HJT-36 Yashas Intermediate Jet Trainer: News & Discussion - 24 April 2019

SBajwa · Post by **SBajwa** » 30 May 2022 10:02

Rakesh is the best. Thank you brother.

Kersi · Post by **Kersi** » 20 Dec 2022 18:01

What is the latest status of our Sitara ?

YashG · Post by **YashG** » 20 Dec 2022 18:04

I saw HJT36 on a test sortie today at HAL.

@Mods - Is it kosher to report any test sorties at HAL here ?

Pratyush · Post by **Pratyush** » 21 Dec 2022 07:38

If it can be seen by general public. Then I don't see why this should be an issue.

ks_sachin · Post by **ks_sachin** » 21 Dec 2022 08:05

Pratyush ji,

Aam aadmi would not know difference between HJT and Su30.
But on BRF we can see and figure out which spin and stall teat has failed and how they dont meet GSQR.

Plus seeing is one thing but reporting it in anotjernmatter as per OSA.

MeshaVishwas · Post by **MeshaVishwas** » 02 Jan 2023 16:15

Nothing to do with the HJT-36 but just saw this old image from 1970 on the Kiran proto and wanted to share this but no active dhaagas on Kiran alive now.

Caption reads:

The HJT-16 second prototype displayed at Expo’70 in Osaka, which has the sliding canopy differed from production model.

Image Source: here

All the best to HJT-36, big shoes to fill.

Kersi · Post by **Kersi** » 03 Jan 2023 11:30

Isn't our Kiran "inspired" from Jet Provost ?

MeshaVishwas · Post by **MeshaVishwas** » 07 Feb 2023 16:31

^^
Couldn't find anything to support that claim.
Kiran is Sh. Raj Mahindra Ji's baby(Iirc, he also happened to be the Chief Designer of the Tejas pgm in initial days?)
Best person to answer would be Jagan gaaru.

Something special from the VayuSena here:

Operating beyond the Operator's limit!!
An enthralling lecture filled with experiences on IJT's spin testing was conducted by W/C Patel & W/C Awasthi from HAL
Our budding testers are now all set to take Kiran ac to its limits of Alpha,in the most thrilling phase of Spin testing

Link: here
Warning: Armchair flying like a kid expected after seeing the Kiran dancing.

Rakesh · Post by **Rakesh** » 13 Aug 2023 19:18

‘Incorrect assessment’ led to delays in development of HAL’s intermediate jet trainer, says CAG
https://theprint.in/defence/incorrect-a ... g/1710694/
11 August 2023

Govt had sanctioned Rs 180 crore for project in 1999. Improper engine selection had a cascading effect on design and development process of aircraft, says auditor.

Pratyush · Post by **Pratyush** » 13 Aug 2023 19:51

I don't particularly appreciate the CAG reports.

If an incorrect selection of engine led to delays?

Was it known in 1999 that the engine being selected was a total failure?

Or would be a total failure in the future?

The answer to above is a resounding NO.

But the CAG is not bothered by such minor distraction.

Just that aircraft was delayed.

prashantsharma · Post by **prashantsharma** » 14 Aug 2023 10:09

CAG is able to identify one issue (the engine selection) because it was easy to pickup because of all that has been written about it in media in the past. CAG won't be able to identify the other reasons which are far more technical such as the aerodynamic design, aerofoil design, design of controls, control surfaces, ease of flying, forces, drag, moments, engine performance, fuel consumption, CoG, weights etc. which are also contributing to the failure of the project. Yes I say failure because I don't see it being inducted into the airforce. It hasn't even been offered to IAF yet for trials.

prashantsharma · Post by **prashantsharma** » 14 Aug 2023 10:43

Having said this, I am not sure if deciding to change the engine midway through design or flight testing due to problems or availability of a better / new option is really an audit issue? Likewise for all the other design and technical choices.

HAL would have been content to let CAG chew on its engine bone and not poke it's nose into all the other issues that plague this aircraft.

Rakesh · Post by **Rakesh** » 06 Oct 2023 18:59

https://x.com/AviationWall/status/17080 ... 37492?s=20 ---> Say cheez. A master shot by @zone5aviation of the HAL IJT HJT-36.

ramana · Post by **ramana** » 06 Oct 2023 21:53

prashantsharma wrote: ↑14 Aug 2023 10:43 Having said this, I am not sure if deciding to change the engine midway through design or flight testing due to problems or the availability of a better / new option is really an audit issue? Likewise for all the other design and technical choices.

HAL would have been content to let CAG chew on its engine bone and not poke it's nose into all the other issues that plague this aircraft.

I know it may sound strange but financial audit reveals and often supports the technical progress report.
When one sees funds being spent and the technical progress report does not explain its time for a deep dive.
Often financial audit gives an X-ray while tech Progress is like a surface scan.
To me the project delay was due to the inadequate engine is what it is saying.

BTW, the article gives an excellent example of the Earned Value Management (EVM) process.
The project was sanctioned in 1999 for Rs 180 crores.
Project complete in March 2022 for Rs 710 crores
Cost over run= 710/180= 3.94

Schedule Overun. They don't give when the original project was to be complete but in 2005 ie 5 years after sanction, they ordered a new engine.
Will take that as the estimated project completion year.
So Schedule overrun is 2022-2005= 17 years(estimated)

They ran into technical problems as the French engine was underpowered for the Sitara.
The new engine took 4 years to arrive. Adds more delay.
Then they find the engine is too powerful and they need to make design changes.

Here it begs the question no one sought fit to use the 4 years to figure out the spin calculations for the new engine.

The report concluded that the HAL should have anticipated the impact of integrating a new engine at a later stage and taken timely measures to resolve issues pertaining to spin and stall characteristics.

Very accurate comment.

BTW, WIKI says: https://en.wikipedia.org/wiki/HAL_HJT-36_Sitara

All production models will use the more powerful NPO Saturn AL-55I engine with about 16.9 kN of thrust, as stipulated by the 2005 air staff requirements from the Air Force.

A low-cost way to learn program management.

The CAG should have mentioned the change in Air Staff requirements in 2005.

fanne · Post by **fanne** » 06 Oct 2023 22:07

One other aspect here that can be further looked is can we develop a similar engine in house. Tech wise, it is 2 generations behind what we have achieved with Kaveri (and at least a generation behind the Jags engine that we manufacture in house). Our issue with Kaveri is mainly in the afterburner section and this engine has none (none is needed for trainer). We should start making these low tech engine ourselves. These engines, once developed good easily serve for 100 years (The HJT engine is from 1969). Yes it will take effort, but the same ecosystem can be leveraged to make so many low tech engines and also support Kaveri/Ganga type initiative. In crawl, walk and run analogy, this is the walk part while Kaveri is the run part.

Rakesh · Post by **Rakesh** » 15 Mar 2024 20:34

S-3854 flew yesterday, as per HVT Sir.

https://x.com/Rethik_D/status/1768576451778142715?s=20 (This link indicates the differences from the earlier prototype).

https://x.com/hvtiaf_bharat/status/1768 ... 74330?s=20 ---> picture @hari_hawker

Rakesh · Post by **Rakesh** » 15 Mar 2024 22:23

Rakesh wrote: ↑15 Mar 2024 20:34 S-3854 flew yesterday, as per HVT Sir.

https://x.com/Rethik_D/status/1768576451778142715?s=20 (This link indicates the differences from the earlier prototype).

https://x.com/hvtiaf_bharat/status/1768 ... 74330?s=20 ---> picture @hari_hawker

This was tweeted on 15 Feb 2024

https://x.com/alpha_defense/status/1758 ... 27336?s=20 ---> HAL is in process of getting this certified.

- All the issues resolved
- Testing

srai · Post by **srai** » 28 Mar 2024 17:56

Old news … I had missed this bit!

https://x.com/zone5aviation/status/1479 ... 76770?s=20

Angad Singh on Jan 7, 2022

A good day for the
@HALHQBLR
HJT-36 ‘Sitara’ — Gp Capts HV Thakur and A Menon carried out six turn spins to either side. HAL says this was the last major item remaining in the test campaign.

Rakesh · Post by **Rakesh** » 05 Oct 2024 22:57

https://x.com/hvtiaf_bharat/status/1841655885422358556 ---> The bigger trainer is perfect for armed roles.

https://x.com/Jagz1975/status/1841674317396115563 ---> Definitely Sir ! I was thinking more on the lines of an armed PC-9 aircraft. That being said, an armed HJT-36 ( with crocodile or eagle camo on the nose cone) in a tank busting and ground attack role would be awesome to watch.

https://x.com/hvtiaf_bharat/status/1841675199684739579 ---> Armed HJT-36 is much much much more awesome than a light prop basic trainer carrying some load in place of fuel. No comparison.

VinodTK · Post by **VinodTK** » 11 Jan 2025 03:09

HAL's HJT-36 Sitara Trainer Overcomes Hurdles Following Design Overhaul, Full-Scale Production of 85 Aircraft for IAF Expected by 2028

srai · Post by **srai** » 11 Jan 2025 09:13

^^^
Next is the Indian engine as well.
HAL HTFE-25

uddu · Post by **uddu** » 11 Jan 2025 12:04

^^^
The next stumbling block will be change in requirement
1) The weight of engine need to be reduced from 350 kg to 315 kg to meet AL-55 weight
2) HAL HTFE-25 is too powerful and hence cannot be used on HJT-36

In reality the Armed variant may need HTFE-25

Rakesh · Post by **Rakesh** » 04 Feb 2025 22:04

https://x.com/hvtiaf_bharat/status/1886387063513022813 ---> Snap of the day

Rakesh · Post by **Rakesh** » 04 Feb 2025 22:04

https://x.com/FighterPiloting/status/18 ... 2526095855 ---> Loving the fin flash and heartbeat of HJT-36

srai · Post by **srai** » 05 Feb 2025 01:25

^^^
Counting the number of protrusion “rectifications” to the original design:
* four on the wings
* two below engine area
* two on side tails below
* two on tail

(The whole tail section was redesigned some while back).

Kartik · Post by **Kartik** » 10 Feb 2025 18:10

HJT-36 'Sitara' renamed as HJT-36 Yashas

Twitter link

suryag · Post by **suryag** » 11 Feb 2025 01:44

IR's video was awesome on the changes that went in. HVT should get Shaurya Chakra very frankly for recovering that plane.

fanne · Post by **fanne** » 11 Feb 2025 05:38

Link to IR video please

V_Raman · Post by **V_Raman** » 11 Feb 2025 06:46

Is there any video of HJT-36 doing spin tests?

suryag · Post by **suryag** » 11 Feb 2025 09:13

V_Raman wrote: ↑11 Feb 2025 06:46 Is there any video of HJT-36 doing spin tests?

https://youtu.be/1r-O7QGwScM

ernest · Post by **ernest** » 11 Feb 2025 09:29

If things hold steady, HVT will turn out to be for fixed wing a/c, what President Kalam was for missiles, and E Shreedharan for Railways/Metro in India. The key person that reenergizes the ecosystem, and brings all the other experts to work together with their vision. There are a lot of smart and capable folks in our aerospace ecosystem, but it takes someone like Kalam to get projects pass the hurdles, navigating the political and bureaucratic hurdles, and keeping the scientists motivated.

I remember, how bad things looked back in 2016 for not just HJT-36, but for our aircraft ecosystem overall. HVT apart from his test pilot duties, took on the job of educating the ecosystem, through his interviews and posts. All the while, also pushing for futuristic and bold projects that led to CATS. I still remember his interview on what was then LCA SPORT. Really ahead of its time.

Khalsa · Post by **Khalsa** » 11 Feb 2025 14:53

ernest wrote: ↑11 Feb 2025 09:29 I still remember his interview on what was then LCA SPORT. Really ahead of its time.

Bingo !!

We need to pitch that for the Naval Tejas Mk1B version for acting in multiple role to augment the Naval Squadrons.
Our carriers need to punch well above their weight.

My 2 cent pitch here
viewtopic.php?p=2639213#p2639213

Rakesh · Post by **Rakesh** » 12 Feb 2025 20:55

https://x.com/livefist/status/1889592904118661354 ---> Indian Air Force asks HAL for proposal on leasing four HJT-36 Yashas stage-2 trainers for evaluation. The four will be LSP airframes upgraded to the "Yashas" standard. Photo of India’s Civil Aviation @RamMNK after a Yashas flight with @hvtiaf_bharat at Aero India 2025.

Avinandan · Post by **Avinandan** » 13 Feb 2025 00:42

suryag wrote: ↑11 Feb 2025 09:13 https://youtu.be/1r-O7QGwScM

Gurus, I am referring to the initial 10 minutes talk by Indranil Saar.

I have few rants:
1. About 2 decades ago, HAL had good references to copy/inspire from IJT trainers to design upon. All the designs have tail well extended beyond engine . Refer viewtopic.php?p=2346833#p2346833. Yet they made that design flaw.

2. Almost all the IJT in that weight category had 16Kt based engine, yet they those Larzac 04-H20. Considering they the scope creep and future proofing they should have gone designed with 17kt or more in the begining itself.

3. Compare specs with other similar examples . E.g. FMA IA-63 Pampa; it is behind is almost all parameters.

4. I hate those air intakes. None of the modern IJT trainers have it ( except for few AJT examples like Aero L-59 Super Albatros or Alka). I believe there is some merit in having air intakes like below which HAL discarded after earlier studies.

courtesy: Wikipedia

Many years back, I had enquired Indranil Saar on why they chose the current air intake design; he told HAL had experience from Kiran trainer which has similar intakes. IMHO it is bad design. Trainers are used and do more runs than an average fighters, hence maintenance hours of them is also higher. Cleaning and Maintaining airintake much lower to ground (near hands reach) like above is much easier than current intakes which are situated pretty high ( Kiran doesn't suffer from this problem as overall aircraft is much height is much less due to side by side seating arrangement)

After 24 or so long years, I think I would have preferred to have a copied pampa with composites and a better engine and avionics etc.

Rakesh · Post by **Rakesh** » 14 Feb 2025 06:26

https://x.com/hvtiaf_bharat/status/1889965309421130094 ---> Yashas & Felon.

Rakesh · Post by **Rakesh** » 14 Feb 2025 21:53

https://x.com/HALHQBLR/status/1890330486200791436 ---> The Chief of Air Staff, Air Chief Marshal AP Singh flew HAL’s newly upgraded HJT 36 'Yashas' jet trainer @AeroIndiashow. The sortie lasted 35 minutes. The CAS was demonstrated the capabilities of the jet trainer, its systems and its improved departure resistance characteristics. He was also given a presentation on the viability of the platform, current status of development and future certification plans.

Rakesh · Post by **Rakesh** » 14 Feb 2025 21:55

https://x.com/hvtiaf_bharat/status/1890359758378414117 ---> Showcasing India's vibrant colors and strong spirit. Hindustan Jet Trainer YASHAS @AeroIndiashow 2025. Photo: Anuraj J Pillai.

prashantsharma · Post by **prashantsharma** » 15 Feb 2025 12:58

Rakesh wrote: ↑12 Feb 2025 20:55 https://x.com/livefist/status/1889592904118661354 ---> Indian Air Force asks HAL for proposal on leasing four HJT-36 Yashas stage-2 trainers for evaluation. The four will be LSP airframes upgraded to the "Yashas" standard. Photo of India’s Civil Aviation @RamMNK after a Yashas flight with @hvtiaf_bharat at Aero India 2025.

Chalo, we arent seeing a final product being serial produced before 2030.
The Kiran replacement is the next shit show on the cards. Sit back and grab a beer and enjoy the show.

Khalsa · Post by **Khalsa** » 16 Feb 2025 15:41

I have a feeling it could go the other way. But yeah a beer is on the cards.

Rakesh · Post by **Rakesh** » 20 Feb 2025 21:53

https://x.com/hvtiaf_bharat/status/1892199820481413621 ---> Neat Forward\\