Why IAF Retained AL-31FP Engines for Su-30MKI Fleet Despite Superior Thrust AL-41F Offer from Russia? Logistics and Training Main Factors

In a decision with significant implications for the Indian Air Force (IAF), India has opted to retain the existing AL-31FP engines for its fleet of 84 Su-30MKI fighter aircraft, declining an offer from Russia to upgrade them with the more advanced AL-41F engines.

While the AL-41F offers superior thrust and improved Mean Time Between Overhauls (MTBO), the IAF's choice reflects a prioritization of logistical efficiency and training continuity.

An official from Hindustan Aeronautics Limited (HAL) confirmed that the decision to stay with the AL-31FP engines was primarily driven by the IAF.

Despite the AL-41F's proven compatibility with the Su-30MKI platform, as demonstrated by the Russian Air Force's transition to these engines on their Su-30SM aircraft, several factors influenced this decision.

Over the years, HAL, in collaboration with the Gas Turbine Research Establishment (GTRE), has successfully addressed early technical issues with the AL-31FP engines.

Furthermore, HAL has achieved the capability to manufacture these engines domestically from raw materials, enhancing India's self-reliance in engine production.

Logistical considerations also played a key role in the IAF's decision. While the AL-41F shares some commonalities with the AL-31FP in terms of service ground tools, transitioning to the new engine would necessitate significant reskilling of ground crew for maintenance and repairs.

Additionally, the higher thrust of the AL-41F could alter the flight dynamics of the Su-30MKI, requiring pilot reorientation and potentially new training modules.

Ultimately, the IAF chose to avoid the additional costs and time associated with transitioning to a new engine type, especially when the existing engines have been effectively localized and improved.

By sticking with the AL-31FP, the IAF can leverage its established supply chain and maintenance ecosystem without significant disruption.

However, this choice means forgoing the potential performance enhancements offered by the AL-41F, including increased thrust and engine longevity. The Su-30MKI, a cornerstone of the IAF's fighter fleet, will still undergo upgrades to become the "Super Sukhoi," but these will focus on avionics, radar systems, and weapon integration rather than a change in propulsion.

This decision reflects a strategic balancing act between technological advancement and operational continuity. The IAF has prioritized minimizing disruption to its existing infrastructure and expertise, even if it means forgoing potential performance gains.

 

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[sanket]

Heavy weapon package and vision about Super Sukhoi to remain in 2060. The IAF should have considered the AL-41 derivative. Some comedian will blame HAL even after it's the IAF's decision to stick with AL-31FP. They have a short memory and forget this, all start blaming after 2 to 3 years. It was the IAF who wanted the GE-404 directly from the US, and even components/spare parts; they wanted GE, which is the OEM, to supply for the GE-404 engine for its maintenance.

 

[beencensured]

Heavy weapon package and vision about Super Sukhoi to remain in 2060. The IAF should have considered the AL-41 derivative. Some comedian will blame HAL even after it's the IAF's decision to stick with AL-31FP. They have a short memory and forget this, all start blaming after 2 to 3 years. It was the IAF who wanted the GE-404 directly from the US, and even components/spare parts; they wanted GE, which is the OEM, to supply for the GE-404 engine for its maintenance.

They have also improved the thrust and efficiency of the AL-31FP engine, so the Air Force is happy and has increased service life, having more control over supply chains. Though thrust issues could be handled by additional flight control laws that would prevent such pilot errors, there may be some technical issue that they choose not to address, as this proposal is very old.

 

[Steel Mathi]

AL-41 and AL-51 engines can be accepted if Russia provides at least 80 percent ToT to India.

 

[abhinav srivastava]

If we have indigenized AL-31F engines by 60+%, we must design our own engine of similar or slightly higher capacity.

 

[P.K Senapati]

The IAF doesn't just need to see indigenization of the AL-31 but also advanced technology like total-life advanced fuel control that comes with new versions like the AL-41. Most of the technology will be common. India can quickly indigenize components of the AL-41. If not now, later they will have to upgrade the engine. Without a superior engine, the Super Sukhoi name is meaningless. Then why not upgrade the engine now?

 

[Kira]

A sound choice as it would be difficult to adopt the AL-41F due to the various issues that will arise.

 

[Baiju Bhaskaran]

Let the upgrade of existing Sukhoi happen with AL31. IAF should order four more squadrons of Sukhoi which should use AL41.

 

[Sangram]

If we make AL-31, why not just try it on the Tejas MK2 design? We can save lots of money here too.

 

[kumar]

If we make AL-31, why not just try it on the Tejas MK2 design? We can save lots of money here too.

It won't fit. And there are many other things to take care of.

 

[Dipesh Debnath]

If we make AL-31, why not just try it on the Tejas MK2 design? We can save lots of money here too.

LCA, since it is light, can take an engine weighing around 1000kg. The Sukhoi engine weighs 500kg extra and is designed for a heavy fighter with thrust vectoring. LCA thrust vectoring is through canards IMO and not through the nozzle. AL-31FP length is also 50+ cm longer than the LCA's original engine. So we cannot redesign LCA in such a case. Better to make a new CA if we have the capability and will.

 

[Ajay Shukla]

If we have indigenized AL-31F engines by 60+%, we must design our own engine of similar or slightly higher capacity.

GTRE, DRDO, and the industry needs to collaborate to create it's own AL31F derived AL51 type engine. Research needs to go in materials, and redesign of sub-components, including possibly engine core.

 

[Akshat]

AL-41 and AL-51 engines can be accepted if Russia provides at least 80 percent ToT to India.

They haven't provided even 50% of ToT for AL31, and you think they will provide 80% ToT for AL51? 🤣🤣🤣Only West can provide real ToT to India.

 

[Akshat]

If we have indigenized AL-31F engines by 60+%, we must design our own engine of similar or slightly higher capacity.

Well we haven't. We are at 53%, and 47% of it was given directly to us by Russia. So our own contribution is negligible.

 

[Ajay Singha]

LCA, since it is light, can take an engine weighing around 1000kg. The Sukhoi engine weighs 500kg extra and is designed for a heavy fighter with thrust vectoring. LCA thrust vectoring is through canards IMO and not through the nozzle. AL-31FP length is also 50+ cm longer than the LCA's original engine. So we cannot redesign LCA in such a case. Better to make a new CA if we have the capability and will.

India needs to get a Competent R&D team in place and fund a separate lab to develop engine derivatives, and have a legal framework with the Russians to be able to do this. I wouldn't discount using a high-performance derivative to do this.

 

[Akshat]

Let the upgrade of existing Sukhoi happen with AL31. IAF should order four more squadrons of Sukhoi which should use AL41.

Su30 MKI are way too expensive at this point, and that is without any upgrades. IAF would much rather spend that money on MRFA planes.

 

[Aravind Raveendran]

This is our reality, pathetic...neither can we make the AL-31 by ourselves (only 53% indigenization) nor can we accept the AL-41 due to obvious reasons.We won't reverse engineer, and we are incapable of learning by ourselves 😔.So the only option left is to continue with the AL-31.

 

[EMD XD41/06MAC]

So you guys can have TOT for two different engines from GE - F404 and F414 at the same time, but not with Russia's AL-31 and AL-41? Have some sense, HAL! Tejas Mk-1A will be our lightweight fighter and Mk-2 will be medium weight, due to which both engines F404 and F414 will be made simultaneously, but for Sukhoi, on transition from AL-31 to AL-41, only the latter (AL-41) would be made! So what's wrong with switching engines, geniuses?

 

[EMD XD41/06MAC]

Also, if not AL-41, and if Super Sukhoi is all set to become near 5th generation, sans stealth body, we can at least make its engines stealthy and change them to the new AL-51 (Izdeliye 30) if needed. As even this engine has similar dimensions to the -31 and -41, and with more modern technology compared to the other two, it will make a good fit for our Super Sukhoi. And who knows? Russia might take inspiration from us to develop their Su-30SM2 (powered by the AL-41F) into Su-30SM3 using this engine.