Securities and Exchange Commission
                             Washington, D. C. 20549

                                  Schedule 13G
                    Under the Securities Exchange Act of 1934
                                (Amendment No. 2)

                               Mesa Air Group Inc
                                  Common Stock
                             CUSIP Number 590479101

Date of Event Which Requires Filing of this Statement:      December 31, 2006

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [ X ]    Rule 13d-1(b)
         [     ]  Rule 13d-1(c)
         [     ]  Rule 13d-1(d)

CUSIP No. 590479101

         1)     Name of reporting person:
                  Batterymarch Financial Management, Inc.
                Tax Identification No.:
                  52-1893111

         2)     Check the appropriate box if a member of a group:
                  a)     n/a
                  b)     n/a

         3)     SEC use only

         4)     Place of organization:
                  Maryland

Number of shares beneficially owned by each reporting person with:
         5)     Sole voting power:           - 0 -
         6)     Shared voting power:         - 0 -
         7)     Sole dispositive power:      - 0 -
         8)     Shared dispositive power:    - 0 -

         9)     Aggregate amount beneficially owned by each reporting person:
                  - 0 -

         10)    Check if the aggregate amount in row (9) excludes certain shares
                  n/a

         11)    Percent of class represented by amount in row (9):
                  0.00%

         12)    Type of reporting person:
                       IA, CO
        _______________________________________________________________________
         Item 1a)     Name of issuer:
                           Mesa Air Group Inc

         Item 1b)     Address of issuer's principal executive offices:
                           410 North 44TH St
                           Suite 700
                           Phoenix AZ 85008

         Item 2a)    Name of person filing:
                           Batterymarch Financial Management, Inc.

         Item 2b)    Address of  principal business office:
                           200 Clarendon Street
                           Boston, MA  02116

         Item 2c)    Citizenship:
                           Maryland Corporation

         Item 2d)    Title of class of securities:
                           Common Stock

         Item 2e)    CUSIP number: 590479101

         Item 3)     If this statement is filed pursuant to Rule 13d-1(b),
                           or 13d-2(b), check whether the person filing is a:
         (a)[ ]Broker or dealer under Section 15 of the Act.
         (b)[ ]Bank as defined in Section 3(a) (6) of the Act.
         (c)[ ]Insurance Company as defined in Section 3(a) (6) of the Act.
         (d)[ ]Investment Company registered under Section 8 of the Investment
                 Company Act.
         (e)[X]Investment Adviser registered under Section 203 of the Investment
                 Advisers Act of 1940.
         (f)[ ]Employee Benefit Plan, Pension Fund which is subject to ERISA
                 of 1974 or Endowment Fund; see 240.13d-1(b)(ii)(F).
         (g)[ ]Parent holding company, in accordance with 240.13d-1(b)(ii)(G).
         (h)[ ]Group, in accordance with 240.13d-1(b)(1)(ii)(H).

         Item 4)    Ownership:
         (a)     Amount beneficially owned:  - 0 -

         (b)     Percent of Class:  0.00%

         (c)     Number of shares as to which such person has:
                  (i)   sole power to vote or to direct the vote:
                                     - 0 -
                  (ii)  shared power to vote or to direct the vote:
                                     - 0 -
                  (iii) sole power to dispose or to direct the disposition of:
                                     - 0 -
                  (iv)  shared power to dispose or to direct the disposition of:
                                     - 0 -

         Item 5)  Ownership of Five Percent or less of a class:
                  If this statement is being filed to report the fact that as of
                  the date hereof the reporting person has ceased to be the
                  beneficial owner of more than 5 percent of the class
                  of securities, check the following [ X ].

         Item 6)    Ownership of more than Five Percent on behalf of another
                    person:
                      n/a

         Item 7)    Identification and classification of the subsidiary which
                    acquired the security being reported on by the parent
                    holding company:

                           n/a

         Item 8)    Identification and classification of members of the group:
                           n/a

         Item 9)    Notice of dissolution of group:
                           n/a

         Item 10)   Certification:

                           By signing below I certify that, to the best of my
         knowledge and belief, the securities referred to above were acquired
         and are held in the ordinary course of business and were not acquired
         and are not held for the purpose of or with the effect of changing or
         influencing the control of the issuer of the securities and were not
         acquired and are not held in connection with or as a participant in
         any transaction having that purpose or effect.

                                    Signature
                                    -----------

                           After reasonable inquiry and to the best of my
         knowledge and belief, I certify that the information set forth in this
         statement is true, complete and correct.

         -------------------------------
         Date - February 12, 2007

         Batterymarch Financial Management, Inc.


         By _________________________________________________
            /s/  Francis X. Tracy, President