IL HB4181

Amends the Airport Authorities Act to clarify that population counts for municipalities within an airport authority must be based on inhabitants who reside within the corporate limits of the authority, not total municipal population

Creates a deannexation referendum process for municipalities not wholly located within the Springfield Airport Authority that have 5,000 or more inhabitants residing in both the municipality and the authority's corporate limits

Referendum can be initiated either by petition signed by at least 8% of voters (based on last gubernatorial election turnout) or by the corporate authorities of an eligible municipality

If voters approve deannexation, the Springfield Airport Authority must within 45 days either deannex all territory within that municipality's corporate limits or accept appointment of one additional commissioner from the municipality that voted for deannexation

Requires all airport authority commissioner appointments to specify whether the appointee resides within or outside a municipality having 5,000 or more inhabitants within the authority's corporate limits