Roughly 3,300 of the public-use airports across the United States have been determined by the Federal Aviation Administration (FAA) to be significant to national air transportation. These airports form a national airport system intended to provide convenient access to air transportation and support important national functions, such as defense, emergency readiness, and postal delivery. These airports are eligible to receive federal Federal Aviation Administration (AIP) grants to help fund their capital development. Commercial service airports -- if they choose and subject to federal approval -- are also authorised to collect local passenger facility charges (PFC) from passengers, which are also used to fund capital development projects. This book discusses how much national system airports received in funding for capital development projects from 2009 through 2013 and from which sources; the estimated costs of airports' planned capital development from 2015 through 2019; how past funding levels compare with planned development costs; and how changes to AIP funding and the maximum allowable PFC might affect airport funding.