Northwest Airlines, Inc. v. Department of Revenue

Plaintiffs, Northwest Airlines, Inc. (Northwest), and Republic Airlines, Inc. (Republic) (collectively referred to as taxpayers), filed a complaint for administrative review, challenging a decision of the Illinois Department of Revenue (Department) which found that “flyover miles” must be included in the numerator of the apportionment fraction applicable to transportation services set forth in section 304(d) of the Illinois Income Tax Act (Act) (35 ILCS 5/304(d) (West 1996)). Flyover miles are miles accrued by “overflights” — flights which do not depart from or land in Illinois, but whose…