Asper your time line, if we start super Sukhoi upgrade today ,the last jet will be completing it's upgradation by 2037.
Depends on how quickly we will upgrade them. It could take anywhere between 6-12 years because of the overhaul interval. The last MKI that was delivered in 2021 can undergo overhaul in 2027, and it could be upgraded then. Or the IAF can continue using the old configuration until its next overhaul cycle in 2033.
Since we can overhaul 42 jets a year, we can easily upgrade all the MKIs in a single sitting regardless of when they were delivered.
And, let's assume the upgraded MKI will serve minimum 15-20 years more and by going IAF track record, we will phaseout mki around 2060. Do we really need to use MKI till then? Also not to forget that the upgradation we envisioned now most probably will be a mediocre one by 2037.
So my question is instead of wasting money on MKI upgradation,why don't we induct more capable fighters ,say by 2035 onwards?
Depends. The full life of the MKI is 25 years. We can opt to use the jet for 25 years, or add another 12 years if necessary through life extension. The bulk of our fleet came in between 2009 and 2015, so they can be replaced from 2034-40, if life extension is not carried out. A 12-year extension will mean 2046-52.
The MKI was originally designed for 17-25 years, but Sukhoi managed to push that to 25-39 years, and it became one of the reasons to kill FGFA.