score:4
Since you have 5 hours in Manchester, there will be plenty of time to pick up your bag and recheck it if you need it.
Even if other sources of information fail you, you can get the straight word from the check-in agent when you actually check the bag. The agent will know whether the bag tag they're applying is only for Manchester or all the way your final destination.
Upvote:3
Your bag should be checked-through to your final destination; in the outbound case, through to Delhi, in the return case, to Philadelphia; and there is no need to collect and re-check your bag en route in either Manchester or Doha.
Manchester Airport is capable of handling international-international bags for AA to QR. (Indeed, it can handle most other interlining, except to/from some very small domestic operators in the UK for some Byzantine customs reasons, which do not concern us here.)
If AA or QR fail to check the bag through properly, ask them to do it, or ask for a supervisor.
Below is the information from the Timatic airline database on customs clearance procedures for United Kingdom. Note exemption 1, through-labelled international baggage does not need to be customs-cleared.
Baggage Clearance:
- If Aberdeen (ABZ) is the first airport of entry, baggage is
cleared at Aberdeen. Baggage of transit passengers with a
final destination of Heathrow (LHR) or Gatwick (LGW) will be
cleared at the first airport of entry. In all other cases,
baggage is cleared at the airport of final destination or at
an International Community Airport (ICA) in the United
Kingdom if it is labeled accordingly.
- Exempt:
1. Baggage of transit passengers with a destination outside
the United Kingdom if it is labeled to that destination;
2. Baggage of passengers who embarked in another EU Member
will not be cleared at all (use Blue Exit).
Upvote:5
Ask the check-in agent if you need to re-check your luggage.
Even if you do, you don't need a visa, thanks to your US visa.