7). Last is the Engine upgrade.
To power a new AESA or a more powerful PESA radar, more powerful mission computer and a new EW suite, both part internal and external poded systems, might require a higher powered engine. Also the engine MTBO and total life might need to be enhanced. For this currently the only option is the Russian AL-41F1S engine. The other option that I proposed above or on the last page was to upgrade the existing AL-31FP engines using latest western tech from the likes of Safran or RR to increase the thrust and also increase the life and serviceability of the engines.
Currently IAF has said that no engine upgrade would be required for the proposed Super Sukhoi upgrade. However, everyone will agree that an upgrade would certainly be desirable. Either we negotiate with Russia for the Al-41F1S engine or see if we can somehow upgrade the existing engine.
If we intend to go on re-engineering of engine, then we should go the US way of getting the license for Ceramic Matrix Composites from Japan.
That itself would give a huge jump in engine optimization. It will provide a jump of up to 200 degrees in hot sections and a considerable amount of weight savings and increased engine output.
That seems extremely unlikely. Generally I don't think we would take up any kind upgrade of the AL-31FP engine without active support from a reliable engine manufacturer. Currently for Western tech, this boils down to either RR or Safran. Going with whosoever we decide to co-develop the next gen 110KN engine with, would obviously make sense.
Another option that I have not listed above would be to partner with Russia to upgrade the AL-31FP engines, rather than replacing them with the AL-41F1S engines. Not an optimum solution and mostly we would opt for this only for cost considerations and to avoid any problems with Russia by upgrading Russian engine with Western help. Maybe some contractual obligations might not allow us to partner with RR or Safran easily.
I personally would not prefer this option, as mostly the Russians would still charge us quite a lot for this kind of upgrade. One more option would be to check for feasibility to reduce the weight and hence improve the thrust to weight ratio with the existing engines.
This would require considerable Russian help, as it would probably also require some flight testing.
From the rest of the likely upgrades required/planned for the as part of the Super Sukhoi program (my own assessment, no official word on that), thete is hardly anything that we would need from Russia.
The only possible contribution could be if we opt for the above options of either weight reduction or Russia led engine upgrade.
One possible area of Russian involvement could be to check the airframes for metal fatigue and assess the residual life left in the airframes and the possibility of repairs and replacement of sections to solve any metal fatigue issues.