AEROSONIC CORPORATION AVIONICS SPECIALTIES, INC. OP TECHNOLOGIES, INC. 14% SUBORDINATED NOTE

The offer and sale of this Note have not been registered under the United States Securities Act of 1933 or the securities law of any state of the United States.  This Note cannot be offered for sale or sold at any time, as a whole or in part, unless the transaction is registered under the United States Securities Act of 1933 and every applicable state securities law or qualifies for an available exemption from registration under those laws. As a condition to allowing any transfer of this note, Aerosonic Corporation, OP Technologies, Inc., and Avionics Specialties, Inc. may require the transferee or transferor to deliver to them an opinion of legal counsel or other evidence satisfactory to them that confirms that the transfer has been registered under all applicable state and federal securities law of the United States or is exempt from registration under those laws.

AEROSONIC CORPORATION (the “Company” ), a Delaware corporation, OP TECHNOLOGIES, INC. , an Oregon corporation, and AVIONICS SPECIALTIES, INC. , a Virginia corporation, (individually, a “Borrower” and, collectively, “Borrowers” ), for value received, jointly and severally promise to pay without setoff, defense, or counterclaim to the order of Bruce J. Stone (the “ Lender ”) , at maturity, the principal amount of One Million United States Dollars (US $1,000,000), and to pay on a monthly basis interest on the unpaid principal amount from the date of this 14% Subordinated Note (this “Note” ) at the rate, on the date, and subject to the conditions and limitations specified in this Note.

1.         Note.

This Note is limited to an aggregate principal amount of $1,000,000, of which $750,000 shall be available to the Borrowers on the Effective Date and $250,000 shall be available to the Borrowers no later than July 5, 2009 (the “Note” ) and issued pursuant to the Loan Agreement dated May 14, 2009, by and between the Company and the Lender (as amended from time to time, the “Loan Agreement” ).  The terms and conditions of the Loan Agreement are incorporated by reference into this Note.

2.         Defined Terms.

“Maturity Date” means the earlier of:  (i) April 10, 2010, or (ii) the maturity of the Existing Loans.  

All capitalized and uncapitalized terms that are defined in Section 1.1 of the Loan Agreement and used in this Note have the meanings attributed to those terms in the Loan Agreement, and those definitions are incorporated by reference into this Note.

3.         Interest.

Interest shall accrue monthly on the unpaid principal amount of this Note from the date of this Note until the April 10, 2010 (the “Maturity Date”) at an annual rate of 14% and shall be payable commencing on June 1, 2009 and continuing on the same calendar day of each consecutive month until the Maturity Date when one final payment of the entire balance of principal, interest, fees (including Event of Default Fee, if applicable), premiums, charges, costs and expenses then outstanding on this Note shall be due and payable in full.  Interest is payable on demand on any payment of principal or interest under this Note that is not paid when due, for the period commencing on the day following the day when Interest was last timely paid in accordance with the terms of this Section 3 and continuing until paid, at an annual rate equal to 16%.  Borrowers and the Lender intend to comply strictly with applicable law regulating the maximum allowable rate or amount of interest that the Lender may charge and collect on this Note.  Accordingly, and notwithstanding anything in this Note to the contrary, the maximum, aggregate amount of interest and other charges constituting interest under applicable law that are payable, chargeable, or receivable under this Note shall not exceed the maximum amount of interest now allowed by applicable law or any greater amount of interest allowed because of a future amendment to existing law.  Borrowers are not liable for any interest in excess of this maximum amount, and any excess interest charged or collected by the Lender will constitute an inadvertent mistake and, if charged but not paid, will be cancelled automatically, or, if paid, will be either refunded to Borrowers or credited against the outstanding principal balance of the Note, at the election of the Lender.

4.         Event of Default Fee.

If the Note is not paid in full when due, whether at stated maturity or upon acceleration of the Maturity Date pursuant to a Default, the Borrowers jointly and severally shall pay to the Lender a fee of $50,000 (the “ Event of Default Fee ”) on the date when the Note became due and payable (whether at stated maturity or upon acceleration of the maturity date pursuant to a Default).  In addition, upon a Default, the Company will immediately register the Advance Shares issued to Stone in connection with the Note and the Warrant Shares issued upon exercise of the Warrants in accordance with the provisions set forth in the Loan Agreement and the Warrant, as applicable.

5.         Maturity.

Borrowers shall pay to the Lender on the Maturity Date all unpaid principal and accrued interest under this Note, and if applicable, the Event of Default Fee.

6.         Payment of Note.

Borrowers may prepay the Note in full at any time or in part from time to time without penalty, premium, or advance notice to the Lender.  Borrowers shall provide the Lender with prior written notice of any prepayment, whether in full or in part.   Upon full payment of this Note (including all costs, principal, and accrued interest), the Lender shall surrender it to the Company for cancellation.

7.         Place and Method of Payment.

Borrowers shall pay all principal and interest under this Note, and if applicable, the Event of Default Fee, by wire transfer to an account designated by the Lender.  If any payment date under this Note occurs on a day that is a Saturday, Sunday, or bank holiday in Tampa, Florida, that payment date will be extended automatically to the next succeeding day that is n