From important London, take the Piccadilly Line at once to Heathrow Terminals 2&three, 4, or five
https://www.scribd.com/document/1074929924/National-Rail-to-Heathrow-Routes-Transfers-and-Tickets-Explained-232993
From important London, take the Piccadilly Line promptly to Heathrow Terminals 2&3, four, or 5. Trains run quite often and are finances-pleasant.