Air service development (ASD) is a broad term that encompasses activities with the ultimate goal of retaining existing air service or improving air access and capacity in order to develop the economy of a community or region. For the purposes of this guidebook, ASD involves all activities directly related to enhancing commercial passenger service at an airport. It includes understanding the local community and what drives its economy, and recruiting community and business leaders to participate in efforts to "sell" the community to the airlines. It includes understanding the air service and fares that airlines offer, and how the airport's service, fares, and facility compare to those of nearby airports. ASD also involves understanding the cost and revenue issues that influence carriers' decisions on which markets to serve. It requires understanding how an airport can extend financial and non-financial incentives to carriers-both those already serving the facility (incumbents) and those being recruited. ASD encompasses understanding what carriers value most and what they want to know about a community. It includes knowing how to make and present a sound business case to airlines. And it includes understanding how to evaluate the ASD efforts and revise them as needed. This guidebook is targeted toward the ASD needs of smaller communities. Many small communities-that is, those communities served by the 426 small- and non-hub airports in the United States-have traditionally had difficulty attracting and retaining service. The guidebook is organized into two major parts. The first part discusses the context for air service development, particularly the financial condition of the U.S. aviation industry and the basic underlying competitive challenges that small communities face in retaining or enhancing their commercial air service. The second part discusses how communities can address those challenges. Part II lays out the basic components of or steps in an ASD program. A word of caution: The approaches outlined in this guidebook cannot guarantee success. As everyone in the industry well knows, there are no guarantees in this business. The industry is subject to external forces that will wreak havoc with the best business models. That being said, there are strategic, proven ways to approach the issue of attracting new service-or simply retaining your existing service. This guidebook is intended to help small communities build and execute an ASD program or improve their existing efforts.