The 3d Field Investigations Squadron (FIS) is a unit within the United States Air Force (USAF) dedicated to conducting investigations related to the USAF’s real property and environmental matters. The squadron, often referred to as the “3d FIS,” operates under the Air Force Real Property Agency and offers services such as land use studies, site surveys, damage assessments, and environmental impact analyses. The mission of the 3d FIS is to ensure compliance with regulations concerning real property and environmental issues in order to support USAF operations efficiently and sustainably.