FOURTH AMENDMENT TO RIGHTS AGREEMENT THIS FOURTH AMENDMENT TO RIGHTS AGREEMENT (this "Fourth Amendment") is made and entered into as of this 30th day of May, 2001, by and between FRONTIER AIRLINES, INC. (the "Company") and COMPUTERSHARE TRUST COMPANY, INC., as Rights Agent (the "Rights Agent"). Recitals A. The Company and American Securities Transfer & Trust, Inc., predecessor in interest to the Rights Agent, entered into a Rights Agreement dated as of February 20, 1997 (the "Rights Agreement"); and B. The Board of Directors of the Company, by resolution duly adopted on May 30, 2001, authorized this Fourth Amendment to the Rights Agreement. Agreement The Company and the Rights Agent hereby amend the Rights Agreement as follows: 1. Section 27 of the Rights Agreement is hereby amended in its entirety to read as follows: Section 27. Supplements and Amendments. Prior to the Distribution Date, the Company may, and the Rights ---------------------------- Agent shall if the Company so directs, supplement or amend any provision of this Agreement without the approval of any holders of certificates representing shares of Common Stock. From and after the Distribution Date the Company and the Rights Agent shall, if the Company so directs, supplement or amend this Agreement without the approval of any holders of Rights in order (i) to cure any ambiguity, (ii) to correct or supplement any provision contained herein that may be defective or inconsistent with any other provisions herein, (iii) to shorten or lengthen any time period or to change the Purchase Price hereunder (which lengthening or shortening, or change to the Purchase Price, following the first occurrence of an event set forth in clauses (i) or (ii) of the first provision to Section 23(a) hereof, shall be effective only if there are Continuing Directors and shall require the concurrence of a majority of such Continuing Directors), or (iv) to change or supplement the provisions hereunder in any manner that the Company deems necessary or desirable and that does not adversely affect the interests of the holders of Rights Certificates (other than any Acquiring Person); provided, this Agreement may not be supplemented or amended to lengthen, pursuant to clause (iii) of this sentence, (A) a time period relating to when the Rights may be redeemed at such time as the Rights are not then redeemable, or (B) any other time period unless such lengthening is for the purpose of protecting, enhancing or clarifying the rights of, and/or the benefits to, the holders of Rights. Without limiting the foregoing, the Company may at any time or from time to time prior to such time as any Person becomes an Acquiring Person amend this Agreement to lower the thresholds set forth in Sections 1(a) and 1(i) to not less than 10%. Prior to the Distribution Date, the interests of the holders of Rights shall be deemed coincident with the interests of the holders of Common Stock. 2. The remainder of the Rights Agreement shall remain unchanged, and the Rights Agreement as amended above, shall remain in full force and effect. IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be fully executed on their behalf as of the date first above written. FRONTIER AIRLINES, INC. By: ------------------------------------------------------ Name: Title: COMPUTERSHARE TRUST COMPANY, INC. By: ------------------------------------------------------ Name: Title: