Exhibit 5.1

                       [Letterhead of Faegre & Benson LLP]

                                  August 1, 2000

Board of Directors
Frontier Airlines, Inc.
12015 East 47th Avenue
Denver, Colorado 80239

RE:      Registration Statement on Form S-8
         Opinion and Consent

Ladies and Gentlemen:

         In connection with the proposed registration on Form S-8 (the
"Registration Statement") under the Securities Act of 1933 of 406,250 shares of
common stock (the "Shares") of Frontier Airlines Inc., a Colorado corporation
(the "Company"), offered and to be offered pursuant to the Employee Stock
Ownership Plan (of 1996), as amended (the "ESOP"), we have examined the
Company's charter documents and the corporate proceedings taken by the Company
in connection with the issuance and sale of the Shares. Based on this review, we
are of the opinion that:

         1.       The Company is duly and validly organized and existing and in
good standing under the laws of the State of Colorado.

         2.       The shares which may be issued pursuant to the ESOP, will be,
upon issuance, validly issued and outstanding and fully paid and nonassessable.

         We consent to the filing of this opinion as an exhibit to the
Registration Statement.

         This opinion is rendered as of the date first written above and we
disclaim any obligation to advise you of facts, circumstances, events, or
developments which hereafter may be brought to our attention and which may
alter, affect, or modify the opinion expressed herein. Our opinion is expressly
limited to the matters set forth above and we render no opinion, whether by
implication or otherwise, as to any other matters relating to the Company or the
Shares.

                             /s/ FAEGRE & BENSON LLP