A Benefit-Cost Analysis (BCA) is required for any project which preserves or enhances capacity AND the total discretionary funds requested exceed $10 million over the life of the project and is not among the exempted items spelled out in the BCA policy.

What does it mean?

Preserve
To extend the useful life of existing infrastructure, e.g. to rehab an apron.
Enhance
To improve upon an existing infrastructure, or to create new infrastructure, e.g., to strengthen an existing apron, or extend or build a runway.
Capacity
Anything which allows more or bigger aircraft to use the airport.

Since FAA's BCA requirement was formalized, FAA field personnel and airport sponsors have asked FAA Headquarters staff to interpret the BCA policy for its applicability. These requests typically occur at critical and time-sensitive points, such as in the development of BCA recommendations, or in the project approval stage. Responding to these issues so late in the process results in delay. In addition, Headquarters is responsible for ensuring proper and consistent application of BCA techniques. As a result, Headquarters, with assistance from a few field offices is developing a "how- to" guide for the preparation and review of BCA's. The guide contains many of the common BCA interpretations that have been collected over time, and uses them as case examples to assist airport sponsors during BCA preparation.

National Policy and Guidance