zero margin given to design constraints. A red flag surely.

I think the only people worried are the folks on BR! Fair concern, but it is very doable. Just stare at the mirage specs for a look. Plus the navy and iaf both seem comfortable pushing the design limits to meet their needs!

[Gyan]

--- Deleted ---

[chola]

If the specs and missions stay at the M2K’s then it is fine. Maybe I am too hung up over terms. For them to say “medium” implies something else to me and that means something like a SHornet.

I will be VERY happy if we end up with an indigenous M2K that you and Karthik-ji suggested.

When desi peeps name everything LIGHT combat aircraft, LIGHT combat helicopter, BABY boomer..

Desis are so self deprecating.. dont spend an ounce in marketing their achievements.. Enough of this light-shite..

When desis name something even a little aggressively..

This is just marketing bullshit.

You just cant please desis.

Yes, very tired of the Light this, Light that.

But it’s not the name. It’s the engine. I would feel more comfortable if we went with heavy engine like the AL-31/F110 for MWF.

The F404 family is a light engine. It is what the Koreans are using for a trainer in the T-50. For their KFX, they are going with two F414s. Just sayin’. But I would be happy if we are successful with an indigenous M2K.

[brar_w]

The KFX has to carry design weight owing to it being a Low Observable design therefore the higher internal fuel load, an internal weapons bay etc. The MWF does not. The Gripen-E already exists in this category with the same engine so not sure that anyone can claim that it is not doable. It will be challenging for sure but nothing that is insurmountable if properly funded and backed by the IAF and the government in power over its development. For the team this will be a very good stepping stone towards completing and putting into production the Ghatak or AMCA.

[Cybaru]

6500kg is weapons is a absurd number!
What mission and loadout needs this?

Singha,

3x 1000 kg class bombs eg Griffin NGLGB/ missiles/ heavy PGMs eg ASB Glide, 3.2 T+ (with pylons, depending on their weight can move this upwards )
2x CCM (2x pylons) + 2x BVR (2x pylons) ~600 kg
3x Fuel tanks (~2000 kg+)
1x LDP/sensor (~220 kg)

This is a standard long range strike config. with the capability to self-defend & escort. As you can see we rapidly approach the 6.5T figure.

I personally think this is the best case payload.. Photo op payload - what the platform is capable of hauling. 95% time it will never ever carry more than 2 2000 pounders. Look through any pics of any real ops and see what the planes are carrying.

[SaiK]

Tejas MWF
- 17,500kg, up from 13,500kg
- 1.35m longer.
- CG change, Canards
- F414-INS6
- 6.5t of external stores, up from 3.3t
- wingtip hardpoints
- cheek stations for stores or sensors.
- internally mounted IRST sensor
- MAWS
- improved cockpit
- Uttam AESA (2 years from now, it will be done testing ) - upgrade all elta ones
- Retractable fuel??
- Towed decoys? [TRD]
- bramos-ng

[Kartik]

The KFX has to carry design weight owing to it being a Low Observable design therefore the higher internal fuel load, an internal weapons bay etc. The MWF does not. The Gripen-E already exists in this category with the same engine so not sure that anyone can claim that it is not doable. It will be challenging for sure but nothing that is insurmountable if properly funded and backed by the IAF and the government in power over its development. For the team this will be a very good stepping stone towards completing and putting into production the Ghatak or AMCA.

I just cannot understand why some people are criticizing the weight and engine choice! Simple facts- it is in the Mirage-2000 ballpark as far as payload/MTOW/empty weight/internal fuel goes. And we have the very real example of the Gripen E, which uses the SAME engine and has a slightly lower MTOW than the projected MTOW for the MWF, then I cannot see why it isn't possible for the MWF.

[Kartik]

Tejas MWF
- 17,500kg, up from 13,500kg
- 1.35m longer.
- CG change, Canards
- F414-INS6
- 6.5t of external stores, up from 3.3t
- wingtip hardpoints
- cheek stations for stores or sensors.
- internally mounted IRST sensor
- MAWS
- improved cockpit
- Uttam AESA (2 years from now, it will be done testing ) - upgrade all elta ones
- Retractable fuel??
- Towed decoys? [TRD]
- bramos-ng

Not cheek, but under the intake. No retractable fueling probe, but a fixed one. No details on Towed Decoys, but definitely doable if the IAF requests it.

[SaiK]

not my words kartik, thx for the corrections

[Kartik]

From AW&ST

BENGALURU, India—India has unveiled a model of an upgraded version of the Light Combat Aircraft (LCA), the Tejas Mk. 2, labeled the Medium Weight Fighter (MWF) and designed to replace the Indian Air Force’s (IAF) aging Dassault Mirage 2000 fleet.

The new version of the indigenously developed Tejas is distinguished by the addition of all-moving foreplanes just behind the cockpit, creating a close-coupled canard-delta configuration similar to that of the Saab Gripen fighter.

“The first prototype is expected to fly by the end of 2023 and we hope to get the initial certification by 2025,” an Indian Defense Research and Development Organization (DRDO) official told Aerospace DAILY on the sidelines of the AeroIndia 2019 show here.

With a maximum takeoff weight of 17,500 kg (38,600 lb.), the Tejas Mk. 2 will be a heavier aircraft than the 13,500-kg Mk. 1 now being produced for the IAF by Hindustan Aeronautics Limited (HAL)—hence the change to MWF from LCA—with the capacity to carry more weapons, he says.

The proposed aircraft will be 14.6-m (48-ft.) long, 1.35 m longer than the Mk. 1, with a more powerful engine and an increase of more than 85% in payload carrying capacity, the official adds. This will allow the Mk. 2 to carry beyond-visual-range air-to-air missiles and standoff precision-guided munitions.

The aircraft will be powered by a 22,000-lb.-thrust General Electric F414-INS6 engine, replacing the 20,200-lb.-thrust GE F404-IN20 powering the Tejas Mk. 1 and improved Mk. 1A. The Mk. 2 will be able to carry 6,500 kg of external stores, up from 3,300 kg for the Mk. 1. A Mirage-style refueling probe is fitted.

The compound delta wing will carry short-range air-to-air missiles on wingtip launch rails, rather than on pylons under the wing as on the Mk. 1, increasing span slightly to 8.5 m. Height also is increased by a small amount to 4.86 m.

ADA data show maneuver capability increasing to 9g, versus 8g for the Mk. 1A.

The MWF will be equipped with an active electronically scanned array radar, an infrared search-and-track sensor on top of the nose and a missile approach warning system, in addition to “smart” cockpit displays, an upgraded digital flight control computer and onboard oxygen generation system.

According to ADA, which designed the LCA, the Tejas Mk. 1 was developed to replace the IAF’s aging MiG-21 lightweight fighters, whereas the Mk. 2 is being designed to replace its newer Mirage 2000s, requiring a larger, more capable medium-weight aircraft.

ADA graphics on display at AeroIndia also show a naval version of the LCA Mk. 2, with larger, more sharply swept versions of the Mk. 1 Navy’s leading-edge vortex control surfaces.

[Rishi_Tri]

Think Tejas Mk2 is set up for tough times, to put it subtly. Why do I say so? Simply because of the number of programs being attempted right now, capabilities being sought and timelines clashing.

Ghatak UAV - Scale model to be tested in 2019-2020 with Tech Demo 2-3 years thereafter, though haven't seen any timelines on that. Given we don't have advanced armed UAV capability and no one likely to share, this program shall stay the course.

AMCA - NGTD comes in 2022, prototype by 2025 or so, and perhaps LSP ready model by 2030! Aircraft should start rolling out from 2030 onwards. Can non stealth version be created to speed up timeline? Very much so and shall offer more than what is being offered by LCA Mk2. AMCA creates 5th gen capability and perhaps more, given we are likely to advance in Network driven warfare. Can easily replace Mirages, Jaguars, Mig 29 / 27s and offers something unique i.e., 5th Gen capability.

Tejas Mk2 (MWF) - Great specs but timelines are worrying. Prototype to come by 2023 (later than NGTD!!), starts flying in operational config 2029. Bang in timeframe of AMCA. Also, Navy Tejas may eat into resources for Tejas Mk2 given same parentage and politicos not understanding Navy Tejas and Tejas Mk2. Does Tejas Mk2 offer anything unique? Perhaps not. Non stealth version of AMCA shall do more than what Tejas Mk2 shall ever do. The scenario I see working for Tejas Mk2 is - speeded up timeline else plays right into the storyline of MRCA 2. But I sincerely hope I am wrong.

Navy Tejas - Given the push from political establishment, this has new lease of life. Offers unique capability to meet unique requirements and can be very strongly argued. There shall fight for budget with Tejas Mk2 but shall live on given that Navy has been perhaps the stronger supporter of Desi stuff and we lack true carrier based aircraft.

Tejas Mk1a - Very natural evolution of Mk1. Offers distinct capability difference from Mk1. Timeline not too far out. Once enters squadron service, may be ordered more than 83 currently approved. Another factor shall be Mk2 timeline.

Strategic planners, finance managers shall have lot to ponder over over next few months. My bet is, it shall be toss up between non stealth AMCA and Tejas Mk2 with non stealth AMCA winning.

[nam]

Mentioned this in another thread.

Given that MK2/MWF detailed design will start in the year end and expected to fly in 2023 year end, they should consider non-stealth version of AMCA instead. AMCA is expected to fly before 2025. Fundamentally one year apart. AMCA is already in detailed design phase,

Get a non-stealth version of AMCA by 2023 and consider this as MWF. Then by 2025 get the stealth version. This will hugely de-risk the program.

Merge the two programs and more efficient use of resources. It is better to produce a non-stealth AMCA, over a bigger LCA in 2029 onwards.

[Rishi_Tri]

Mentioned this in another thread.

Given that MK2/MWF detailed design will start in the year end and expected to fly in 2023 year end, they should consider non-stealth version of AMCA instead. AMCA is expected to fly before 2025. Fundamentally one year apart. AMCA is already in detailed design phase,

Get a non-stealth version of AMCA by 2023 and consider this as MWF. Then by 2025 get the stealth version. This will hugely de-risk the program.

Merge the two programs and more efficient use of resources. It is better to produce a non-stealth AMCA, over a bigger LCA in 2029 onwards.

Yes sir. ++

[viveks]

I wonder if they are going for the GE414G variant which would enable to aircraft to supercruise. Would be very awesome.

[SaiK]

The performance specs for 414g and ins6 is the same. Where do you think G makes it better?

[Rakesh]

From the GE website....

F414-INS6 (powers the Tejas Mk2) ---> https://www.geaviation.com/sites/defaul ... GE-39E.pdf

F414-GE-39E (powers the Gripen E) ---> https://www.geaviation.com/sites/defaul ... Family.pdf

F414 EPE (powers future variants of the F/A-18E/F and E/A-18G) ---> https://www.geaviation.com/sites/defaul ... hanced.pdf

[viveks]

I read in the wiki after my post that ins6 is a variant of the g variant. If they can field and achieve super cruise with it it will be really awesome. The g variant was used in Saab with 4 missiles.

[SaiK]

If not the orders have placed, we could consider the EPE, with more thrust. What are the designers thinking? We have only the AeroIndiaphiles reporting and no details have come out yet.

[brar_w]

There is no "EPE" to consider. GE has not completed all development and testing and likely won't do it until they get put on contract by the US Navy. Since this engine family has the largest global installed base of any engine in its class the chances that these upgrades will be available to order in the latter half of the 2020's are quite good.

[Karan M]

https://www.flightglobal.com/news/artic ... oo-455948/

India’s Aeronautical Development Agency (ADA) has detailed a number of improvements for the planned Hindustan Aeronautics (HAL) Tejas Mk2 fighter.

The Mk2 benefits from Indian Air Force experience with the Mk1, says an ADA official. A prototype of the new aircraft, which features the addition of canards behind the cockpit, will likely fly in late 2023.

Key changes the Air Force asked for were additional range and the ability to carry advanced standoff weapons, he adds.

The maximum all-up weight will grow to 17,500kg, up from 13,500kg for the baseline Tejas, and the aircraft is 1.35m longer. The longer fuselage allows for more fuel behind the cockpit, and the Mk2 will be able to carry more drop tanks.

The extra length changed the fighter’s center of gravity, requiring the addition of a forward lifting surface. The ADA looked at a number of options, including leading edge extensions, but finally decided on canards, which also help with maneuverability. The new aircraft also sees improvements made to the fighter’s delta wing.

“The forward canards help in other areas too,” says the official.

Other improvements include an upgraded engine, the General Electric F414-INS6, of which four examples have already been obtained. The related, but less powerful, F404 powers the Tejas Mk1 and Mk1A.

The Mk2 will be able to accommodate 6.5t of external stores, up from 3.3t for the baseline jet. The new fighter will have wingtip hardpoints added for air-to-air missiles, as well as two cheek stations for stores or sensors.

To highlight the Mk2's differences from the Mk1, a company brochure labels it the Medium Weight Fighter (MWF), whereas the Mk1 was labeled as the Light Combat Aircraft (LCA).

The Mk2 also receives an internally mounted infrared search and track (IRST) sensor, a missile approach warning system (MAWS), and an improved cockpit.

[Karan M]

Aero India 2019: ADA unveils Tejas AF Mk 2 Medium Weight Fighter
https://www.janes.com/article/86671/aer ... ht-fighter

The Tejas AF Mk 2 MWF, which was displayed on 20 February, is being pitched to the Indian Air Force (IAF) to fit into its medium multirole fighter requirement and as a potential replacement of the Dassault Mirage 2000 fleet.

The Tejas AF Mk 2 MWF is an enhanced version of the Tejas Light Combat Aircraft (LCA), with modifications comprising a slightly longer length of 14.6 m and wingspan of 8.5 m (compared with 13 m and 8.2 m respectively for the LCA) to enhance its payload-carrying capabilities. The Tejas AF Mk 2 MWF also has a compound delta wing with close-coupled canards to help reduce drag in almost all angles of attack.

The maximum weight of the aircraft is 17.5 tonnes, which enhances its weapons carrying capacity to up to 6.5 tonnes, and it is equipped with a higher thrust General Electric GE-F414-INS6 engine that features a Full Authority Digital Electronics Control (FADEC) system. Additional features of the Tejas AF Mk 2 MWF include an infrared search-and-track (IRST) sensor, a missile approach warning system (MAWS), and an active electronically scanned array (AESA) radar.

[Karan M]

Indranil, JayS - time for you guys to chip in.
BTW, VKThakur is very dismissive re: the canards. I think he may be mistaken!

[ks_sachin]

Tejas Mk2 is done with inputs from the IAF. There are three basic points that IAF wanted from Mk2:
1. Better transonic and supersonic performance
2. Better STR
3. Better endurance payload

You cannot have all of that with just a 10% increase in thrust. Hence, such an elaborate change. By the way, MWF is very easy on my eye.
1. With the canard, elongated and reshaped body, the plane will have much lower wave drag. Even with the larger body, it will have a drag reduction of about 10-15%. You can see that translated at the top end itself.More details in the write up.
2. The Canard can also allow much better L/D ratio. Again coupled with better thrust, it will lead to significantly better STR. Actually ITR may also go up because they have done lots of tweaks to get better CnBeta performance (the limiter on LCA Mk1).
3. Although they have increased the payload carrying capacity, they have done it judiciously. The wingtips essentially come free. They can carry 11% more fuel externally than the current tanks at reduced drag! In other words, Mk1 with two 1200 ltr tanks has almost the same drag as Mk2 with two 1320 ltr tanks and about 1000 ltr more fuel carried internally. That's huge.

Of course, in the max load configuration, it is a bomb truck. But that is fine with IAF. I don't think they are looking for swing role. They want a lightweight multirole fighter which is nimble in the A2A role, and a can carry a lot of load in the A2G role.

The writeup is ready. It provides details on a lot of subtle changes that are easy to miss. We have handed it over to the publishers, who will take care of it now.

IR two questions while we wait for the magnum opus..

1 - what typically is the variance in the wind tunnel figures and real life re the Mk1
2 - who are the publishers who are still sitting on your article?

[JayS]

Sachin saar, everyone is busy with Aero India. Dawn to dusk they are at Aero India collecting data by GBs and later they have to work on their own things, getting stuff post-processed and published later in evening/night. i was so fcking tired after one day at AI. Wonder how these guys manage whole week long blizkrig.

On WT vs real life data, let me just say, since one cannot make any quantitative statement on it, the differences are enough to make designers go to flight testing and collecting real data rather than depending on WT or CFD data.

[Kakarat]

https://twitter.com/writetake/status/10 ... 1056533505

In this video, #ADA chief Dr Girish Deodhare speaks about MWF #TejasMk2.

From the interview the design is complete and metal cutting to start soon. First flight should happen in end 2021 or early 2022 (before Mk1A?). 4 Prototypes are planned and all will be production standard aircrafts

[ks_sachin]

Jay I understand.
I wish I could go to AI. Covered the inaugural two for my newspaper.
Are you in Bangalore?

[Haridas]

Singha,

3x 1000 kg class bombs eg Griffin NGLGB/ missiles/ heavy PGMs eg ASB Glide, 3.2 T+ (with pylons, depending on their weight can move this upwards )
2x CCM (2x pylons) + 2x BVR (2x pylons) ~600 kg
3x Fuel tanks (~2000 kg+)
1x LDP/sensor (~220 kg)

This is a standard long range strike config. with the capability to self-defend & escort. As you can see we rapidly approach the 6.5T figure.

I personally think this is the best case payload.. Photo op payload - what the platform is capable of hauling. 95% time it will never ever carry more than 2 2000 pounders. Look through any pics of any real ops and see what the planes are carrying.

Multi role Tejas in deep strike bomber mode , looks like will out perform current Jaguar by fat margin, not to speak of its added abelity to defend itself, making mission very effective in terms of aircraft resources, cost and effectiveness.

[gaurav.p]

http://forceindia.net/ada-rolls-mwf-version-tejas/

...
first Tejas AF Mk.2 MWF’s first fully integrated flying prototype is expected to be rolled out by late 2026 by Hindustan Aeronautics Ltd (HAL), following which around 2,000 hours of flight-tests will be required to be conducted by no less than with four flying prototypes over a period of three years prior to receiving the certificate of airworthiness. So, for all intents and purposes, the Tejas AF Mk.2 MWF will not enter series-production until 2030.

So uptill now, jingos can expect to see PV MWF flying anywhere between 2021-2026

[suryag]

where does force india get its share of offal meal ?

https://twitter.com/i/status/1098841211056533505

[Kakarat]

https://twitter.com/SJha1618/status/1098871677977452544

Yeah, you have heard this. You have heard that. By this evening @delhidefence will be publishing two blockbuster articles on the evolution of the Tejas by a couple of hands on authors. Watch this space.

[JayS]

where does force india get its share of offal meal ?

https://twitter.com/i/status/1098841211056533505

Key takeaway from this short interview of Dr Girish Deodhar is the 4 flight test vehicles for MWF are going to be production standard.

What I said some time back:

Its ambitious, but for once we shouldn't fault HAL for targeting an ambitious schedule. the need of the hour is to get the Mk2 into the air by late 2020 or early 2021 so that at least the IOC flight testing can be completed by 2025 and production can begin in 2026.

I think it will fly in 2021. Also as the maturity of program goes up, we should see production starting much ahead of flight testing completion as ADA/HAL will have better and better grip on changes. I dont think we will have to wait for Mk2 production till 2026 or so. More like 2023-24 or so. They will quickly get IOC and induct it. FOC will happen overtime.

This is better than what I expected. I was expecting LSP. Basically we should see, the line setup from the word go for serial production. First 4 aircrafts would be used for Flight testing. And the line will continue churning SPs without stopping. Given the maturity and experience ADA/HAL have now, they can easily design the basic Airframe which will basically need no significant changes once the design is frozen. Changes will be in LRUs and SW, for which there is no need to stop production. We should see seamless production running in background without any impact of flight testing as such. Of coarse this assuming IAF/MoD actually order the aircrafts and do not wait for FOC. HAL did manage to start producing LCH without orders, but may not be able to have enough money everytime.

[Rishi_Tri]

http://forceindia.net/ada-rolls-mwf-version-tejas/

...
first Tejas AF Mk.2 MWF’s first fully integrated flying prototype is expected to be rolled out by late 2026 by Hindustan Aeronautics Ltd (HAL), following which around 2,000 hours of flight-tests will be required to be conducted by no less than with four flying prototypes over a period of three years prior to receiving the certificate of airworthiness. So, for all intents and purposes, the Tejas AF Mk.2 MWF will not enter series-production until 2030.

So uptill now, jingos can expect to see PV MWF flying anywhere between 2021-2026

2021 - So now, MWF is coming before AMCA NGTD. Also, Mk1 + Uttam is going to fly before Mk1A. Looks like Modiji has created competitive teams and fired up everyone.

[JayS]

Jay I understand.
I wish I could go to AI. Covered the inaugural two for my newspaper.
Are you in Bangalore?

Yes. I went there yesterday.

[Prasad]

Should've said hi

[JayS]

Where did HAL say it will come out in 2026..?

2022 is realistic date.

My hypothesis is that the decision on MWF was taken as the same time when Mk1A was accepted as an interim solution. ADA worked on the design for almost 4-5 yrs now and is very close to finalise detailed design phase, if not already done that. Which is evident from the Jig RFI. (They kept it carefully under the wraps through AI2017. Its not possible to do so much work in mere 2yrs. Perhaps burnt by the constant negative press coverage they thought its better to go public only after having something concrete in hand). So considering manufacturing in 4-5yrs from design freeze, since we are talking of setting up of entire MFG facilities and not just a repeat order like Rafale for which 3yrs is lead time, late 2022 or 2023 is a realistic timeline for first flight. In fact I wont be surprised to see it happening it ahead of schedule. Based on RFI of jigs alone I estimated late 2021 or early 2022.

My expected schedule (+/- few months):

Metal cutting - Soon, in 2019 itself
Sub-assembly start - end of 2020
Full structural assembly finish - end 2021
Final assembly finish - early 2022.
First flight - end of 2022.

Of coarse this is considering funds flow. As of now, DRDO has asked for 800Cr more grant-in-aid for MK2 recently and I have not seen any news or document saying FSED-3 has got this additional funding. ADA is totally helpless without funds. Hopefully HAL will put some of its money, given GOI does not screw their cashflow.

OT but I think despite Uttam, MK1A will continue with Elta. When Uttam comes it will replace Mk1 MMR, if IAF is willing to pay.

[gaurav.p]

I seem to have misinterpreted the forceindia article which says "rolled out by late 2026 by Hindustan Aeronautics Ltd (HAL)" as dates given by HAL. Editing the above post.

Further clarification
https://twitter.com/zone5aviation/statu ... 3689123840

On LCA Mk.2 (now rechristened MWF) — @HALHQBLR CMD says it’s not a HAL programme right now, responsibility rests with ADA.

But HAL has said that Mk1A will come 3yr from the date of signing contract (nowhere earlier than 2022). Let's hope Mk2 PV comes at that time as well.

[ks_sachin]

Should've said hi

Ah thought u are based in Blore.
Will be there in April if any BRFites are in town.

[ramana]

Where did HAL say it will come out in 2026..?

2022 is realistic date.

My hypothesis is that the decision on MWF was taken as the same time when Mk1A was accepted as an interim solution. ADA worked on the design for almost 4-5 yrs now and is very close to finalise detailed design phase, if not already done that. Which is evident from the Jig RFI. (They kept it carefully under the wraps through AI2017. Its not possible to do so much work in mere 2yrs. Perhaps burnt by the constant negative press coverage they thought its better to go public only after having something concrete in hand). So considering manufacturing in 4-5yrs from design freeze, since we are talking of setting up of entire MFG facilities and not just a repeat order like Rafale for which 3yrs is lead time, late 2022 or 2023 is a realistic timeline for first flight. In fact I wont be surprised to see it happening it ahead of schedule. Based on RFI of jigs alone I estimated late 2021 or early 2022.

My expected schedule (+/- few months):

Metal cutting - Soon, in 2019 itself
Sub-assembly start - end of 2020
Full structural assembly finish - end 2021
Final assembly finish - early 2022.
First flight - end of 2022.

Of coarse this is considering funds flow. As of now, DRDO has asked for 800Cr more grant-in-aid for MK2 recently and I have not seen any news or document saying FSED-3 has got this additional funding. ADA is totally helpless without funds. Hopefully HAL will put some of its money, given GOI does not screw their cashflow.

OT but I think despite Uttam, MK1A will continue with Elta. When Uttam comes it will replace Mk1 MMR, if IAF is willing to pay.

The paper design takes about 3-4 years.
I think they now got Authority To Proceed(ATP). The 800 crore is for the production of the prototypes etc. Will have annual funding tranches based on program plans.
I agree with your milestones from planning perspective.

[SaiK]

https://twitter.com/writetake/status/1098841211056533505

In this video, #ADA chief Dr Girish Deodhare speaks about MWF #TejasMk2.

From the interview the design is complete and metal cutting to start soon. First flight should happen in end 2021 or early 2022 (before Mk1A?). 4 Prototypes are planned and all will be production standard aircrafts

He was very confident, and it is going to be from 124th aircraft onwards.
so, we will have 40 Mk1, 83 Mk1A, and rest is Mk2

[Indranil]

MK1A: Hal’s baby. HAL trying to buy some time by saying 3 years etc. if it limits its scope, MK1A is almost ready. IFR:done. Hot refueling:done. 2052 integration: done (on Jaguar). Production doesn’t need to stop for integrating SPJ pod. IAF happy with MK1 performance. IMHO, HAL should swallow a little pride and talk to ADA. It doesn’t have the fixed wing design and testing capability of ADA. ADA has done a lot of studies on Mk2 which can be retrofitted to MK1A: reshaping of the spine, aft fuselage, pylons and fuel tanks would give significant drag reduction. Introduction of nose chine, and wingtip pylons would provide better AoA performance. Going with The letter box auxiliary intakes will improve take off performance. HAL has 2 years before it finishes the manufacture of the 40 Mk1s. It is doable.

Mk2/MWF is ADAs baby. It will require significantly more time to hone this. At least 2-3 years of testing. So ADA required 6 years for this. Which exactly the time they have: 2 years of MK1 run, followed by 5 years of MK1A run.

Problem is ADA and HAL designers don’t talk. Too much pride and ego. Unfortunate, but true.

Indranil