14 CFR 271.2 - Definitions.
As used in this part:
Eligible place means a place in the United States that -
(1) Was an eligible point under section 419 of the Federal Aviation Act of 1958 as in effect before October 1, 1988;
(2) Received scheduled air transportation at any time between January 1, 1990, and November 4, 1990; and
Essential air service is that air transportation which the Department has found to be essential under Subchapter II of Chapter 417 of the Statute.