Grey skies and rain greeted Queen Elizabeth II’s coffin as it was taken to Buckingham Palace after arriving in London on a military transport plane on Tuesday, before Britain says a final farewell to its longest-serving monarch. The giant C-17 Globemaster, using the callsign “Kittyhawk” to signal the queen’s presence on board, touched down from Edinburgh at Royal Air Force base Northolt at 6:54 pm (1754 GMT). The late monarch’s heavy lead-lined oak coffin, draped in the royal standard, was transferred slowly by eight RAF pallbearers into a waiting state hearse for the journey back to Buckingha…