<Page> Exhibit 3.15 ARTICLES OF INCORPORATION OF CHICAGO EXPRESS AIRLINES, INC. ARTICLE ONE Name The name of the corporation is Chicago Express Airlines, Inc. ARTICLE TWO Authorized Shares The total number of shares of all classes which the Corporation has authority to issue is 1,300,000 of which 1,000,000 shares shall be designated as "Common Stock," and 300,000 shares shall be designated as "Preferred Stock." The designations and the preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption of the shares of each class of stock are as follows: PREFERRED STOCK The Preferred Stock may be issued from time to time by the Board of Directors as shares of one or more series. The description of shares of each series of Preferred Stock, including any preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption shall be as set forth in resolutions adopted by the Board of Directors, and articles of amendment shall be filed with the Georgia Secretary of State as required by law to be filed with respect to issuance of such Preferred Stock, prior to the issuance of any shares of such series. The Board of Directors is expressly authorized, at any time, by adopting resolutions providing for the issuance of, or providing for a change in the number of, shares of any particular <Page> series of Preferred Stock and, if and to the extent from time to time required by law, by filing articles of amendment which are effective without Shareholder action to increase or decrease the number of shares included in each series of Preferred Stock, but not below the number of shares then issued, and to set or change in any one or more respects the designations, preferences, conversion or other rights, voting powers, restrictions, limitations as to dividends, qualifications, or terms and conditions of redemption relating to the shares of each such series. Notwithstanding the foregoing, the Board of Directors shall not be authorized to change the right of holders of the Common Stock of the Corporation to vote one vote per share on all matters submitted for shareholder action. The authority of the Board of Directors with respect to each series of Preferred Stock shall include, but not be limited to, setting or changing the following: (a) the annual dividend rate, if any, on shares of such series, the items of payment and the date from which dividends shall be accumulated, if dividends are to be cumulative; (b) whether the shares of such series shall be redeemable and, if so, the redemption price and the terms and conditions of such redemption; (c) the obligation, if any, of the Corporation to redeem shares of such series pursuant to a sinking fund; (d) whether shares of such series shall be convertible into, or exchangeable for, shares of stock of any other class or classes and, if so, the terms and conditions of such exchange, including the price or prices or the rate or rates of conversion or exchange and the terms of adjustment, if any; (e) whether the shares of such series shall have voting rights. In addition to the voting rights provided by law, and, if so, the extent of such voting rights; (f) the rights of the shares of such series in the event of voluntary or involuntary liquidation, dissolution or winding-up of the Corporation; and -2- <Page> (g) any other relative rights, powers, preferences, qualifications, limitations or restrictions thereof relating to such series. The shares of Preferred Stock of any one series shall be identical with each other in all respects except as to the dates from and after which dividends thereon shall cumulate, if cumulative. COMMON STOCK Subject to all of the rights of the Preferred Stock as expressly provided herein, by law or by the Board of Directors pursuant to this Article Two, the Common Stock of the Corporation shall possess all such rights and privileges as are afforded to capital stock by applicable law in the absence of any express grant of rights or privileges in the Corporation's Articles of Incorporation, including, but not limited to, the following rights and privileges: (a) dividends may be declared and paid or set apart for payment upon the Common Stock out of any assets or funds of the Corporation legally available for the payment of dividends; (b) the holders of Common Stock shall have the right to vote for the election of directors and on all other matters requiring stockholder action, each share being entitled to one vote; and (c) upon the voluntary or involuntary liquidation, dissolution or winding-up of the Corporation, the net assets of the Corporation available for distribution shall be distributed pro rata to the holders of the Common Stock in accordance with their respective rights and interests. ARTICLE THREE Registered Office and Agent The initial registered office of the corporation is located at 1201 Peachtree Street, N.E., Atlanta, Georgia 30361. The initial registered agent of the corporation at its registered office is CT Corporation System. -3- <Page> ARTICLE FOUR Incorporator The name and address of the incorporator is as follows: William H. Avery Alston & Bird 100 Galleria Parkway Suite 1200 Atlanta, Georgia 30339 ARTICLE FIVE Principal Office The mailing address of the initial principal office of the corporation is 1777 Phoenix Parkway, Suite 303, Atlanta, Georgia 30349. ARTICLE SIX Limitation of Director Liability 6.1 A director of the corporation shall not be personally liable to the corporation or its shareholders for monetary damages for breach of duty of care or other duty as a director, except for liability (i) for any appropriation, in violation of his duties, of any business opportunity of the corporation, (ii) for acts or omissions which involve intentional misconduct or a knowing violation of law, (iii) of the types set forth in Section 14-2-832 of the Georgia Business Corporation Code, or (iv) for any transaction from which the director derived an improper personal benefit. 6.2 Any repeal or modification of the provisions of this Article by the shareholders of the corporation shall be prospective only, and shall not adversely affect any limitation on the personal liability of a director of the corporation with respect to any act or omission occurring prior to the effective date of such repeal or modification. 6.3 If the Georgia Business Corporation Code is hereafter amended to authorize the further elimination or limitation of the liability of directors, then the liability of a director of the -4- <Page> corporation, in addition to the limitation on personal liability provided herein, shall be limited to the fullest extent permitted by the amended Georgia Business Corporation Code. 6.4 In the event that any of the provisions of this Article (including any provision within a single sentence) is held by a court of competent jurisdiction to be invalid, void or otherwise unenforceable, the remaining provisions are severable and shall remain enforceable to the fullest extent permitted by law. ARTICLE SEVEN Initial Board of Directors The initial Board of Directors shall consist of two members whose names and addresses are as follows: Carol J. Brady 1777 Phoenix Parkway, Suite 303 Atlanta, Georgia 30349 Bryan K. Bedford 1777 Phoenix Parkway, Suite 303 Atlanta, Georgia 30349 ARTICLE EIGHT Shareholder Action by Less Than Unanimous Written Consent Any action that is required or permitted to be taken at a meeting of the shareholders may be taken without a meeting if the action is taken by persons who would be entitled to vote at a meeting shares having voting power to cast not less than the minimum number (or numbers, in the case of voting by groups) of votes that would be necessary to authorize or take such action at a meeting at which all shareholders entitled to vote were present and voted. The action must be evidenced by one or more written consents describing the action taken, signed by shareholders entitled to take action without a meeting and delivered to the corporation for inclusion in the minutes or filing with the corporate records. -5- <Page> IN WITNESS WHEREOF, the undersigned executes these Articles of Incorporation this 12th day of February, 1993. William H. Avery -------------------------------- Incorporator ALSTON & BIRD 100 Galleria Parkway Suite 1200 Atlanta, Georgia 30339 (404) 881-7000 -6-