Unused runway capacity at Ronald Reagan Washington National airport could be used to add additional flights, finds the US government.

The Government Accountability Office (GAO) found that there were only about 53 take-offs and landings per hour in April 2012 compared to a maximum capacity of 67 movements, in a report looking at the impact of eight new beyond-perimeter slot pairs at National on the Washington DC area airports that was released earlier this month.

The shortfall is attributed to a decline in general aviation and unscheduled flights after the 11 September 2001 terrorist attacks, according to the report. There were on average 17 of these movements per day in 2011, which is down from about 210 prior to 2001.

"Reagan National has sufficient runway capacity to accommodate the new beyond-perimeter flights and, with some improvements to baggage handling and security screening facilities, will have sufficient terminal capacity," says the report.

The majority of flights from National must operate within a perimeter of 2,012km (1,250 miles), which was put in place in 1986, except for a 22 beyond-perimeter slot pairs that are awarded by the US Department of Transportation.

The Metropolitan Washington Airports Authority (MWAA) agrees that National has free runway space but says that the terminals are at capacity, in a letter to the GAO. The combined impact of the slot swap between Delta Air Lines and US Airways, and the new eight beyond-perimeter slot pairs has resulted in congested security checkpoints, inconvenient passenger connections and no excess gate capacity at the airport, it says.

"Passengers bear the brunt of squeezing more flights into Reagan, given that the legislative framework has not provided the airport operator sufficient time or additional resources to upgrade facilities," says the airport authority, which operates both Dulles and National airports.

MWAA and the GAO agree on most points except gate usage at National. The report states that there are an average of 7.7 turns per day per gate at the airport, which is within the suggested six to eight turns per gate by the US Transportation Research Board. However, the authority says that gates at National average 9.9 turns per day with the new beyond-perimeter slots - well beyond the recommended limits.

The authority would need time and funds to expand the terminal facilities at National if flights were increased, it says. It is evaluating long-term capital investment opportunities in the airport.

MWAA is in the midst of a $45 million upgrade to terminal A - the oldest at National - that includes an expanded security checkpoint and baggage handling systems.

JetBlue Airways would like additional slots at National. Dave Barger, chief executive of the low-cost carrier, said that the airport is "underserved" for its size and that the airline would "jump" on any slots that would become available at the airport, at the Boyd Group International Aviation Forecast Summit in Dallas.

Source: Air Transport Intelligence news