Why India Sticks With Modernized AL-31FP Engine Over AL-41F-1S for Su-30MKI Upgrade, Despite Latter Having Better Performance

In a move that has raised some eyebrows in the international defence community, India has opted to stick with modernized AL-31FP engines for its Su-30MKI "Super-30" upgrade program, despite Russia's state-owned arms exporter, Rosoboronexport, advocating for the superior AL-41F-1S engine.

While the AL-41F-1S, also known as the article 117S, boasts an 18% increase in thrust generation, improved fuel efficiency, and seamless compatibility with the Su-30MKI airframe, India's decision-makers have cited cost considerations, technology transfer opportunities, and the existing logistical and maintenance infrastructure supporting the AL-31FP as key factors in their choice.

The AL-31FP, though less powerful than its successor, has proven its reliability and effectiveness over the years, meeting the operational requirements of the Indian Air Force (IAF).

Moreover, India's plan to manufacture 240 AL-31FP engines domestically underscores the country's emphasis on self-reliance in defence production.

The decision also highlights India's pragmatic approach to defence procurement in a complex geopolitical landscape.

While the AL-41F-1S undoubtedly offers superior performance, the transition would necessitate substantial investments in upgrades and training, a burden India seems unwilling to bear under current budget constraints.

Despite Russia's disappointment with India's decision, the move reflects a carefully calculated balance between performance enhancement and fiscal prudence.

The modernized AL-31FP engines, with their upgraded FADEC-type digital control system, offer a significant improvement over the existing powerplants, ensuring that India's Su-30MKI fleet remains a formidable force in the region.

As India continues to strengthen its defence capabilities, the AL-31FP engine upgrade represents a strategic choice that prioritizes stability, reliability, and self-reliance.

 

[Akshat]

Why?. Your master America is not giving us any engine technology and same is the case with French and England. That leaves us with the option of only Russian.

And Russia will give us engine tech? 😂😂😂

 

[Varaaah]

Ask Russia to de develop an engine specially for India with all rights for India and full ToT. They can ask a few billion $$ for it.

 

[indiadefenselover]

If AL41 gives lifespan of 6000 hrs with mean time to overhaul of 1000 hrs it's worth. Otherwise AL31FP is far more good than AL41. We don't need more thrust we need reliability and local production from scratch.

 

[Pad UwU]

Ask Russia to de develop an engine specially for India with all rights for India and full ToT. They can ask a few billion $$ for it.

Indian government doesn't have budget to pay at least a minimum of $15~25 billion for new infrastructure tech transfer and equipment plus the alloys and order of 200 engine

 

[abhinav srivastava]

By 2030 the indigenous would be around 60-65% , currently it is 54%

Godrej & other private companies & MSMEs are getting matured..

70% is indigenisation is very good number in any jet Engine.

That era is gone. Time for full indegenisation of core systems

 

[PKPRS]

Time to indiginize AL31FP and increase MTBO.

Time to fit AL-31FP engine in TEDBF and ORCA too.

 

[Air Commodore DB Murali VSM Retd]

Bearing material of the Inter Rotor Bearing (IRB) of AL31FP to be changed to higher grade steel will make it at par with AL 41 ... But a distinct advantage of AL 41 engine is doing away with ISB Inter Shaft Bearing and no flexible shaft ... A great upgrade ... Also, the turbine blade tip clearances are easier to manage in overhaul as they are shrouded blades. More so, the Graphite sealing ring after IRB has improved fit with IRB location shifted forward for better loading .... In short AL 41 was the best choice to opt for the long run but in IRB material can be changed to improved steel grade it will be good for SUs

 

[potka11]

then what's the point of upgrade when your power source is outdated??

A little learning is a dangerous to your mental wellness dude

 

[jassi14792]

According to cost and changes required to install engine it's the best course to skip this and wait for 51 engine. Not every upgrade is worth the cost.

 

[vyoma]

We should make additional 126+ Super Su-30MKI powered by AL-41 engines and change present AL-31 engines but seek 80% TOT for AL-41 engines ! Upgraded engines will make Super SU-30MKI even superior to SU-35 !

Superiority doesn't come by thrusts alone. What is the point of extra thrusts when none of your missions need it. Of course we could think super cruise.

More importantly, we need to take ownership of changing the skin of MKI to Tejas composite skins. That along with new lpi radar, ram coatings will make it superior to 35.

 

[Hridoy Ranjan Baruah]

Engines were always the Achilles heels of Russian aircraft technology. Mainly their efficiency and reliability have stayed at least 10 years behind the west.

If this were a technology transfer deal, we should have been all over it. As us being a zero, anything by Russians would have been a net positive. But alas, AL-41 woujd be another off the shelf sale at best. So, no point putting good money into an obsolete product.

Rather invest into private players such as Kirloskar, PBS India, Godrej & Boyce etc. who have the wherewithal to design a turbojet successfully.

Can't India produce at least a prototype of AL-41 fighter engine with reverse engineering like Chana always do. If successful then we may go for production such engine.

 

[Air Commodore DB Murali VSM Retd]

The question to opt for upgraded AL 31 is understandably AL 31 117 version... is did they incorporate some of the good features of AL 41 ??? Like no flexible shaft, ISB (though difficult), full FADEC, more impact resistant 1st & 2nd stage blades etc

 

[Air Commodore DB Murali VSM Retd]

From my study having seen AL 41 upclose, the engine in AL 31 family under proposal is AL31-117, three stage wide chord fan blades, increasing fan pressure ratio to 4.2, keeping frontal dimensions same & FFF with existing airframe, Most importantly grounded ISB, FADEC control engine, improving thrust to weight ratio. Highpoint is Aircraft accessory gear box will be accommodated on engine, rather than aircraft & will avoid Flexible shaft. With wide chord fan blades, better FOD resistance and bird impact.

 

[Air Commodore DB Murali VSM Retd]

Can't India produce at least a prototype of AL-41 fighter engine with reverse engineering like Chana always do. If successful then we may go for production such engine.

Impossible. We are too late as technology has grown leaps & bounds esp Hote end parts, coatings and Compressor efficiency enhancement designs

 

[Air Commodore DB Murali VSM Retd]

Grounded ISB offloads Inter Rotor Beraring radial loads to a great extent reducing Graphite sealing ring failures at rear support ... In AL 41, Inter Shaft Bearing is removed. New bearing configure

 

[Air Commodore DB Murali VSM Retd]

Can't India produce at least a prototype of AL-41 fighter engine with reverse engineering like Chana always do. If successful then we may go for production such engine.

Please do not misunderstand my word impossible. I said that because we have wasted lots of time on developing Kaveri engine with no focus to absorb critical technologies from a friendly Engine OEM with a G 2 G help. Probably the Ego didn't permit to take help with the confidence obtained in successfull dry engine operational proving .... Without realising the afterburner & Nozzle design maturing complexity

 

[Air Commodore DB Murali VSM Retd]

Impossible. We are too late as technology has grown leaps & bounds esp Hot end parts, coatings and Compressor efficiency enhancement despite dry power success in Kaveri

... Leaning on Engine OEMs for Few left out critical technologies and processes. Mainly TBC & assembly standards for full life. I also feel we lack test bed proving methodology with reliability quotient build up for defining SII - Safe Inspection Intervals for overhaul life fixation & remedies based on test results

Though HAL has succeeded in developing STFE but fixing long term usage template through SIIs Safe Inspection Intervals, Defect recoveries & Life fix a long way to go ... This affects final product certification as well as operationalisation & hence import happens

 

[Air Commodore DB Murali VSM Retd]

Superiority doesn't come by thrusts alone. What is the point of extra thrusts when none of your missions need it. Of course we could think super cruise.

More importantly, we need to take ownership of changing the skin of MKI to Tejas composite skins. That along with new lpi radar, ram coatings will make it superior to 35.

Super cruise in max dry requires higher core with the available TET (Turbine Entry Temp) limits. If we can increase TET with higher metallurgy, single crystal and cooling, we lower the engine core ... So now a larger diameter engine bay gives aircraft a larger size & radar capture in stealth scenario. But F 35 engines have the highest TET & therefore an optimal tail size

 

[Senapati]

Al41 is basically engine for Su35. Not a must for Su30 upgradation.
India can continue with Al31 FP the latest in this series with FADEC fuel control and thrust vector control nozzle.
If India planning to produce in India Su57 or Su75 type 5th generation fighter as make in India then we will be making Al51 advanced engine.
So no need of Al41 now.

 

[vyoma]

Russia has been touting its AL-41F-1S for a long time but IAF chose AL-31FP to keep the present Manfacturing knowledge and possibly more indigenization.

Right now local manufacturing is at 54% and is very poor. Remember GE F-414INS6 is getting 80% TOT and local manufacturing.

I think India will face problems with AL-31FP as Russia will not be working on it anymore.
For every problem resolution, India has to pay exorbitant amounts to get the issues fixed.

AL-41F-1S would be the best for all SU-30MKis upgrades to Super Sukhois.

This is exactly the problem jugaadish desis are ignoring. No matter GE or Saturn, once it gets outdated, no parts will be available at an agreeable cost. We love to do it this way!

The only long-term option for jagaadizing is modernizing ourselves.. we have our own terms, methods and timeframes. chalta hai