That unintentional spelling mistake gave me an idea. We should name the facility where Tejas is made as "Tejas Tajas" a la Newport News Shipbuilding.

As of 2015, media reports indicated that India had a few FTBs, operated by various defence research laboratories such as the Centre for Airborne Systems (CABS). They were usually flown by qualified Indian Air Force (IAF) test crews from the Aircraft and Systems Testing Establishment (ASTE) in Bangalore. The media had then reported that India had modified HS-748s, Dornier Do-228s and a single modified IL-76 as test beds. The IL-76 was and is still based at the Gromov Flight Research Institute in Moscow.
The Hawker Siddeley HS- 748- a British-origin, twin-engine turboprop military transport and freighter has been used to test several indigenous systems like the Multi-Mode Radar (MMR) and Multi-Sensor Warning System (MSWS) for standalone testing and evaluation. The ground support equipment and an experienced maintenance crew support the HS-748 -based light Test Facility. India also possesses Dornier Do-228s as test beds. These aircraft are manufactured by the Transport Aircraft Division of HAL, located at Kanpur. DRDO received the first modified Dornier in May 2014 and has been used for testing aerospace systems.
Embraer was one of the candidates that was considered for this. However, since the test and design data of an imported aircraft are not shared owing to the proprietary clause, India would not have been able to fly our own FTB without knowing these details. The plan to import was dropped, and Do-228 became the automatic choice.
However, India still lacks a high-altitude flight test facility with an FTB for its military afterburning turbofan projects. This has led to the country being dependent on France and Russia for testing experimental engine programs, rendering them vulnerable to external espionage. GTRE and DRDO have been insisting on acquiring a capable indigenous FTB.
The issue in acquiring a new test bed seems to be one of intention. Procuring IL-76 or any other commercially available plane to be used as a Flying Test Bed (FTB) is not a very difficult task. The fact that the country still does not have it shows the lack of seriousness on the part of the Ministry of Defence (MoD). Over the last 30 years, the MoD has not even invested in fundamental testing facilities in the nation. With such support, the expectation from engineers and scientists to build a workable engine on a tight budget seems unrealistic.
There still is a future, though. The DRDO, which currently does not have a supersonic FTB, is aggressively following the project to acquire one. To look into the possibilities for obtaining the same, a committee has already been set up. The committee has representatives from the IAF and HAL, alongside members from DRDO. While Sukhoi is leading the fray, the committee is also considering the advantages of MiG 29.
Bala sir, this is not new news. It is the same that is explained by GTRE director Dr. Ramana Murthy in Aero India. Basically the KDE for UCAV is near ready. The current Kaveri 1.0 needs to improve the T/W ratio from 6.5 to 8.0 to power the Tejas 1A series and then we need Kaveri 2.0 for Tejas 2.0 and AMCA. Sounds like there is renewed momentum to get all these projects streamlined with some funding and infusion of needed tools. However, we need to be a bit patient, and make sure there is sustained funding to see the light of the day on a complex decade long development effort. I still believe we are 8-10 years away from Kaveri 1.0 replacing current GE F404 engines and perhaps Kaveri 2.0 will replace F414 in few years after that. If things happen before that, it will be a huge surprise. Until then we need to swallow the pride and dance with the Western and Russian OEMs. We have to walk the thin rope of geopolitics to keep the supply lines running. It is a hard pill to swallow, but our patience will be well rewarded in the future. Instead of having some Chinese style paper-tiger propaganda mall, we will have true sixth generation end-end aeronautic ecosystem.bala wrote: ↑29 May 2025 04:50 This report in "India News analysis" claims that the tests for Kaveri in Russia are going favorably well with another few more hours left. After this inflight testing can be done.
Today - India’s indigenous Kaveri engine, developed by DRDO, has officially been cleared for inflight testing - a major breakthrough in the nation’s journey towards self-reliant aero-engine development. Set to power the upcoming stealth UCAV Ghatak, the dry Kaveri is now ready to soar.
Flight Testing clearance for Kaveri Engine
May 28, 2025
youtube.com/watch?v=bQ6H0A9C5OU
copy url to browser and watch, tis in Hindi.
// so far the engines are performing with no major issue. This is good news. Some inflight testing (on ghatak) and on towards certification for the engine.
// getting a Indian high altitude flight test bed for further refinement, and uprated engines is a must. Babus in MoD must sanction more funds.
AFAIK, this does not give full picture. What happens if TWR is 6.5? It puts certain constraints. So what are they? Are they worth consideration? What's the point of having an engine with great TWR and is not supplied at all? The airframe is useless unless there is any engine. And if they pull plugs/strings on engines, they can AND will do for fighters, armaments AND upgrades. So one has to take a strategic and pragmatic view. Which is largely (or contextually) absent in the IAF....Kaveri 1.0 needs to improve the T/W ratio from 6.5 to 8.0
You are right. But IAF is used to buying off the self mature western products. They are expecting the same from local production houses and are not ready to participate in iterative development. It is more of a culture thing. We need all our Sarkar orgs + ASTE and IAF to become "learning organizations". They need to be open to some level of immaturity and give some chance for these local products. I think some training and communication between these orgs will work better is my guess.basant wrote: ↑29 May 2025 14:57AFAIK, this does not give full picture. What happens if TWR is 6.5? It puts certain constraints. So what are they? Are they worth consideration? What's the point of having an engine with great TWR and is not supplied at all? The airframe is useless unless there is any engine. And if they pull plugs/strings on engines, they can AND will do for fighters, armaments AND upgrades. So one has to take a strategic and pragmatic view. Which is largely (or contextually) absent in the IAF....Kaveri 1.0 needs to improve the T/W ratio from 6.5 to 8.0
See today's news. The IAF chief again. 'Not a single project completed on time'. That's rich coming from IAF that took eternity testing MRCA and AJT. Moreover, it also shows he does not seem to read news on complex projects even in Western countries, F-35 being a classic case.
Over the years I have come to the sad conclusion that to improve matters, acquisitions should be handed over to Civil servants rather than services. The Services can give feedback and input, but the final say should not be with them.
What is being tested is KDE (Kaveri Derivative Engine) for the stealth UCAV program. It sounds like we might see its first full model flight with the KDE this year. There is also rumors floating around that there is approval for current Kaveri with a better AB to fly with one of the older Tejas LSP models. Sounds like incremental work to reduce weight will go on for some time until the required T/W ratio is achieved. I am going to write it now, but it will be written in the history books that DJTs dumbo tweets immensely helped boost the sluggish Indian MIC into a potent one
Confirmed report is Ghatak UCAV platform is in advanced stage of flying with Kaveri KDE - watch the latest interview with Dr Kota Ji (he calls them flying wing).
I think the erstwhile mig corp was merged to the sukhoi
No takeoff without A/B. Either too many milestones have been kept well hidden, or we are still a few years off. It will be interesting to wartime a scenario where 404 supplies stop abruptly and we are forced to integrate an underpowered, over weight Kaveri on to Tejas pronto/stat. Sadly we have neither the production capacity nor the imagination...
Certifying KDE (GTX-35VS) is a very important as of now. Flying the Ghatak with it will provide a lot a learning and I am sure some of the weight reduction strategies employed in the KDE will be further refined as the platform starts flight trails. Something is cooking with the Brahmos A/B section. There were news about its success with additional thrust of 28-30 kN. But all such news got suppressed when GE-414 potential deal was announced.fanne wrote: ↑01 Jun 2025 19:04 Certify the kde engine without afterburner. Basically that plane cannot take lca to fight (it does not have an afterburner) and has thrust of 48kn. 404 has 52 dry and 80 something wet. Lca pv-5 etc will be used to certify this engine, then it will be used in ghatak.
Certifying kde should help the normal Kaveri that has dry thrust of 52 and current wet stops at 73, which is being reworked with help of Brahmos corp to push is to 80 something.
Tejas is a platform to do certain missions which require certain weight. It assumed certain thrust was available : having a lesser TW ratio means either it can’t carry the required armaments reducing its effectivity - less A-A missiles as an example or it affects its performance in parameters such as time to target, turn ratios etc. Both can be fatal for the pilot … hence the comment on pilot safety.
Fanne ji, I'm in 100% agreement. Kinetic performance like speed and maneuveability though vital, is not everything in today's war. Speed of fighter design can't catchup with speed of missile or radar development, or speed of EW development. Beauty is it doesn't have to.
williams wrote: ↑04 Jun 2025 01:27 Here are some historical notes on Kaveri.
<snip>
2002 - +3 years IAF cancels plan to use Kaveri for Tejas (at this time there were blade issues and FADEC problems. Some Snecma help was sought, but nothing came to fruition.
2003 - F404 engine chosen for Tejas LSPs. Initial TD and LSPs were flown on F2J3 versions (of 79KN thrust class).
2004 - Kaveri failed High Altitude tests in Russia
2005-7 - GE came up with IN20 version of F404, of 84-85KN Thrust-class - which was selected for all future Tejas.
2010 - + 6 years - High altitude tests succeeded - Design dry thrust rating of 51KN achieved.
The engine weighed 1235 kg (improved from 1423 kg) - The engine could produce 70 - 75 kN, but IAF desired90-95kN - I think the requirement remained at 81-82KN (Wet Thrust), though F404-IN20 were already at 84KN level.
<snip>
2016 - GE delivers the last IN20 version (from an order of 75, incl F2J3s) and stops production of F404-IN20 due to lack of any further orders.
2021 - +5 years after seeing Snecma's true colors - DRDO Could manage some Tech breakthroughs.
1 Isothermal forging tech mastered for all five stages of HPC disks
2. Single-crystal casting tech achieved by DMRL
Well SC technology (second Gen SX, CMSX4) was already used in the Sakti engines a few years earlier - that got adapted for KDE usage maybe around 2021-22. Ofcourse, there's a world of diff between what gets used in Shakti vs what may have gotten into KDE.
2022 - DMRL - Nickel bas super-alloy SN 742 developed.
- Now, in the high altitude tests, the core engine achieved 48.5 kN (from the previous 46 kN)
2024 - Weight now reduced to 1180 kg - overall improvement in metallurgy, FADEC - K9+ standard
2024 - Brahmos 29 kN A/B section ready and K9+ can now produce
79 kN thrust (F404 thrust 78.7 KN - but 1024 Kg weight) - IN20 version produces ~85KN, but are non flat-rated
2025 - 49 kN thrust (expecting 52 kN),
T/W ratio 6.5 - (Need 8.0)
TET 2000 K (2300 K expected) - Since When? Frankly if they have been able to breach the 1500deg C TeT mark, that'd be brilliant
- New tech added Blisk design, bolt-less blade arrangement in the turbine, and Powdered metallurgy disk in HPT.
I doubt these have been implemented yet - as if they have been indeed achieved these, the weight would definitely be at sub-1T level. Yes the Fan may have gotten blisks, but I doubt the HPC stages (atleast the 1st three) have got blisks yet.
<snip>
Maityaji,maitya wrote: ↑04 Jun 2025 12:20
The engine weighed 1235 kg (improved from 1423 kg) - The engine could produce 70 - 75 kN, but IAF desired90-95
1 Isothermal forging tech mastered for all five stages of HPC disks
2. Single-crystal casting tech achieved by DMRL
Well SC technology (second Gen SX, CMSX4) was already used in the Sakti engines a few years earlier - that got adapted for KDE usage maybe around 2021-22. Ofcourse, there's a world of diff between what gets used in Shakti vs what may have gotten into KDE.
2022 - DMRL - Nickel bas super-alloy SN 742 developed.
- Now, in the high altitude tests, the core engine achieved 48.5 kN (from the previous 46 kN)
2024 - Weight now reduced to 1180 kg - overall improvement in metallurgy, FADEC - K9+ standard
K9+ can now produce
79 kN thrust (F404 thrust 78.7 KN - but 1024 Kg weight) - [
2025 - 49 kN thrust (expecting 52 kN),
T/W ratio 6.5 - (Need 8.0)
TET 2000 K (2300 K expected) - ]Since
Ofcourse, Theoretically yes doable - but practically, where's such a program (2 engine Tejas etc) in the first place - betw this mythical ORCA is anything but twin-engine Tejas, it's just de-navalised TEDBF (in the lines of Rafale-M -> Rafale-C program), if any that is.Cain Marko wrote: ↑04 Jun 2025 19:00Maityaji,
If current Kaveri is close to 50/80kgf at 1024kg weight, it is already close to baseline RD33. In fact wrt tet and weight, it's ahead.
https://en.m.wikipedia.org/wiki/Klimov_RD-33
Maybe it's time to stick it into a modified 2 engine Tejas/orca/tedbf airframe that's about 10 tons? That'll provide better twr than rafale and very close to Mig29, better than 1.0, quite respectable for 4 5 gen fighter.
They want foreign collab because they learned "foreign" is the only word that will move funds from GOI and commitment from Indian armed forces. Unless we launch a program like IGMDP to create a jet engine eco system, nothing will change.Prem Kumar wrote: ↑04 Jun 2025 23:18
I think even the GTRE wants foreign collaboration because they are too lazy to do this in-house
Jay wrote: ↑05 Jun 2025 00:35They want foreign collab because they learned "foreign" is the only word that will move funds from GOI and commitment from Indian armed forces. Unless we launch a program like IGMDP to create a jet engine eco system, nothing will change.Prem Kumar wrote: ↑04 Jun 2025 23:18
I think even the GTRE wants foreign collaboration because they are too lazy to do this in-house