SECURITIES AND EXCHANGE COMMISSION

                                Washington, D.C.


                                    FORM 8-K

                                 CURRENT REPORT


     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934



         Date of Report (Date of earliest event reported): July 30, 2003



                                   AAON, INC.
                                   ----------
             (Exact name of registrant as specified in its charter)



            Nevada                  33-18336-LA                  87-0448736
            ------                  -----------                  ----------
(State or other jurisdiction        (Commission                (IRS Employer
      of incorporation)             File Number)             Identification No.)


                     2425 South Yukon, Tulsa, Oklahoma 74107
                     ---------------------------------------
                    (Address of principal executive offices)


       Registrant's telephone number, including area code: (918) 583-2266



Item 5.  Other Events.
         ------------

         Registrant executed the Ninth Amendment to Second Restated Revolving
Credit Loan Agreement on July 30, 2003.


Item 7.  Financial Statements and Exhibits.
         ---------------------------------

         (c)      A copy of the Ninth Amendment to Second Restated
                  Revolving Credit Loan Agreement is filed herewith as
                  Exhibit 99.1.


                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                              AAON, INC.



Date: July 31, 2003                           By:    /s/ John B. Johnson, Jr.
                                                 -------------------------------
                                                 John B. Johnson, Jr., Secretary

                                      -1-


                                  Exhibit 99.1

                               NINTH AMENDMENT TO
                 SECOND RESTATED REVOLVING CREDIT LOAN AGREEMENT

         This Ninth Amendment to Second Restated Revolving Credit Loan Agreement
("Amendment") is made and entered into effective this 30th day of July, 2003, by
and among AAON, INC., an Oklahoma corporation, and AAON COIL PRODUCTS, INC., a
Texas corporation (formerly known as CP/Aaon, Inc.) (separately and
collectively, the "Borrower"), and BANK OF OKLAHOMA, NATIONAL ASSOCIATION
("Bank").

                                    RECITALS

         A.    Reference is made to the Second Restated Revolving Credit Loan
Agreement dated effective July 1, 1996, which was amended by the Amendment One
dated June 30, 1997, the Amendment Two dated effective June 30, 1998, the Third
Amendment dated September 9, 1999, the Fourth Amendment dated November 9, 1999,
the Fifth Amendment dated July 27, 2000, the Sixth Amendment dated July 30,
2001, the Seventh Amendment dated September 4, 2001 and the Eighth Amendment
dated July 30, 2002, all between Borrower and Bank (as amended, the "Credit
Agreement"), pursuant to which currently exists a $15,150,000 Revolving Line
committed through July 30, 2003. Terms used herein shall have the meanings given
in the Credit Agreement, unless otherwise defined herein.

         B.    Borrower has requested Bank to extend the maturity date of the
$15,150,000 Revolving Line to July 30, 2004; and Bank has agreed to accommodate
such request, subject to the terms and conditions set forth below:

                                    AGREEMENT

         For valuable consideration received, it is agreed as follows:

         1.    Amendments to Credit Agreement. The Credit Agreement is hereby
amended as follows:

                  1.1   Section 1.52 (Termination Date) is hereby amended to
         evidence that the date "July 30, 2003" shall now mean and read "July
         30, 2004."

         2.    Conditions for the Amendment to the $15,150,000 Revolving Line.
As a condition for the Amendment to the $15,150,000 Revolving Line, the
following shall be satisfied:

                  2.1   Borrower shall execute and deliver to Bank a $15,150,000
         Promissory Note in form and content as set forth in Schedule "2.1"
         attached hereto, which constitutes a modification of the $15,150,000
         Promissory Note dated effective July 31, 2002.

                  2.2   Borrower hereby represents and certifies to Bank that
         (i) no Initial Default or Matured Default exists under the Credit
         Agreement, and all representations and warranties set forth therein
         remain true and correct in all material respects as of the date hereof,
         and (ii) all schedules attached the Credit Agreement remain true and
         correct.

                                      -1-


         3.    Ratification of Documents. Borrower hereby ratifies and confirms
the Credit Agreement and the Note, and agrees that they remain in full force and
effect, enforceable in accordance with their terms.

         4.    Ratification of Guaranty. Aaon, Inc., a Nevada corporation,
hereby ratifies and confirms the Guaranty Agreement dated effective July 1,
1996, and acknowledges and agrees that the Guaranty shall remain in full force
and effect notwithstanding the amendments to the Credit Agreement in Section 1,
above.

         5.    Binding Effect. This Amendment shall be governed by and construed
in accordance with the laws of the State of Oklahoma, and shall inure to the
benefit of the parties hereto, their successors and assigns.

         6.    Costs, Expenses and Fees. Borrower hereby agrees to pay the
reasonable costs, expenses and fees of Bank incurred in connection with the
preparation of this document and all related instruments, documents and
agreements.

                                   "Bank"

                                   BANK OF OKLAHOMA, NATIONAL
                                   ASSOCIATION


                                   By /s/ Pamela J. Amburgy
                                      ---------------------------------
                                      Pamela J. Amburgy, Vice President

                                   "Borrower"

                                   AAON, INC., an Oklahoma corporation


                                   By:    /s/ Norman H. Asbjornson
                                       --------------------------------
                                       Norman H. Asbjornson, President

                                   AAON COIL PRODUCTS, INC., a Texas
                                   corporation (formerly known as CP/AAON, Inc.)


                                   By:    /s/ Norman H. Asbjornson
                                       --------------------------------
                                       Norman H. Asbjornson, President

                                   "Guarantor"

                                   AAON, INC., an Oklahoma corporation


                                   By: /s/ Norman H. Asbjornson
                                       --------------------------------
                                       Norman H. Asbjornson, President

                                      -2-


                                 Schedule "2.1"

                       ($15,150,000 Revolving Credit Note)
                                 PROMISSORY NOTE


$15,150,000                                        Effective Date: July 30, 2003
                                                   Tulsa, Oklahoma


         FOR VALUE RECEIVED, the undersigned, AAON, INC., AN Oklahoma
corporation and AAON COIL PRODUCTS, INC., a Texas corporation (formerly known as
CP/AAON, Inc.) (separately and collectively "Maker"), jointly and severally
promise to pay to the order of BANK OF OKLAHOMA, NATIONAL ASSOCIATION
("Lender"), at its offices in Tulsa, Oklahoma, the principal sum of FIFTEEN
MILLION ONE HUNDRED FIFTY THOUSAND DOLLARS ($15,150,000), or, if less, the
aggregate sum of advances made by Lender to Maker under the Second Restated
Revolving Credit Agreement dated July 1, 1996, as amended ("Credit Agreement"),
as follows:

         a.       Principal. Principal shall be payable on July 30, 2004.

         b.       Interest. Interest shall be payable on the last day of each
                  month (except for interest on LIBOR Loans which shall be
                  payable on the last day of the applicable Interest Period) and
                  at maturity, commencing August 31, 2003, based upon the type
                  of loan and interest rate related thereto as more specifically
                  described in the Credit Agreement, which terms are
                  incorporated herein by reference.

         This Note is the "Note" referred to in the Credit Agreement. Reference
is made to the Credit Agreement for provisions for interest accrual, the
interest rate, the payment and prepayment hereof and for the acceleration of the
maturity hereof, all of which are incorporated herein and made a part hereof.
Terms defined in said Credit Agreement are used herein as therein defined.

         All payments under this Note shall be made in legal tender of the
United States of America or in other immediately available funds at Lender's
office described above, and no credit shall be given for any payment received by
check, draft of other instrument or item until such time as the holder hereof
shall have received credit therefor from the holder's collecting agent or, in
the event no collecting agent is used, from the bank or other financial
institution upon which said check, draft or other instrument or item is drawn.

         From time to time the maturity date of this Note may be extended or
this Note may be renewed, in whole or in part, or a new note of different form
may be substituted for this Note and/or the rate of interest may be changed, or
changes may be made in consideration of loan extensions, and the holder, from
time to time, may waive or surrender, either in whole or in part, any rights,
guarantees, security interests or liens given for the benefit of the holder in
connection herewith; but no such occurrences shall in any manner affect, limit,
modify or otherwise impair any rights, guarantees or security of the holder not
specifically waived, released or surrendered in writing, nor shall any maker,
guarantor, endorser or any person who is or might be liable hereon, either
primarily person who might be liable hereon; and such release shall not affect
or discharge the liability of any other person who is or might be liable hereon.

                                      -1-


         The Maker and any endorsers, guarantors and sureties hereby severally
waive protest, presentment, demand, and notice of protest and nonpayment in case
this Note or any payment due hereunder is not paid when due; and they agree to
any renewal, extension, acceleration, postponement of the time of payment,
substitution, exchange or release of collateral and to the release of any party
or person primarily or contingently liable without prejudice to the holder and
without notice to the Maker or any endorser, guarantor or surety. Maker and any
guarantor, endorser, surety or any other person who is or may become liable
hereon will, on demand, pay all costs of collection, including reasonable
attorney fees of the holder hereof in attempting to enforce payment of this Note
and reasonable attorney fees for defending the validity of any document securing
this Note as a valid first and prior lien.

         This Note is given for an actual loan of money for business purposes
and not for personal, agricultural or residential purposes, and is executed and
delivered in the State of Oklahoma and shall be governed by and construed in
accordance with the laws of the State of Oklahoma. This Note is an extension and
change in form of the $15,150,000 Promissory Note dated effective July 31, 2002.


                                   AAON, INC., an Oklahoma corporation



                                   By    /s/ Norman H. Asbjornson
                                      --------------------------------
                                      Norman H. Asbjornson, President


                                   AAON COIL PRODUCTS, INC.,
                                   A Texas corporation (formerly known as
                                   CP/AAON, Inc.)



                                   By    /s/ Norman H. Asbjornson
                                      --------------------------------
                                      Norman H. Asbjornson, President

                                      -2-