47 CFR § 22.873 - Construction requirements for commercial aviation air-ground systems.
Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation air-ground spectrum allocation (see § 22.857) must make a showing of “substantial service” as set forth in this section. Failure by any such licensee to meet this requirement will result in forfeiture of the license and the licensee will be ineligible to regain it. Licensees authorized to use one megahertz or less of the 800 MHz commercial aviation air-ground spectrum allocation are not subject to the requirements in this section.
(a) “Substantial service” is defined as service that is sound, favorable, and substantially above a level of mediocre service that just might minimally warrant renewal.
(b) Each commercial aviation air-ground system subject to the requirements of this section must demonstrate substantial service within 5 years after grant of the authorization. Substantial service may be demonstrated by, but is not limited to, either of the following “safe harbor” provisions:
(2) Provision of service to the airspace of 25 of the 50 busiest airports (as measured by annual passenger boardings).
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