<PAGE>
                                                                   Exhibit 10.14

                                             * TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                           UNDER 17 C.F.R. SECTION 200.80(B)(4),
                                                            200.83 AND 240.24b-2

                          FIFTH AMENDMENT TO CODE SHARE
                          AND REVENUE SHARING AGREEMENT

     THIS FIFTH AMENDMENT TO CODE SHARE AND REVENUE SHARING AGREEMENT ("Fifth
Amendment") is made and entered into as of January 28, 2005 (the "Effective
Date"), among AMERICA WEST AIRLINES, INC., a Delaware corporation ("AWA"), MESA
AIRLINES, INC., a Nevada corporation ("Mesa"), AIR MIDWEST, INC., a Kansas
corporation ("AM"), and FREEDOM AIRLINES, INC., a Nevada corporation
("Freedom"). Mesa, AM and Freedom are referred to collectively as the "Mesa
Group".

     RECITALS:

     A. AWA and the Mesa Group are parties to that certain Code Share and
Revenue Sharing Agreement, dated to be effective February 1, 2001, as amended by
that certain First Amendment to Code Share and Revenue Sharing Agreement, dated
to be effective April 27, 2001, that certain Second Amendment to Code Share and
Revenue Sharing Agreement, dated to be effective October 24, 2002 ("Second
Amendment"), that certain Third Amendment to Code Share and Revenue Sharing
Agreement, dated to be effective January 29, 2003 ("Third Amendment"), and that
certain Fourth Amendment to Code Share and Revenue Sharing Agreement and
Release, dated to be effective September 5, 2003 (collectively, the "Code Share
Agreement"). All capitalized terms used herein, but not otherwise defined
herein, shall have the meanings given to such terms in the Code Share Agreement.

     B. The Code Share Agreement requires the Mesa Group to provide certain
Flight Services for AWA, pursuant to the terms and conditions of the Code Share
Agreement.

     C. The Mesa Group and AWA desire to amend the Code Share Agreement pursuant
to the terms and conditions of this Fifth Amendment.

     D. The Mesa Group and AWA desire to terminate certain Subcontracting of
Services and allow for Subcontracting of Services under limited circumstances.

     NOW, THEREFORE, in consideration of the promises, covenants,
representations and warranties hereinafter set forth, and for other valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, AWA
and the Mesa Group agree as set forth below.

     AMENDMENTS:

<PAGE>

     1.   The parties agree that Section 2.2.2(b) of the Code Share Agreement is
          amended in its entirety as follows:

          (b) AWA shall have the options to expand the CRJ Fleet from the Option
          Aircraft. On or before each option "Exercise Date" (as set forth on
          Exhibit A), AWA, by written notice to Mesa (the "Option Notice"),
          shall have the option to require Mesa to increase the CRJ Subfleet by
          the addition of the applicable CRJ Aircraft (as set forth on Exhibit
          A) in the applicable "In Service Months" (as set for on Exhibit A)
          (each, a "Fleet Expansion Option"). Each Option Notice shall specify
          whether AWA is selecting either a CRJ Model 700 or 900. If the Option
          Notice does not specify the CRJ Model, then AWA shall be deemed to
          have selected a CRJ Model 900. The Fleet Expansion Options are
          separate and individual options and may be exercised or not exercised
          on a separate and individual basis. If AWA does not exercise a Fleet
          Expansion Option timely, then the applicable Option Aircraft shall not
          be added to the CRJ Subfleet and shall not be placed into Flight
          Services. The Aircraft that are the subject of each exercise of a
          Fleet Expansion Option shall be added to the Fleet by Mesa in the
          applicable In Service Months. Mesa shall provide AWA with at least 90
          days prior written notice of the week each Option Aircraft will be
          placed into Flight Service under this Agreement and at least 60 days'
          prior written notice of the Scheduled Delivery Date for each Option
          Aircraft that is the subject of each exercised Fleet Expansion Option.

     2.   The parties agree that Section 8.1 of the Code Share Agreement is
          amended in its entirety as follows:

          Term. The term of this Agreement (the "Term") commences on the
          Effective Date retroactive to the Contract Date (the "Commencement
          Date") and shall expire at 11:59 p.m., Phoenix time, on June 30, 2012
          ("Expiration Date"), unless earlier terminated as provided in this
          Agreement. Notwithstanding the foregoing to the contrary, if any of
          the Option Aircraft is added to the CRJ Subfleet pursuant to Section
          2.2.2(b), then the Expiration Date shall be extended to 11:59 p.m.,
          Phoenix time, on the date eight (8) years after the last day of the In
          Service Month (as set forth on Exhibit A) for the last Option Aircraft
          added to the CRJ Subfleet. By way of example, if AWA adds the Option
          Aircraft with the December 2006 In Service Month and does not add any
          of the remaining seven Option Aircraft from January 2007 through July
          2007, the Expiration Date shall be extended to 11:59 p.m., Phoenix
          time, on December 31, 2014. AWA, by written notice to Mesa at least
          180 days prior to the Expiration Date, may further extend the
          Expiration Date for two years, expiring at 11:59 p.m., Phoenix time,
          on either (i) June 30, 2014; or (ii) the date ten (10) years after the
          last day of the In Service Month for the last Option Aircraft added to
          the CRJ Subfleet, if applicable. Unless AWA


                                        2

<PAGE>

          does not exercise any of the Fleet Expansion Options, Mesa and AWA
          shall execute an amendment to this Section 8.1 following the Exercise
          Date for the last Option Aircraft specifying the revised Expiration
          Date.

     3.   The parties agree that the second page of Exhibit A of the Code Share
          Agreement is amended in its entirety as set forth in Exhibit 1 to this
          Fifth Amendment.

     AGREEMENTS:

     4.   900 Election Notice. Mesa acknowledges: (i) receipt of AWA's 900
          Election Notice dated April 29, 2004, rejecting the twelve (12) CRJ
          Model 900s pursuant to Section 2.2.5(e) of the Code Share Agreement;
          and (ii) as a result thereof, the twelve (12) CRJ Model 900s scheduled
          to be delivered into Flight Services from April 2005 to November 2005,
          pursuant to the Delivery Schedule, will not be added to the CRJ
          Subfleet and will not be placed into Flight Services.

     5.   Termination of Consent to Subcontracting. AWA and the Mesa Group agree
          that AWA's consent to subcontracting granted to both Freedom and AM
          pursuant to the Code Share Agreement is terminated, except as set
          forth in Section 6 below. Notwithstanding the preceding sentence, (i)
          Freedom's assumption relating to the CRJ 700 Services (as set forth in
          Section 2 of the Second Amendment) and relating to the CRJ 900
          Services (as set forth in Section 2 of the Third Amendment) shall
          remain in effect for all CRJ 700 Services and CRJ 900 Services
          previously provided by Freedom pursuant to the Code Share Agreement
          and (ii) AM's assumption relating to the AM Services shall remain in
          effect for all AM Services previously provided by AM pursuant to the
          Code Share Agreement. AM confirms and acknowledges that for all AM
          Services previously provided by AM pursuant to the Code Share
          Agreement, AM assumed and agreed to be bound by all of the
          liabilities, obligations, and duties of Mesa applicable to the AM
          Services. Nothing in this Section 5 shall prohibit Mesa, after the
          Effective Date of this Fifth Amendment, from seeking AWA's consent for
          the Subcontracting of Services pursuant to Section 2.1 of the Code
          Share Agreement.

     6.   Consent to Subcontracting for Beech 1900s. The consent to
          subcontracting granted to AM and Freedom shall remain in effect only
          for the limited circumstance in which irregular operations make a
          Flight for which a Dash 8 Aircraft is scheduled to be used by Mesa
          subject to cancellation ("Swap Flight"), and AM or Freedom is
          available to provide Flight Services for the Swap Flight (and avoid
          cancellation of the Swap Flight) using a Beech 1900 Aircraft. For such
          Swap Flights, Freedom and AM assume and agree to discharge,


                                        3

<PAGE>

          perform, and satisfy on behalf of Mesa all the obligations,
          liabilities and duties of Mesa under the Code Share Agreement relating
          to the provision of these Flight Services, in the time and manner
          required by the Code Share Agreement, to the same extent Mesa is
          required to perform and satisfy such obligations, liabilities and
          duties under the Code Share Agreement. AWA shall make payments for the
          Swap Flights to Mesa for negotiated activity costs for the Beech 1900
          Aircraft, which shall include de-icing expenses (if any), fuel costs,
          landing fees, security outside AWA Service locations (if any), the
          B1900 station cost per departure (as set forth in Exhibit B to the
          Code Share Agreement), the Beech 1900 flight crew cost per block hour
          and dispatcher cost per departure (as set forth in Exhibit C to the
          Code Share Agreement), and the Beech 1900 maintenance cost per block
          hour and maintenance cost per departure (as set forth in Exhibit D to
          the Code Share Agreement). Payments for the Swap Flights shall not
          include any fixed monthly costs relating to the Beech 1900 Aircraft.

     7.   Effect. Except as set forth in this Fifth Amendment, all of the terms
          and conditions of the Code Share Agreement shall remain in full force
          and effect and be applicable to this Fifth Amendment.

     8.   Counterparts. This Fifth Amendment may be executed in counterparts,
          all of which when taken together shall be one and the same document.

     9.   Entire Agreement. This Fifth Amendment constitutes the entire
          agreement between the parties with respect to the subject matter
          hereof and supersedes all prior understandings with respect thereto.

                        [SIGNATURES APPEAR ON NEXT PAGE]


                                        4

<PAGE>

                                        AMERICA WEST AIRLINES, INC.


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        MESA AIRLINES, INC.


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        FREEDOM AIRLINES, INC.


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        AIR MIDWEST, INC.


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------


                                        5

<PAGE>

                                    Exhibit 1


                                        6

<PAGE>

                                    EXHIBIT A
                               OPTION CRJ-700/900
                                DELIVERY SCHEDULE

<TABLE>
<CAPTION>
            Option
          CRJ-7/900
          ---------
<S>       <C>
 Nov-05
 Dec-05
 Jan-06
 Feb-06
 Mar-06
 Apr-06
 May-06
*Jun-06      [*]
*Jul-06      [*]
*Aug-06      [*]
 Sep-06      [*]
 Oct-06      [*]
 Nov-06      [*]
 Dec-06      [*]
 Jan-07      [*]
 Feb-07      [*]
 Mar-07      [*]
 Apr-07      [*]
 May-07      [*]
 Jun-07      [*]
 Jul-07       *
             ---
 Totals       *
             ===
</TABLE>

Note: [*]

*[*]


                                        7