You are flying towards London from Paris, so you are heading (more or less) north. You arrive over London itself, so you can see some of the 'sights' from out of the plane window (Buckingham Palace, the Houses of Parliament, the 'Eye' etc.).Your plane then makes a left turn ~ more or less, again ~ towards Heathrow, and heading 'upstream' over the River Thames.In which direction is the plane flying as it approaches Heathrow?