80,000,000 FRONTIER AIRLINES, INC. 5% CONVERTIBLE DEBENTURES DUE 2025 UNDERWRITING AGREEMENT

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Exhibit 1.1

$80,000,000

FRONTIER AIRLINES, INC.

5% CONVERTIBLE DEBENTURES DUE 2025

UNDERWRITING AGREEMENT

December 1, 2005

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated
Citigroup Global Markets Inc.

c/o: Morgan ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Dear Sirs and Mesdames:

Frontier Airlines, Inc., a Colorado corporation (the "Company"), proposes to issue and sell to the several Underwriters named in Schedule II hereto (the "Underwriters") $80,000,000 principal amount of its 5% Convertible Debentures due 2025 (the "Firm Securities") to be issued pursuant to the provisions of an indenture to be dated as of December 7, 2005 and a supplemental indenture (together the "Indenture") between the Company and U.S. Bank National Association, as Trustee (the "Trustee"). The Company also proposes to issue and sell to the several Underwriters not more than an additional $12,000,000 principal amount of its 5% Convertible Debentures due 2025 (the "Additional Securities") if and to the extent that you, as Managers of the offering, shall have determined to exercise, on behalf of the Underwriters, the right to purchase such 5% Convertible Debentures due 2025 granted to the Underwriters in Section 2 hereof. The Firm Securities and Additional Securities are hereinafter collectively referred to as the "Securities". The Securities will be convertible into shares of common stock (the "Common Stock"), no par value per share, of the Company (the "Underlying Securities").

The Company has filed with the Securities and Exchange Commission (the "Commission") a registration statement, including a prospectus, (the file number of which is set forth in Schedule I hereto) on Form S-3, relating to certain of its debt and equity securities (the "Shelf Securities"), including the Securities, to be issued from time to time by the Company. The registration statement as amended to the date of this Agreement, including the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A or Rule 430B under the Securities Act of 1933, as amended (the "Securities Act"), is hereinafter referred to as the "Registration Statement," and the related prospectus covering the Shelf Securities dated November 25, 2005 in the form first used to confirm sales of the Securities (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the "Basic Prospectus." The Basic Prospectus, as supplemented by the prospectus supplement specifically relating to the Securities in the form first used to confirm sales of the Securities (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the "Prospectus," and the term "preliminary prospectus" means any preliminary form of the Prospectus. For purposes of this Agreement, "free writing prospectus" has the meaning set forth in Rule 405 under the Securities Act and "Time of Sale Prospectus" means the preliminary prospectus, together with the free writing prospectuses, if any, each identified in Schedule I hereto. As used herein, the terms "Registration Statement," "Basic Prospectus," "preliminary prospectus," "Time of Sale Prospectus" and Prospectus shall include the documents, if any, incorporated by reference therein. The terms "supplement," "amendment," and "amend" as used herein with respect to the Registration Statement, the Basic Prospectus, the Time of Sale Prospectus, any preliminary prospectus or free writing prospectus shall include all documents subsequently filed by the Company with the Commission pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange Act"), that are deemed to be incorporated by reference therein.

SECTION 1. Representations and Warranties. The Company represents and warrants to and agrees with each of the Underwriters that:

(a) The Registration Statement has become effective; no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose are pending before or, to the knowledge of the Company, threatened by the Commission.

(b) (i) Each document, if any, filed or to be filed pursuant to the Exchange Act and incorporated by reference in the Time of Sale Prospectus or the Prospectus complied or will comply when so filed in all material respects with the Exchange Act and the applicable rules and regulations of the Commission thereunder, (ii) each part of the Registration Statement, when such part became effective, did not contain, and each such part, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (iii) the Registration Statement as of the date hereof does not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (iv) the Registration Statement and the Prospectus comply, and as amended or supplemented, if applicable, will comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (v) the Time of Sale Prospectus does not, and at the time of each sale of the Securities in connection with the offering and at the Closing Date (as defined in Section 4), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (vi) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and warranties set forth in this paragraph do not apply to (A) statements or omissions in the Registration Statement, the Time of Sale Prospectus or the Prospectus based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein or (B) that part of the Registration Statement that constitutes the Statement of Eligibility (Form T-1) under the Trust Indenture Act of 1939, as amended (the "Trust Indenture Act"), of the Trustee.

(c) The Company is not an "ineligible issuer" in connection with the offering of the Securities pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule I hereto, and electronic road shows each furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior consent, prepare, use or refer to, any free writing prospectus.

(d) The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has the corporate power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect on the Company. The Company has no existing subsidiaries.

(e) This Agreement has been duly authorized, executed and delivered by the Company.

(f) The authorized capital stock of the Company conforms as to legal matters to the description thereof contained in the Time of Sale Prospectus.

(g) The shares of capital stock of the Company outstanding prior to the issuance of the Securities have been duly authorized and are validly issued, fully paid and non-assessable.

(h) The Securities have been duly authorized and, when executed and authenticated in accordance with the provisions of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will be valid and binding obligations of the Company, enforceable in accordance with their terms, subject to the effects of applicable bankruptcy, insolvency and similar laws affecting creditors' rights generally and equitable principles of general applicability, and will be entitled to the benefits of the Indenture.

(i) The Underlying Securities issuable upon conversion of the Securities have been duly authorized and reserved and, when issued upon conversion of the Securities in accordance with the terms of the Securities, will be validly issued, fully paid and non-assessable, and the issuance of the Underlying Securities will not be subject to any preemptive or similar rights.

(j) The Indenture has been duly authorized, and on the Closing Date (as defined below) will be executed and delivered by, and a valid and binding agreement of, the Company, enforceable in accordance with its terms, subject to the effects of applicable bankruptcy, insolvency and similar laws affecting creditors' rights generally and equitable principles of general applicability, and the Indenture has been duly qualified under the Trust Indenture Act.

(k) The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement, the Indenture and the Securities will not contravene any provision of applicable law or the articles of incorporation or By-laws of the Company or any agreement or other instrument binding upon the Company that is material to the Company, or any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by the Company of its obligations under this Agreement, the Indenture or the Securities, except such as have been obtained under the Securities Act and the Exchange Act, and except such as may be required by the securities or Blue Sky laws of the various states in connection with the offer and sale of the Securities.

(l) There has not occurred any material adverse change, or any development involving a prospective material adverse change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company, from that set forth in the Time of Sale Prospectus (exclusive of any amendments or supplements thereto subsequent to the date of this Agreement).

(m) There are no legal or governmental proceedings pending or threatened to which the Company is a party or to which any of the properties of the Company is subject that are required to be described in the Registration Statement or the Prospectus and are not so described or any statutes, regulations, contracts or other documents that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described or filed as required. The Time of Sale Prospectus contains in all material respects the same description of the foregoing matters contained in the Prospectus.

(n) Each preliminary prospectus filed as part of the registration statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder.

(o) The Company is not, and after giving effect to the offering and sale of the Securities and the application of the proceeds thereof as described in the Prospectus will not be, required to register as an "investment company" as such term is defined in the Investment Company Act of 1940, as amended.

(p) The Company (i) is in compliance with any and all applicable foreign, federal, state and local laws and regulations, judgments, orders or binding agreements relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants ("Environmental Laws"), (ii) has received all permits, licenses or other approvals required under applicable Environmental Laws to conduct its businesses and (iii) is in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, have a material adverse effect on the Company.

(q) There are no costs or liabilities associated with Environmental Laws (including, without limitation, any fines or penalties, settlement or damage awards, or capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, singly or in the aggregate, have a material adverse effect on the Company.

(r) There are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company (except as otherwise disclosed in the Registration Statement) or to require the Company to include such securities with the Securities registered pursuant to the Registration Statement.

(s) Subsequent to the date as of which information is given in the Time of Sale Prospectus, (i) the Company has not incurred any material liability or obligation, direct or contingent, or entered into any material transaction, in each case, not in the ordinary course of business or as described in or contemplated by the Prospectus; (ii) the Company has not purchased any of its outstanding capital stock, nor declared, paid or otherwise made any dividend or distribution of any kind on its capital stock; (iii) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company except in each case as described in or contemplated by the Prospectus; and (iv) there has been no prohibition or suspension of the operation of the Company's aircraft, including as a result of action taken by the Federal Aviation Administration or the Department of Transportation.

(t) The Company has good and marketable title in fee simple to all real property and good and marketable title to all personal property owned by it which is material to the business of the Company, free and clear of all liens, encumbrances and defects except such as are described in the Time of Sale Prospectus or the Registration Statement or such as do not materially affect the value of such property or do not interfere with the use made and proposed to be made of such property by the Company; and any real property and buildings held under lease by the Company are held by it under valid, subsisting and enforceable leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such property and buildings by the Company, in each case except as described in or contemplated by the Time of Sale Prospectus.

(u) (i) The Company possesses such permits, licenses, approvals, consents and other authorizations (collectively "Government Licenses") issued by the appropriate federal, state, local or foreign regulatory agencies or bodies, including the Department of Transportation, the Federal Aviation Administration or the Federal Communications Commission necessary to conduct the business now operated by it; (ii) the Company is in compliance with the terms and conditions of all such Governmental Licenses, except where the failure so to comply would not, singly or in the aggregate, have a material adverse effect on the Company; (iii) all of the Government Licenses are valid and in full force, except where the invalidity of such Governmental Licenses or the failure of

such Governmental Licenses to be in full force and effect would not have a material adverse effect on the Company; and (iv) the Company has not received any notice of proceedings relating to the revocation or modification of any such Governmental Licenses which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a material adverse effect on the Company.

(v) Except as described in the Time of Sale Prospectus, no material labor dispute with the employees of the Company exists or, to the knowledge of the Company, is imminent; and the Company is not aware, but without any independent investigation or inquiry, of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that could have a material adverse effect on the Company.

(w) The Company is insured by insurers that the Company reasonably believes to be of recognized financial responsibility against such losses and risks and in such amounts as are customary in the businesses in which it is engaged; the Company has not been refused any insurance coverage sought or applied other than in connection with instances where the Company was seeking to obtain insurance coverage at more attractive rates; and the Company has no reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not have a material adverse effect on the Company, except as described in or contemplated by the Time of Sale Prospectus.

(x) The Company maintains a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management's general or specific authorizations in all material respects, (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability and (iii) regarding prevention or timely detection of unauthorized acquisition, use or disposition of the Company's assets that could have a material effect on the Company's financial statements. Except as described in or incorporated by reference into the Time of Sale Prospectus, since the most recent audit of the effectiveness of the Company's internal control over financial reporting, there has been (i) no material weakness in the Company's internal control over financial reporting (whether or not remediated) and (ii) no change in the Company's internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company's internal control over financial reporting.

(y) The Company (i) is an "air carrier" within the meaning of 49 U.S.C. Section 40102(a); (ii) holds an air carrier operating certificate issued by the Secretary of Transportation pursuant to Chapter 447 of Title 49 of the United States Code for aircraft capable of carrying 10 or more individuals or 6,000 pounds or more of cargo; and (iii) is a "citizen of the United States" as defined in 49 U.S.C. Section 401102.

SECTION 2. Agreements To Sell and Purchase. The Company hereby agrees to sell to the several Underwriters, and each Underwriter, upon the basis of the representations and warranties herein contained, but subject to the conditions hereinafter stated, agrees, severally and not jointly, to purchase from the Company the respective principal amounts of Firm Securities set forth in Schedule II hereto opposite its name at the purchase price set forth in Schedule I hereto.

On the basis of the representations and warranties contained in this Agreement, and subject to its terms and conditions, the Company agrees to issue and sell to the Underwriters the Additional Securities, and the Underwriters shall have the right to purchase, severally and not jointly, up to $12,000,000 principal amount of Additional Securities at the Purchase Price plus accrued interest, if any, to the date of payment and delivery. You may exercise this right on behalf of the Underwriters in whole or from time to time in part by giving written notice of each election to exercise the option not later than 30 days after the date of this Agreement. Any exercise notice shall specify the principal

amount of Additional Securities to be purchased by the Underwriters and the date on which such securities are to be purchased. Each purchase date must be at least one business day after the written notice is given and may not be earlier than the Closing Date for the Firm Securities nor later than ten business days after the date of such notice. Additional Securities may be purchased as provided in Section 4 hereof solely for the purpose of covering over allotments made in connection with the offering of the Firm Securities. On each day, if any, that Additional Securities are to be purchased (an "Option Closing Date"), each Underwriter agrees, severally and not jointly, to purchase the principal amount of Additional Securities (subject to such adjustments to eliminate fractional securities as you may determine) that bears the same proportion to the total number of Additional Securities to be purchased on such Option Closing Date as the principal amount of Firm Securities set forth in Schedule II hereto opposite the name of such Underwriter bears to the total principal amount of Firm Securities.

The Company hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated and Citigroup Global Markets Inc. on behalf of the Underwriters, it will not, during the period ending 90 days after the date of the Prospectus, (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise.

The foregoing sentence shall not apply to (i) the Securities to be sold hereunder or the Underlying Securities, (ii) the issuance by the Company of shares of Common Stock upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof and as described in the Prospectus or (iii) the issuance by the Company of any shares of Common Stock, options, or other securities to or for the benefit of employees of the Company on or after the date hereof pursuant to the Company's employee stock ownership plan or equity incentive plans as described in the Prospectus and the issuance by the Company of shares of Common Stock upon the exercise of any such options.

SECTION 3. Terms of Public Offering. You have advised the Company that the Underwriters propose to make a public offering of their respective portions of the Securities as soon after the Registration Statement and this Agreement have become effective as in your judgment is advisable.

SECTION 4. Payment and Delivery. Payment for the Firm Securities shall be made to the Company in Federal or other funds immediately available in New York City against delivery of such Firm Securities for the respective accounts of the several Underwriters at 10:30 a.m., New York City time, on December 7, 2005, or at such other time on the same or such other date, not later than December 14, 2005, as shall be designated in writing by you. The time and date of such payment are hereinafter referred to as the "Closing Date."

Payment for any Additional Securities shall be made to the Company in Federal or other funds immediately available in New York City against delivery of such Additional Securities for the respective accounts of the several Underwriters at 10:30 a.m., New York City time, on the date specified in the corresponding notice described in Section 3 or at such other time on the same or on such other date, in any event not later than January 10, 2006, as shall be designated in writing by you.

The Firm Securities and Additional Securities shall be in definitive form or global form, as specified by you, and in such denominations as you shall request in writing not later than one full business day prior to the Closing Date or the applicable Option Closing Date, as the case may be. The Firm Securities and Additional Securities shall be delivered to you on the Closing Date or an Option Closing Date, as the case may be, for the respective accounts of the several Underwriters, with any

transfer taxes payable in connection with the transfer of the Securities to the Underwriters duly paid, against payment of the Purchase Price therefor plus accrued interest, if any, to the date of payment and delivery.

SECTION 5. Conditions to the Underwriters' Obligations. The obligations of the Company to sell the Securities to the Underwriters and the several obligations of the Underwriters to purchase and pay for the Securities on the Closing Date are subject to the following conditions:

(a) Subsequent to the execution and delivery of this Agreement and prior to the Closing Date:

(i) there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible change that does not indicate the direction of the possible change, in the rating accorded any of the Company's securities by any "nationally recognized statistical rating organization," as such term is defined for purposes of Rule 436(g)(2) under the Securities Act; and

(ii) there shall not have occurred any change, or any development involving a prospective change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company, from that set forth in the Time of Sale Prospectus (exclusive of any amendments or supplements thereto subsequent to the date of this Agreement) that, in your judgment, is material and adverse and that makes it, in your judgment, impracticable to market the Securities on the terms and in the manner contemplated in the Time of Sale Prospectus.

(b) The Underwriters shall have received on the Closing Date a certificate, dated the Closing Date and signed by an executive officer of the Company, to the effect set forth in Section 5(a)(i) above and to the effect that the representations and warranties of the Company contained in this Agreement are true and correct as of the Closing Date and that the Company has complied in all material respects with all of the agreements and satisfied in all material respects all of the conditions on its part to be performed or satisfied hereunder on or before the Closing Date. The officer signing and delivering such certificate may rely upon the best of his or her knowledge as to proceedings threatened.

(c) The Underwriters shall have received on the Closing Date an opinion of Faegre & ▇▇▇▇▇▇ LLP, outside counsel for the Company, dated the Closing Date, to the effect that:

(i) the Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has the corporate power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and (based solely on an examination of certificates of government officials and agencies) is duly qualified to transact business and is in good standing in each jurisdiction set forth in a schedule to such opinion, except where the failure to be so qualified or be in good standing would not have a material adverse effect on the Company;

(ii) the authorized capital stock of the Company conforms as to legal matters in all material respects to the description thereof contained in the Time of Sale Prospectus;

(iii) the shares of capital stock of the Company outstanding prior to the issuance of the Securities have been duly authorized and are validly issued and, to the knowledge of such counsel, fully paid and non-assessable;

(iv) the Securities have been duly authorized and, when executed and authenticated in accordance with the provisions of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will be valid and binding obligations of the Company, enforceable in accordance with their terms, subject to the effects

of applicable bankruptcy, insolvency and similar laws affecting creditors' rights generally and equitable principles of general applicability, and will be entitled to the benefits of the Indenture;

(v) the Underlying Securities issuable upon conversion of the Securities have been duly authorized and reserved and, when issued upon conversion of the Securities in accordance with the terms of the Securities, will be validly issued, fully paid and non-assessable, and the issuance of the Underlying Securities will not be subject to any preemptive or similar rights under (A) the laws of the State of Colorado; (B) the articles of incorporation or by-laws of the Company or (C) to the knowledge of such counsel, any agreement or instrument to which the Company is a party;

(vi) the Indenture has been duly authorized, executed and delivered by, and is a valid and binding agreement of, the Company, enforceable in accordance with its terms, subject to the effects of applicable bankruptcy, insolvency and similar laws affecting creditors' rights generally and equitable principles of general applicability; and the Indenture has been duly qualified under the Trust Indenture Act;

(vii) this Agreement has been duly authorized, executed and delivered by the Company;

(viii) except for such conflicts or violations, when considered alone or taken together with all other conflicts or violations, would not have a material adverse effect on the Company, the execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement, the Indenture and the Securities will not contravene any provision of applicable law or the articles of incorporation or By-laws of the Company or, to such counsel's knowledge, any agreement or other instrument binding upon the Company that is material to the Company, or, to such counsel's knowledge, any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by the Company of its obligations under this Agreement, the Indenture or the Securities, except such as may be required by the securities or Blue Sky laws of the various states (as to which we express no opinion) in connection with the offer and sale of the Securities;

(ix) the statements relating to legal matters, documents or proceedings included in (A) the Time of Sale Prospectus and the Prospectus under the captions "Description of the Debentures," "Description of Capital Stock," "Underwriters" (except relating to price, stabilization, short positions and passive market-making activities, as to which such counsel need not express an opinion), "Description of Debt Securities" and "Description of Common Stock" and (B) the Registration Statement in Item 15, in each case insofar as such statements constitute summaries of the legal matters, documents or proceedings referred to therein fairly summarize in all material respects such matters, documents or proceedings;

(x) after due inquiry, such counsel does not know of any legal or governmental proceedings pending or threatened to which the Company is a party or to which any of the properties of the Company is subject that are required to be described in the Registration Statement or the Prospectus and are not so described or of any statutes, regulations, contracts or other documents that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described or filed as required;

(xi) the Company is not, and after giving effect to the offering and sale of the Securities and the application of the proceeds thereof as described in the Prospectus will not be,

required to register as an "investment company" as such term is defined in the Investment Company Act of 1940, as amended;

(xii) the statements set forth under "Certain U.S. Federal Income Tax Considerations," insofar as they purport to describe the material tax consequences to a U.S. Holder of an investment in the Securities, fairly summarize the matters therein described; and

(xiii) nothing has come to the attention of such counsel that causes such counsel to believe that (A) the Registration Statement or the Time of Sale Prospectus (except for the financial statements and the notes and financial schedules thereto and other financial, statistical and accounting information and data included or incorporated by reference therein, collectively, the "Excluded Information", as to which such counsel need not express any belief) do not comply as to form in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder, or (B) each document filed pursuant to the Exchange Act and incorporated by reference in the Registration Statement and the Prospectus (except for the Excluded Information, as to which such counsel need not express any belief), on the date such document was filed with the Commission, did not comply as to form in all material respects with the requirements of the Exchange Act and the applicable rules and regulations of the Commission thereunder.

In addition, such counsel shall state that, although such counsel has not undertaken to determine independently and, therefore, except for the opinions set forth in clauses (c)(ii), (ix) and (xii) above, does not assume any responsibility, explicitly or implicitly, for the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Prospectus and the Time of Sale Prospectus, such counsel has participated in the preparation of the Registration Statement, the Prospectus and the Time of Sale Prospectus, including review and discussion of the contents thereof, and that, based upon and subject to the foregoing and the other qualifications and limitations set forth in such counsel's opinion, nothing has come to the attention of such counsel that causes such counsel to believe that (1) any part of the Registration Statement (except for the Excluded Information, as to which such counsel need not express any belief), when such part became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (2) the Registration Statement or the Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) on the date of this Agreement contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (3) the Time of Sale Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) as of the date of this Agreement or as amended or supplemented, if applicable, as of the Closing Date contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made not misleading or (4) the Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) as amended or supplemented, if applicable, as of the Closing Date contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made not misleading.

In giving such opinion and belief, counsel for the Company may (x) as to matters of fact, rely on certificates of the Company or officers of the Company and other information from governmental officials, (y) state that it is opining only as to matters of federal and Colorado, and (z) state that its opinion and belief are based upon its participation in the preparation of the Registration Statement, the Time of Sale Prospectus and Prospectus and any amendments or supplements thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified.

The opinion described in Section 5(c) above shall be rendered to the Underwriters at the request of the Company and shall so state therein.

(d) The Underwriters shall have received on the Closing Date an opinion of ▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇, general counsel for the Company, dated the Closing Date, to the effect that:

(i) to such counsel's knowledge, the Company possesses the Government Licenses necessary to conduct its commercial airline operations as described in the Time of Sale Prospectus and the Company is in compliance with the terms and conditions of all such Government Licenses, except where the failure to so comply would not, singly or in the aggregate, have a material adverse effect on the Company, and all of the Government Licenses are valid and in full force and effect, except where the invalidity of such Government Licenses or the failure of such Governmental Licenses to be in full force and effect would not have a material adverse effect on the Company; and

(ii) the Company is an "air carrier" within the meaning of that portion of the United States Code comprising those provisions formerly referred to as the Federal Aviation Act of 1958, and now primarily codified in Title 49 of the United States Code, as amended, and holds an "air carrier operating certificate issued by the Secretary of Transportation" within the meaning of 11 U.S.C. Section 1110. The routes presently operated by the Company as described in the Time of Sale Prospectus are being operated pursuant to valid certificates or authorizations issued by the Federal Aviation Administration.

In addition, such counsel shall state that, although such counsel has not undertaken to determine independently, and therefore, does not assume any responsibility, explicitly or implicitly, for, the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Prospectus and the Time of Sale Prospectus, such counsel has participated in the preparation of the Registration Statement, the Prospectus and the Time of Sale Prospectus, including review and discussion of the contents thereof, and that, based upon and subject to the foregoing and the other qualifications and limitations set forth in such counsel's opinion, nothing has come to the attention of such counsel that causes such counsel to believe that (A) any part of the Registration Statement (except for the Excluded Information, as to which such counsel need not express any belief), when such part became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (B) the Registration Statement or the Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) on the date of this Agreement contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (C) the Time of Sale Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) as of the date of this Agreement or as amended or supplemented, if applicable, as of the Closing Date contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made not misleading or (D) the Prospectus (except for the Excluded Information, as to which such counsel need not express any belief) as amended or supplemented, if applicable, as of the Closing Date contains any untrue statement of a material fact or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made not misleading.

In giving such opinion and belief, such counsel may (1) as to matters of fact, rely on certificates of the Company or officers of the Company and other information from governmental officials, (2) state that it is opining only as to matters of federal and Colorado law, and (3) state that its opinion and belief are based upon its participation in the preparation of the Registration Statement, the Time of Sale Prospectus and the Prospectus and any amendments or supplements

thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified.

(e) The Underwriters shall have received on the Closing Date an opinion of Cravath, Swaine & ▇▇▇▇▇ LLP, counsel for the Underwriters, dated the Closing Date, in form and substance reasonably satisfactory to you.

(f) The Underwriters shall have received, on each of the date hereof and the Closing Date, a letter dated the date hereof or the Closing Date, as the case may be, in form and substance satisfactory to the Underwriters, from KPMG LLP, independent registered public accountants, containing statements and information of the type ordinarily included in accountants' "comfort letters" to underwriters with respect to the financial statements and certain financial information contained in or incorporated by reference into the Registration Statement, the Time of Sale Prospectus and the Prospectus; provided that the letter delivered on the Closing Date shall use a "cut-off date" not earlier than the date hereof.

(g) The "lock-up" agreements, each substantially in the form of Exhibit A hereto, between you and officers and directors, and holders of warrants, of the Company listed on Schedule III hereto relating to sales and certain other dispositions of shares of Common Stock or certain other securities, delivered to you on or before the date hereof, shall be in full force and effect on the Closing Date.

(h) The Underwriters shall have received on the Closing Date such documents as you may reasonably request with respect to the good standing of the Company, the due authorization and issuance of the Securities and other matters related to the issuance of the Securities.

The several obligations of the Underwriters to purchase Additional Securities hereunder are subject to the delivery to you on the applicable Option Closing Date of each of the documents referred to above dated as of the Option Closing Date (except that insofar as any documents relate to Securities, they may be limited to covering only Additional Securities).

SECTION 6. Covenants of the Company. In further consideration of the agreements of the Underwriters herein contained, the Company covenants with each Underwriter as follows:

(a) To furnish to you, without charge, five signed copies of the Registration Statement (including exhibits thereto) and for delivery to each other Underwriter a conformed copy of the Registration Statement (without exhibits thereto) and to furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Section 6(e) or (f) below, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

(b) Before amending or supplementing the Registration Statement, the Time of Sale Prospectus or the Prospectus, to furnish to you a copy of each such proposed amendment or supplement and not to file any such proposed amendment or supplement to which you reasonably object, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c) To furnish to you a copy of each proposed free writing prospectus to be prepared by or on behalf of, used by, or referred to by the Company and not to use or refer to any proposed free writing prospectus to which you reasonably object.

(d) Not to take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

(e) If the Time of Sale Prospectus is being used to solicit offers to buy the Securities at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus in order to make the statements therein, in the light of the circumstances, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement then on file, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not, in the light of the circumstances when delivered to a prospective purchaser, be misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f) If, during such period after the first date of the public offering of the Securities as in the reasonable opinion of counsel for the Underwriters the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) under the Securities Act) is required by law to be delivered in connection with sales by an Underwriter or dealer, any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) under the Securities Act) is delivered to a purchaser, not misleading, or if, in the reasonable opinion of counsel for the Underwriters, it is necessary to amend or supplement the Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to the dealers (whose names and addresses you will furnish to the Company) to which Securities may have been sold by you on behalf of the Underwriters and to any other dealers upon request, either amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) under the Securities Act) is delivered to a purchaser, be misleading or so that the Prospectus, as amended or supplemented, will comply with law.

(g) To endeavor to qualify the Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions as you shall reasonably request.

(h) If the third anniversary of the initial effective date of the Registration Statement occurs before all the Securities have been sold by the Underwriters, prior to the third anniversary to file a new shelf registration statement and to take any other action necessary to permit the public offering of the Securities to continue without interruption; references herein to the Registration Statement shall include the new registration statement declared effective by the Commission.

(i) To make generally available to the Company's security holders and to you as soon as practicable an earning statement covering the twelve-month period ending December 31, 2006 that satisfies the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

SECTION 7. Expenses. Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Company agrees to pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including: (i) the fees, disbursements and expenses of the Company's counsel and the Company's accountants in connection with the registration and delivery of the Securities under the Securities Act and all other fees or expenses in connection with the preparation and filing of the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on

behalf of, used by, or referred to by the Company and amendments and supplements to any of the foregoing, including all printing costs associated therewith, and the mailing and delivering of copies thereof to the Underwriters and dealers, in the quantities hereinabove specified, (ii) all costs and expenses related to the transfer and delivery of the Securities to the Underwriters, including any transfer or other taxes payable thereon, (iii) any expenses incurred in connection with the qualification of the Securities for offer and sale under state securities laws as provided in Section 6(g) hereof or in connection with the review and qualification of the offering of the Securities by the NASD, including any filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection with such qualification, (iv) all costs and expenses incident to listing the Underlying Securities on the Nasdaq National Market, (v) the cost of printing certificates representing the Securities, (vi) the costs and charges of the Trustee and any transfer agent, registrar or depositary, (vii) the costs and expenses of the Company relating to investor presentations on any "road show" undertaken in connection with the marketing of the offering of the Securities, including, without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel and lodging expenses of the representatives and officers of the Company and any such consultants, and the cost of any aircraft chartered in connection with the road show and (viii) all other costs and expenses incident to the performance of the obligations of the Company hereunder for which provision is not otherwise made in this Section. It is understood, however, that except as provided in this Section, Section 9 entitled "Indemnity and Contribution", and the last paragraph of Section 11 below, the Underwriters will pay all of their costs and expenses, including fees and disbursements of their counsel, stock transfer taxes payable on resale of any of the Securities by them and any advertising expenses connected with any offers they may make.

SECTION 8. Covenant of the Underwriters. Each Underwriter severally covenants with the Company not to take any action that would result in the Company being required to file with the Commission under Rule 433(d) a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

SECTION 9. Indemnity and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or the Prospectus (as supplemented if the Company shall have furnished any amendments or supplements thereto), or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or omission or alleged untrue statement or omission based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein; provided, however, that the foregoing indemnity agreement with respect to any preliminary prospectus shall not inure to the benefit of any Underwriter from whom the person asserting any such losses, claims, damages or liabilities purchased Securities, or any person controlling such Underwriter, if a copy of the Prospectus (as then amended or supplemented if the Company shall have furnished any amendments or supplements thereto) was not sent or given by or on behalf of such Underwriter to such person, if required by law so to have been delivered, at or prior to the written confirmation of the sale of the Securities to such person, and if the Prospectus (as so amended or supplemented) would

have cured the defect giving rise to such losses, claims, damages or liabilities, unless such failure is the result of noncompliance by the Company with Section 6(a) hereof.

(b) Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as the foregoing indemnity from the Company to such Underwriter, but only with reference to information relating to such Underwriter furnished to the Company in writing by such Underwriter through you expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any other free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or the Prospectus or any amendment or supplement thereto.

(c) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to Section 9(a) or 9(b), such person (the "Indemnified Party") shall promptly notify the person against whom such indemnity may be sought (the "Indemnifying Party") in writing and the indemnifying party, upon request of the indemnified party, shall retain counsel reasonably satisfactory to the indemnified party to represent the indemnified party and any others the indemnifying party may designate in such proceeding and shall pay the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and the indemnified party shall have mutually agreed to the retention of such counsel or (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all such indemnified parties and that all such fees and expenses shall be reimbursed as they are incurred. Such firm shall be designated in writing by ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated, in the case of parties indemnified pursuant to Section 9(a), and by the Company, in the case of parties indemnified pursuant to Section 9(b). The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by the second and third sentences of this paragraph, the indemnifying party agrees that it shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding.

(d) To the extent the indemnification provided for in Section 9(a) or 9(b) is unavailable to an indemnified party or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each indemnifying party under such paragraph, in lieu of indemnifying such indemnified party thereunder, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the

relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Securities or (ii) if the allocation provided by clause 9(d)(i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause 9(d)(i) above but also the relative fault of the Company on the one hand and of the Underwriters on the other hand in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other hand in connection with the offering of the Securities shall be deemed to be in the same respective proportions as the net proceeds from the offering of the Securities (before deducting expenses) received by the Company and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate public offering price of the Securities. The relative fault of the Company on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties' relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Underwriters' respective obligations to contribute pursuant to this Section 9 are several in proportion to the respective number of Securities they have purchased hereunder, and not joint.

(e) The Company and the Underwriters agree that it would not be just or equitable if contribution pursuant to this Section 9 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in Section 9(d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages and liabilities referred to in the immediately preceding paragraph shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 9, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 9 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

(f) The indemnity and contribution provisions contained in this Section 9 and the representations, warranties and other statements of the Company contained in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Underwriter, any person controlling any Underwriter or any affiliate of any Underwriter or by or on behalf of the Company, its officers or directors or any person controlling the Company and (iii) acceptance of and payment for any of the Securities.

SECTION 10. Termination. The Underwriters may terminate this Agreement by notice given by you to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on, or by, as the case may be, any of the New York Stock Exchange, the American Stock Exchange or The Nasdaq National Market, (ii) trading of any securities of the Company shall have been suspended on any exchange or in any over-the-counter market, (iii) a material disruption in securities settlement, payment or clearance services in the United States shall have occurred, (iv) any moratorium on commercial banking activities shall have been declared by either Federal or New York State authorities or (v) there shall have occurred any outbreak or escalation of hostilities or any change in financial markets or any calamity or

crisis that, in your judgment, is material and adverse and which singly or together with any other event specified in this clause (v), makes it, in your judgment, impracticable or inadvisable to proceed with the offer, sale or delivery of the Securities on the terms and in the manner contemplated in the Time of Sale Prospectus or the Prospectus.

SECTION 11. Effectiveness; Defaulting Underwriters. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

If, on the Closing Date or an Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase Securities that it has or they have agreed to purchase hereunder on such date, and the aggregate principal amount of Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than one-tenth of the aggregate principal amount of the Securities to be purchased on such date, the other Underwriters shall be obligated severally in the proportions that the principal amount of Firm Securities set forth opposite their respective names in Schedule II bears to the aggregate principal amount of Firm Securities set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as you may specify, to purchase the Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date; provided that in no event shall the principal amount of Securities that any Underwriter has agreed to purchase pursuant to this Agreement be increased pursuant to this Section 11 by an amount in excess of one-ninth of such principal amount of Securities without the written consent of such Underwriter. If, on the Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Firm Securities and the aggregate principal amount of Firm Securities with respect to which such default occurs is more than one-tenth of the aggregate principal amount of Securities to be purchased, and arrangements satisfactory to you and the Company for the purchase of such Firm Securities are not made within 36 hours after such default, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter or the Company. In any such case either you or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration Statement, in the Time of Sale Prospectus, in the Prospectus or in any other documents or arrangements may be effected. If, on an Option Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Additional Securities and the aggregate principal amount of Additional Securities with respect to which such default occurs is more than one-tenth of the aggregate principal amount of Additional Securities to be purchased on such Option Closing Date, the non-defaulting Underwriters shall have the option to (i) terminate their obligation hereunder to purchase the Additional Securities to be sold on such Option Closing Date or (ii) purchase not less than the principal amount of Additional Securities that such non-defaulting Underwriters would have been obligated to purchase in the absence of such default. Any action taken under this paragraph shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

If this Agreement shall be terminated by the Underwriters, or any of them, because of any failure or refusal on the part of the Company to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason the Company shall be unable to perform its obligations under this Agreement, the Company will reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, severally, for all out-of-pocket expenses (including the reasonable fees and disbursements of their counsel) reasonably incurred by such Underwriters in connection with this Agreement or the offering contemplated hereunder.

SECTION 12. Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

SECTION 13. Applicable Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

SECTION 14. Headings. The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of this Agreement.

SECTION 15. Entire Agreement. (a) This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not superseded by this Agreement) that relate to the offering of the Securities, represents the entire agreement between the Company and the Underwriters with respect to the preparation of any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, the conduct of the offering, and the purchase and sale of the Securities.

(b) The Company acknowledges that in connection with the offering of the Securities: (i) the Underwriters have acted at arms length, are not agents of, and owe no fiduciary duties to, the Company or any other person, (ii) the Underwriters owe the Company only those duties and obligations set forth in this Agreement and (iii) the Underwriters may have interests that differ from those of the Company. The Company waives to the full extent permitted by applicable law any claims it may have against the Underwriters arising from an alleged breach of fiduciary duty in connection with the offering of the Securities.

		Very truly yours,
		FRONTIER AIRLINES, INC.
		by		Name: ▇▇▇▇ ▇. ▇▇▇▇▇▇ Title: President and Chief Executive Officer
		by		Name: ▇▇▇▇ ▇. ▇▇▇▇ Title: Chief Financial Officer

Accepted as of the date hereof ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & CO. INCORPORATED CITIGROUP GLOBAL MARKETS INC., Acting severally on behalf of themselves and the several Underwriters named in Schedule II hereto
by	▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & CO. INCORPORATED,
	by	Name: ▇▇▇ ▇▇▇▇ Title: Managing Director

SCHEDULE I

Indenture:		Indenture dated as of December 7, 2005 between the Company and the Trustee and the Supplemental Indenture to be dated as of December 7, 2005 between the Company and the Trustee
Trustee:		U.S. Bank National Association
Registration Statement File No.:		333-128407
Time of Sale Prospectus		Prospectus dated November 25, 2005 relating to the Shelf Securities
		Preliminary prospectus supplement dated November 29, 2005 relating to the Securities
		Free writing prospectus dated December 1, 2005 relating to the final terms of the Securities
Securities to be purchased:		5% Convertible Debentures due ▇▇▇▇
▇▇▇▇▇▇▇▇▇ Principal Amount:		$80,000,000 ($92,000,000 if overallotment option exercised in full)
Purchase Price:		96.75% of the principal amount of the Securities, plus accrued interest, if any, from December 7, 2005
Maturity:		December 15, 2025
Interest Rate:		5% per annum, accruing from December 7, 2005
Interest Payment Dates:		June 15 and December 15 commencing June 15, 2006
Closing Date and Time:		December 7, 2005 10:30 a.m.
Closing Location:		Cravath, Swaine & ▇▇▇▇▇ LLP Worldwide Plaza ▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇
Address for Notices to Underwriters:		▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated ▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇
Address for Notices to the Company:		Frontier Airlines, Inc. ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇

SCHEDULE II

Underwriter		Principal Amount of Firm Securities To Be Purchased
▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated		$	52,000,000
Citigroup Global Markets Inc.		$	28,000,000
	Total:	$	80,000,000

SCHEDULE III

Parties to Lock-Up Agreements

▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
D. ▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇▇ ▇. ▇▇▇▇▇▇▇
▇▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇
▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
B. ▇▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇▇ ▇. ▇▇▇▇▇▇
▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
▇▇▇ ▇. Block
▇▇▇▇ ▇. ▇▇▇▇
▇▇▇▇▇▇ ▇▇▇▇▇▇▇
▇▇▇▇ ▇▇▇▇
▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇
▇▇▇▇▇▇ ▇. ▇▇▇▇
▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇
▇▇▇▇▇▇ ▇. ▇▇▇▇
▇▇▇▇▇ ▇▇▇▇▇▇▇▇▇
▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇
▇▇▇▇▇▇▇▇ ▇. Van Leuven

EXHIBIT A

[FORM OF LOCK-UP LETTER]

November , 2005

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated
Citigroup Global Markets, Inc.

c/o: Morgan ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

Dear Sirs and Mesdames:

The undersigned understands that ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated ("▇▇▇▇▇▇ ▇▇▇▇▇▇▇"), Citigroup Global Markets Inc. ("Citigroup") (the "Underwriters") severally propose to enter into an Underwriting Agreement (the "Underwriting Agreement") with Frontier Airlines, Inc., a Colorado corporation (the "Company") providing for the public offering by the Underwriters, of Convertible Debentures of the Company (the "Convertible Debentures") (such offering referred to as the "Offering"). The Convertible Debentures will be convertible into shares of common stock of the Company (the "Common Stock").

To induce the Underwriters that may participate in the Offering to continue their efforts in connection with the Offering, the undersigned hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ and Citigroup on behalf of the Underwriters, it will not, during the period commencing on the date hereof and ending 90 days after the date of the final prospectus relating to the Offering (the "Prospectus"), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (a) transactions relating to shares of Common Stock or other securities acquired in open market transactions after the completion of the Offering, provided that no filing under Section 16(a) of the Securities Exchange Act of 1934, as amended (the "Exchange Act") shall be required or shall be voluntarily made in connection with subsequent sales of Common Stock or other securities acquired in such open market transactions or (b) transfers of shares of Common Stock or any security convertible into Common Stock as a bona fide gift; provided that in the case of any transfer or distribution pursuant to clause (b), (i) each donee shall sign and deliver a lock-up letter substantially in the form of this letter and (ii) no filing under Section 16(a) of the Exchange Act, reporting a reduction in beneficial ownership of shares of Common Stock, shall be required or shall be voluntarily made during the restricted period referred to in the foregoing sentence. In addition, the undersigned agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ and Citigroup on behalf of the Underwriters, it will not, during the period commencing on the date hereof and ending 90 days after the date of the Prospectus, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company's transfer agent and registrar against the transfer of the undersigned's shares of Common Stock except in compliance with the foregoing restrictions.

The undersigned understands that the Company and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward consummation of the Offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned's heirs, legal representatives, successors and assigns.

The undersigned understands that whether or not either Offering actually occurs depends on a number of factors, including market conditions. Any Offering will only be made pursuant to an Underwriting Agreement, the terms of which are subject to negotiation between the Company and the Underwriters.

		Very truly yours,
		(Name)
		(Address)

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$80,000,000 FRONTIER AIRLINES, INC. 5% CONVERTIBLE DEBENTURES DUE 2025 UNDERWRITING AGREEMENT

80,000,000 FRONTIER AIRLINES, INC. 5% CONVERTIBLE DEBENTURES DUE 2025 UNDERWRITING AGREEMENT

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