DCA High Density (Slot) Rule:
The High Density Rule (or "Slot" rule) is a federal regulation established in 1969 (14 CFR §93.123) to manage congestion at five high density airports: Reagan National, JFK, LaGuardia, Newark and O'Hare. Reagan National’s "Slot" Rule limits the number of Instrument Flight Rules (IFR) operations to 62 flights (slots) per hour. A slot is a IFR reservation for an arrival or a departure. A "slot pair" is equivalent to a round trip flight.
Congress must propose and approve federal legislation to change the number of flights (slots) at a designated high density airport. Over the strong opposition of the Airports Authority, Congress has added the following slot exemptions per day at Reagan National.
- 2000: 24 slot exemptions
- 2003: 22 slot exemptions
- 2012: 8 slot exemptions
DCA Perimeter Rule:
The Perimeter Rule is a federal regulation established in 1966 (49 U.S. Code § 49109) when jet aircraft began operating at Reagan National. The initial Perimeter Rule limited non-stop service to/from Reagan National to 650 statute miles, with some exceptions for previously existing service. By the mid-1980s, Congress had expanded Reagan National non-stop service to 1,250 statute miles. Ultimately, Reagan National serves primarily as a "short-haul" airport while Washington Dulles International Airport serves as the region's "long-haul" growth airport.
Congress must propose and approve federal legislation to allow the U.S. Department of Transportation to issue "beyond-perimeter" exemptions which allows an airline to operate non-stop service to cities outside the perimeter. As a result of recent federal exemptions, non-stop service is now offered between Reagan National and the following cities: Austin, Denver, Las Vegas, Los Angeles, Phoenix, Salt Lake City, San Francisco, San Juan, Seattle and Portland, Ore.