Airline Competition Preservation Act of 2001

Airline Competition Preservation Act of 2001 - Amends Federal transportation law to authorize the Secretary of Transportation, on his own initiative or on a complaint, to: (1) investigate whether an air carrier is charging an unreasonably high fare or an average fare for interstate air transportation on a route; and (2) upon an affirmative finding, order the carrier to reduce the fare, offer the reduced fare for a specific number of seats on the route, and offer rebates to individuals who have been charged the fare.

Prescribes fare offering requirements for a dominant air carrier (which accounts for more than 50 percent of total annual boardings) that institutes or changes its fares with respect to a route in interstate air transportation to or from a hub airport in a manner that: (1) results in fares lower than or comparable to fares offered by a new entrant air carrier; and (2) increases the passenger capacity at which such fares are offered on the route to a level two or more times the capacity previously offered by the air carrier at such fares on the route, and two or more times the total capacity offered by the new entrant air carrier on the route. Requires such a dominant air carrier to continue (in the two-year period beginning on the date that such fares and additional capacity are instituted) to offer such fares with respect to not less than 80 percent of the highest number of seats per week for which the dominant air carrier has offered them.

Authorizes the Secretary, on his own initiative or on complaint, to: (1) investigate whether a dominant air carrier at a hub airport is charging higher than average fares at the airport; and (2) upon an affirmative finding, order the carrier to take specified actions to increase opportunities for competition at the hub airport.

Makes this Act effective immediately upon the Secretary's determination that three or fewer air carriers account for 70 percent or more of the scheduled revenue passenger miles in interstate air transportation as a result of specified consolidations, mergers, or acquisitions.