UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 2)*

                          Northrop Grumman Corporation
                 -----------------------------------------------
                                (Name of Issuer)

                                  Common Stock
                 -----------------------------------------------
                         (Title of Class of Securities)

                                   666807 10 2
                 -----------------------------------------------
                                 (CUSIP Number)

                                Thomas P. Hyatte
                                  Unitrin, Inc.
                              One East Wacker Drive
                                Chicago, IL 60601
                                 (312) 661-4520
                 -----------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)


                                February 11, 2002
                 -----------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition that is the subject of this Schedule 13D, and is filing this
schedule because of ss.ss.240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the
following box. [ ]

Note: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See ss.240.13d-7 for other
parties to whom copies are to be sent.

* 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
disclosures provided in a prior cover page.

The information required on 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).

                                  Page 1 of 6





                                                                     Page 2 of 6

                                  SCHEDULE 13D

    CUSIP No. 666807 10 2
--------------------------------------------------------------------------------

1.   Names of Reporting Persons.
     I.R.S. Identification Nos. of above persons (entities only).

     Unitrin, Inc.
     95-4255452
--------------------------------------------------------------------------------
2.   Check the Appropriate Box if a Member of a Group (See Instructions)
                                                                     (a) [   ]
                                                                     (b) [   ]
--------------------------------------------------------------------------------

3.   SEC Use Only
--------------------------------------------------------------------------------
4.   Source of Funds (See Instructions)
     N/A
--------------------------------------------------------------------------------
5.   Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d)
     or 2(e) [   ]
--------------------------------------------------------------------------------
6.   Citizenship or Place of Organization
     Delaware
--------------------------------------------------------------------------------

                            7.   Sole Voting Power
                                 1,617,140
        Number of          -----------------------------------------------------
         Shares             8.   Shared Voting Power
      Beneficially               7,665,281
        Owned by           -----------------------------------------------------
          Each              9.   Sole Dispositive Power
        Reporting                1,617,140
         Person            -----------------------------------------------------
          With             10.   Shared Dispositive Power
                                 7,665,281
--------------------------------------------------------------------------------
11.  Aggregate Amount Beneficially Owned by Each Reporting Person
     9,282,421
--------------------------------------------------------------------------------
12.  Check if the Aggregate Amount in Row (11) Excludes Certain Shares
     (See Instructions)        [   ]
--------------------------------------------------------------------------------
13.  Percent of Class Represented by Amount in Row (11)
     9.36%
--------------------------------------------------------------------------------
14.  Type of Reporting Person (See Instructions)
     HC, CO




                                                                     Page 3 of 6



CUSIP No. 666807 10 2
--------------------------------------------------------------------------------
1.   Names of Reporting Persons.
     I.R.S. Identification Nos. of above persons (entities only).

     Trinity Universal Insurance Company
     75-0620550
--------------------------------------------------------------------------------
2.   Check the Appropriate Box if a Member of a Group (See Instructions)
                                                                     (a) [   ]
                                                                     (b) [   ]
--------------------------------------------------------------------------------
3.   SEC Use Only
--------------------------------------------------------------------------------
4.   Source of Funds (See Instructions)
     N/A
--------------------------------------------------------------------------------
5.   Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d)
     or 2(e) [   ]
--------------------------------------------------------------------------------
6.   Citizenship or Place of Organization
     Texas
--------------------------------------------------------------------------------

                           7.   Sole Voting Power
                                0
        Number of         -----------------------------------------------------
         Shares            8.   Shared Voting Power
      Beneficially              4,329,189
        Owned by          -----------------------------------------------------
          Each             9.   Sole Dispositive Power
        Reporting               0
         Person           -----------------------------------------------------
          With            10.   Shared Dispositive Power
                                4,329,189
--------------------------------------------------------------------------------
11.  Aggregate Amount Beneficially Owned by Each Reporting Person
     4,329,189
--------------------------------------------------------------------------------
12.  Check if the Aggregate Amount in Row (11) Excludes Certain Shares
     (See Instructions)        [   ]
--------------------------------------------------------------------------------
13.  Percent of Class Represented by Amount in Row (11)
     4.36%
--------------------------------------------------------------------------------
14.  Type of Reporting Person (See Instructions)
     IC, CO
--------------------------------------------------------------------------------



                                                                     Page 4 of 6

CUSIP No. 666807 10 2
--------------------------------------------------------------------------------
1.   Names of Reporting Persons.
     I.R.S. Identification Nos. of above persons (entities only).

     United Insurance Company of America
     36-1896670
--------------------------------------------------------------------------------
2.   Check the Appropriate Box if a Member of a Group (See Instructions)
                                                                     (a) [   ]
                                                                     (b) [   ]
--------------------------------------------------------------------------------
3.   SEC Use Only
--------------------------------------------------------------------------------
4.   Source of Funds (See Instructions)
     N/A
--------------------------------------------------------------------------------
5.   Check if Disclosure of Legal Proceedings Is Required Pursuant to Items 2(d)
     or 2(e) [   ]
--------------------------------------------------------------------------------
6.   Citizenship or Place of Organization
     Illinois
--------------------------------------------------------------------------------

                           7.   Sole Voting Power
                                0
           Number of       -----------------------------------------------------
            Shares         8.   Shared Voting Power
         Beneficially           3,336,092
           Owned by        -----------------------------------------------------
             Each          9.   Sole Dispositive Power
           Reporting            0
            Person         -----------------------------------------------------
             With          10.  Shared Dispositive Power
                                3,336,092

--------------------------------------------------------------------------------
11.  Aggregate Amount Beneficially Owned by Each Reporting Person
     3,336,092
--------------------------------------------------------------------------------
12.  Check if the Aggregate Amount in Row (11) Excludes Certain Shares
     (See Instructions)        [   ]
--------------------------------------------------------------------------------
13.  Percent of Class Represented by Amount in Row (11)
     3.36%
--------------------------------------------------------------------------------
14.  Type of Reporting Person (See Instructions)
     IC, CO




                                                                     Page 5 of 6

Amendment No. 2 to Schedule 13D

     This Amendment No. 2 amends and supplements the Schedule 13D originally
filed by Unitrin, Inc., Trinity Universal Insurance Company and United Insurance
Company of America, dated April 3, 2001, as amended by Amendment No. 1 thereto,
dated May 18, 2001. Terms used herein and not otherwise defined have the
meanings given such terms in the original Schedule 13D, dated April 3, 2001.

Item 1.  Security and Issuer.

     The class of equity securities to which this Schedule 13D relates is the
common stock, par value $1.00 per share (the "Common Stock"), of Northrop
Grumman Corporation (formerly NNG, Inc.), a Delaware corporation (the "Issuer").
The principal executive offices of the Issuer are located at 1804 Century Park
East, Los Angeles, California 90067.

Item 4.  Purpose of Transaction.

     Although their plans may change in the future, except as otherwise noted,
the reporting persons do not have, as of the date of this filing, any plans or
proposals that relate to or would result in any of the actions set forth in
sub-items (a) through (j) of Item 4, except that Unitrin or its affiliates may,
from time to time or at any time, subject to market conditions and other
factors, purchase additional shares of Common Stock or the Issuer's Series B
Convertible Preferred Stock in the open market, in privately negotiated
transactions or otherwise, or sell at any time all or a portion of shares of
Common Stock or Series B Convertible Preferred Stock now owned or hereafter
acquired by them to one or more purchasers.

Item 5.  Interest in Securities of the Issuer.

     On February 11, 2002, Trinity, a wholly-owned subsidiary of Unitrin,
transferred to Unitrin in the form of a dividend 312,498 shares of Series B
Convertible Preferred Stock, which are convertible into 284,736 shares of Common
Stock, representing all of Trinity's holdings in the Issuer's Series B
Convertible Preferred Stock. Prior to this dividend, Unitrin beneficially owned
such shares of Series B Convertible Preferred Stock indirectly through Trinity.
Accordingly, this dividend merely changes Unitrin's interest in the transferred
shares from indirect to direct.

     As indicated on the cover pages, Unitrin beneficially owns 1,617,140 shares
of Common Stock over which it has sole voting and dispositive power and such
beneficial ownership is attributable to Unitrin's direct ownership of 1,774,812
shares of Series B Convertible Preferred Stock which are convertible into
1,617,140 shares of Common Stock. Unitrin beneficially owns 7,665,281 shares of
Common Stock over which it has shared voting and dispositive power and such
beneficial ownership is attributable to Trinity's and United's ownership of
7,665,281 shares of Common Stock in the aggregate.

     As indicated on the cover pages, Trinity beneficially owns 4,329,189 shares
of Common Stock over which it has shared voting and dispositive power and such
beneficial ownership is attributable to Trinity's direct ownership of such
number of shares of Common Stock.

     As indicated on the cover pages, United beneficially owns 3,336,092 shares
of Common Stock over which it has shared voting and dispositive power and such
beneficial ownership is attributable to United's direct ownership of such number
of shares of Common Stock.






                                                                     Page 6 of 6

     Except as set forth elsewhere in this Amendment No. 2, neither of Unitrin,
Trinity or United acquired or disposed of any shares of the Issuer's Common
Stock since May 18, 2001, the date of Amendment No. 1 to Schedule 13D. However,
in addition to the changes in Unitrin's and Trinity's beneficial ownership
resulting from the dividend described above, the ownership percentage of
Unitrin, Trinity and United changed as a consequence of an increase in the
number of outstanding shares of the Issuer's Common Stock since May 18, 2001.
The result of these changes is that the ownership percentage of Unitrin, Trinity
and United has decreased from 10.9%, 5.4% and 3.9%, respectively, as reported in
Amendment No. 1 to Schedule 13D to approximately 9.36%, 4.36%, and 3.36%,
respectively, as of the date of this Amendment.

                                    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 13, 2002                  UNITRIN, INC.


                                          By: /s/ David F. Bengston
                                              ----------------------------------
                                              David F. Bengston
                                              Vice President

                                          TRINITY UNIVERSAL INSURANCE COMPANY


                                          By: /s/ Johm M. Boschelli
                                              ----------------------------------
                                              John M. Boschelli
                                              Assistant Treasurer

                                          UNITED INSURANCE COMPANY OF AMERICA


                                          By: /s/ Scott Renwick
                                              ----------------------------------
                                              Scott Renwick
                                              Vice President