EXHIBIT 10.5.7


                                                                  EXECUTION COPY

           AMENDMENT NO. 4 TO SECURITY AGREEMENT AND CHATTEL MORTGAGE
                            (AIRCRAFT NO. N355MC)(1)

            THIS FOURTH  AMENDMENT TO THE SECOND SECURITY  AGREEMENT AND CHATTEL
MORTGAGE is dated as of November 30, 2004, (this "AMENDMENT"),  and entered into
by and between ATLAS AIR, INC., a Delaware corporation ("COMPANY"), and DEUTSCHE
BANK TRUST COMPANY AMERICAS, as agent for and representative of ("ADMINISTRATIVE
AGENT") the financial  institutions  ("LENDERS")  party to the Credit  Agreement
referred to below.  Unless otherwise defined herein,  all capitalized terms used
herein and defined in the Credit Agreement  referred to below are used herein as
therein defined.

                              W I T N E S 5 E T H;

            WHEREAS, Company is party to that certain Fifth Amended and Restated
Credit Agreement,  dated as of July 27, 2004, among Company, Atlas Air Worldwide
Holdings,   Inc.,   the  Lenders  from  time  to  time  party  thereto  and  the
Administrative  Agent (as amended,  modified  and/or  supplemented  from time to
time, the "CREDIT AGREEMENT").

            WHEREAS,  Company and the  Administrative  Agent are parties to that
certain  Second  Security  Agreement  and Chattel  Mortgage  with respect to one
Boeing  741-341,  U.S.  Registration  No. N355MC,  Manufacturer's  Serial Number
23395,  dated May 18, 2000,  between Atlas Air, Inc. as debtor and Deutsche Bank
Trust  Company  Americas  (formerly  Bankers  Trust  Company)  as Agent  for and
Representative  of the  Lenders  referred  to  therein,  recorded by the Federal
Aviation Administration on July 5, 2000, as Conveyance No. XX015580,  amended by
the First Amendment to Second Security  Agreement and Chattel Mortgage (Aircraft
No. 23395) dated as of May 1, 2002,  recorded  June 14, 2002, as Conveyance  No.
M000794,  further amended by the Second  Amendment to Second Security  Agreement
and Chattel Mortgage (Aircraft No. N355MC) dated as of April 30, 2004,  recorded
May 27, 2004, as Conveyance No. MM026455,  further amended by Amendment No. 3 to
Second Security Agreement and Chattel Mortgage (Aircraft No. N355MC) dated as of
July 27,  2004,  recorded  August 25,  2004,  as  Conveyance  No.  Q073444  (the
"AIRCRAFT CHATTEL MORTGAGE") and

            WHEREAS,  subject to the terms and conditions  set forth below,  the
parties hereto wish to amend certain provisions of the Aircraft Chattel Mortgage
as provided herein.

            NOW THEREFORE, it is agreed:

- ----------
(1) This  Amendment to the Second  Security  Agreement and Chattel  Mortgage has
been  executed  in  several  counterparts.  To the  extent,  if any,  that  this
Amendment to the Second  Security  Agreement  and Chattel  Mortgage  constitutes
chattel  paper (as such term is defined  in the  Uniform  Commercial  Code as in
effect in any applicable  jurisdiction),  no security interest in this Amendment
to the Second Security Agreement and Chattel Mortgage may be created through the
transfer  or  possession  of  any  counterpart  other  than  the  original.  The
counterpart to be deemed the original shall be the counterpart that contains the
receipt  therefor  executed  by  Deutsche  Bank  Trust  Company   Americas,   as
Administrative  Agent, on the signature page thereof and no security interest in
this  Amendment to the Second  Security  Agreement  and Chattel  Mortgage may be
created  through  the  transfer  of any  counterpart  other  than said  original
counterpart.



      1. Section 1(b)(i) of the Aircraft  Chattel  Mortgage is hereby amended by
deleting such  subsection  in its entirety and  inserting the following  text in
lieu thereof:

      (i) all the tolls, rents,  issues,  profits,  revenues and other income of
the property subject or required to be subject to the lien of this Mortgage;

      2. Section 1(b)(xvi) of the Aircraft Chattel Mortgage is hereby amended by
deleting the period and inserting a semi-colon at the end thereof;

      3. Section 1(b) is hereby  amended by inserting the  following  text after
Section 1(b)(xvi):

      "PROVIDED,   HOWEVER,  that  in  no  event  shall  such  Aircraft  Related
      Collateral  include or be deemed or  construed to include any accounts (as
      such term is defined in the  Uniform  Commercial  Code as in effect in any
      applicable  jurisdiction)  or other  rights to  payment  arising  from the
      rendition of any ACMI Contract."

      4. This Amendment may be executed in any number of counterparts and by the
different parties hereto on separate  counterparts,  each of which  counterparts
when  executed  and  delivered  shall be an  original,  but all of  which  shall
together constitute one and the same instrument.  A complete set of counterparts
executed  by all the  parties  hereto  shall  be  lodged  with  Company  and the
Administrative Agent.

      5. This  Amendment  is limited as  specified  and shall not  constitute  a
modification,  acceptance  or  waiver  of any other  provision  of the  Aircraft
Chattel Mortgage.

      6. From and after the date hereof,  all references in the Aircraft Chattel
Mortgage  shall be deemed to be references to the Aircraft  Chattel  Mortgage as
modified hereby.

                                      * * *




            IN WITNESS  WHEREOF,  the  parties  hereto  have  caused  their duly
authorized  officers to execute and deliver this  Amendment as of the date first
above written.

                                        ATLAS AIR, INC.


                                        By: /s/ Dorinda Pannozzo
                                            ---------------------------------
                                            Name: Dorinda Pannozzo
                                            Title: Assistant Treasurer

                                                  Security Agreement and Chattel
                                        Mortgage Amendment to the First Security
                                                  Agreement and Chattel Mortgage
                                                           (Aircraft No. N355MC)



                                        DEUTSCHE BANK TRUST COMPANY
                                        AMERICAS,

                                        as Administrative Agent


                                        By: /s/ David J Bell
                                            ---------------------------------
                                            Name: David J Bell
                                            Title: Managing Director

                                                  Security Agreement and Chattel
                                        Mortgage Amendment to the First Security
                                                  Agreement and Chattel Mortgage
                                                           (Aircraft No. N355MC)






                           Schedule to Exhibit 10.5.7

The agreements listed below are substantially identical to this exhibit and are
not being filed separately as exhibits pursuant to instruction 2 to Regulation
S-K, Item 601.



- -------------------- ------------------------ ---------------- ------------------------- -----------------------------
REGISTRATION         MANUFACTURER'S SERIAL    AGENT            BORROWER                  AGREEMENT
NUMBER               NUMBER(S)
- -------------------- ------------------------ ---------------- ------------------------- -----------------------------
                                                                             
N540MC               22508                    Deutsche Bank    Atlas Air, Inc.           Amendment No. 2 to Second
                                              Trust Company                              Security Agreement (N540MC)
                                              Americas                                   dated as of November 30,
                                                                                         2004 to secure obligations
                                                                                         under the Aircraft Credit
                                                                                         Facility.
- -------------------- ------------------------ ---------------- ------------------------- -----------------------------

N536MC               21576                    Deutsche Bank    Atlas Air, Inc.           Amendment No. 3 to Second
                                              Trust Company                              Security Agreement (N536MC)
                                              Americas                                   dated as of November 30,
                                                                                         2004 to secure obligations
                                                                                         under the Aircraft Credit
                                                                                         Facility.
- -------------------- ------------------------ ---------------- ------------------------- -----------------------------