Two federal statutes enacted in 2000 and 2003 modified the slot and  perimeter rules at Reagan National Airport. Figure 2 shows each  market by number of slots and airline. FAA Indicates Some Additional Capacity Could Be Added, but Airports Authority Cites Airport Infrastructure Constraints as an Obstacle

According to FAA officials, whose estimate is based on airside capacity  (principally runways) and not landside infrastructure (such as terminals  and parking facilities), Reagan National can presently accommodate four  additional slots per hour. Airport officials were unsure of how many additional flights, if any, the  airport could accommodate. Even without increasing the number of slots,  there are opportunities to accommodate more flights and passengers. The  study estimated that the airport’s balanced capacity is 67 flights per hour,  or 4 more than what is currently in place, resulting in an additional 60  flights per day based on an 15-hour operating period. Airports Authority Questions Reagan National’s Capacity to Accommodate Additional Slots

Airport officials disagree with FAA’s estimate because it assumes balanced  capacity, whereas the airport prefers to measure capacity differently. Airport official said the absence of general  aviation flights helped the airport to absorb the additional slots that were  authorized under AIR-21 and Vision 100. These limitations involve several aspects of the  airport’s infrastructure. For the recent slots awarded under AIR-21 and Vision 100, the airports  authority has been able to accommodate new entrants with gates and  other facilities. The second way in which current capacity could be expanded is to reduce  the number of smaller commuter planes using slots that are allocated for  larger jet planes that carry more passengers. Airlines with Nonstop Service between Beyond-Perimeter Airports and Reagan National Gained Significant Market Share of Traffic in Those Markets, While the Effect on Flights to Other Area Airports Is Not Evident

Airlines awarded slots for nonstop service between Reagan National and  airports beyond the 1,250 mile perimeter have been able to gain a  significant market share of traffic for routes. In half of the cases the nonstop fare was on average $25 to $50 higher than  the connecting flight fares to and from Reagan National. The Effect of Beyond- Perimeter Slots on Area Airports Is Not Evident

We did not find evidence that beyond-perimeter flights to and from Reagan  National affected flights from the same airports to or from Dulles or BWI. DOT  acknowledges that all available slots at Reagan National Airport are not  used to maximum effect and agreed that there are a number of reasons for  this, including curfew restrictions, the commercial viability of slots in the  early morning or late evening under current regulations, and the  concentration of the majority of slot holdings among a relatively small  number of carriers. While the airports  authority believes that the airport can accommodate some additional  capacity, it is something less than the 4 slots per hour as suggested by  DOT. Appendix I: Scope and Methodology

To determine how many additional slots Reagan National Airport can  accommodate, we analyzed Federal Aviation Administration (FAA) and  Metropolitan Washington Airports Authority (airports authority)  operational data, reviewed prior capacity studies, and interviewed airports  authority, FAA, and Department of Transportation (DOT) officials. To assess traffic between Washington, D.C., area airports and the six  beyond-perimeter airports for which nonstop service to Reagan National  was awarded since 1999, we analyzed DOT’s Origin and Destination ticket  data; we used these data to examine changes in fares and passenger levels  between Reagan National, Dulles International (Dulles) and Baltimore- Washington Thurgood Marshall International Airport (BWI), and these  airports. For this  analysis, we conducted a historical look at traffic between the six airports  and the three Washington-Baltimore area airports.
Why GAO Did This Study

In 1999, GAO reported that Reagan National Airport could accommodate at least 36 more slots, which are authorizations from the Department of Transportation (DOT) for a takeoff or landing. In 2000 and 2003, two federal statutes, known as AIR-21 and Vision 100, permitted DOT to award 44 new slots to airlines, 24 of which could be used for flights to cities more than 1,250 miles, which was the statutorily mandated limit for non stop flights from Reagan National. The DOT awards went to airlines serving six cities (Denver, Las Vegas, Los Angeles, Phoenix, Salt Lake City, and Seattle). For this year's reauthorization of the Federal Aviation Administration (FAA), GAO was asked for an update on the capacity of Reagan National to accommodate additional slots and the effect of relaxing the perimeter rule. GAO updated its 1999 study to answer these key questions: (1) To what extent can Reagan National accommodate additional flights? (2) Since AIR-21 and Vision 100, what changes have occurred in market share and fares for flights operating between the six beyond-perimeter cities and the three Washington, D.C., area airports? In commenting on this report, DOT and the airports authority generally agree with our findings but with one exception, the airports authority disagrees with DOT's estimate of slots because it disputes their methodological assumptions. We believe the department's methodology for estimating airport capacity is appropriate.

What GAO Found

Reagan National Airport can accommodate some additional in capacity, but airport infrastructure constrains how much can be added. FAA officials believe that some additional slots can be added, while airport officials have not made an estimate. FAA, using the results of a 1995 DOT capacity study, determined that the airport's airside infrastructure (e.g., runways) could accommodate four additional slots per hour. Airport officials said they were unsure how many additional slots, if any, the airport could accommodate but cited several factors that could limit the airport's capacity to absorb additional slots including the limited number of gates currently available for loading airplanes and other infrastructure constraints. GAO's work shows that even if the number of slots is not increased, there is some opportunity to expand current capacity by filling unused slots and increasing the size of aircraft on existing slots to increase the number of flights and the number of passengers served. Currently, nearly 80 slots are unused because they are at early morning or late evening times and airlines have not applied to use these time slots. In addition, many of the slots reserved for large passenger jets are currently being used by smaller regional jets. Airlines awarded slots for direct flights between Reagan National and the six beyond-perimeter cities gained significant market share in those selected cities, but the effect of these slots on competing flights operating between these cities and the other Washington, D.C. area airports is not evident. For each of the six beyond-perimeter cities, the direct flights to and from Reagan National captured the majority of passengers flying between that city and Reagan National. In most cases, the airlines charged higher fares than competing connecting flights. GAO did not find evidence in passengers or fare data that would indicate that the new service between Reagan National and the six beyond perimeter cities had substantially affected service from Dulles or Baltimore-Washington International airports to these cities.