National Aviation Capacity Expansion Act

National Aviation Capacity Expansion Act - Directs the Administrator of the Federal Aviation Administration to implement the redesign and reconstruction of Chicago O'Hare International Airport in Cook and DuPage Counties, Illinois, in accordance with a specified runway redesign plan, and the development of a south suburban airport in the Chicago metropolitan region, by facilitating approval, funding, construction, and implementation of such plan and suburban airport.

Requires all environmental reviews, analyses, and opinions related to issuance of permits, licenses, or approvals relating to such plan or airport to be conducted on an expedited and coordinated basis.

States that approval by the Administrator of an airport layout plan submitted by Chicago that includes the runway redesign plan shall: (1) provide that any runway located more than 2500 feet south of existing runway 9R-27L shall not begin construction before January 2011; and (2) be subject to the condition that noise impact of aircraft operations at O'Hare after the year in which the first new runway is first used will be less than that in 2000. Prohibits the consideration of such a plan unless it includes public roadway access through the western boundary of O'Hare to passenger terminal and parking facilities.

Directs the Administrator to give priority consideration to a letter of intent application submitted by the State of Illinois (or a political subdivision thereof) for construction of the suburban airport.

Sets forth requirements regarding the construction of the runway redesign plan as a Federal project on or after July 1, 2004.

Requires the withholding of all airport grant funds for O'Hare (other than grants involving national security and safety) until January 1, 2026, unless specified conditions with respect to operations at Merrill C. Meigs Field have been met.