<PAGE>

                                                                   Exhibit 10.29

No. R-1                                                               $1,800,000

                            UNITED STATES OF AMERICA
                                STATE OF FLORIDA
                            PINELLAS COUNTY, FLORIDA
                        PINELLAS COUNTY INDUSTRY COUNCIL
                INDUSTRIAL DEVELOPMENT REVENUE BOND, SERIES 1987
                         (AEROSONIC CORPORATION PROJECT)

     KNOW ALL, MEN BY THESE PRESENTS, that the Pinellas County Industry Council,
a special district and a public body corporate and politic existing in Pinellas
County, Florida (hereinafter called the "Issuer"), for value received, hereby
promises to pay to the order of Barnett Bank of Pinellas County (the "Original
Purchaser"), or registered assigns, solely from the Revenues hereinafter
mentioned and from no other source, the principal sum of one Million Eight
Hundred Thousand Dollars ($1,800,000) and to pay solely from the Revenues,
interest from the date hereof commencing March 17, 1988 and on the 17th day of
each March, June, September and December thereafter on the unpaid balance of
said principal sum outstanding from time to time at the Base Percentage
(hereinafter defined). Principal shall be payable in equal installments of
$18,556.70 commencing December 17, 1988 and on the 17th day of each March, June,
September and December thereafter. A final payment of all unpaid principal.
($18,556.80) plus accrued interest shall be due and payable on December 17,
2012.

     The "Base Percentage" shall be the percentage applied to the Prime Rate
(hereinafter defined) in determining the interest this Bond will bear. The Base
Percentage is currently 87% for the period from the date of delivery of this
Bond through December 31, 1987, and 90% thereafter subject to adjustment as
provided herein. No adjustment to the Base Percentage shall result in the
interest on this Bond accruing or becoming payable at a rate in excess of the
Taxable Rate (as hereinafter defined). The "Prime Rate" shall mean a rate of
interest equal to the announced prime rate per annum of Barnett Banks, Inc. The
Prime Rate is a reference rate for the information and use of the Original
Purchaser in establishing the actual rate to be charged to the Company. The
Prime Rate is not necessarily the rate of interest charged any particular class
of borrower. The Prime Rate shall be adjusted from time to time without notice
or demand, as of the effective date of any announced change thereof. Such rate
which is in effect as of the close for business on each business day shall be
the effective applicable rate for that day and for any succeeding non-business
day. The initial Prime Rate shall be the Prime Rate in effect at the opening of
business on the date of delivery of this Bond. The "Interest Rate" on this Bond
shall mean the Base Percentage multiplied by the Prime Rate as modified by the
adjustments provided

<PAGE>

for herein, but shall not by reason of such adjustments exceed the Prime Rate
plus one percent (1%) (the "Taxable Rate"). Interest shall he computed on the
basis of a three hundred sixty (360) day year consisting of 12 30-day months.

     Determination of Taxability. In the event of a Determination of Taxability
(as defined in the Indenture as defined below) the interest rate on this Bond
shall be increased to a rate equal to the Taxable Rate and such increased rate
of interest shall be payable from the Date of Taxability (as defined in the
Indenture as defined below) and compounded quarterly until this Bond is redeemed
as required herein. Payment shall be made to the current holders of this Bond
and any former holders from the Date of Taxability until this Bond is redeemed
as required herein. Payment shall be made to such holders and former holders
from the Date of Taxability for the period of time that such person was the
registered owner of this Bond. The holder or former holder shall also be
entitled to reimbursement of any penalties, additions or interest on overdue
taxes and any taxes payable because of receipt of such reimbursement.

     The Interest Rate on this Bond shall be adjusted as follows (but shall not,
by reason of such adjustments, exceed the Taxable Rate):

     (i) Change in Maximum Corporate Tax Rate. If the maximum federal corporate
income tax rate for the holder of this Bond or its parent holding company during
any period in which interest is accruing, shall be other than 40% for 1987 or
34% for 1988 and subsequent years, then the interest on this Bond during such
period shall be modified by multiplying the Base Percentage (as adjusted) by a
fraction equal to 1 - A
                  -----
                  1 - B
where A equals the maximum marginal corporate income tax rate then in effect and
B equals the immediately preceding maximum marginal corporate income tax rate.

     (ii) Alternative Minimum Tax Where Bond Interest is a Direct Tax Preference
Item. If the holder of this Bond or its parent holding company pays an
alternative minimum tax in any tax year and the interest on this Bond is a
direct tax preference item under section 57(a) (5) or any successor provision of
the Internal Revenue Code of 1986 (the "Code") then the Interest Rate on this
Bond for the period during such tax year in which interest is accruing on this
Bond shall be increased during such accrual period by an amount equal to (A - B)
x C where:

          (a) A equals the Interest Rate on this Bond expressed as a percentage;

          (b) B equals the Adjusted Bank's Cost of Funds (as hereinafter
     defined); and

          (c) C equals the maximum marginal rate of the alternative maximum tax
     expressed as a decimal (currently .20).

                                       2

<PAGE>

     "Adjusted Bank's cost of Funds" shall mean the fraction (expressed as a
percentage) and as determined by the holder of this Bond or its parent holding
company, of the total interest expense of the Original Purchaser (or any
successor institutional holder of this Bond) for each calendar year divided by
the total monthly average of all assets of the Original Purchaser (or any
successor institutional holder of this Bond) during the calendar year.

     (iii) Alternative Minimum Tax Where Bond Interest is an Indirect Tax
Preference Item. If the holder of this Bond or its parent holding company pays
an alternative minimum tax in any tax year and the interest on this Bond is not
a tax preference item under section 57(a)(5) of the Code, but is an indirect tax
preference item because of the application of Section 56(f) or Section 56(g) or
any successor provision of the Code then the Interest Rate on this Bond for the
period during such tax year in which interest is accruing on this Bond shall be
increased during such accrual period by an amount equal to (A - B) x C where:

          (a) A equals the Interest Rate on this Bond expressed as a percentage;

          (b) B equals the Adjusted Bank's Cost of Funds; and

          (c) C equals one half of the maximum marginal rate of the alternative
     minimum tax expressed as a decimal (currently 1/2 of .20 or .10) for tax
     years of the original Purchaser beginning before January 1, 1990 and C
     equals 75% of the maximum marginal rate of the alternative minimum tax
     expressed as a decimal for tax years of the Original Purchaser beginning
     after December 31, 1989.

     (iv) Loss of Federal Income Tax Deduction for State Income Taxes. If the
federal income tax deduction for state income taxes paid on the interest
payments received under this Bond during any period is reduced because of any
change in the tax laws or regulations then the Interest Rate on this Bond shall
be increased during such period by an amount equal to A x B x C x D where:

          (a) A equals the fraction (expressed as a decimal) of the total state
     income tax disallowed as a result of such tax law change;

          (b) B equals the rate of the applicable state income tax (expressed as
     a decimal);

          (c) C equals the corporate tax rate then in effect (expressed as a
     decimal); and

          (d) D equal the Interest Rate on this Bond (expressed as a
     percentage).

                                       3

<PAGE>

     (v) Partial Taxability. If the interest payments received under this Bond
during any period become partially taxable because of any change in the tax laws
or regulations, then the Interest Rate on this Bond shall be increased during
such period by an amount equal to (A - B) x C where:

          (a) A equals the Taxable Rate (expressed as a percentage);

          (b) B equals the Interest Rate on this Bond (expressed as a
     percentage); and

          (c) C equals the fraction of the Interest Rate on this Bond which has
     become taxable as the result of such tax change (expressed as a decimal).

     (vi) Other Change in Tax Laws. If the tax laws or regulations are amended
to cause the interest on this Bond to be taxable, to be subject to a minimum tax
or an alternative minimum tax or to otherwise decrease the after tax yield on
this Bond to the holder of this Bond (directly or indirectly, other than a
change described in (i) through (v) above or because of a Determination of
Taxability) then the Interest Rate on this Bond shall be adjusted to cause the
interest received by the holder of this Bond, after payment of any increase in
tax, to equal the interest the holder of this Bond would have received in the
absence of such change or amendment in the tax laws or regulations. If the
tax laws or regulations are amended to increase the after tax yield on this
Bond to the holder of this Bond, then the Trustee (as defined in the Indenture
as hereinafter defined) shall adjust the Interest Rate on this Bond to cause the
interest received by the holder of this Bond to equal the interest the holder of
this Bond would have received in the absence of such change or amendment in the
tax laws or regulations.

     The above adjustments shall be cumulative, but in no event shall the
Interest Rate on this Bond exceed the maximum rate permitted by law. The above
adjustments to the Interest Rate on this Bond shall be effective on the
effective date of the applicable change in the tax laws or regulations. Interest
on this Bond and all other tax rates and interest rates are expressed as annual
rates. However, proper partial adjustment shall be made if the tax law change is
effective after the first day of the holder's tax year or if interest on this
Bond does not accrue for the entire tax year of the holder. Adjustments which
create a circular calculation because the Interest Rate on this Bond is affected
by the calculation shall be carried out sequentially, increasing the Interest
Rate accordingly in each successive calculation using as the new value the
increase in the Interest Rate on this Bond, until the change on the Interest
Rate on this Bond caused by the next successive calculation of the adjustment is
de minimis. If more than one of paragraphs (i) through (v) apply, then the
Interest Rate shall be adjusted in the order in which listed above.

                                       4

<PAGE>

     To the extent allowed by applicable law, in the event any payment of
interest and principal on or other amounts payable under this Boand shall not
be paid when due, the amount so due shall, to the extent legally enforceable,
continue to bear interest from the date such payment became due until payment
thereof at a rate equal to the Default Rate (as defined in the Agreement as
hereinafter defined), and, if the holder of this Bond or the Trustee (as
defined in the Indenture as hereinafter defined) should employ attorneys or
incur other expenses for the collection of amounts payable under this Bond, the
Issuer shall pay the reasonable fees of such attorneys and such other expenses
so incurred by the holder of this Bond and the Trustee.

     Principal of and interest and other payments on this Bond are payable in
lawful money of the United States of America by check or draft on the Trustee
mailed to the registered owner, at the address shown on the registration books
maintained by the Trustee as Registrar or such other address as is furnished to
the Trustee in writing by the registered owner of this Bond. Payment of the
final installment of principal of and interest on this Bond shall be made upon
the presentation and surrender of this Bond at the principal office of the
Trustee. All payments shall be applied first to accrued but unpaid interest and
then to principal, except that payments in partial redemption of this Bond shall
be applied in accordance with Section 701 of the Indenture.

     This Bond is one of an issue of Bonds of the Issuer in the aggregate
principal amount of $1,800,000 issued to finance all or a portion of the cost of
constructing and equipping a manufacturing facility and related facilities in
Pinellas County, Florida, (the "Project") for the benefit of the Company. The
Bonds will be repaid by the Issuer from installment financing payments and other
amounts under the terms of a Financing Agreement (hereinafter sometimes called
the "Agreement") and a Promissory Note (the "Note") both dated December 17,
1987. The issuance of the Bonds and the construction, equipping and financing of
the Project are under the authority of and in full compliance with the
Constitution and Statutes of the State of Florida, including particularly
Chapter 69-1490, Laws of Florida, Special Acts of 1969 and Chapter 159, Part II,
Florida Statutes (hereinafter called the "Act") and other applicable provisions
of law, and a resolution duly adopted by the Issuer on November 4, 1987, and
consented to by the Board of County Commissioners of Pinellas County on November
24, 1987 (hereinafter called the "Resolution"), and is subject to all the terms
and conditions of such Resolution.

     The Bonds are all issued under and equally and ratably secured by and
entitled to the security of a Trust Indenture dated December 17, 1987 (herein
sometimes called the "Indenture"), duly executed and delivered by the Issuer to
Barnett Banks Trust Company, N.A., as trustee under the Indenture (the
"Trustee"). Reference is made to the Indenture for the terms of the Indenture
and the provisions, among others, with respect to the nature and extent of the
security, the rights, duties and obligations of the Issuer and the Trustee and
the rights of the owners of the Bonds.

                                       5

<PAGE>

     As additional security for payment of the Bonds the Company has conveyed
its interest, in certain real and personal property pursuant to a Mortgage and
Security Agreement dated December 17, 1987 from the Company as Mortgagor to the
Issuer as Mortgagee and assigned to the Trustee (the "Mortgage").

     The Issuer shall not be obligated to pay this Bond or the interest hereon
except from the revenues, receipts and the funds pledged to the payment of this
Bond including those payable pursuant to the Agreement and the Note and those
received by the Trustee pursuant to the Mortgage and any other moneys pledged
for such payment under the Indenture including but not limited to those moneys
on deposit from time to time in the Bond Fund and the Construction Fund, as each
is defined in the Indenture (collectively the "Revenues"), and neither the faith
and credit nor the taxing power of the State of Florida or of any other
political subdivision thereof is pledged to the payment of the principal of or
the interest on this Bond.

                     OPTIONAL REDEMPTION IN WHOLE OR IN PART

     This Bond may be redeemed by the Issuer, at the request of the Company on
any principal payment date, prior to maturity, in whole or in part (but if in
part, in $5,000 increments), at 102% of the principal then outstanding if
redeemed on or prior to the first anniversary date of the date of delivery of
this Bond, at 101% of the principal then outstanding if redeemed after the
first anniversary date of the date of delivery of this Bond but on or before
the second anniversary date of the date of delivery of this Bond, and at 100% of
the principal then outstanding if redeemed after the second anniversary date of
the date of delivery of this Bond, plus accrued interest to the redemption date,
plus all other amounts due under the Mortgage, the Indenture or the Agreement.

                              MANDATORY REDEMPTION

     This Bond shall be redeemed in part in the manner provided in Section 2.03
of the Agreement, at par, plus accrued interest, to the extent that Bond
proceeds and investment earnings thereon exceed the amount necessary for the
construction and equipping of the Project.

                      SPECIAL MANDATORY REDEMPTION IN WHOLE

     If interest on this Bond is declared taxable as a result of a Determination
of Taxability, or should an Adjudication of Invalidity (as defined in the
Indenture, in which case the Company shall promptly notify the Trustee and
original Purchaser of its existence) occur in connection with the Bonds then
this Bond shall be redeemed as provided in Section 8.05 of the Agreement at the
then outstanding principal amount of this Bond, plus accrued interest, plus in
the case of a Determination of Taxability all other amounts due under the
Mortgage, the Indenture or the Agreement and other amounts calculated as
provided in Section 202 of the Indenture.

                                       6

<PAGE>

                                       PUT

     This Bond may be redeemed by the holder in whole at the principal amount
plus accrued interest on the anniversary date of the date of delivery of this
Bond in the years 1992, 1997, 2002 and 2007. The holder may exercise this option
by written notice to the Trustee and the Company at least 6 months prior to the
redemption date. Upon receipt of the notice, the Company must pay all amounts
due under this Bond on or before the redemption date.

     All partial redemption of the Bonds shall be applied to principal
installments in inverse order of maturity except that partial redemption from
unexpended Bond proceeds shall be applied ratably to reduce future principal
installments.

     Notice of any such redemption shall be given in the manner required by the
Indenture.

     All Bonds so called for redemption will cease to bear interest on the
specified redemption date, provided funds for their redemption are on deposit at
the place of payment at that time, and shall no longer be protected by the
Indenture and shall not be deemed to be outstanding under the provisions of the
Indenture.

     The Issuer reserves the right to issue additional bonds payable on a parity
with the Bonds of the issue of which this Bond is one, subject to the conditions
and in the manner provided in the Agreement and the Indenture.

     Neither the Issuer, the State of Florida, nor any political subdivision
thereof, is or shall be obligated to pay this Bond or the interest hereon except
from the payments from the Company and neither the faith and credit nor the
taxing power of Pinellas County, the State of Florida or of any political
subdivision thereof is pledged to the payment of the principal of or the
interest on this Bond. The issuance of this Bond shall not directly or
indirectly or contingently obligate the State of Florida or any political
subdivision thereof to levy or to pledge any form of taxation whatever therefor
or to make any appropriation for their payment.

     NO RECOURSE SHALL BE HAD FOR THE PAYMENT OF THE PRINCIPAL OF, PREMIUM, IF
ANY, OR INTEREST ON THIS BOND OR FOR ANY CLAIM BASED THEREON OR UPON ANY
OBLIGATION, COVENANT OR AGREEMENT CONTAINED IN THIS BOND, THE INDENTURE OR THE
AGREEMENT AGAINST ANY PAST, PRESENT OR FUTURE MEMBER, OFFICER OR EMPLOYEE OF
THE ISSUER, OR ANY INCORPORATOR, MEMBER, COMMISSIONER, DIRECTOR, TRUSTEE,
OFFICER OR EMPLOYEE OF ANY SUCCESSOR OF THE ISSUER, AS SUCH, EITHER DIRECTLY OR
THROUGH THE ISSUER OR ANY SUCCESSOR OF THE ISSUER, UNDER ANY RULE OF LAW OR
EQUITY, STATUTE OR CONSTITUTION.

     The owner of this Bond shall have no right to enforce the covenants under
the Agreement or the Indenture, or to take any action with respect to any event
of default under the Agreement or

                                       7

<PAGE>

the Indenture, or to institute, appear in or defend any suit or other
proceedings with respect thereto, except as provided in the Agreement or the
Indenture.

     In certain events, on the conditions, in the manner and with the effect
set forth in the Agreement and the Indenture, the principal of the Bond
issued under the Agreement and the Indenture and then outstanding may become or
may be declared due and payable before the stated maturity thereof, together
with interest accrued thereon. Modifications or alterations of the Agreement
and the Indenture, or of any supplements thereto, may be made only to the extent
and in the circumstances permitted by the Agreement and the Indenture.

     IT IS HEREBY CERTIFIED, RECITED AND DECLARED that all acts, conditions and
things required to exist, happen and be performed precedent to and in the
execution and delivery of the Indenture and the issuance of this Bond do exist,
have happened and have been performed in due time, form and manner as required
by law; and that the issuance of this Bond and the series of which it forms a
part, together with all other obligations of the Issuer, does not exceed or
violate any constitutional or statutory limitation.

     This Bond shall have and is hereby declared to have all the qualities and
incidents, including negotiability, of investment securities under the Uniform
Commercial Code - Investment Securities law of the State of Florida.

     This Bond shall not be valid or become obligatory for any purpose or be
entitled to any security or benefit under the Indenture until the certificate of
authentication hereon shall have been duly executed by the Trustee.

     IN WITNESS WHERE0F, the Pinellas County Industry Council has issued this
Bond and has caused the same to be executed in its name by the manual signature
of its Chairman, and attested by the manual signature of its Secretary and its
official seal to be impressed hereon, the 17th day of December, 1987.

(SEAL)                                       PINELLAS COUNTY INDUSTRY COUNCIL


                                             By /s/ Charles E. Rainey
                                               ---------------------------------
                                                Chairman

ATTEST:


/s/ William M. Castoro
---------------------------------
Secretary

                                       8

<PAGE>

                     Trustee's Certificate of Authentication

     This Bond represents an issue of Bonds described in the within-mentioned
Trust Indenture.

                                             BARNETT BANKS TRUST COMPANY,
                                             N.A., as Trustee


                                             By /s/ Ramsay D. Breazeale
                                               ---------------------------------
                                                Authorized Officer

                    PROVISIONS FOR REGISTRATION AND EXCHANGE

     As provided in the Indenture and subject to certain limitations set forth
therein, this Bond is transferable upon the books of the Trustee, by the
registered owner hereof in person or by such owner's attorney duly authorized in
writing, upon surrender hereof together with a written instrument of transfer
satisfactory to the Trustee, duly executed by the registered owner or such
owner's duly authorized attorney. Upon such transfer the Issuer will cause to be
issued in the name of the transferee a new fully registered Bond or Bonds of the
same aggregate principal amount, maturity and interest rate as the surrendered
Bond, subject to reimbursement for any tax, fee or governmental charge required
to be paid by the Issuer or the Trustee with respect to such transfer and for
any cost of printing Bonds.

                                   ASSIGNMENT

                               FOR VALUE RECEIVED

     The undersigned hereby sells, assigns and transfers unto
                                                              ------------------
                             the within Bond of the Pinellas County Industry
----------------------------
Council, and does hereby constitute and appoint                                ,
                                                -------------------------------
attorney to transfer the said Bond on the books of the within named Issuer, with
full power of substitution in the premises.

Date:
      ---------------------


Signature Guaranteed:
                      -----------------------------------   --------------------
                                                            Registered Owner

Notice: Signature(s) must be guaranteed by a member firm of the
New York Stock Exchange or a commercial bank or trust company.

                                       9