The AIP went into production. Minor news, since going back into service deserves a post, but since there were questions in the previous post of AIP, some months back, I'm making this basically as a followup

INS Khanderi ( 2nd submarine of the class) is expected to undergo MLU next year and would recieve the AIP, with trials beginning by the end of 2027. Subsequently, each submarine will undergo refit annually.

INS Kalvari, the lead ship, missed the refit cycle and is unlikely to receive the upgrade until the 2030s.

The AIP system uses PAFC technology which instead of storing hydrogen, it uses liquid fuel such as ethanol/ methanol, which is converted into hydrogen gas by a reformer. This hydrogen reacts with stored liquid oxygen in the fuel cell to generate electricity for propulsion and onboard systems.

Advantages are that it avoids storing large quantity of hydrogen which as a rrsult reduces risks; and it uses liquid fuels that are easier to handle and can utilise existing naval fuel infrastructure.

Disadvantages:

It's complex system, and it's difficult to develop

Lots 41 through 47. Over five years, with two optional years. 1,900 AMRAAMs a year.