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                                                                   EXHIBIT 10.12

RACC
DEFERRAL NOTE
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                      RAYTHEON AIRCRAFT CREDIT CORPORATION

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         1.   Restructuring Agreement. Reference is hereby made to that certain
Restructuring Agreement (as amended and in effect from time to time, the
"Restructuring Agreement"), dated as of December 31, 2002, by and between Great
Lakes Aviation, Ltd., an Iowa corporation (the "Debtor") and Raytheon Aircraft
Credit Corporation, a Kansas corporation ("RACC"). Capitalized terms used and
not otherwise defined herein shall have the meanings assigned to them in the
Restructuring Agreement.

         2.   Promise to Pay. FOR VALUE RECEIVED, the undersigned hereby
absolutely and unconditionally promises to pay to the order of RACC, at 10511
East Central, Wichita, Kansas 67206 (together with its successor and assigns
hereinafter referred to as "RACC"), in lawful money of the United States of
America and in immediately available funds, the principal sum of ONE MILLION TWO
HUNDRED THOUSAND DOLLARS ($1,200,000.00) (the "Principal Sum"). All payments
made pursuant to this promissory note (this "Promissory Note") will be made free
and clear of, and without deduction for, withholding, setoff, recoupment or
counterclaim of any kind.

         3.   Interest Rate. In addition to Debtor's payment of the Principal
Sum, Debtor shall pay interest to RACC on the outstanding Principal Sum at the
rate per annum equal to LIBOR plus three hundred seventy five basis points.
Interest on this Promissory Note shall be payable in cash quarterly in arrears
on the last day of each calendar quarter commencing on March 31, 2003. The
annual rate of interest applicable hereunder from time to time, as specified
above, is referred to herein as the "Interest Rate." All interest shall be
calculated on the basis of a 360-day year and actual days outstanding.
Notwithstanding anything set forth in this Promissory Note to the contrary, in
no event shall the rate of interest payable pursuant to this Section 3 be higher
than the maximum amount permitted under applicable law. "LIBOR" shall mean the
rate of interest determined by RACC at which Dollar deposits for ninety (90)
days are offered based on information provided in The Wall Street Journal on the
second business day prior to the date of the issuance of this Promissory Note or
the first day of January, April, July and October, as applicable, provided,
however, that if the rate described above does not

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appear in The Wall Street Journal on any applicable interest determination date,
LIBOR shall be the rate determined by RACC in good faith based on the offered
rates for deposits in Dollars for ninety (90) days that are then offered by
major banks in the London interbank market. LIBOR shall be adjusted on the first
business day of each calendar quarter to reflect any increase or decrease in
LIBOR as of that date.

         4.   Late Payment Charge. While an Event of Default (as defined below)
is continuing, Debtor agrees to pay to RACC interest on the unpaid principal
balance hereunder or other amounts payable hereunder (compounded monthly and
payable on demand in respect of overdue amounts) at a rate per annum which is
equal to LIBOR plus six hundred basis points (the "Default Interest Rate") until
such Event of Default has been cured or waived in writing by RACC (after as well
as before judgment).

         5.   Repayment. The Principal Sum shall be paid by the Debtor to RACC
in quarterly payments at the end of each calendar quarter commencing on June 30,
2003. In 2003, Debtor shall make three principal payments on June 30, September
30 and December 31 of $133,333.33 each, in 2004, there shall be four quarterly
principal payments of $125,000 each and in 2005, there shall be four quarterly
principal payments of $75,000 each, with the last such payment due on December
31, 2005 (the "Due Date"). All amounts of principal and interest not repaid by
Debtor prior to December 31, 2005 shall be paid in full on the Due Date.

         6.   Taxes. All payments (whether of principal, interest or otherwise)
made by Debtor to RACC pursuant to this Promissory Note will be free and clear
of and without deduction for any taxes, levies, duties, charges, fees or
withholdings of any nature, provided, however, that taxes based on the net
income of RACC are specifically excluded from the provisions of this Section 6.
If Debtor is required by law to make any such deduction or withholding, the sum
due from Debtor will be increased to the extent necessary to ensure that RACC
receives a sum equal to what it would have received had no such deduction or
withholding been required. Within thirty (30) days after Debtor has made any
payment from which it is required by law to make any deduction or withholding,
Debtor will deliver to RACC a receipt issued by the applicable tax or other
authority evidencing the deduction or withholding.

         7.   Prepayment. This Promissory Note shall be subject to mandatory
prepayment from Excess Cash Flow as provided in Section 11(A) of the
Restructuring Agreement. In addition, Debtor may prepay this obligation in part
or in full at any time without any premium or penalty. Any partial prepayment
shall be applied to the installments of principal in inverse order of maturity
and in accordance with Section 11(C) of the Restructuring Agreement.

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         8.   Covenants. Debtor covenants and agrees that, until the payment and
satisfaction in full of all the obligations of and amounts owed by Debtor under
this Promissory Note, Debtor will:

              (a)   furnish RACC with such financial information with respect to
         Debtor or the collateral described in the Security Agreements and in
         Section 13 of the Restructuring Agreement (the "Collateral") as RACC
         may reasonably request;

              (b)   keep true and accurate books of account with respect to the
         Collateral and to permit RACC or its designated representatives to
         inspect the Collateral and the Aircraft and to examine and be advised
         as to such records upon the request of RACC;

              (c)   comply with any law, treaty, rule, regulation or
         determination of an arbitrator, court, or other governmental authority,
         in each case applicable to or binding upon Debtor or affecting any of
         its property;

              (d)   notify RACC promptly in writing of (i) the occurrence of any
         Default or Event of Default, (ii) any change of name or address of
         Debtor, (iii) any threatened or pending litigation or similar
         proceeding affecting Debtor or any material change in any such
         litigation or proceeding previously reported and (iv) any claims of any
         nature against the Collateral or the Aircraft; and

              (e)   cooperate with RACC, take such action, execute such
         documents, and provide such information as RACC may from time to time
         request in order further to effect the transactions contemplated by and
         the purposes of this Promissory Note and the other Transaction
         Documents.

         9.   Security Agreement. The payment and performance of all of the
Obligations due RACC by Debtor under this Promissory Note, and any renewals,
extensions or changes hereof, including all such Obligations that would become
due but for the operation of the automatic stay pursuant to section 362(a) of
the Federal Bankruptcy Code and the operation of sections 502(b) and 506(b) of
the Federal Bankruptcy Code and including, without limitation, post-petition
interest (collectively, the "Obligations"), shall be secured by the Corporate
Security Documents, the Group B Security Documents and any other collateral
security now or hereafter granted to RACC by the Debtor.

         10.  Purpose of Loan; Usury. Debtor warrants and represents to RACC
that this loan is for business and commercial purposes and not for personal,
family, household or agricultural purposes. It is agreed, notwithstanding any
provision to the contrary in any of the Transaction Documents, in no event will
this Promissory

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Note require the payment of interest or charges in excess of the maximum amount
permitted by applicable law (the "Maximum Rate") and the payment of obligations
of Debtor under this Promissory Note are hereby limited accordingly. If under
any circumstances, whether by reason of advancement or acceleration of the
maturity of the unpaid principal balance hereof or otherwise, the aggregate
amounts paid on this Promissory Note shall include amounts which by law are
deemed interest and would exceed the Maximum Rate, Debtor stipulates that
payment and collection of such excess amounts shall have been and will be deemed
to have been the result of a mistake on the part of both Debtor and RACC, and
RACC shall promptly credit such excess (to the extent only of such payments in
excess of the Maximum Rate) against the unpaid principal balance hereof and any
portion of such excess payments not capable of being so credited shall be
refunded to Debtor.

         11.  Waiver. The Debtor hereby waives presentment, demand for payment,
notice of non-payment, notice of dishonor, and all other notices or demands in
connection with the delivery, acceptance, performance, default or endorsement of
this Promissory Note, protest and impairment of collateral, as well as diligence
in collecting this Promissory Note or enforcing any of the security therefor,
and consents to all extensions, deferrals, partial payments and refinancings
hereof before or after maturity.

         12.  Events of Default; Acceleration. If any of the following events
(each an "Event of Default") shall occur:

              (a)   Debtor shall fail to pay any principal of interest on this
         Promissory Note or any other sum due under this Promissory Note, any
         Transaction Document, or any other note or other agreement between
         Debtor and RACC when the same becomes due and such failure shall
         continue for ten (10) days beyond the due date of such payment;

              (b)   Debtor shall fail to perform any term, covenant or agreement
         contained in any of the Transaction Documents and such failure shall
         continue for thirty (30) days after written notice;

              (c)   any representation or warranty of Debtor in any of the
         Transaction Documents or in any certificate or notice given in
         connection therewith shall have been false or misleading in any
         material respect at the time made or deemed to have been made;

              (d)   Debtor shall be in default under any agreement or agreements
         evidencing (i) any other debt and similar monetary obligations
         (including, without limitation, capitalized leases, synthetic leases or
         securitization transactions) (collectively, "Indebtedness") owing to
         RACC or any of its affiliates, or (ii) any other Indebtedness in excess
         of $100,000.00 in aggregate

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         principal amount, or shall fail to pay any such Indebtedness when due
         or within any applicable period of grace;

              (e)   any of the Transaction Documents shall cease to be in full
         force and effect;

              (f)   Debtor (i) shall make an assignment for the benefit of
         creditors; (ii) shall be adjudicated bankrupt or insolvent; (iii) shall
         seek the appointment of, or be the subject of an order appointing, a
         trustee, liquidator or receiver as to all or part of its assets, (iv)
         shall commence, approve or consent to, any case or proceeding under any
         bankruptcy, reorganization or similar law and, in the case of an
         involuntary case or proceeding, such case or proceeding is not
         dismissed within forty-five (45) days following the commencement
         thereof, or (v) shall be the subject of an order for relief in an
         involuntary case under federal bankruptcy law;

              (g)   Debtor shall be unable to pay its debts as they mature;

              (h)   there shall remain undischarged for more than thirty (30)
         days any final judgment or execution action against Debtor that,
         together with other outstanding claims and execution actions against
         Debtor, respectively, exceeds $100,000.00 in the aggregate;

              (i)   the prospect of payment or performance by Debtor or
         realization on the Collateral, in the reasonable opinion of RACC, is or
         becomes significantly impaired;

              (j)   any of the Aircraft shall have been lost, stolen or
         confiscated or shall have incurred substantial damage or have been
         destroyed to such an extent that the repair thereof is impracticable
         (as determined solely by RACC); or

              (k)   Debtor (i) sells, transfers or disposes of all or
         substantially all of its respective stock, assets or property, (ii)
         becomes the subject of, or engages in, a leveraged buy-out, or (iii)
         terminates its existence by merger, reorganization or consolidation.

              THEN, or at any time thereafter:

              (1)   In the case of any Event of Default under clauses (f) or
         (g), the entire unpaid principal amount of this Promissory Note and all
         other amounts payable hereunder, shall automatically become forthwith
         due and payable, without presentment, demand, protest or notice of any
         kind, all of which are hereby expressly waived by Debtor; and

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              (2)   In the case of any Event of Default other than under clauses
         (f) or (g), RACC may, by written notice to Debtor, declare the unpaid
         principal amount of this Promissory Note and all other amounts payable
         hereunder, to be forthwith due and payable, without presentment,
         demand, protest or further notice of any kind, all of which are hereby
         expressly waived by Debtor.

         In addition to and without in any way limiting the foregoing, upon the
occurrence of an Event of Default or at any time thereafter, RACC may employ all
remedies allowed by law, including, without limitation, those available to a
secured party under the Uniform Commercial Code. No remedy herein conferred upon
RACC is intended to be exclusive of any other remedy and each and every remedy
shall be cumulative and in addition to every other remedy hereunder, now or
hereafter existing at law or in equity or otherwise.

         13.  Obligations Absolute. Debtor's payment and performance obligations
under this Promissory Note and the other Transaction Documents are absolute and
unconditional. Any claim that Debtor may now or hereafter have against RACC or
any affiliate thereof arising out of or in connection with the Aircraft, any of
the other Collateral or any other matter shall not affect or excuse the
unconditional obligation of Debtor to make any payment required to be made to
RACC under the Transaction Documents, and shall not be used or asserted as a
defense to payment of such obligation or as set-off, counterclaim or deduction
against such payment. RACC shall have no obligation or responsibility with
respect to any dispute that may arise between Debtor and any such foregoing
person, and no such dispute shall prevent RACC from taking such action as it may
deem appropriate in order to preserve, protect or enforce its rights hereunder.

         14.  Debtor's Agreement to Pay Enforcement Costs, Etc. Debtor further
agrees to pay to RACC, on demand, all costs and expenses (including court costs
and legal expenses) incurred or expended by RACC in connection with the
Obligations, this Promissory Note and the enforcement hereof, together with
interest on amounts recoverable under this Section 14 from the time when such
amounts become due until payment, whether before or after judgment, at the
Default Interest Rate, provided that if such interest exceeds the maximum amount
permitted to be paid under applicable law, then such interest shall be reduced
to such maximum permitted amount.

         15.  Waiver of Default. No waiver by RACC of any default shall be
effective unless in writing, nor operate as a waiver of any other default or of
the same default in the future.

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         16.  Change of Address. Debtor will notify RACC in writing of any
change of address from that shown herein within ten (10) days of such change.

         17.  GOVERNING LAW AND CHOICE OF FORUM. THIS PROMISSORY NOTE WAS MADE
AND ENTERED INTO IN THE STATE OF KANSAS AND THE LAW GOVERNING THIS TRANSACTION
SHALL BE THAT OF THE STATE OF KANSAS AS IT MAY FROM TIME TO TIME EXIST. THE
PARTIES AGREE THAT ANY LEGAL PROCEEDING BASED UPON THE PROVISIONS OF THIS
PROMISSORY NOTE SHALL BE BROUGHT EXCLUSIVELY IN EITHER THE UNITED STATES
DISTRICT COURT FOR THE DISTRICT OF KANSAS AT WICHITA, KANSAS, OR IN THE
EIGHTEENTH JUDICIAL DISTRICT COURT OF SEDGWICK COUNTY, KANSAS, TO THE EXCLUSION
OF ALL OTHER COURTS AND TRIBUNALS. NOTWITHSTANDING THE ABOVE, IN THE EVENT AN
EVENT OF DEFAULT SHOULD OCCUR, RACC (AT ITS SOLE OPTION) MAY INSTITUTE LEGAL
PROCEEDINGS IN ANY JURISDICTION AS MAY BE APPROPRIATE IN ORDER FOR RACC TO
OBTAIN POSSESSION OF THE COLLATERAL OR OTHERWISE REALIZE UPON ITS SECURITY. THE
PARTIES HEREBY CONSENT AND AGREE TO BE SUBJECT TO THE JURISDICTION OF THE
AFORESAID COURTS IN SUCH PROCEEDINGS.

         18.  WAIVER OF RIGHT TO JURY TRIAL. ALL PARTIES TO THIS AGREEMENT
HEREBY VOLUNTARILY, KNOWINGLY AND IRREVOCABLY WAIVE ANY CONSTITUTIONAL OR OTHER
RIGHT EACH MAY HAVE TO A TRIAL BY JURY IN THE EVENT OF LITIGATION CONCERNING
THIS PROMISSORY NOTE.

         19.  Damages. To the extent that any party hereto is subject to
liability for any breach under this Promissory Note, the liability of such party
shall be limited to the actual and direct monetary damages caused by such
breach. In no event shall any party hereto be liable for indirect, special,
consequential, multiple or punitive damages, or any damage deemed to be of an
indirect or consequential nature arising out of or related to its performance
hereunder, whether based upon breach of contract, warranty, negligence and
whether grounded in tort, contract, civil law or other theories of liability,
including strict liability. To the extent that this limitation of liability
conflicts with any other provision(s) in this Promissory Note, said provision(s)
shall be regarded as amended to whatever extent required to make such
provision(s) consistent with this Section 19.

         20.  Enforceability. The unenforceability of any provision hereof shall
not affect the validity of any other provision hereof.

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         21.  Binding Agreement. All obligations of Debtor hereunder shall bind
the heirs, agents and attorneys-in-fact, successors and assigns of Debtor. All
rights of RACC hereunder shall inure to the benefit of its successors and
assigns.

         22.  Assignment. RACC may transfer or assign all or any part of its
interest in this Promissory Note without the consent of Debtor or any other
party. Debtor shall not sell, assign, transfer, encumber or convey any of its
interests in the Collateral or in this Promissory Note without the prior written
consent of RACC.

         23.  Entire Agreement. The Transaction Documents constitute the entire
agreement between and among the parties with respect to the subject matter
hereof. There are no verbal understandings, agreements, representations or
warranties not expressly set forth herein. This Promissory Note shall not be
changed orally, but only by writing signed by the parties hereto.

DEBTOR HEREIN ACKNOWLEDGES THAT IT HAS READ AND FULLY UNDERSTANDS ALL OF THE
TERMS AND CONDITIONS OF THIS PROMISSORY NOTE. BY EXECUTION HEREOF, THE
UNDERSIGNED HEREBY CERTIFIES THAT HE/SHE IS DULY AUTHORIZED TO EXECUTE THIS
PROMISSORY NOTE IN THE CAPACITY STATED BELOW.

Executed this 31st day of December, 2002.

Debtor:  Great Lakes Aviation, Ltd.

         /s/ Charles R. Howell IV   CEO
         ---------------------------------
         (signature)                (title)

Address: 1022 Airport Parkway
         Cheyenne, Wyoming 82001

RAYTHEON AIRCRAFT CREDIT CORPORATION

By:  /s/ Andrew A. Mathews
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             "RACC"