EXHIBIT 3.31

                            ARTICLES OF INCORPORATION

                                       OF

                                NINE PAC COMPANY

                              A NEVADA CORPORATION

         KNOW ALL MEN BY THESE PRESENTS: That I, the undersigned, for the
purpose of forming a corporation under the laws of the State of Nevada, do
certify:

                                   ARTICLE I

         The name of the corporation is: NINE PAC Company.

                                   ARTICLE II

         The principal place of business of the corporation shall be:

                  1325 Airmotive Way, Suite 100, Reno 89502.

         The corporation's resident agent shall be:

                  The Corporation Trust Company of Nevada
                  One East First Street, Reno, Nevada 89502

                                  ARTICLE III

         The nature of the business and the objects and purposes to be
transacted, promoted, or carried on by the corporation are to engage in any
lawful act or activity for which corporation may be organized under the General
Corporation Law of Nevada.

                                   ARTICLE IV

         The corporation shall have authority to issue the following:

                  The number of shares of common stock which this
                  corporation is authorized to issue is One Hundred
                  thousand (100,000) shares with a par value of One
                  Cent ($.01) per share.



                                   ARTICLE V

         The number of the Board of Directors shall be:

                  The Board of Directors will consist of one
                  (1) to nine (9). The person who is to serve
                  as Director until the first annual meeting of
                  shareholders or until his successor is elected
                  and qualified is:

         Charles J. Bayer, 3240 E. Pershing, Phoenix, Az. 85032

                                   ARTICLE VI

         The name and address of the incorporator is:

         J. Scott Askew, 2721 N. Central Avenue, Phoenix, Az. 85004

                                  ARTICLE VII

         The period of existence of the corporation shall be:

                                   Perpetual

IN WITNESS WHEREOF, I the aforementioned incorporator have signed the Articles
of Incorporation this 13th day of January, 1995

                                                    /s/  J. Scott Askew
                                                    ---------------------------
                                                    J. Scott Askew, Incorporator



STATE OF ARIZONA

COUNTY OF MARICOPA

         THIS IS TO CERTIFY that on the 13th day of January, 1995 before me, a
Notary Public, personally appeared J. Scott Askew, who I am satisfied is the
person named in and who executed the foregoing Articles of Incorporation and I
first having made known to him the contents thereof, did acknowledge that he had
signed the same as his voluntary act and deed for the uses and purposes therein
expressed.

         IN TESTIMONY WHEREOF, I have hereunto set my hand and affixed my
official seal this 13th day of January, 1995.

         (NOTARIAL SEAL)                             /s/ Blanche I. Passolt
                                                     ---------------------------
                                                     Blanche I. Passolt
                                                     NOTARY PUBLIC