Which document is likely to include data on airports and heliports?

The Airport Facility Directory (AFD), also known as Chart Supplements, is specifically designed to provide comprehensive information about airports and heliports. This document includes operational data, location information, and facility details for both public-use and private-use airports across the United States.

The AFD is a key resource for pilots, as it offers essential information such as runway specifications, communication frequencies, and services available at various airports. Its format and content are tailored to deliver quick access to pertinent data that pilots need during flight planning and operational phases. Therefore, it is the most likely document to contain detailed data specific to various aviation facilities, including heliports, making it the correct choice in this context.

In contrast, the Airport Capital Improvement Plan focuses on future development projects and funding for airports, while state aviation grant programs detail financial support available for aviation projects. The bond use overview generally discusses financial mechanisms used for airport funding, not specific data on facilities.