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                                  EXHIBIT 10.1

                                 PROMISSORY NOTE



$2,600,000.00                                             Minneapolis, Minnesota
                                                              September 21, 2001



1.       FOR VALUE RECEIVED, Aero Systems Engineering, Inc., a Minnesota
         corporation (the "Borrower"), hereby promises to pay to the order of
         Minnesota ASE, LLC, a Minnesota limited liability company (the
         "Holder"), at such location as the Holder may direct, the principal sum
         of Two Million Six Hundred Thousand and 00/100 Dollars ($2,600,000), in
         lawful money of the United States and immediately available funds,
         together with interest on the unpaid balance accruing as of and from
         the date hereof at a variable interest with an initial rate equal to
         6.250 percent per annum. The interest rate on this Note is subject to
         change from time to time based on changes in an index which is the
         National City Bank Base Rate (the "Index"). The Index currently is
         6.000% per annum. The interest rate to be applied to the unpaid
         principal balance of this Note will be at a rate of 0.250 percentage
         points over the Index, resulting in an initial rate of 6.250% per
         annum.

2.       The entire outstanding principal balance of this Note, together with
         any and all accrued and unpaid interest hereon, shall be due and
         payable January 11, 2002.

3.       The outstanding principal balance of this Note may be prepaid at any
         time at the option of the Borrower, in whole or in part without premium
         or penalty.

4.       All payments and prepayments shall, at the option of the Holder, be
         applied first to any costs of collection, second to accrued interest on
         this Note, and lastly to principal.

5.       Notwithstanding anything to the contrary contained herein, if the rate
         of interest or any other amounts due hereunder are determined by a
         court of competent jurisdiction to be usurious, then said interest rate
         and/or amounts shall be reduced to the maximum amount permissible under
         applicable Minnesota law.

6.       Upon the occurrence at any time of an Event of Default (as defined
         herein) or at any time thereafter, the Borrower promises to pay all
         costs of collection of this Note, including but not limited to
         reasonable attorneys' fees, paid or incurred by the Holder on account
         of such collection, whether or not suit is filed with respect thereto
         and whether such cost or expense is paid or incurred, or to be paid or
         incurred, prior to or after the entry of judgment.

7.       As used herein, the term "Event of Default" shall mean the occurrence
         of any one or more of the following:



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         a.       The Borrower shall fail to pay, when due, any amounts required
                  to be paid by the Borrower under this Note; or

         b.       The Borrower shall file or have filed against him a petition
                  in bankruptcy or for an arrangement pursuant to any present or
                  future state or federal bankruptcy act or under a similar
                  federal or state law, or shall be adjudicated a bankrupt or
                  insolvent, or shall make a general assignment for the benefit
                  of creditors, or shall be unable to pay his debts generally as
                  they become due, or any property of the Borrower shall be
                  levied upon or attached in any proceeding.

8.       Demand, presentment, protest and notice of nonpayment and dishonor of
         this Note are hereby waived.

9.       This Note shall be governed by and construed in accordance with the
         laws of the State of Minnesota.



                                       AERO SYSTEMS ENGINEERING, INC.
                                       a Minnesota Corporation


                                       By: /s/ CHARLES LOUX
                                          --------------------------------------
                                               Charles Loux
                                               Its: President and Chief
                                                     Executive Officer