(a) Terminations, suspensions, or reductions by certificated carriers. The notice described in § 323.4(a) shall be filed by any certificated carrier that intends to:

(1) Terminate or suspend all passenger air transportation that it is providing to any eligible place in the United States when that termination or suspension will leave no certificated carriers serving that place. Service shall be considered to be terminated or suspended whenever it is operated less than 5 days per week, with three or more intermediate stops, or in one direction only between the two places;

(2) Reduce passenger air transportation so that any eligible place receives less than the level of essential air service determined by DOT;

(3) Terminate or suspend all passenger air transportation that it is providing to any eligible place in the United States for which DOT has not issued an essential air service determination under either § 325.5 or § 325.7 of this chapter, when that termination or suspension will leave only one certificated carrier serving that place. Service shall be considered to be terminated or suspended whenever it is operated less than 5 days per week, with three or more intermediate stops, or in one direction only between the two places;

(4) Reduce passenger air transportation to any eligible place in Alaska for which DOT has not determined the level of essential air service so that the service between that place and every other place served by a certificated carrier is either:

(i) Less than two round trip flights per week, or

(ii) Less than the average weekly number of round trip flights actually provided during calendar year 1976, or

(iii) Less than the number of flights specified under an agreement between DOT and the State of Alaska; or

(5) Terminate, suspend, or reduce passenger air transportation at an eligible place for which DOT has issued, or is required to issue, an essential air service determination under section 41731 or section 41733 of 49 U.S.C. Subtitle VII so that the total available seats of all the carriers linking that place to FAA-designated hubs will be reduced by 33 percent or more during a 90-day period. Service to a hub shall be considered to be terminated or suspended whenever it is operated less than 5 days per week, with three or more intermediate stops, or in one direction only between two places.

(b) [Reserved]

(c) Uncertificated carriers. The notice described in § 323.4(a) shall be filed by any uncertificated carrier that intends to terminate, suspend, or reduce:

(1) Air transportation so that any eligible place receives less than the level of essential air service determined by the DOT;

(2) Passenger air transportation to any eligible place for which DOT has not determined the level of essential air service, other than a place in Alaska, so that there is no FAA-designated hub from which the place receives at least two round trip flights per day, 5 days per week; or

(3) Passenger air transportation to any eligible place in Alaska, for which DOT has not determined the level of essential air service, so that the service between that place and every other place served by a certificated carrier is either:

(i) Less than two round trip flights per week, or

(ii) Less than the average number of weekly round trip flights actually provided during calendar year 1976, or

(iii) Less than the number of flights specified under an agreement between DOT and the State of Alaska.

(d) For the purpose of this section, in ascertaining the level of air transportation being provided to a place or between two places, air transportation that has been the subject of a notice filed under this section shall be considered not in operation for the duration of the notice period.

(e) If a certificated carrier was, before October 24, 1978, granted authority to suspend air transportation, and that authority ends on a stated date, the carrier shall comply with the requirements of this part before continuing the suspension beyond that date.

(f) If a certificated carrier was, before October 24, 1978, granted authority to terminate or suspend air transportation, but has not suspended service, the carrier shall comply with the requirements of this part before terminating or suspending service.