Issues and background
North/South flow imbalance
Flights flow either North or South from DCA's runway. Rather than striving to maintain an equitable split, nearly 65% of aircraft traffic currently follow a North flow path. Check out the FAA rhetoric.
FAA analysis claiming North flow advantages
CWG identifies that 6% of North flow decisions by FAA controllers not based on its criteria
DCA, LGA, and JFK operate under slot rules
Read the DCA perimeter and slot rules
MWAA identified risks of adding slots/expanding the perimeter at DCA
Unless otherwise authorized by FAA Air Traffic Control, Reagan National is limited to 60 slots/operations (arrivals and departures) per hour for specified aircraft classes between 6 a.m. and midnight (12 a.m).
There are, on average, 2 to 3 departures and no arrivals per day between 5am and 6am. If all assigned slots are being flown, this means there are 57 to 58 available slots between 5am and 6am. If assigned slots are not being flown, these numbers will be lower.