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                                                                   EXHIBIT 10.16


                                 LEASE AGREEMENT

                                     BETWEEN

                          TERMINAL REAL ESTATE COMPANY

                                       AND

                            S.T. RESEARCH CORPORATION



                     (Lease Agreement consists of 14 pages.)







                                                     Billy Lanier
                                                     140 Kings Landing Road
                                                     Hampstead, NC 28443


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                                 LEASE CONTENTS



1.  Rental .....................................................  3
2.  Timely Payment .............................................  4
3.  Utilities ..................................................  4
4.  Use ........................................................  4
5.  Assignment .................................................  5
6.  Good Condition .............................................  5
7.  Damages ....................................................  5
8.  Subordination ..............................................  5
9.  Repairs, Alterations, Fixtures .............................  6
10. Insurance ..................................................  8
11. Governmental Requirements ..................................  9
12. Eminent Domain .............................................  10
13. Signs ......................................................  10
14. Interior Repairs ...........................................  10
15. Default ....................................................  10
16. Legal Fees .................................................  10
17. Real Estate Taxes ..........................................  10
18. Rent Adjustment ............................................  11
19. Landlord's Permission ......................................  11
20. Landlord's Maintenance Responsibilities ....................  11
21. Removal of Fixtures ........................................  12
22. Late Charges ...............................................  12
23. No Waiver ..................................................  12
24. Tenant's Bankruptcy ........................................  13
25. Fire .......................................................  13
26. Tenancy by Sufferance ......................................  13
27. Successors .................................................  14
28. Construction ...............................................  14


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                                 LEASE AGREEMENT


       THIS LEASE AGREEMENT made this 11th day of December, 1989, by and between
TERMINAL REAL ESTATE COMPANY, a general partnership, hereinafter referred to as
the Landlord, and S.T. RESEARCH CORPORATION, a Virginia corporation, hereinafter
referred to as the Tenant.

                               W I T NE S S E T H:

       That the Landlord hereby leases and demises to the Tenant, and the Tenant
does hereby take, lease and hold of the Landlord subject to the covenants and
agreements herein contained the premises located at 8419-H Terminal Road,
Newington, Fairfax County, Virginia, on which is situated a building containing
11,230 square feet, approximately, of heated and air-conditioned office and
laboratory space, for a term of six (6) years commencing December 15, 1989, and
ending on December 14, 1995, and for an optional three (3) years ending December
14, 1998, upon the terms and conditions hereinafter set forth. 

1.     Rental. The Tenant agrees and covenants to pay the Landlord a fixed
annual rent for each square foot of building space rented, and it is stipulated
by the Landlord and the Tenant that the amount of building space shall be 11,230
square feet, approximately, as set forth in the appraisal made by Thomas E.
Barlow, M.A.I. dated November 17, 1977, and the plans for additional office
space made by The Calvert Company dated August 24, 1984.


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       The fixed annual rate based upon the aforesaid rental schedule shall be
paid to the Landlord in equal monthly installments in advance of the fifteenth
(15th) day of each month during the term of this lease at such place as the
Landlord designates.

       As rent for said premises, Tenant agrees to pay the Landlord a guaranteed
minimum rental of Seventy-One Thousand Three Hundred and Ten Dollars ($71,310)
per annum in consecutive equal monthly installments of Five Thousand Nine
Hundred Forty-Two Dollars and Fifty Cents ($5,942.50).

       The Tenant has deposited with the Landlord the sum of One Thousand One
Hundred Sixty-Three Dollars and Fifty-Nine Cents ($1,163.59) as security for the
full and faithful performance by the Tenant of all the terms of this lease
required to be performed by the Tenant. Such sum shall be returned to the Tenant
or applied to the last month's rent provided the Tenant has fully and faithfully
carried out all of the terms of this lease. In the event the Tenant defaults in
respect to any of the terms, covenants and conditions of this Lease, including
but not limited to payment of any rentals, the Landlord may use, apply or retain
the whole or part of the security so deposited for the payment of any such
rentals in default or for any other sum the Landlord may expend or be reuqired
to expend by reason of the Tenant's default, including any damages or deficiency
in the reletting of the subject property. 

2.     Timely Payment. The Tenant agrees that it will pay said rent at time and
place specified without demand or deduction in equal monthly payments. 

3.     Utilities. The Tenant agrees that it will pay all water and sewer
charges, gas and electrical bills, and utilities as the same become due.


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4.     Use. The Tenant agrees that it will use said premises for the full term
hereof for engineering research and development, manufacturing and related use,
and for no other purposes whatsoever, and it will not use nor permit said
premises or any part thereof to be used, for any disorderly or unlawful purpose.

5.     Assignment. The Tenant agrees that it will not transfer or assign this
lease, not let nor sublet the whole or any part of said premises without the
written consent of Landlord first obtained, which consent Landlord agrees not to
unreasonably withhold.

6.     Good Condition. The Tenant agrees it will keep said premises in good
order and condition, and surrender same at the expiration of the term herein in
the same order in which they are received, usual wear and tear and damage by
fire, storm and public enemies only excepted. Upon surrender of the premises,
Tenant shall have removed all rubbish, advertisements and signs from interior,
exterior and windows thereof, and on failure to do so authorizes Landlord to
forthwith remove the same at Tenant's expense.

7.     Damages. The Tenant agrees that all personal property in said premises
shall be and remain at his sole risk, and the Landlord shall not be liable for
any damage to, or loss of such personal property arising from any acts of
negligence of any other persons, nor from the leaking of the roof, nor from the
bursting, leaking or overflowing of water, sewer or steam pipes, nor from
heating or plumbing fixtures, nor from the handling of electric wires or
fixtures, nor from any other cause whatsoever, nor shall the Landlord be liable
for any injury to the person of the Tenant or other persons in or about the
premises, the Tenant expressly agreeing to save the Landlord harmless in all
such cases.

8.     Subordination. The Tenant agrees that this lease is subject and
subordinate to the lien of any mortgage, or deed of trust encumbrance or
encumbrances now or at any 


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time hereafter placed upon said premises, and the Tenant does hereby agree to
execute, acknowledge and record any and all instruments to effect such
subordination which the Landlord may request or require. Tenant irrevocably
appoints Landlord, his successors and assigns, as and for his attorney-in-fact
to execute any such instruments for and on his behalf.

9.     Repairs, Alterations, Fixtures. The Tenant covenants: that no waste or
damage shall be committed upon or to the said Demised Premises; that the
premises shall be used for only the purposes hereinabove stated, that said
premises shall not be used for any unlawful purpose and no violations of law or
ordinance or duly constituted authority shall be committed thereon. Throughout
said term, Tenant shall: take good care of the Demised Premises, fixtures and
appurtenances and all alterations, additions and improvements to same; make all
repairs in and about the same necessary to preserve them in good order and
condition, which repairs shall be equal in quality to the original work;
promptly pay the expense of such repairs; suffer no waste or injury to Demised
Premises; give prompt notice to the Landlord of any damage that may occur;
execute and comply with all laws, rules, orders, ordinances and regulations at
any time issued or in force, applicable to the Demised Premises or to the
Tenant's use and occupancy thereof, of the City, County, State and Federal
Governments and Landlord, and of each and every department, bureau and official
thereof, and of the Board of Fire Underwriters having jurisdiction thereof.

       Landlord will keep in repair the exterior of the Demised Properties
except any doors or windows provided that Tenant shall give Landlord written
notice of the necessity of such repairs, and provided that the damage thereto
shall not have been 


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caused by negligence of Tenant in which event Tenant shall be responsible
therefore. Landlord's obligation with respect to repairs to Demised Premises
shall be only as expressly set forth in this paragraph.

       Tenant may, at its expense, make such alterations and improvements to the
Demised Premises and install interior partitions as it may require, provided
that the written approval of the Landlord be first obtained and that such
improvements and alterations are done in a workmanlike manner in keeping with
all building codes and regulations and in no way harm the structure of the
Demised Premises, provided that at the expiration of this lease or any extension
thereof, Tenant, at its expense, restores the within Demised Premises to its
original condition and repairs any damage to the premises resulting from the
installation or removal of such partitions, fixtures, or equipment as may have
been installed by tenant if requested to do so by Landlord.

       The Landlord reserves the right, before approving any such changes,
additions, or alterations, to require the Tenant to furnish it a good and
sufficient bond, conditioned that it will save Landlord harmless from the
payment of any claims either by way of damager or liens. All of such changes,
additions, or alteration shall be made solely at the expense of the Tenant; and
the Tenant agrees to protect, indemnify and save harmless the Landlord on
account of any injury to third persons or property, by reason of any such
changes, additions, or alterations, and to protect, indemnify and save harmless
Landlord from the payment of any claim of any kind of character on account of
bills for labor or material in connection therewith.


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       Tenant reserves the right to request improvements to the exterior of the
facilities. Any such work approved by the Landlord will be performed by the
Landlord and charged to the Tenant under terms and conditions as mutually agreed
upon.

10.    Insurance. Tenant shall not do or permit to be done any act or thing in
or upon the Demised Premises which will invalidate or be in conflict with the
Certificate of Occupancy or the terms of the Virginia standard form of fire,
boiler, sprinkler, water damage, or other insurance policies covering the
Building and/or the fixtures, equipment, and property therein; and Tenant shall,
at its own expense, comply with all rules, orders, regulations, or requirements
of the Southeastern Board of Fire Underwriters or any other similar body having
jurisdiction, provided same relate to its use or occupancy of the Demised
Premises.

       Tenant at Tenant's own cost and expense shall maintain insurance
protecting and indemnifying Landlord against any and all claims for injury or
damage to persons or property or for the loss of life or of property occurring
upon, in or about the Demised Premises, its employees, agents, contractors,
customers, and invitees; such insurance to afford minimum protection during the
term of this Lease, of not less than One Million Dollars ($1,000,000) in respect
of bodily injury or death in respect of any one occurrence or accident, and not
less than One Hundred Thousand Dollars ($100,000) for property damage.

       All such insurance shall be effected under valid and enforceable
policies; shall be issued by insurers of recognized responsibility acceptable by
Landlord and shall contain a provision whereby the insurer agrees not to cancel
the insurance without twenty (20) days prior written notice to Landlord.


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       On or before the Commencement Date, Tenant shall furnish Landlord with a
certificate evidencing the aforesaid insurance coverage, and renewal
certificates shall be furnished to Landlord at least thirty (30) days prior to
the expiration date of each policy for which a certificate was theretofore
furnished.

       Tenant shall insure the Building against all-risk fire and other extended
coverage perils in an amount equal to at least ninety percent (90%) of the
replacement value, as reasonably determined by Landlord from time to time, or
such other amount as may be required by the holder of the first trust
indebtedness secured by the Building. Such policy or policies shall be issued by
a company licensed to do business in Virginia and approved by Landlord and shall
name Landlord, the holder of any indebtedness, secured by a lien on the Demised
Premises, as additional insureds as their respective interests may appear. 

11.    Governmental Requirements. The Tenant agrees that it will, at its cost,
promptly comply with and carry out all orders, requirements, or conditions now
or hereafter imposed upon him by the Ordinances, Laws and/or Regulations of the
Federal Government, State of Virginia or Fairfax County, in which said premises
are located, or by any of its various departments whether required of Landlord
or otherwise, to be done or performed during the term of this agreement, insofar
as they are occasioned by or required in the conduct of the business of Tenant,
or in the Tenant's use and occupancy of said premises for the purpose permitted.

12.    Eminent Domain. The Tenant agrees that in the event eminent domain
proceedings shall be instituted against the leased premises, it will be entitled
to claim for compensation for its damages in the proceedings, but agrees that
this lease shall 


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terminate when title to the leased premises is taken by the condemning
authority, provided the rental is abated from such date.

13.    Signs. The Tenant agrees that it will not erect nor place any signs upon
the windows, doors or outside walls of said premises without the written consent
of the Landlord first had and obtained.

14.    Interior Repairs. The Tenant agrees that it will make all interior
repairs, replacements and decorations at its own cost and expense, and that it
will allow Landlord or its Agent to have access to said premises at any time for
the purpose of inspection, or in the event of fire or other property damage, or
for the purpose of making any repairs Landlord considers necessary, desirable,
or Landlord's responsibility, and will permit Landlord to place a sign on the
premises during the last three (3) months of this lease offering the property
for sale or lease.

15.    Default. The Tenant agrees that should it fail to perform any of its
duties hereunder, Landlord may cause the same to be performed and paid for.
Payment of such sums, or expense of prosecuting or defending any matter or
action, by reason of its default in any wise, shall be deemed additional rent
and due from Tenant to Landlord on the first day of the month following filling
for said charges incurred.

16.    Legal Fees. The Tenant agrees that in the event legal proceedings are
instituted against Tenant by the Landlord, either for payment of rent or for
possession, then Tenant agrees to pay all court costs instant to such
proceedings, together with a reasonable attorney's fee, if held liable.

17.    Real Estate Taxes. The Tenant agrees when the same becomes due and
payable, to pay all real estate taxes, which are assessed against the Demised
Premises 


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and which are applicable to and become due and payable during the term of this
lease. All real estate taxes, for the years in which the lease commences and
terminates shall be apportioned and adjusted. If the Tenant fails to pay any
such real estate taxes, which it is obligated to pay pursuant to this paragraph
and if such default shall continue for a period of thirty (30) days after the
Landlord shall have given the Tenant notice in writing of the existence thereof,
then and in such event the Landlord may pay such real estate taxes together with
the interest and penalties thereon and the amount so paid shall be deemed
additional rent due and payable by the Tenant to the Landlord, payable together
with the next regular payment due thereafter.

18.    Rent Adjustment. If the Tenant elects to exercise its three (3) year
option from December 15, 1995 to December 14, 1998, the minimum annual rental
will be adjusted as follows: 3.0% increase per year in annual rental.

19.    Landlord's Permission. The Landlord agrees that wherever its permission
is required in this Agreement that it will not be unreasonable in withholding
such permission.

20.    Landlord's Maintenance Responsibilities. The Landlord agrees to maintain
and keep in good repair the structure of the building, exterior walls (excluding
doors and windows) and roof, provided that Tenant shall give Landlord sufficient
notice of the necessity of repairs and provided that such repairs are not made
necessary by the negligence or affirmative acts of Tenant, his employees,
agents, guests or servants, or any other persons not under Landlord's control,
in which event Tenant shall be responsible for such repairs and costs related
thereto. Landlord's obligation with respect 


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to repairs of the Demised Premises shall be only as expressly set forth in this
paragraph and paragraph 9 hereof.

21.    Removal of Fixtures. The Landlord agrees to permit Tenant to install
business fixtures and equipment in premises, and at a later date to remove them
subject to Tenant's (a) being current in its monthly installments, (b) not being
in violation of any of the herein covenants, conditions, and provisions, and (c)
restoring at its expense any damage to the premises wherever caused by the
installation of such fixtures and equipment.

22.    Late Charges. If Tenant fails to pay its rent when due, then a late
charge of five percent (5%) shall be charged by the Landlord and if Tenant fails
to pay the rent payment plus the late charge within fifteen (15) days of its due
date, although there should have been no legal or formal demand made, or break
or violate any of the within covenants, conditions or agreements, then and in
any of said events, this lease and all things herein contained shall, at the
option of the Landlord cease and determine and shall operate as a Notice to
Quit, the thirty (30) days written Notice to Quit being hereby expressly waived,
and Landlord may proceed to recover possession of said premises under and by
virtue of the laws of the State of Virginia.

23.    No Waiver. If proceedings shall at any time be instituted as aforesaid
and compromise or settlement shall be effected either before or after judgment
whereby Tenant shall be permitted to retain possession of said premises then
such proceedings shall not constitute a waiver of any covenant, condition or
agreement contained herein or of any subsequent breach of this agreement.


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24.    Tenant's Bankruptcy. In the event Tenant is adjudicated a bankrupt or
makes an assignment for the benefit of its creditors, this agreement shall, at
the option of Landlord, cease and determine and said premises shall be
surrendered to Landlord, who hereby reserved the right, in either of said
events, to forthwith re-enter and repossess said premises.

25.    Fire. If said premises, or any part thereof, shall at any time be
destroyed by fire (or other unavoidable casualty), as to be unfit for occupancy
or use, then the rents herein reserved, or a fair and just proportion thereof,
according to the nature and extent of the damage sustained, shall, until the
said premises shall have been rebuilt or restored and made fit for occupancy or
use, be suspended and cease to be payable, or these presents shall, at the
election of the Landlord thereby be determined and ended, provided however, that
in the event of partial damage to the Demised Premises from fire or other
casualty not involving the repair or reconstruction of a substantial portion
thereof, the Landlord shall promptly restore same to such condition as will
permit Tenant to use and occupy said premises for the purpose herein set forth.

26.    Tenancy by Sufferance. If the Tenant shall elect and be suffered to
remain in possession of the said premises at the expiration of the term hereby
created, said Tenant shall, by virtue of this agreement, become a Tenant by the
month of the ten plus percent (10%) rental per month of the last monthly
installment of rent above provided to be paid as aforesaid, which said monthly
tenancy shall be subject to all the conditions and covenants of said lease as
though the same had been a monthly tenancy, instead of a tenancy as provided
herein, and shall give to the Landlord at least thirty (30) days written notice
of its intention to remove from said premises, and shall be entitled to a like
notice 


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from Landlord in the event Landlord desires possession of said premises,
provided, however, that said Tenant by the month shall not be entitled to any
notice in event the said rent is not paid in advance without demand, the usual
thirty (30) days written notice being hereby expressly waived.

27.    Successors. It is understood and agreed that the covenants, conditions
and agreements contained in the within lease to be performed by the respective
parties are binding on, and may be legally enforced by, the said parties, their
heirs, executors, administrators, successors and assigns, respectively, and that
no waiver of any breach of any covenant hereof shall be construed to be a waiver
of the covenant itself or of any subsequent breach thereof, or of this
agreement.

28.    Construction. This lease shall be constricted and governed in accordance
with the laws of the State of Virginia.




ATTEST:          (Tenant)           S.T. RESEARCH CORPORATION

/s/ Yvonne L. Stuart                /s/ R.R. Bower           (SEAL)
-------------------------           --------------------------

ATTEST:         (Landlord)          TERMINAL REAL ESTATE COMPANY

/s/ S.R. Perrino                   /s/ B.R. Lanier/Partner  (SEAL)
-------------------------           --------------------------
                                    12-26-89