Exhibit
10.8

    


    State
of Florida documentary excise tax in the amount of

    $1750.00
has been paid or will be paid directly to the Florida

    Department
of Revenue.

    


    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

    AVIONICS
SPECIALTIES, INC.

    OP
TECHNOLOGIES, INC.

    14% SUBORDINATED
NOTE

    


    
      
        	
                U.S.
      $500,000.00

              	
                May
      14, 2009 (the “Effective
Date”)

              


      

    

     

    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 MARTIN L. SCHAFFEL (the “Lender”),
at maturity, the principal amount of Five Hundred Thousand Dollars (US
$500,000), 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 $500,000 shall be available to
the Borrowers on the Effective Date (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 $25,000 (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 Redmond 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 not a Business Day.  Borrowers shall pay all
principal and interest due under this Note, and if applicable, the Event of
Default Fee, without any presentation of this Note.  Any partial
prepayment of this Note before the Maturity Date will be applied first to
accrued interest, and then to principal.  Any payment or prepayment of
this Note in full will be applied first to the then accrued interest, and then
to principal.

    


    
      	
              8. 

            	
              Subordination.

            


    

    


    By
accepting this Note, the Lender agrees that the Loan is subordinated and subject
to the right of prior payment in full of all the Existing
Loans.  Borrowers shall not make any payment on account of the Loan,
or apply any of their respective assets or property to retire or purchase any of
the Loan, if, at the time of payment or application, a default or event of
default exists and is continuing in the payment of any principal or interest
then due and payable under the terms of the Existing Loans.  Nothing
in this Note prevents the Lender from exercising all remedies otherwise
permitted by law, this Note, or the other Financing Documents upon the
occurrence of a “Default,” subject to the provisions of the Financing Documents
and any rights of the holder of Existing Loans under the foregoing subordination
provisions to receive cash, property, or securities otherwise payable and
distributable to the Lender on account of this Note.


    
      
         


      

      
        2

        
          

        

      

      
         


      

    

     

    
      	
              9. 

            	
              Events
      of Default.

            


    

    


    The
occurrence of one or more of the following events will constitute a “Default”
under this Note:

    


    (a)         the
failure of Borrowers to pay within ten (10) days following its due date, any
payment described herein, whether of principal, interest or
otherwise;

    


    (b)         any
default or event of default under the Existing Loan Documents;

    


    (c)         any
default, or event of default under any of the Financing Documents;

    


    (d)         any
default, or event of default under any loan to an Other Lender; or

    


    (e)         a
borrowing by one or more of the Borrowers for the purpose of repaying any amount
payable under the Existing Loan Documents, unless the borrowing is on more
favorable terms to the Borrowers.

    


    If a
“Default”
occurs, the entire unpaid principal amount of this Note, together will all
amounts owing under this Note, including interest, will become immediately due
and payable without further demand or notice by the Lender, and the Lender may
proceed to protect its rights in the manner provided by applicable law and the
Financing Documents.  As set forth in Section 3, if a Default occurs,
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 and continuing until paid, at an
annual rate equal to 16%.  If this Note is not paid in full whenever
it becomes due and payable, Borrowers agree to pay all costs and expenses of
collection, including reasonable attorneys’ fees.  Notwithstanding any
of the foregoing, at any time during the term of the Loan the Existing Lender
waives (or is deemed to have waived through extension, forbearance or otherwise)
any Default under any of the Existing Loans, such waiver shall constitute a
waiver of such Default under the Loan.

    


    
      	
              10. 

            	
              Waivers;
      Consents.

            


    

    


    Each
Borrower and every other person liable at any time for payment of this Note
waives presentment, protest, notice of protest, and notice of
dishonor.  A waiver, discharge, extension, amendment, termination, or
modification of this Note will be valid and effective only if it is evidenced by
a writing signed by or on behalf of the party against whom the waiver is sought
to be enforced.  No delay or course of dealing by the Lender in
exercising any power, right, or remedy under this Note will operate as a waiver
of any power, right, or remedy of the Lender, except to the extent expressly
manifested in a writing signed by or on behalf of the Lender.  In
addition, the written waiver by the Lender of a power, right, or remedy under
any provision of this Note will not constitute a waiver of any other succeeding
exercise of the power, right, or remedy or a waiver of the provision
itself.  A written waiver or consent by the Lender is binding on every
subsequent holder of this Note.

    


    Each
Borrower consents to all extensions and renewals of this Note (as a whole or in
part) and all delays and indulgences in time of payment or other performance
under this Note that the Lender grants at any time and from time to time,
without limitation and without notice to or further consent of any
Borrower.


    
      
         


      

      
        3

        
          

        

      

      
         


      

    


    
      	
              11. 

            	
              Transfer
      Restrictions.

            


    

     

    No state
or federal agency has passed on this Note.  The issuance of this Note
has not been, and will not be, registered under the Securities Act, the
securities laws of any state of the United States, or the securities law of any
foreign country.  This Note cannot be offered for sale or sold at any
time unless the transaction is registered under the Securities Act, every
applicable state securities law of the United States, and any foreign securities
laws or qualifies for an available exemption under those laws.  The
Company has not agreed, and is not obligated, to register any resale or other
transfer of this Note under the Securities Act or any state or foreign
securities law, or to supply the holder of this Note with any necessary
information or take any other action to enable the holder of this Note to
qualify any resale or other transfer of this Note for the exemption provided by
SEC Rule 144 or any other exemption from registration under any of those
laws.  Borrowers may require, as a condition to allowing any transfer
or exchange of this Note, that the transferee or the holder (as the case might
be) deliver to the Company a notice describing the proposed sale or transfer and
either (a) evidence that the transfer or exchange has been registered or
qualified under the Securities Act and every applicable state and foreign
securities law or (b) an opinion of legal counsel or other evidence satisfactory
to the Company that confirms that the transfer or exchange has been registered
under all applicable foreign laws and state and federal securities laws of the
United States or is exempt from registration under those laws.  Each
Note issued in exchange or substitution for this Note will bear a legend
substantially identical to the one appearing on the face of this
Note.

    


    
      	
              12. 

            	
              Legal
      Matters.

            


    

    


    The
validity, construction, interpretation, and enforcement of this Note are
governed by the laws of the State of Florida and the federal laws of the United
States of America, excluding the laws of those jurisdictions relating to the
resolution of conflicts with laws of other jurisdictions.  Borrowers
and the Lender (a) consent to the personal jurisdiction of the state and
federal courts in the State of Florida, (b) stipulate that the proper,
exclusive, and convenient venue for any legal proceeding in state or federal
court relating to the enforcement of this Note is the Circuit Court for Pinellas
County, Florida, for a state trial court proceeding, and the United States
District Court for the Middle District of Florida, Tampa Division, for a federal
district court proceeding, (c) waive any defense, whether asserted by
motion or pleading, that these venues are improper or inconvenient, and (d)
KNOWINGLY, VOLUNTARILY, AND
IRREVOCABLY WAIVE ANY RIGHT TO A JURY TRIAL IN ANY LAWSUIT OR COUNTERCLAIM
RELATING TO THIS NOTE OR ANY SECURITY FOR THIS NOTE, INCLUDING ANY LAWSUIT BY
THE LENDER TO ENFORCE AND COLLECT THIS NOTE.  In any lawsuit
arising out of this Note, Borrowers jointly and severally shall reimburse the
Lender, on demand, for all costs incurred by the Lender in enforcing, defending,
or prosecuting the lawsuit.

    


    
      	
              13. 

            	
              Notices.

            


    

    


    Every
demand or notice required or permitted by this Note will be valid only it is
given and delivered in the manner required by the Loan Agreement.

    


    
      	
              14. 

            	
              Severability.

            


    

    


    Each
provision of this Note should be construed and interpreted so it is valid and
enforceable under applicable law.  If a provision of this Note is held
by a court to be invalid or unenforceable under applicable law, the provision
will be deemed separable from the remaining provisions of this Note and will not
affect the validity or interpretation of the other provisions of this Note or
the application of that provision to a person or circumstance to which it is
valid and enforceable.

    


    
      	
              15. 

            	
              Miscellaneous.

            


    

    


    The titles and headings preceding the
text of the sections of this Note are solely for convenient reference and
neither constitute a part of this Note nor affect its meaning, interpretation,
or effect.  Time is of the essence with respect to the performance and
satisfaction by Borrowers of every obligation and condition to be performed or
satisfied by them under this Note.  This Note is binding on, and
inures to the benefit of, any successor or approved assignee of a Borrower and
the holder of this Note.  The Existing Lender and any subsequent
holder of the Existing Loans are third party beneficiaries of the provisions of
Section 8 of this Note.


    
      
         


      

      
        4

        
          

        

      

      
         


      

    

    


    EXECUTED:  May14,
2009

    


    
      
        
          
            
              
                
                  
                    	 
      	 
      	
                            AEROSONIC
      CORPORATION

                          
	 
      	 
      	
                            AVIONICS
      SPECIALTIES, INC.

                          
	 
      	 
      	
                            OP
      TECHNOLOGIES, INC.

                          
	 
      	 
      	 
      
	
                            WITNESSES:

                          	 
      	
                            By:

                          	
                                /s/ Douglas J.
      Hillman

                          
	 
      	 
      	 
      	
                            Douglas
      J. Hillman

                          
	 
      	 
      	 
      	
                            President
      and Chief Executive
Officer

                          


                  

                

              

            

          

        

      

    

    
      
        
          
            	
                      

                  	 
      	 
      
	
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