NINTH AMENDMENT
                                       TO
                                CREDIT AGREEMENT


         NINTH AMENDMENT, dated as of November 4, 2004 (the "Amendment"), to
Credit Agreement dated June 30, 2000 (as amended, the "Agreement") by and
between AeroCentury Corp., a Delaware corporation ("AeroCentury"), the banking
institutions signatories hereto and such other institutions that hereafter
become a "Bank" pursuant to Section 10.4 of the Agreement (collectively the
"Banks" and individually a "Bank") and National City Bank, a national banking
association, as Agent for the Banks under the Agreement ("National City" which
shall mean in its capacity as Agent unless specifically stated otherwise). All
capitalized terms used herein and not otherwise defined shall have the
respective meanings ascribed to them in the Agreement.

                              Preliminary Statement

         WHEREAS, National City and AeroCentury, together with the other Banks,
desire to amend the Agreement in the manner hereinafter set forth; and

         WHEREAS, Section 10.2 of the Credit Agreement requires that the written
consent of the Banks be obtained for certain amendments, modifications or
waivers contemplated herein.

         NOW THEREFORE, in consideration of the premises and promises
hereinafter set forth and intending to be legally bound hereby, the parties
hereto agree as follows:

1. Amendments to Agreement.

(a) Section 2.1 of the Agreement. The Revolver Termination Date of "November 5,
2004" as set forth on the fourth line of Section 2.1(a) of the Agreement shall
be and hereby is amended to "October 31, 2005".

(b) Article 7 of the Agreement. The following sections as set forth in Article 7
of the Agreement are hereby amended and restated in their entirety to be as
follows:

                  "7.1. Minimum Tangible Net Worth. Minimum Tangible Net Worth
                  will not at any time be less than the sum of (i) $16,000,000,
                  (ii) 50% of Net Income for each Fiscal Quarter ending after
                  September 30, 2004 without deduction for net losses, (iii) 50%
                  of the net proceeds from any sale of equity securities after
                  the date of this Agreement, and (iv) 50% of any incremental
                  additive equity associated with any acquisition.

                  "7.2.  EBITDA to Interest Ratio.  The ratio of EBITDA to
                  Interest as at the end of any Fiscal Quarter and for the
                  period of such Fiscal Quarter will not be less than 2.25:1."

                   "7.4. Absence of Net Loss. Beginning with the Fiscal Quarter
                  ending December 31, 2004, AeroCentury shall not suffer a
                  consolidated net loss (i) at December 31, 2004 for the prior
                  Fiscal Quarter; (ii) at March 31, 2005 for the prior two
                  Fiscal Quarters; (iii) at June 30, 2005 for the prior three
                  Fiscal Quarters; and (iv) at each Fiscal Quarter end
                  thereafter, for the prior four Fiscal Quarters."

(c) Article 10 of the  Agreement.  The following new section is inserted at the
 end of Article 10 of the Agreement:

                  "10.22. USA Patriot Act. Each Bank that is subject to the
                  requirements of the USA Patriot Act (Title III of Pub. L.
                  107-56 (signed into law October 26, 2001)) (the "Patriot Act")
                  hereby notifies AeroCentury that pursuant to the requirements
                  of the Patriot Act, it is required to obtain, verify and
                  record information that identifies AeroCentury, which
                  information includes the name and address of AeroCentury and
                  other information that will allow such Bank to identify
                  AeroCentury in accordance with the Patriot Act."

(d) Amended and Restated Exhibit D to the Agreement. Exhibit D to the Agreement
shall be and is hereby amended and restated in its entirety as attached hereto.

(e) Amended and Restated Schedule 2 to the Agreement. Schedule 2 to the
Agreement shall be and is hereby amended and restated in its entirety as
attached hereto.

2. Representations and Warranties. Except as otherwise disclosed herein,
AeroCentury hereby restates the representations and warranties made in the
Agreement, including but not limited to Article 3 thereof, on and as of the date
hereof as if originally given on this date.

3. Covenants. AeroCentury hereby represents and warrants that it is in
compliance and has complied with each and every covenant set forth in the
Agreement (including this Amendment), including but not limited to Articles 5
and 6 thereof, on and as of the date hereof.

4. Waiver. With respect to the Fiscal Quarter ending as of September 30, 2004
only, National City hereby waives the financial covenant requirements set forth
in Section 7.2 "EBIDTA to Interest Ratio" and Section 7.4 "Absence of Net Loss"
which AeroCentury was required to maintain so long as the Revolving Loan
Commitments are in effect or any Obligation remains unpaid or outstanding.

5. Effectiveness Conditions. This Amendment shall be effective upon completion
of the following conditions precedent (all documents to be in form and substance
satisfactory to National City and the Banks, and dated the date hereof):

(a) execution and delivery of this Amendment;

(b) delivery of an Officer's Certificate in the form attached as Annex A hereto
confirming certain matters set forth therein executed by an officer of
AeroCentury; and

(c) execution and delivery of such other documents, instruments and agreements
as National City shall reasonably request in connection with the foregoing
matters.

6. Affirmation. AeroCentury hereby affirms its absolute and unconditional
promise to pay to the Banks the Loans and all other amounts due under the
Agreement and any other Loan Document on the maturity dates(s) provided in the
Agreement or any other Loan Document, as such documents may be amended hereby.

7. Effect of Amendment. This Amendment amends the Agreement only to the extent
and in the manner herein set forth, and in all other respects the Agreement is
ratified and confirmed. The waiver set forth above is granted precisely as
written and shall not be deemed (i) to be a waiver of or a consent to, or
amendment, supplement or modification of, any other term or condition of the
Agreement or any of the instruments or agreements referred to therein or (ii) to
prejudice any other right or rights which the Banks may now have or may have in
the future under or in connection with the Agreement or any of the instruments
or agreements referred to therein.

8. Counterparts. This Amendment may be signed in any number of counterparts,
each of which shall be an original, with the same effect as if the signatures
hereto were upon the same instrument.


<PAGE>




         IN WITNESS WHEREOF, the parties hereto have each caused this Amendment
to be duly executed by their duly authorized representatives as of the date
first above written.


    AEROCENTURY CORP.


    By       ________________________
             Name:
             Title:



    NATIONAL CITY BANK


    By       ________________________
             Name:    Michael J. Labrum
             Title: Senior Vice President



    CALIFORNIA BANK & TRUST


    By       ________________________
             Name:
             Title:



    FIRST BANK DBA
    FIRST BANK & TRUST


    By       ________________________
             Name:
             Title:


<PAGE>





                         COVENANT COMPLIANCE CERTIFICATE


         The undersigned Officer of AeroCentury Corp. ("AeroCentury"), does
hereby certify to National City Bank, Agent (the "Bank"), as required by that
certain Credit Agreement, dated June 28, 2000, as amended, by and between
AeroCentury and the Bank (as amended, the "Agreement") (terms not otherwise
defined herein shall have the meanings given to such terms in the Agreement),
that as such officer he is authorized to execute this Compliance Certificate
(this "Certificate") on behalf of AeroCentury and does further certify that:

         1.    Except as otherwise disclosed herein, AeroCentury has complied
               and is in compliance with all covenants, agreements and
               conditions in the Agreement and each of the other Loan
               Documents on the date hereof.

         2.    Each representation and warranty contained in the Agreement
               and each of the other Loan Documents is true and correct on
               the date hereof.

         3.    No Potential Default or Event of Default has occurred and is
               continuing as of the date of this Compliance Certificate.

         4.    There has been no Material  Adverse Change since [insert the date
               of the most recent  financial  statements  delivered  to the Bank
               pursuant  to the terms of Section  5.1 of the Credit  Agreement],
               except as disclosed on the attached schedules.

          5.   The covenant  compliance  calculations  set forth in Attachment
               1 hereto are true and correct on the dates specified.

          IN WITNESS  WHEREOF,  the undersigned has executed this Certificate in
          his  capacity  as an  officer  of  AeroCentury  on  this  ___  day  of
          ___________, _____.

    AeroCentury Corp.





    By:
        -------------------------------------------------
    Name:
    Title:





<PAGE>



                        COVENANT COMPLIANCE CALCULATIONS
                                AeroCentury Corp.
                     for the (quarter, year) ending _______


Section 7.1       MINIMUM TANGIBLE NET WORTH

           REQUIREMENT: - Minimum Tangible Net Worth will not at any time be
           less than the sum of (i) $16,000,000, (ii) 50% of Net Income for each
           Fiscal Quarter ending after September 30, 2004 without deduction for
           net losses, (iii) 50% of the net proceeds from any sale of equity
           securities after the date of this Agreement, and (iv) 50% of any
           incremental additive equity associated with any acquisition.
<table>
           
   <c>                                                                          <c>
           Tangible Net Worth on [date]
                 Capital Stock                                                                 $
                 Paid-In Capital                                                               +
                 Retained Earnings                                                             +
                 Subtotal

                 less:    Net Worth of Unrestricted subsidiaries                               $

                 Tangible Net Worth                                                            $

           Required Tangible Net Worth

                 (i) $16,000,000                                                               $16,000,000
                 (ii) 50% of Net Income                                                        +
                 (iii) 50% of net proceeds from any sale of equity                             +
                          securities
                 (iv)     50% of any incremental additive equity + associated
                          with any acquisition

                 Required Tangible Net Worth                                                     $

              Excess (deficiency) of Actual Tangible Net Worth                                   $
compared with Required Tangible Net Worth
</table>

<PAGE>







Section.7.2       EBITDA TO INTEREST RATIO

          REQUIREMENT:  - The ratio of EBITDA to  Interest  as at the end of any
          Fiscal  Quarter and for the period of such Fiscal  Quarter will not be
          less than 2.25:1.
<table>
           
   <c>                                                     <c>
           EBITDA
                 Net Income for the                                      $
                 Fiscal Quarter ended ___________

                 Interest deducted with respect to                       + $
                 the Fiscal Quarter ended ___________

                 Taxes deducted with respect to                          + $
                 the Fiscal Quarter ended ___________

                 Depreciation deducted with respect to                   + $
                 the Fiscal Quarter ended ___________

                 Amortization deducted with respect to                   + $
                 Fiscal Quarter ended ___________

             EBITDA for the Fiscal Quarter ended ___________              $

           Interest

                  Interest for the Fiscal Quarter ended __________       $


           Interest                                                      $

                   RATIO OF EBITDA TO INTEREST                 ___________

</table>

<PAGE>




Section 7.3       RECOURSE FUNDED DEBT TO TANGIBLE NET WORTH

  REQUIREMENT: - The ratio of Recourse Funded Debt (including Recourse
  Funded Debt represented by the Notes) to Tangible Net Worth will not
  at any time exceed 3.25:1.

  Recourse Funded Debt on [date]:                         $


  Tangible Net Worth on [date]                            $

  RATIO OF RECOURSE FUNDED DEBT TO TANGIBLE NET WORTH





<PAGE>




Section 7.4       ABSENCE OF NET LOSS

          REQUIREMENT:  - Beginning with the Fiscal Quarter ending  December 31,
          2004,  AeroCentury  Corp. shall not suffer a consolidated net loss for
          the following periods:

  Net Income for the Fiscal Quarter ended December 31, 2004      $
  Net Income for the two Fiscal Quarters ended March 31, 2005
  Net Income for the three Fiscal Quarters ended June 30, 2005
  Net Income for the four Fiscal Quarters ended thereafter.


Section 7.5       BORROWING BASE

           REQUIREMENT: - The aggregate principal amount of Loans outstanding
           shall not at any time exceed the Borrowing Base or the Aggregate
           Revolving Loan Commitment, whichever is less; provided, however, that
           this covenant shall not be deemed breached if, at the time such
           aggregate amount exceeds said level, within three Business Days after
           the earlier of the date AeroCentury first has knowledge of such
           excess or the date of the next Borrowing Base Certificate disclosing
           the existence of such excess, a prepayment of Loans shall be made in
           an amount sufficient to assure continued compliance with this
           covenant in the future.
<table>
           
                                                                                  <c>
           Collateral Loan Value

           Total Borrowing Base                                                                  $

           Maximum Loans

           Aggregate Revolving Loan Commitment                                                   $__,000,000

           Credit Usage

           Aggregate Loan Balance (principal) at date of certificate                             $

           Collateral Loan Value exceeds Credit Usage                                            $

           Collateral Loan Value is less than Credit Usage                                       $

</table>

<PAGE>



                                    SCHEDULE 2


                       APPLICABLE MARGINS, COMMITMENT FEE

<table>

                                <c>                       <c>                        <c>
Ratio of Funded
Debt to Tangible                   Alternate Base            LIBO                       Commitment
Net Worth                           Rate Margin               Rate Margin               Fee

I *      > 3.00                     150 bp                    375 bp                    50 bp
II       2.00 - 3.00                100 bp                    325 bp                    50 bp
III      < 2.00                     50 bp                     275 bp                    40 bp
</table>



* Regardless of the Borrower's ratio of Funded Debt to Tangible Net Worth, Tier
I pricing shall be in effect through March 31, 2005.


<PAGE>



                                     ANNEX A

                          FORM OF OFFICER'S CERTIFICATE

                                  See attached.


<PAGE>



                             CERTIFICATE OF OFFICER
                                       OF
                                AEROCENTURY CORP.


                  The undersigned, [___________________], hereby certifies that
[he/she] is the duly elected and qualified [_______________] of AeroCentury
Corp., a Delaware corporation, (the "Company") and that, as such, [he/she] is
authorized to execute this certificate on behalf of the Company as required
pursuant to that certain Ninth Amendment to Credit Agreement, dated as of the
date hereof, among the Company, the banks which are signatories thereto
("Banks") and National City Bank, as Agent for such Banks (the "Ninth
Amendment"; unless otherwise defined herein, capitalized terms used herein shall
have the meanings given to them in the Ninth Amendment), and further certifies
that:

                  (i) Except as pertaining to the Financial Covenants set forth
in Section 7.2 EBITDA to Interest Ratio and Section 7.4 of the Agreement
regarding Absence of Net Loss, no Potential Default or Event of Default under
the Agreement has occurred and is continuing; and

                  (ii) All representations and warranties set forth in Section 3
of the Agreement (other than those which, by their terms, specifically are made
as of a certain date prior to the date hereof) are true and correct in all
material respects as of the date hereof.

                  IN WITNESS WHEREOF, I have hereunto set my hand and caused the
corporate seal of the Company to be hereunto affixed this ___ day of _________,
_____.


---------------
Name:
Title: