SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13G

                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                              (AMENDMENT NO.: 3 )*



Name of issuer:                             Alaska Air Group, Inc.


Title of Class of Securities:               Common Stock


CUSIP Number:                               011659109


Date of Event Which Requires Filing of this Statement: December 31, 2002

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)

*    The  remainder  of this  cover  page  shall be filled  out for a  reporting
     person's  initial  filing on this form with respect to the subject class of
     securities,  and for any subsequent amendment containing  information which
     would alter the disclosures provided in a prior cover page.

     The  information  required in the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 ("Act") or otherwise  subject to the  liabilities of that section of
the Act but shall be subject to all other  provisions of the Act  (however,  see
the Notes).


(Continued on the following page(s))


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                                       13G

CUSIP No.:  011659109


1.       NAME OF REPORTING PERSON
         S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                  Vanguard PRIMECAP Fund

2.       CHECK THE APPROPRIATE [LINE] IF A MEMBER OF A GROUP

                     A.                                B.          X
                                                      ---------------------

3.       SEC USE ONLY



4.       CITIZENSHIP OF PLACE OF ORGANIZATION

                  Delaware

(For  questions  5-8,  report  the number of shares  beneficially  owned by each
reporting person with:)

5.       SOLE VOTING POWER

                  2,540,000

6.       SHARED VOTING POWER

                  -0-

7.       SOLE DISPOSITIVE POWER

                  -0-

8.       SHARED DISPOSITIVE POWER

                  2,540,000

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  2,540,000

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

                  N/A

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                  9.57

12.      TYPE OF REPORTING PERSON

                  IV
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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                   ----------

                                  SCHEDULE 13G
                        UNDER THE SECURITIES ACT OF 1934
                                   ----------


Check the following [line] if a fee is being paid with this statement    n/a

Item 1(a) - Name of Issuer:

                  Alaska Air Group, Inc.


Item 1(b) - Address of Issuer's Principal Executive Offices:

                  19300 Pacific Highway South
                  Seattle, WA  98188


Item 2(a) - Name of Person Filing:

                  Vanguard PRIMECAP Fund

Item 2(b) - Address of Principal Business Office or, if none, residence:

          100 Vanguard Blvd., Malvern, PA  19355

Item 2(c) - Citizenship:

          The  fund  is a  business  trust  organized  under  the  laws  of  the
          Commonwealth of Delaware.

Item 2(d) - Title of Class of Securities:

                  Common Stock

Item 2(e) - CUSIP Number

                  011659109


Item 3 - Type of Filing:

          This  statement  is being filed  pursuant  to Rule  13d-1.  The person
          filing is an  investment  company  registered  under  Section 8 of the
          Investment Company Act.


Item 4 - Ownership:

         (a) Amount Beneficially Owned:

                  2,540,000

         (b) Percent of Class:

                  9.57

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         (c)  Number of shares as to which such person has:

              (i)  sole power to vote or direct to vote:      2,540,000

              (ii)  shared power to vote or direct to vote:   -0-

              (iii) sole power to dispose of or to direct the disposition of:
                           -0-

              (iv)  shared power to dispose or to direct the disposition of:
                           2,540,000

Item 5 - Ownership of Five Percent or Less of a Class:

         Not applicable

Item 6 - Ownership of More Than Five Percent on Behalf of Another Person:

         Not applicable

Item 7 - Identification  and Classification of the Subsidiary Which Acquired The
Security Being Reported on by the Parent Holding Company:

         Not applicable

Item 8 - Identification and Classification of Members of Group:

         Not applicable

Item 9 - Notice of Dissolution of Group:

         Not applicable

Item 10 - Certification:

     By signing  below I certify  than,  to the best of my knowledge and belief,
the  securities  referred  to above  were  acquired  in the  ordinary  course of
business  and were not acquired for the purpose of and do not have the effect of
changing or  influencing  the control of the issuer of such  securities and were
not acquired in connection  with or as a participant in any  transaction  having
such 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    2-14-2003                         BY /S/  JOSEPH F. DIETRICK
    ---------------                           -------------------------------
                                              JOSEPH F. DIETRICK



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