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

[Rakesh]

HJT-36 Sitara - Intermediate Jet Trainer

Thanks to BRF Member, Indranil for all his help.

Acronyms:
• PT: Prototype
• LSP: Limited Series Production

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HAL’s HJT-36 Intermediate Jet Trainer Rises From The Ashes: A Detailed Look
http://delhidefencereview.com/2019/04/2 ... iled-look/
By Indranil Roy

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Milestones Achieved
• PT-01 (S3466) conducted her first flight on 07 March 2003. The trainer was piloted by Squadron Leader Baldev Singh (retd).

• PT-02 (S3474) conducted her first flight on 26 March 2004.

• A redesigned prototype aircraft (Serial # S3854) flew on 17 April 2019. The trainer was piloted by Wing Commander Pratyush Awasthi (retd) and Group Captain Subroto Chaki.

Production Run
Construction Number ... Serial Number ... Aircraft First Flight ... Pilot(s)
• PT-01 ... S3466 ... 07-Mar-2003 ... Squadron Leader Baldev Singh (Retd)
• PT-02 ... S3474 ... 26-Mar-2004 ... Not Known

Construction Number ... Serial Number ... Aircraft First Flight ... Pilot(s)
• LSP-01 ... S3851 ... 01-Jan-2010 ... Not Known
• LSP-02 ... S3852
• LSP-03 ... S3853
• LSP-04 ... S3854 ... 17-Apr-2019 ... Wing Commander Pratyush Awasthi (Retd) and Group Captain Subroto Chaki
• LSP-05 ... S3855
• LSP-06 ... S3856
• LSP-07 ... S3857
• LSP-08 ... S3858
• LSP-09 ... S3859
• LSP-10 ... S3860
• LSP-11 ... S3861

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Accidents:

• 07 February 2007: PT-1 (S3466) was damaged when she veered off the runway while taking off for a flight display on the inaugural day of Aero India 2007. Aircraft was piloted by Squadron Leader Baldev Singh (Retd). The pilot survived the incident.

• 04 February 2009: PT-2 (S3474) belly landed at Yelahanka before the commencement of Aero India 2009. Aircraft was piloted by Squadron Leader Baldev Singh (Retd) and Wing Commander C Subramaniam. Both pilots survived the incident.

• 28 April 2011: PT-1 (S3466) crashed while attempting a difficult manoeuvre. Aircraft was piloted by Wing Commander Shailendra Patra of the IAF's Aircraft & Systems Testing Establishment (ASTE) and Group Captain Anant Mathur (Retd). Both pilots ejected and survived the incident, but the aircraft was a write-off. Visit this link for more info on this crash ---> https://aviation-safety.net/wikibase/wiki.php?id=121985

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Design Specifications
• Crew: Two
• Length: 11 metres
• Wingspan: 10 metres
• Height: 4.4 metres
• Wing Area: 17.5 square metres
• Gross Weight: 4,250 kg
• Maximum Take Off Weight: 5,400 kg
• Fuel Capacity: 917 kg
• Engine: Prototype aircraft have one Senecma Larzac 04-H20 non-afterburning turbofan @ 14.12 kN (3,170 lbf) thrust and production aircraft have one Saturn/UMPO AL-55I non-afterburning turbofan @ 21.6 kN (4,900 lbf) thrust.

Performance
• Maximum Speed: Mach 0.75 (750 km/h)
• Range: 1,000 km
• G Limits: +7g / -2.5g
• Service Ceiling: 30,000 feet

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First Prototype - Registration # S3466



Redesigned Prototype - Registration # S3854

[Rakesh]

Starting a new thread on the HJT-36 IJT for two reasons;

1) First flight of the re-designed HJT-36 which requires detailed discussion best suited in its own thread.

2) IR Saar's excellent article which is a perfect launch pad for a detailed discussion.

Please review the info above and provide moderators with updated and/or corrected info. I pulled everything from web searches, but some info is incomplete. If you have info to add above, please let us know.

Post Away and Enjoy!

Also, please provide inputs on the following queries;

1) Is it safe to assume that redesigned prototype will be designated PT-3? Logic tells me it will, but advise please.

2) Wiki Chacha says four LSPs were built. Is there any info on the serial numbers and first flights?

P.S. ---> Mods, please do not move posts (on the IJT) from other threads into this one, as the time stamp of the earlier post will move the first post in this thread further down. Let us start fresh and you can quote (as I did with JTull's post below) from another thread, into this one.

[Rakesh]

13 IJTs have been built to date!

Quick google only shows only following serial nos.

S3466
S3474
S3851
S3854

What is source info on the 13 built IJTs?

I am assuming S3851 is one of the LSPs, as the first two were PT aircraft. Please advise.

[ramana]

Rakesh, Good job!

Also people please put info on the jet engine here only for sake of completeness.

[Rakesh]

Thank you and here you go Ramana-ji....

Senecma Larzac 04-H20
https://en.wikipedia.org/wiki/SNECMA_Turbomeca_Larzac

NPO Saturn AL-55
https://en.wikipedia.org/wiki/NPO_Saturn_AL-55

[ramana]

Also any data on the HTFE-25 engine for that will be used to power this plane.

[Rakesh]

A google search pulled up this article from last July. The latest info, AFAIK. The article was updated in July 2018, but Manohar Parrikar had left the Defence Ministry in March 2017. The late Minister's visit occurred on 27 February 2017, based on the info in the article. Thanks.

Boost for 'Make in India': HAL's 25 kN aero engine completes inaugural run; can be used for trainer aircraft
https://economictimes.indiatimes.com/ne ... 173767.cms

15 July 2018



In a boost for India, the inaugural run of the core of 25 kN indigenous Aero Engine (Hindustan Turbo Fan Engine - HTFE 25) was successfully completed in the presence of Defence Minister Manohar Parrikar at HAL's Engine Division on Monday. Also known as the Hindustan Turbo Fan Engine (HTFE-25), it can be used for basic, intermediate and advanced trainer aircraft. The engine can also be used on business jets and five ton weight class aircraft in single engine configuration and on aircraft of up to nine ton weight class with twin engine configuration.

Parrikar also launched the design and development project of Hindustan Turbo Shaft Engine (HTSE-1200) which can be used for helicopters. The HTSE-1200 can be used for helicopters of 3.5 ton class in the single engine configuration (e.g. LUH) and for 5 to 8 ton class in twin engine configuration (e.g. ALH, LCH). The engine develops a power of 1200 kW at sea level and can operate up to an altitude of 7 km. This project too is undertaken by HAL with its internal resources with an aim of developing the capability of indigenous design and development of turboshaft engines. Complimenting HAL for undertaking these projects, Parrikar said all out efforts should be made to achieve maximum in the aeronautical engineering with active participation of HAL and the private sector together.

"The recent expansion of activities in the aerospace sector as seen in HAL and has potential to turn India into aerospace manufacturing hub. The country would need 4000 to 6000 helicopter engines in the coming years and efforts of HAL to in this direction needs to be appreciated," Parrikar said. T Suvarna Raju, CMD of HAL said successful running of the 25 kN engine is one of the major mile-stones achieved by the company in its platinum jubilee year contributing to Make-in-India efforts of the government. "Aero Engine Research & Design Centre (AERDC), HAL, Bengaluru had taken up the Design and Development of a 25 kN thrust class turbofan engine for basic military trainer aircraft. HAL used its internal resources with an aim of producing indigenously designed and developed aero engines in a time frame of six years beginning from 2013. In the first phase of the programme, the design of the full engine and manufacture and testing of the technology demonstrator of the core engine are covered. In the subsequent phases the manufacture and testing of the full engine will follow," the press release said.

[ramana]

Thanks.

[Rakesh]

https://twitter.com/zone5aviation/statu ... 9073521664 ---> After a lengthy series of modifications HAL’s HJT-36 intermediate jet trainer (IJT) is back airborne. The return to flight was piloted by Wing Cdr P Awasthi (left) and Group Captain S Chaki.

[Rakesh]

https://twitter.com/SJha1618/status/1118779913006239744 ---> The Indian Air Force needs an Intermediate Jet Trainer. The two-stage training paradigm implemented as a stop-gap measure will not suffice. Let's hope HAL has indeed managed to solve the spin-issue with the HJT-36 Sitara which has resumed flight-testing.

https://twitter.com/SJha1618/status/1118779719992762368 ---> If the resurrected HJT-36 proves successful, it can also have a future as a light strike/ armed reconnaissance aircraft.

[Rakesh]

Also, please provide inputs on the following queries;

1) Is it safe to assume that redesigned prototype will be designated PT-3? Logic tells me it will, but advise please.

2) Wiki Chacha says four LSPs were built. Is there any info on the serial numbers and first flights?

Answered both my own queries and first post has been updated ---> https://www.facebook.com/Scramblemagazi ... 451775638/

[Rakesh]

A wallpaper sized photograph of the redesigned HJT-36 (LSP-4) after her first flight on 17 April 2019.

Picture will take long to load for folks with slow internet connections. So just posting the link below.

https://hal-india.co.in/Common/Uploads/ ... %20PIC.JPG

I got the photograph from this HAL press release --->

HAL Re-Commences Flight Testing of Modified Intermediate Jet Trainer (HJT 36)
https://hal-india.co.in/HAL%20Re-Commence/ND__261

[JayS]

Also any data on the HTFE-25 engine for that will be used to power this plane.

https://twitter.com/nileshjrane/status/ ... 4601576448

[Rakesh]

Beautiful JayS, just beautiful. Gold mine of info. You rock boss!

[JTull]

13 IJTs have been built to date!

Quick google only shows only following serial nos.

S3466
S3474
S3851
S3854

What is source info on the 13 built IJTs?

I am assuming S3851 is one of the LSPs, as the first two were PT aircraft. Please advise.

Last para of IR's DDR article.

[maitya]

Also any data on the HTFE-25 engine for that will be used to power this plane.

https://twitter.com/nileshjrane/status/ ... 4601576448

Interesting, really really interesting ...
HTFE TET: 1450 deg C but using equiaxed HPT blades (Wow!! in fact double Wow!!). Also OPR of 20 is respectable (but 27 would have been the WoW factor).

HTSE: Uses SCB (but doesn't say the TET achieved there) - assuming the TET is 1550deg C (one can have license to dream, right ), one wonders why didn't they "port" it to HTFE HPT. Surely if SCB HPT blades are mastered, vanes (diff metallurgy etc) wouldn't be too tough to achieve, right?

What JayS needs to find out (if possible) is, are they anywhere wrt
i) any CMC (SiC/SiC based) usage HPT shrouds and vanes
ii) any CMC (again SiC/SiC based) for A/B flaps
iii) any TiAl based later (say 5th and maybe 4th as well) HPC stage blades
iv) Carbon Fiblre based LPC

i) and ii) above as HAL already uses DMLS for manufacturing HPT of HTFE-25 while MIDHANI has had 300KW (and also 150KW) EBM furnaces from 2015 onward.

[Neela]

....................HTFE-25.....................................Al-55

Thrust ......... 25kN Dry, close to 40kN wet.........17.26 kN
SFC .............0.71 kg/kgf.hr...........................0.69 kg/kgf.hr
T/W ratio .......5.66 .....................................5.58
MFR ..............43 kg/s.................................28kg/s
BPR ..............0.5.......................................0.515
OPR ..............20.43....................................17.5
Max TET ........1450 K...................................1445 K
Max Op alti ....11km.......................................
Relight envlp ..0-9 km.....................................
Weight ...........450kg...................................315kg
Config ...........3 LPC - 5 HPC - 1 HPT - 1 LPT ........3 LPC - 5 HPC - 1 HPT - 1 LPT


sourced from various places.

[maitya]

^^ Neelaji, is the HTFE weight of 450kg correct (even JayS mentions it) ... asking as I have seen a weight of 350Kg mentioned at quite a few places.

Another point is, the bulleted-points that I mentioned in my previous post, all would help reducing the weight (and few other things as well), quite a bit.

[Prasad]

HAL info board at defexpo and ai mention 350kgs.

[Aditya_V]

Any chance this HTFE engine can make it as part of the Jaguar upgrade?

[Snehashis]

HAL info board at defexpo and ai mention 350kgs.

https://www.flickr.com/photos/delhidefe ... 126291597/

[Rakesh]

What is source info on the 13 built IJTs?

I am assuming S3851 is one of the LSPs, as the first two were PT aircraft. Please advise.

Last para of IR's DDR article.

Thanks JTull.

IR Saar, is there any source info on these 13 IJTs? Any serial numbers?

[Rakesh]

Any chance this HTFE engine can make it as part of the Jaguar upgrade?

By the time the engine will be certified, it will be too late for the Jaguar.

[Indranil]

Rakesh,

No source other than chaiwalla and paanwallas. HAL stopped production after producing the 11th LSP (out of a 12 LSP order).

In this picture for example you can see tail numbers 3858 and 3859 which are the 8th and 9th LSP.

[Rakesh]

Rakesh,

No source other than chaiwalla and paanwallas. HAL stopped production after producing the 11th LSP (out of a 12 LSP order).

In this picture for example you can see tail numbers 3858 and 3859 which are the 8th and 9th LSP.

That is actually perfect and helps a lot.

So if S3851 was LSP-1, S3854 was LSP-4, S3858 was LSP-8 and S3859 was LSP-9, it means we have the sequence of serial numbers of the LSPs starting from S3851 to S3861. That is excellent which I will add in the first post as reference. Please give my pranaams to your chaiwallas and paanwallas for this info. Deeply appreciated for a serial # follower

Would you know or can you find out from them if any of these LSPs actually flew? The dates would be too much to ask, but I can wish

We know S3851 flew on 01 Jan 2010 and S3854 (the re-designed prototype) flew on 17 Apr 2019.

Thus 11 LSPs + 2 PTs = 13 aircraft built to date. Fantastic!!

[Neela]

HAL info board at defexpo and ai mention 350kgs.

^^ Neelaji, is the HTFE weight of 450kg correct (even JayS mentions it) ... asking as I have seen a weight of 350Kg mentioned at quite a few places.

Another point is, the bulleted-points that I mentioned in my previous post, all would help reducing the weight (and few other things as well), quite a bit.

Yes, 350 kgs is seen on the HAL display boards.

[Neela]

Corrected weight

....................HTFE-25.....................................Al-55

Thrust ......... 25kN Dry, close to 40kN wet.........17.26 kN
SFC .............0.71 kg/kgf.hr...........................0.69 kg/kgf.hr
T/W ratio .......5.66 .....................................5.58
MFR ..............43 kg/s.................................28kg/s
BPR ..............0.5.......................................0.515
OPR ..............20.43....................................17.5
Max TET ........1450 K...................................1445 K
Max Op alti ....11km.......................................
Relight envlp ..0-9 km.....................................
Weight ...........350kg...................................315kg
Config ...........3 LPC - 5 HPC - 1 HPT - 1 LPT ........3 LPC - 5 HPC - 1 HPT - 1 LPT

[V_Raman]

If they can get this engine certified at 350kg and 25kN dry thrust - it will be a world beater!

[rrao]

Kiran MK-II and Sitara have lot of similarities as far as air intakes,wing structure is concerned..Kiran already has wing-fences incorporated, which is now addition to modified sitara...Its very relieving to note that IJT has bee revived.... IJT also has similarities with Argentina's PAMPA jet trainer....but with wings above the intakes..IR saar which config is better ...wings above intakes are below? and also kiran wings droop up compared to IJT.. since KIRAN MKII is proven as SKAT ,why dont we resurrect KIRAN with HTFE-25(if it fits) and Glass cockpit and new avionics..With cannon it can become a mini A-10.. JMT

[suryag]

Sirs what is exactly the difference between sitara and hawk ? Why can’t sitara be used for third part of training ? The difference that I see is hawk has more powerful engine but if htfe25 gets installed then sitara can give similar performance as hawk ? What am I missing here ?

[rrao]

IJT SITARA sisters!!!

[Indranil]

Kiran MK-II and Sitara have lot of similarities as far as air intakes,wing structure is concerned..Kiran already has wing-fences incorporated, which is now addition to modified sitara...Its very relieving to note that IJT has bee revived.... IJT also has similarities with Argentina's PAMPA jet trainer....but with wings above the intakes..IR saar which config is better ...wings above intakes are below? and also kiran wings droop up compared to IJT.. since KIRAN MKII is proven as SKAT ,why dont we resurrect KIRAN with HTFE-25(if it fits) and Glass cockpit and new avionics..With cannon it can become a mini A-10.. JMT

shoulder mounted or low mounted wings by themselves don't say much. Kiran will shred to pieces if you mount a cannon on it.

Sirs what is exactly the difference between sitara and hawk ? Why can’t sitara be used for third part of training ? The difference that I see is hawk has more powerful engine but if htfe25 gets installed then sitara can give similar performance as hawk ? What am I missing here ?

Suryag, we don't want to make an IJT as capable as an AJT. Think about the poor trainee pilot. step by step.

I want the Indian's AJT to be single-engined AB-variant of HTFE. If it has the same mass as a Hawk, you are speaking of an aircraft between a Hawk and a SPORT-class LIFT.

[Indranil]

IJT SITARA sisters!!!

You forgot the JL-8/K-8, and the upcoming M-345 HET, SR-10.

But, my favourite in this sector is the Super Galeb.

[JayS]

https://twitter.com/nileshjrane/status/ ... 4601576448

Interesting, really really interesting ...
HTFE TET: 1450 deg C but using equiaxed HPT blades (Wow!! in fact double Wow!!). Also OPR of 20 is respectable (but 27 would have been the WoW factor).

HTSE: Uses SCB (but doesn't say the TET achieved there) - assuming the TET is 1550deg C (one can have license to dream, right ), one wonders why didn't they "port" it to HTFE HPT. Surely if SCB HPT blades are mastered, vanes (diff metallurgy etc) wouldn't be too tough to achieve, right?

What JayS needs to find out (if possible) is, are they anywhere wrt
i) any CMC (SiC/SiC based) usage HPT shrouds and vanes
ii) any CMC (again SiC/SiC based) for A/B flaps
iii) any TiAl based later (say 5th and maybe 4th as well) HPC stage blades
iv) Carbon Fiblre based LPC

i) and ii) above as HAL already uses DMLS for manufacturing HPT of HTFE-25 while MIDHANI has had 300KW (and also 150KW) EBM furnaces from 2015 onward.

Saar Kelvin not deg C.

IIRC, HPC are Ti64. Made by Wipro 3D at least some of them if not all.

[maitya]

Interesting, really really interesting ...
HTFE TET: 1450 deg C but using equiaxed HPT blades (Wow!! in fact double Wow!!). Also OPR of 20 is respectable (but 27 would have been the WoW factor).

HTSE: Uses SCB (but doesn't say the TET achieved there) - assuming the TET is 1550deg C (one can have license to dream, right ), one wonders why didn't they "port" it to HTFE HPT. Surely if SCB HPT blades are mastered, vanes (diff metallurgy etc) wouldn't be too tough to achieve, right?
<snip>

Saar Kelvin not deg C.

IIRC, HPC are Ti64. Made by Wipro 3D at least some of them if not all.

Thank a lot ...

So age has caught up with some of us, I guess!!


Or maybe some of us are so "deprived" of good news , any good news actually, on indigenous Turbofan tech etc, even a small tid-bit and we practically start hallucinating about stuff which are simply not there (e.g. 1450deg C TeT with equiaxed blades).

And go onto full-fledged day-dreaming mode of assuming 1550deg C TeT etc with just a mention of SCB etc.
While reality is 2nd Gen SCB and a contemporary DS (like in Kabini), both with fairly contemporary thermal-mgmt tech like TBC and internal cooling etc, would provide ~50-75deg C (max 100deg C for giants like GE et all) TeT advantage.
Ditto wrt >27 OPR etc.

Anyway, Thanks a lot ... you saved quite a bit of my effort, as I's buoyed-up enough to dust-off my old-excel-based-turbofan anal-sis etc and start comparing Thermal efficiency etc.

However, would still applaud HAL for atleast trying and actually embracing contemporary mfg practices etc, and coming close to have an usable product etc.

[Kartik]

Read the full article at:

HJT-36 flight test resumption renews hope for AL-55I engine

....

Working out remedies to improve spin characteristics for an otherwise promising and mature design required extensive wind testing on scale models. During the past three years, HAL also addressed issues of excessive airframe weight, while its program partners in Russia had more time to improve the engine that powers the HJT-36. Back in 2005, NPO Saturn won a $300 million Indian contract to develop the AL-55I, a version of the baseline AL-55 customized to match the airframe. Three engine examples were shipped in December 2008, including one for the first prototype, which was refurbished and flew in May 2009.

Replacing the previously fitted Snecma Turbomeca Larzac 04-30 (04-H-20) engine reduces fuel burn by 10- to 13 percent through higher turbine temperatures (by 15 to 45 degrees C) while keeping the same mass flow (at 28kg/62 pounds per second). The maximum thrust increase from 14.24 to 17.27 kN (3,200 to 3,880 pounds) is important in view of airframe overweight issues, and is necessary to meet the customer requirements for rate-of-climb, ceiling, and weapons load. Developing the AL-55I required considerable changes to the baseline design, chiefly to reduce weight by more than 50 kg (110 pounds). This was necessary to match the respective figure for the 295-kg (650-pound) Larzac, and thus eliminate the need to re-balance the airframe and onboard equipment for center-of-gravity position.

Russia insists that the 2005 contact was fulfilled in 2013, when AL-55I pre-production specimens demonstrated a 300-hour lifetime. Further plans called for the extension to 600, and then to over 1,200 hours, the latter being an Indian Air Force requirement. According to developers, the engine’s cold section is designed to withstand 6,400 hours and the hot section 4,000 hours. So far, however, Russia has delivered only about 20 engines, due to the HJT-36 production program being halted by the spin issue.

For NPO Saturn and its patron United Engine Corporation, the IJT program resumption means a boost to the AL-55 effort. If the engine goes into quantity production, unit costs would decrease to a level affordable for more foreign and local customers. Russian aircraft makers are yet to place their orders, with the AL-55 fit to power the 3,100-kg (6,830-pound) SAT SR-10 jet trainer with forward-swept wings and the 2,300-kg (8,380-pound) Argument UCAV derived from it. With more than 85 flights performed on a single SR-10 prototype, the project won a positive MoD assessment, but experiences financial issues related to establishing serial production. Apart from SAT, there are some other Russian companies interested in the AL-55 version generating 17.35 to 19.6 kN (3,900-4,400 pounds') thrust at military power and up to 29.4 kN (6,600 pounds') thrust when fitted with an afterburner.

[Indranil]

Nice. This allows good growth potential of IJT.

[ramana]

I would propose get the SItara flight testing completed and order the first batches with the AL-55 and meantime accelerate the HTFE-25 engine certification and cut in by SP-30.

[Haridas]

.. since KIRAN MKII is proven as SKAT ,why dont we resurrect KIRAN with HTFE-25(if it fits) and Glass cockpit and new avionics..With cannon it can become a mini A-10.. JMT

What will be mini-A10 fate in current / real war front that will have many man portables Anti aircraft missiles?

Perhaps we can send the mini-A10 back to 1971 Longewal battle or 1965 Khemkaran, just need time travel machine to be made by HAL. I would add to that list my wish to add 4 guns of Hunter to make the resurrected Kiran become a mini-Canberra

I would say while at it , in time travel back to 1970's we can have HAL make 90 more extra airframes, so that in 2020 they can be use those airframe with glass cockpit and HTFE-25. + 4x 30mm guns.

Oh well I stop my craze here.

[Neela]

I would propose get the SItara flight testing completed and order the first batches with the AL-55 and meantime accelerate the HTFE-25 engine certification and cut in by SP-30.

This leads to an interesting question....what is the business case for HTFE? Yes, I know we have heard of trainers and business jets. But Jaguar is on its way out. And trainer numbers are not high (?). Business jets is just a pipe-dream for now.