San Francisco International Airport (SFO/KSFO), CA, USA

San Francisco International Airport (SFIA) is an extremely busy airport in San Francisco, California, USA. The airport has four runways and is the 23rd largest in the world and 13th largest in the US.

The runways are configured so that the airport can conduct up to 60 arriving flight operations per hour. However the weather patterns in this area often lead to delays. The airport has recorded that only 64% of flights are on time.

The airport opened a new 2.5 million ft² international terminal in December 2000 worth one billion dollars. Construction started in 1996, replacing the old Terminal 2 and has 28 gates plus some additional gates on a rotunda A. All but one gate have two jetways and six are designed for super jumbos. A new rental car facility was added in 2003, and an extension of the bay area rapid transit to the international terminal was also completed in 2003. The terminal houses the main BART station near boarding area G. This was part of a $2.4 billion capital expansion project. Since then all the emphasis on expansion at the airport has been on developing and reconfiguring the new runways. Expansion is crucial because the airport is losing business to its nearby neighbours San Jose and Oaklands – although San Francisco has the best land connections out of the three.

The international terminal opened in 2000 and has the distinction of being the largest terminal building in North America, constructed on base isolators to protect against earthquake damage. The terminal was designed by Craig W. Hartman. Skidmore, Owings & Merrill, Del Campo & Maru Architects, and Michael Willis Associates all worked on the main terminal building while Hellmuth, Obata and Kassabaum (boarding area G) and Gerson/Overstreet Architects were responsible for the design of boarding area A. Parsons carried out the construction work on the international terminal.

To cope with the spiralling demands of its increasing traffic, the airport created an airfield development programme. This required the expansion of the airport runway into the San Francisco Bay (requiring the reclamation of land). Obviously this met with opposition from environmentalists and local people who do not believe the airport would improve even if it were able to build a new runway.

Current construction work at the airport includes the renovation of terminal two and the demolition of the outmoded rotunda A. Other projects underway in 2007 and expected to be completed in the next thirty months include boarding area D, which is being reconstructed in readiness for residence by Virgin America. There will be around 14 gates and the area will be shared with Southwest Airlines who have stated that they will require capacity to undertake 100 aircraft movements per day.

RUNWAY RECONFIGURATION

The current runway configuration at SFIA consists of four runways. The separation between parallel runways is 750ft. While simultaneous landings can take place on parallel runways in good weather, Federal Aviation Authority (FAA) rules for landing aircraft restrict the airport to one runway in bad weather which can lead to increased delays.

In good weather, SFIA can accommodate a maximum of 105 planes an hour; bad weather can reduce that to as few as 65 planes per hour depending on which runways can be used. These numbers include takeoffs and landings.

Another primary motivation for moving runways out into the bay is noise reduction. Noise at airports is a major problem for those who live near airport flight paths. Shifting runways further into the bay reduces the number of people in the CNEL 65 noise level region from around 5,000 to 300, according to SFIA.

The runway reconfiguration programme is a proposal being developed by San Francisco International Airport to modify the layout of its four existing runways.

As well as hoping to solve the problem of excessive delays, the development programme is intended to limit the noise impact on the surrounding area. It is also necessary for the airport to accommodate increasing numbers of larger aircraft. The goals of the programme are to:

• Reduce flight delays during poor weather conditions
• Reduce the noise impact of aircraft operations
• Accommodate larger aircraft
• Achieve net environmental gains for the San Francisco Bay Area (via mitigation)

San Francisco International Airport recognises the environmental importance of San Francisco Bay. Through its commission, the airport has already committed nearly $17 million to the restoration of wetlands in the Bay as mitigation to the airport master plan. The commission is fully committed to the continued restoration, enhancement and health of the bay.

One proposal for the extension of the airfield into the bay has been to construct a floating runway (which would be earthquake proof). Float Inc submitted a proposal to SFIA in 2000; this has been considered by SFIA but the costs have been thought too great and there are environmental issues over casting a shadow on the bottom of the bay (marine ecology may be affected). Float Inc consists of a consortium of expert companies, including Weidlinger Associates. (structural engineering), Pre Con Inc, (a subsidiary of Blue Circle Industries PLC - concrete forming), Ferma Corporation (general engineering), ECM Assoc (cost estimating), Olivia Chen Consultants (environmental issues).

FIVE RUNWAY ALTERNATIVES

A feasibility study has identified more than 30 alternative layouts for runways at the airport. A layout has not yet been selected but the airport has identified the five alternatives that are most likely to be chosen:

A3 alternative: this would only partially meet the airport objectives. It would provide a fairly large delay reduction for prevailing wind conditions and would result in a minor reduction in the number of people most affected by aircraft noise. This alternative requires the least amount of bay fill.

F2 alternative: this would fully meet the four airport objectives. There would be a large aircraft delay reduction for prevailing wind conditions. It would significantly reduce the noise impact to people living within affected areas. It would require a large amount of fill in the bay and the construction costs would be substantial.

BX refined alternatives: this alternative also meets airport objectives. It provides separation for both sets of runaways, thereby achieving significant delay reduction. The primary difference from F2 is that BX provides for dual simultaneous Instrument Flight Rules (IFR) landing during all wind conditions. The noise reduction benefits would be significant, similar to those in alternative F2. There would be bay fill impact but the airport is committed to the development of an extensive mitigation programme for this type of alternative.

Do-nothing alternative: in this case there would not be any cost or bay filling but the situation would stay the same.

No build with improvement alternative: systems and operational improvement would include the use of new technology such as radar and global positioning. These approaches might generate up to 15% aircraft delay reduction. However there would be no reduction of exposure to aircraft noise.

MAIN CONTRACTORS

HNTB was selected to evaluate the different runway configurations. ATAC, an expert in airspace modelling, noise and airfield capacity issues. Olivia Chen Consultants, a specialist in utilities master planning at the airport; and Manna Consultants, a key provider of drafting, survey and civil engineering support services, also took part in the planning and evaluation.

VHB was also asked to undertake sustainability planning in conjunction with the City of San Francisco and San Francisco International Airport (Environmental Sustainability Report). This project was part of an effort to instigate an environmental management system (EMS) for the airport.