Storm9

Unfortunately I did not book the AI flight, instead opting for the 6am Jet Airways flight. As I too was afraid about how the AI booking worked, among other things such as going through immigrations again at DEL and then HYD.
Also I did not want to incontinence my family at such an odd hour arrival.

Mr. Bean

Yeah, none of the AI numbers (US-based) ever seem to work. I'm doing a similar connection in BOM in June (LHR-BOM-HYD on AI 140 ==> AI 130). All AI coded flights depart from the Intl terminal at BOM/DEL, but someone mentioned that you might have to go through immigration/customs if you are switching carriers. I've not done this before so I don't know if that is correct. I would imagine that, if your connection departs from the Intl Terminal, your bags would be checked through, but I could be wrong.

I don't really know if it is a huge deal, going through customs in BOM/DEL vs. HYD. I've never gone through customs at HYD (not when entering India anyway ). I expect similar treatment at any of the airports. The convenience is not having to travel to the Domestic airport with bags in tow.

I purchased via airindia.co.in and it was charged in GBP to my CC. If you book just the DEL-HYD segment, it will be charged in INR. It is an e-ticket, OLCI is allowed.

Storm9

Do you guys know what happens in Frankfurt? Are you allowed to leave the airplane or do you have sit in your seat? And also how easy is it to request upgrade during check in and can I use UA miles to upgrade?