Exhibit 10.3

                            DEBT EXTENSION AGREEMENT

This Agreement is made and entered into as of this 1st day of November 2008, by
and between G. S. Beckwith Gilbert, of 35 Vista Drive, Greenwich, Connecticut
06830 ("Lender"), and PASSUR Aerospace, Inc. (formerly MEGADATA CORPORATION), a
New York corporation, with a principal place of business at 47 Arch Street,
Greenwich, Connecticut 06830 ("Borrower" or "PASSUR Aerospace"):

                                   WITNESSETH

      WHEREAS, PASSUR Aerospace has issued a promissory note to Lender for value
received;

      WHEREAS, the total amount due and owing under the promissory note and
accrued interest as of November 1, 2008 is $13,814,880; and

      WHEREAS, Lender and PASSUR Aerospace desire to modify certain terms and
conditions of the outstanding promissory note as of the date of this Agreement
and issue a replacement promissory note for value received upon the terms and
conditions set forth herein.

      NOW, THEREFORE, in consideration of the foregoing and the agreements
contained herein, the parties hereby agree as follows:

1. MODIFICATION OF PREVIOUS NOTES:

      The outstanding promissory note previously issued to Lender plus accrued
interest totaling $13,814,880 in aggregate principal amount shall be modified as
set forth herein.

2. ISSUANCE AND TERMS OF REPLACEMENT NOTE:

      For value received, PASSUR Aerospace shall issue a Replacement Note (the
"Replacement Note") to Lender in the aggregate principal amount of $13,814,880.
The Replacement Note will be in the form attached as Exhibit A hereto.

      (a)   TERM. The principal amount of the Replacement Note, together with
            any and all accrued and unpaid interest thereon, shall be paid in
            full on November 1, 2011.

      (b)   INTEREST. The Replacement Note or any New Replacement Note shall
            bear interest on the unpaid principal amount, from the date of
            issuance until paid in full at maturity. Interest shall be payable
            at the annual rate of 4.5% from November 1, 2008 to January 31, 2009
            payable in cash. Beginning February 1, 2009 through October 31, 2011
            the annual interest rate will be 9% payable as follows: (i) interest
            at the annual rate of 6% will be payable in cash and (ii) the
            remaining interest at the annual rate of 3% will be payable, at the
            option of the Company in cash or "paid in kind" and added to the
            principal of the note. Interest payments shall be made annually at
            October 31 of each year.
<PAGE>

      (c)   NEW REPLACEMENT NOTES. If at October 31, 2009 any interest for the
            year has been "paid in kind" rather than cash, a New Replacement
            Note shall be issued in the aggregate amount of the Replacement
            Note, plus any interest "paid in kind". If at October 31, 2010 any
            interest for the period from November 1, 2009 to October 31, 2010
            has been "paid in kind" rather than cash, a second New Replacement
            Note shall be issued in the aggregate amount of either the
            Replacement Note or the New Replacement Note, whichever is
            outstanding at October 31, 2009 plus any interest "paid in kind"
            during that fiscal year.

      (d)   PREPAYMENT TERMS. The Replacement Note or any New Replacement Note
            plus accrued interest may be prepaid in full at anytime without
            penalty.

3. MISCELLANEOUS.

      (a)   AMENDMENT AND MODIFICATION. This Agreement may be amended, modified
            and supplemented only by a written instrument signed by all of the
            parties hereto expressly stating that such instrument is intended to
            amend, modify or supplement this Agreement.

      (b)   ENTIRE AGREEMENT. This Agreement contains the entire agreement
            between the parties hereto with respect to the subject matter hereof
            and supersedes all prior agreements and understandings, oral or
            written, with respect to such matters.

      (c)   SEVERABILITY. If any provision of this Agreement shall be determined
            to be invalid or unenforceable under law, such determination shall
            not affect the validity or enforceability of the remaining
            provisions of this Agreement.

      (d)   GOVERNING LAW; JURISDICTION. This Agreement shall be governed by and
            construed in accordance with the laws of the State of New York,
            without regard to the conflicts of law rules of such state.

      (e)   COUNTERPARTS. This Agreement may be executed in one or more
            counterparts, each of which shall be deemed an original, and all of
            which shall constitute one and the same agreement and shall become
            effective when one or more counterparts have been signed by each of
            the parties and delivered to the other party, it being understood
            that both parties need not sign the same counterpart.
<PAGE>

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
day and year written above.

                               PASSUR Aerospace, Inc.
                               47 Arch Street
                               Greenwich, CT 06830

                               By: /s/ James T. Barry
                                   -------------------------
                                   Name:  James T. Barry
                                   Title: President and Chief Executive Officer

                               By: /s/ Jeffrey P. Devaney
                                   -------------------------
                                   Name:  Jeffrey P. Devaney
                                   Title: Chief Financial Officer

                               LENDER
                                   G.S. Beckwith Gilbert
                                   35 Vista Drive
                                   Greenwich, Connecticut 06830

                               By: /s/ G.S. Beckwith Gilbert
                                   -------------------------
                                   Name: G.S. Beckwith Gilbert
<PAGE>

                                                                       EXHIBIT A

                             SECURED PROMISSORY NOTE

$13,814,880                                               GREENWICH, CONNECTICUT
                                                          AS OF NOVEMBER 1, 2008

      (a)   For value received, PASSUR Aerospace, Inc. (formerly MEGADATA
            CORPORATION), a New York corporation (hereinafter referred to as
            "Borrower"), hereby unconditionally PROMISES TO PAY to the order of
            G.S. Beckwith Gilbert ("Lender"), or his permitted assigns, to an
            account designated by Lender, in lawful money of the United States
            of America and in immediately available funds, the principal sum of
            Thirteen million eight hundred fourteen thousand and eight hundred
            eighty dollars ($13,814,880) together with interest on the unpaid
            principal amount of this Note. Interest shall be payable at the
            annual rate of 4.5% from November 1, 2008 to January 31, 2009
            payable in cash. Beginning February 1, 2009 through October 31, 2011
            the annual interest rate will be 9% payable as follows: (i) interest
            at the annual rate of 6% will be payable in cash and (ii) the
            remaining interest at the annual rate of 3% will be payable, at the
            option of the Company, in cash or "paid in kind" and added to the
            principal of the Note. Interest payments shall be made annually at
            October 31 of each year.

      The principal amount evidenced hereby will be repaid in full on November
1, 2011. All accrued and unpaid interest hereunder as of November 1, 2011, shall
be payable on such date.

      Notwithstanding the foregoing, the principal amount of the indebtedness
evidenced hereby, together with all accrued interest, shall be immediately due
and payable upon written notice to Borrower from Lender upon the happening of
any of the following Events of Default:

            (a) Any representation or warranty in the Securities Purchase
      Agreement, dated September 18, 1996, between Borrower and Lender shall be
      untrue or incorrect in any material respect;

            (b) Any of the assets of Borrower shall be attached, seized, levied
      upon or subjected to a writ or distress warrant, or come within the
      possession of any receiver, trustee, custodian or assignee for the benefit
      of creditors of Borrower and shall remain unstayed or undismissed for
      thirty (30) consecutive days; or any person other than Borrower shall
      apply for the appointment of a receiver, trustee or custodian for any of
      the assets of Borrower and shall remain unstayed or undismissed for thirty
      (30) consecutive days; or Borrower shall have concealed, removed or
      permitted to be concealed or removed, any part of its property, with the
      intent to hinder, delay or defraud its creditors or any of them or made or
      suffered a transfer of any of its property or the incurring of an
      obligation which may be fraudulent under any bankruptcy, fraudulent
      conveyance or other similar law;
<PAGE>

            (c) A case or proceeding shall have been commenced against Borrower
      in a court having competent jurisdiction seeking a decree or order in
      respect of Borrower (i) under title 11 of the United States Code, as now
      constituted or hereafter amended, or any other applicable federal, state
      or foreign bankruptcy or other similar law, (ii) appointing a custodian,
      receiver, liquidator, assignee, trustee or sequestrator (or similar
      official) of Borrower or of any substantial part of its properties, or
      (iii) ordering the winding-up or liquidation of the affairs of Borrower
      and such case or proceeding shall remain undismissed or unstayed for
      thirty (30) consecutive days or such court shall enter a decree or order
      granting the relief sought in such case or proceeding;

            (d) Borrower shall (i) file a petition seeking relief under title 11
      of the United States Code, as now constituted or hereafter amended, or any
      other applicable federal, state or foreign bankruptcy or other similar
      law, (ii) consent to the institution of proceedings thereunder or to the
      filing of any such petition or to the appointment of or taking possession
      by a custodian, receiver, liquidator, assignee, trustee or sequestrator
      (or similar official) of Borrower or of any substantial part of its
      properties, (iii) fail generally to pay its debts as such debts become
      due, or (iv) take any corporate action in furtherance of any such action;

            (e) Final judgment or judgments (after the expiration of all times
      to appeal therefrom) for the payment of money in excess of $100,000 in the
      aggregate shall be rendered against Borrower and the same shall not be
      vacated, stayed, bonded, paid or discharged for a period of thirty (30)
      days; or

            (f) Any other event shall have occurred which would have a material
      adverse effect on Borrower or its assets or financial condition in
      Lender's reasonable judgment and Lender shall have given Borrower at least
      twenty (20) days notice thereof.

      As security for any and all liabilities of the Borrower to Lender, now
existing or hereafter arising hereunder, or otherwise, Lender is hereby given a
lien upon and a security interest in any and all moneys or other property (i.e.,
goods and merchandise, as well as any and all documents relative thereto; also,
funds, securities, chooses in action and any and all other forms of property
whether real, personal or mixed, and any right, title or interest of the
Borrower therein or thereto), and/or the proceeds thereof, including (without
limitation of the foregoing) that in safekeeping or in which Borrower may have
any interest. In the event of the happening of any one or more Events of
Default, Lender shall have all of the rights and remedies provided to a secured
party by the Uniform Commercial Code in effect in New York State at that time
and, in addition thereto, the Borrower further agrees that (1) in the event that
notice is necessary, written notice delivered to the Borrower at its principal
executive offices ten business days prior to the date of public sale of the
property subject to the lien and security interest created herein or prior to
the date after which private sale or any other disposition of said property will
be made shall constitute reasonable notice, but notice given in any other
reasonable manner or at any other reasonable time shall be sufficient, (2) in
the event of sale or other disposition of such property, Lender may apply the
proceeds of any such sale or disposition to the satisfaction of Lenders
reasonable attorneys' fees, legal expenses and other costs and expenses incurred
in connection with the retaking, holding, preparing for sale, and selling of the
property, and (3) without precluding any other methods of sale, the sale of
property shall have been made in a commercially reasonable manner if conducted
in conformity with reasonable commercial practices of banks disposing of similar
property.
<PAGE>

      Demand, presentment, protest and notice of nonpayment and protest are
hereby waived by Borrower.

      This Note has been executed, delivered and accepted in the State of New
York and shall be interpreted, governed by, and construed in accordance with,
the laws of the State of New York.

                                              PASSUR Aerospace, Inc.

                                              By: /s/ Jeffrey P. Devaney
                                                  ----------------------
                                                  Jeffrey P. Devaney
                                                  Title: Chief Financial Officer