Avianca Brazil O6 8500 GRU-JFK has been consistently delayed for 6+ hours over the past two weeks.
Does anyone know what's the deal with it? It only left on time twice in the last 14 days: https://www.flightaware.com/live/flight/ONE8500

The reverse flight has been pretty much on time, which is also weird: https://www.flightaware.com/live/flight/ONE8501