When weather or congestion cuts an airport's landing capacity, air traffic managers impose Ground Delay Programs that keep your flight at the gate. The system does this because waiting on the ground burns a fraction of the fuel and creates…

Europe's answer to a US-style ground delay program is CASA — the Computer Assisted Slot Allocation algorithm that has assigned Calculated Take-Off Times since 1995. When several active regulations hit the same flight at once, the documented rule is blunt:…