Based on assumptions from what you posted - AAdvantage
With 7 cheapest returns LHR-RDU, you would get:
- 3872 x 2 x 7 = 54208 AAdvantage elite qualifying miles (=AA Platinum, oneworld Sapphire)
OR
- 20TP x 2 x 7 = 360 BAEC Tier Points (=BA Bronze, oneworld Ruby)
If you are able to optimise your flight patterns, ticket types and/or AAdvantage butchers earnings rates, these parametres are no longer valid.