Clean Airport Bus Act of 2003 (sic) - Directs the Secretary of Transportation to establish a pilot program for: (1) awarding grants on a competitive basis to eligible entities for facilitating the use of natural gas buses at public airports through airport bus replacement and fleet expansion programs; and (2) entering into cooperative agreements with private sector developers for the development of fuel cell-powered airport buses, and subsequently with public agencies using natural gas-powered airport buses and such private sector fuel cell bus developers to demonstrate the use of fuel cell-powered airport buses.
Prescribes implementation guidelines.