A friend of mine took British Airways flight 69 from LHR to PHL this past Wednesday, March 4. When I asked how his flight was, he said that it took them like 3 hours longer than it should have to arrive in Philadelphia due to a headwind in excess of 200mph. It seemed unlikely to me that a headwind could slow the plane (767- no extra stops to refuel or anything) down that much so I looked it up here and FlightAware tracking said that the flight arrived at 9:14 EST instead of the 8:35 EST original arrival time and that the flight time was 8:37. Basically, that they were 45 minutes late in total. The British Airways website (I was able to see the previous day’s flight yesterday) said the same by a difference of maybe 5 minutes or so. Seeing as how the flight was tracked to the minute from the time it took off until it landed it doesn’t seem that there can be any error in the flight tracking?********
For that flight the posted departure/arrival times look spot on. You can compare the departure/arrival times to the times of the first and last position in the tracklog to verify – in this case they’re exactly the same.