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                                                                 EXHIBIT 10.5.12

                                  850 E. TETON
                               INDUSTRIAL SUBLEASE






                      EFFECTIVE DATE:      January 1, 2000




               PARTIES AND ADDRESSES:


                         "AUTHORITY":      Tucson Airport Authority, Inc.,
                                               an Arizona nonprofit corporation
                                           7005 S. Plumer Avenue
                                           Tucson, Arizona 85706



                            "TENANT":      AAS-Complete Controls, Inc.
                                             an Arizona Corporation
                                           850 E. Teton Rd. Suite 8
                                           Tucson, Arizona 85706




                            EXHIBITS:      Exhibits  lettered A, B and C are
                                           annexed to this Sublease and
                                           incorporated herein by this
                                           reference.


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<TABLE>
<CAPTION>
                                TABLE OF CONTENTS

<S>                                                                                 <C>
RECITALS              ...............................................................1
COVENANTS AND CONDITIONS.............................................................1
ARTICLE I             - PREMISES.....................................................1

         1.1      Premises...........................................................1
         1.2      Access.............................................................1
         1.3      Security...........................................................1
         1.4      Parking............................................................1
         1.5      Entry Upon Premises................................................2

ARTICLE II            - TERM.........................................................2

         2.1      Initial Term.......................................................2
         2.2      Extensions.........................................................2

ARTICLE III           - RENT AND DEPOSITS ...........................................2

         3.1      Base Rent..........................................................2
         3.2      Commencement of Rental Obligation..................................2
         3.3      Late Fees..........................................................3
         3.4      Security Deposit...................................................3

ARTICLE IV            - USE OF PREMISES..............................................3

         4.1      Purposes...........................................................3
         4.2      Indemnity..........................................................4
         4.3      Dangerous Conditions...............................................4
         4.4      Alterations........................................................4
         4.5      Utilities..........................................................4

                  A.       Tenant's Responsibilities.................................4
                  B.       Authority's Rights and Responsibilities...................4

         4.6      Maintenance and Repair.............................................5

                  A.       Tenant....................................................5
                  B.       Authority.................................................5

ARTICLE V             - INSURANCE AND CASUALTY.......................................5

         5.1      Insurance Required.................................................5
         5.2      Deductible.........................................................6
         5.3      Modification of Requirements.......................................6
         5.4      Certificates.......................................................6
         5.5      Additional Insurance...............................................7
         5.6      Additional Insureds................................................7
         5.7      Waiver of Subrogation..............................................7
         5.8      Insurance by Authority.............................................7
         5.9      Casualty to Premises...............................................7
</TABLE>

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<TABLE>
<S>                                                                                 <C>
ARTICLE VI            - TAXES........................................................7

         6.1      Tenant's Responsibility............................................7
         6.2      Protest............................................................8

ARTICLE VII           - RULES, REGULATIONS AND LAWS..................................8

         7.1      Compliance with all Applicable Laws................................8
         7.2      Non-Discrimination.................................................8

                  A.       Non-Discrimination Covenants..............................8
                  B.       Non-Compliance............................................9
                  C.       Subleases.................................................9

         7.3      Compliance with FAR Part 77........................................9
         7.4      FAR Part 107; Airport Access......................................10
         7.5      State and Federal Aviation Regulations............................10
         7.6      Exclusive Rights Prohibited.......................................10
         7.7      Environmental Laws................................................10

                  A.       Definitions..............................................10
                  B.       Superfund................................................11
                  C.       Compliance...............................................11

                           (i)      Compliance with Environmental Laws Generally....11
                           (ii)     Cleanup.........................................11
                           (iii)    Governmental Submittals.........................12
                           (iv)     Information Sharing.............................12
                           (v)      Change in Use of Premises.......................12

                  D.       Indemnity................................................12
                  E.       Subtenants...............................................13

ARTICLE VIII          - SUPERIOR RIGHTS.............................................13

         8.1      Agreements with United States.....................................13
         8.2      Rights of Government During War or National Emergency.............13
         8.3      Rights of Authority...............................................14
         8.4      Agreements with City of Tucson....................................14
         8.5      Superfund Consent Decree..........................................14
         8.6      Abatement of Obligation to Construct or Rebuild...................15

ARTICLE IX            - RESERVATION OF AVIGATION EASEMENT...........................15

         9.1      Easement..........................................................15
         9.2      Structures; Elevation Limit.......................................15
         9.3      Purposes..........................................................15

ARTICLE X             - ASSIGNMENT AND SUBLEASE.....................................16

         10.1     Consent of Authority..............................................16
         10.2     Continuing Responsibility of Tenant...............................16
</TABLE>

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<TABLE>
<S>                                                                                 <C>
         10.3     Subject to this Sublease..........................................16

ARTICLE XI            - DEFAULTS AND REMEDIES.......................................16

         11.1     Default by Tenant.................................................16
         11.2     Remedies of Authority.............................................17

                  A.       Termination..............................................17

                           (i)      Damages.........................................18
                           (ii)     Credit..........................................18

                  B.       Reentry Without Termination..............................18

                           (i)      Reentry.........................................18
                           (ii)     Reletting.......................................19
                           (iii)    Credit..........................................19

         11.3     Remedies Cumulative...............................................19
         11.4     No Waiver.........................................................19
         11.5     Notice............................................................20
         11.6     Interest..........................................................20

ARTICLE XII           - TERMINATION BY TENANT.......................................20

         12.1     Termination Events................................................20
         12.2     Cure..............................................................20
         12.3     No Waiver.........................................................21

ARTICLE XIII          - SURRENDER OF POSSESSION, CONDITION OF PREMISES..............21

         13.1     Surrender.........................................................21
         13.2     Good Condition....................................................21
         13.3     Removal of Property...............................................21

ARTICLE XIV           - MISCELLANEOUS...............................................21

         14.1     Notification Of Changes...........................................21
         14.2     Successors and Assigns Bound......................................21
         14.3     Article Headings..................................................21
         14.4     Severability......................................................22
         14.5     Applicable Law....................................................22
         14.6     Construction of Sublease..........................................22
         14.7     Costs and Attorneys' Fees.........................................22

                  A.       Authority's Review.......................................22
                  B.       Enforcement of Rights....................................22

         14.8     Notices...........................................................23

                  A.       To Authority.............................................23
                  B.       To Tenant................................................23
                  C.       Timing...................................................23
                  D.       Change in Address........................................23

         14.9     Authority to Execute..............................................23
</TABLE>

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                                    RECITALS

A.       Authority has leased from the City of Tucson, a municipal corporation,
         the airport known as Tucson International Airport located in Pima
         County, State of Arizona (the "Airport").

B.       Tenant is the Tenant under that certain Industrial Sublease dated
         January 1, 1998 (the "Original Sublease") pursuant to which Tenant
         leases from Authority approximately 41,900 square feet in "hangar one"
         (the "Building") of the Tucson Industrial Center located on the
         Airport, at 850 E. Teton, Tucson, Arizona. The Original Sublease
         expires December 31, 1999.

C.       Tenant desires to continue leasing the premises from Authority under
         the terms and conditions herein.

                            COVENANTS AND CONDITIONS

                              ARTICLE I - PREMISES

1.1      PREMISES

         Authority does hereby demise and let on to Tenant, for its exclusive
         use and occupancy, and Tenant does hereby lease from Authority,
         APPROXIMATELY THIRTY EIGHT THOUSAND FOUR HUNDRED (38,400) SQUARE FEET
         IN THE NORTH END OF HANGAR ONE, AND APPROXIMATELY TWO THOUSAND (2,000)
         SQUARE FEET ON THE EAST SIDE OF THE BUILDING, AND THREE THOUSAND FIVE
         HUNDRED (3,500) SQUARE FEET OF OFFICE SPACE DIRECTLY EAST OF HANGAR ONE
         as shown on Exhibit A (the "Premises"), subject to the further terms of
         this Lease Agreement.

1.2      ACCESS

         Tenant shall be granted the right of reasonable or necessary access to
         the Premises. Authority reserves the right to designate the location of
         such access and to change its location from time to time as the
         Authority deems reasonably necessary and appropriate, so long as any
         such modification does not materially diminish the ability of Tenant to
         access the Premises as needed and as is available to Tenant at the time
         of commencement of the Lease.

1.3      SECURITY

         Tenant is responsible for securing Tenant's Premises, and neither the
         Authority nor its agents or employees will be responsible for any loss
         of or damage to Tenant's possessions while stored on the Premises.

1.4      PARKING

         Tenant shall be entitled to utilize the parking areas associated with
         the Building in common with other tenants of the Building. The
         Authority reserves the right, but shall not be obligated, to assign
         specific parking spaces to tenants.


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1.5      ENTRY UPON PREMISES

         Authority may enter upon the Premises subleased exclusively to Tenant
         hereunder at any reasonable time in an emergency or upon 24 hours
         written notice, for any purpose necessary, incidental to or connected
         with the exercise of its governmental functions. Authority shall, in
         addition, have the right to enter upon the Premises and perform any
         actions necessary or appropriate in connection with any environmental
         investigation or remediation, including but not limited to testing,
         investigation, and cleanup of waste in drains

                                ARTICLE II - TERM

2.1      INITIAL TERM

         The initial term of the Sublease shall be for a period of five (5)
         years beginning on the Effective Date hereof (the "Initial Term").

2.2      EXTENSIONS

         The term hereof shall be deemed to be automatically extended on each of
         the first five anniversaries of the Effective Date hereof, for an
         additional one-year period, unless the Authority, at least ninety (90)
         days prior to such date, notifies Tenant that the Authority does not
         elect to so extend the term. The intent of this provision is to
         automatically extend the term of this Sublease each year (unless
         otherwise elected by Authority) so that a remaining term of
         approximately 5 years is maintained, for a possible maximum total term
         of (10) years.

                         ARTICLE III - RENT AND DEPOSITS


3.1      BASE RENT

         Tenant covenants and agrees to pay Authority rent from the Effective
         Date of this Sublease in an amount equal to NINE THOUSAND ONE HUNDRED
         FOURTEEN DOLLARS AND NO CENTS ($9,114.00) per month with four percent
         increases annually beginning with the start of year three as set forth
         on the rent schedule attached as Exhibit B. Monthly rent is due and
         payable to Authority in advance. Rent payments shall be delivered to
         Authority's Property Manager who is currently Tucson Industrial
         Centers, Inc., located at 850 E. Teton, Suite 1, Tucson, AZ 85706, or
         such other person as directed by Authority in writing.

3.2      COMMENCEMENT OF RENTAL OBLIGATION

         The first monthly payment, prorated to reflect the partial month for
         which it is paid, shall be due on the Effective Date hereof and
         subsequent installments shall be due on the first day of each
         succeeding calendar month thereafter during the term of this Sublease.



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3.3      LATE FEES

         If any rent or any other sum due from the Tenant shall not be received
         within SEVEN (7) DAYS after such amount shall be due, Tenant shall pay
         a late fee equal to FIVE PERCENT (5%) of such overdue amount.
         Acceptance of such late fees shall in no event constitute a waiver of
         Tenant's default with respect to such overdue amount nor prevent
         Authority from exercising any of the other right and remedies granted
         hereunder.

3.4      SECURITY DEPOSIT

         Simultaneously with the entry into this Sublease by the parties hereto,
         the Tenant shall deposit with Authority, $5,000 which shall be retained
         by Authority as security for the Tenant's payment of the Rent and
         performance of all of its other obligations under the provisions of
         this Lease, and shall not be deemed to represent payment of any rent.
         On the occurrence of an Event of Default (as defined in Section 11.1
         hereinbelow), Authority shall be entitled, at its sole discretion, (a)
         to apply any or all of such sum in payment of (i) any Rent due and
         unpaid, (ii) any expense incurred by Authority in curing any such
         default, and/or (iii) any damages incurred by Authority by reason of
         such default (including, by way of example rather than by limitation,
         reasonable attorney's fees), in which event the Tenant shall,
         immediately on its receipt of a written demand there for from
         Authority, pay to Authority a sum equaling the amount so applied, so as
         to restore the security deposit to its original amount; and /or (b) at
         Authority's election, to retain any or all of such sum not otherwise
         applied pursuant to the provisions of clause (a) of this sentence in
         liquidation of any or all damages suffered by Authority by reason of
         such default. On the termination of this Sublease, any of such sum
         which is not so applied or retained shall be returned to Tenant. Such
         sum shall not bear interest while being held by Authority.

                          ARTICLE IV - USE OF PREMISES

4.1      PURPOSES

         The Premises shall not, without prior written consent of Authority, be
         used for any purpose other than or in addition to storage and repair of
         Airplane parts and Interior components. The prior written consent of
         the Authority shall not be unreasonably withheld should the Tenant
         propose a change in use of the Premises consistent with the zoning and
         any other applicable restrictions pertaining to the subject Premises.



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4.2      INDEMNITY

         Tenant agrees to fully indemnify and save and hold harmless Authority
         and the City of Tucson from and against all claims, fines, damages,
         penalties, actions and all expenses, including reasonable attorneys'
         fees incidental to the investigation and defense thereof, related to or
         arising out of the fault or negligence of or violation of law by
         Tenant, its agents, employees or subtenants in the use, occupancy, or
         maintenance of the Premises by any of them.

4.3      DANGEROUS CONDITIONS

         Tenant agrees to exercise reasonable care when using the Premises and
         all improvements thereon to discover and promptly remedy any conditions
         that may pose an unreasonable risk of harm to members of the general
         public or that may constitute a violation of law. If an unsafe,
         defective or dangerous condition, or violation of the law is
         discovered, Tenant warrants that no one other than Tenant and Authority
         employees, agents and representatives will be admitted to the Premises
         and no property belonging to any party other than Tenant and Authority
         will be transported to, collected at or stored upon the Premises until
         the unsafe, defective or dangerous condition, or violation of law is
         corrected.

4.4      ALTERATIONS

         Tenant shall not construct or substantially alter or modify any
         buildings, structures, or other improvements on the Premises without
         the Authority's prior written approval of its plans and specifications,
         which approval may not be unreasonably withheld.

         In the event that Tenant makes any improvements or modifications to the
         Premises, Tenant shall promptly pay all suppliers and contractors and
         will not cause or permit any lien to be filed against either the
         Premises or the Tenant's interest in the Premises or this Lease. In the
         event that any such lien is filed, Tenant will promptly cause such lien
         to be removed.

4.5      UTILITIES

         A.       TENANT'S RESPONSIBILITIES:

                  Tenant shall pay for all utility services supplied to it or
                  its subtenants on the Airport.

         B.       AUTHORITY'S RIGHTS AND RESPONSIBILITIES:

                  Notwithstanding the execution of this Sublease, Authority
                  retains the right to the continued use of such utility lines
                  and services as are presently on the Premises and the right to
                  repair the same when necessary. Authority shall conduct such
                  repairs in such manner and at such times as to not
                  unreasonably interfere with Tenant's operations.



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4.6      MAINTENANCE AND REPAIR

         A.       TENANT:

                  (1)      Tenant shall, at no expense to Authority, maintain
                           the Premises in a neat, clean, safe condition and in
                           a manner that is compatible with the rest of the
                           Building and in compliance with all applicable laws,
                           rules, regulations and orders. Tenant shall be
                           responsible for all minor repairs and maintenance.

                  (2)      General combustible storage shall not exceed 12 feet
                           in height.

                  (3)      Aisle separation shall be between 4 feet to 8 feet
                           wide. (Width to be determined by Fire Department and
                           classification of commodities being stored).

                  (4)      Must have stable storage piles (No leaning stacks).

         B.       AUTHORITY:

                  Subject to Section 5.9 the Authority shall be responsible for
                  all structural repairs in the Premises and the Building,
                  unless necessitated by any negligence or willful misconduct of
                  Tenant or Tenant's subtenants, employees, agents, invitees or
                  guests. Notwithstanding the above, the Authority shall not be
                  required to replace major building systems (such as HVAC). In
                  the event that failure of any major building system renders
                  the Premises unsuitable for Tenant's operation, and the
                  Authority elects not to replace the system, and the Authority
                  determines that the system cannot be repaired economically,
                  Tenant may elect to repair or replace the system at its
                  expense, or may elect to terminate this Lease.

                       ARTICLE V - INSURANCE AND CASUALTY

5.1      INSURANCE REQUIRED

         Tenant shall obtain and maintain in full force, with a company or
         companies authorized to transact the business of insurance in the State
         of Arizona and of sound and adequate financial responsibility, selected
         by Tenant and acceptable to Authority, comprehensive insurance policy
         (either as part of any other policy or policies carried by Tenant, or
         separately) providing for the protection of the Authority and the City
         of Tucson and officers, directors, agents and employees of either of
         them, against:

                  (1)      general liability, including all direct or contingent
                           loss or liability for damages for bodily injury,
                           personal injury, death or damage to property,
                           including loss of use thereof, occurring on or in any
                           way related to the Premises or occasioned by reason
                           of occupancy by and the operations of



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                           Tenant upon, in and around the Premises, with limits
                           of $1,000,000 per occurrence for personal injury or
                           death or damage to property, with coverage at least
                           as broad as that provided by INSURANCE SERVICES
                           OFFICE COMMERCIAL GENERAL LIABILITY COVERAGE form
                           CG0001 (Occurrence Form), and such policy or policies
                           shall cover all of Tenant's operations on the entire
                           Premises, including but not limited to any elevators
                           and escalators therein and any sidewalks, streets or
                           other public ways adjoining the Premises; and

                  (2)      automobile liability covering owned, non-owned,
                           leased and hired vehicles with combined single limits
                           of no less than $250,000 per occurrence.

5.2      DEDUCTIBLE

         The deductible for any policy required hereunder shall not exceed
         $5,000.

5.3      MODIFICATION OF REQUIREMENTS

         Authority may adjust or increase liability insurance amounts and
         requirements as Authority deems reasonably necessary, or as may be
         required because of changes in the insurance requirements imposed by
         Authority's insurer or by applicable law. Tenant shall comply with such
         adjustments or increases within such reasonable time period as is
         requested by Authority.

5.4      CERTIFICATES

         Upon or prior to the commencement of the term of this Sublease and at
         least annually thereafter Tenant shall furnish to Authority
         certificates of insurance showing the amount and type of the insurance
         then in effect that is required to be procured and maintained by it
         hereunder and stating the date and term of the policies evidencing such
         insurance. Tenant shall, upon request, supply Authority with certified
         copies of all applicable insurance policies, riders, endorsements and
         declaration pages. Certificates evidencing any renewal, replacement or
         extension of any or all of the insurance required hereunder, or of
         renewals, replacements or extensions of such renewals, replacements or
         extensions, shall be delivered by Tenant to Authority not less than
         thirty (30) days prior to the expiration of any policy of insurance
         renewed, replaced or extended by the insurance represented by any such
         certificate. Each policy of insurance required hereunder shall provide
         for not less than thirty (30) days notice to Authority and Tenant
         before such policy may be canceled.



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5.5      ADDITIONAL INSURANCE

         The provisions of this Sublease as to insurance required to be procured
         and maintained shall not limit or prohibit, or be construed as limiting
         or prohibiting, Authority or Tenant from obtaining any other or greater
         insurance with respect to the Premises or improvements thereon or the
         use and occupancy thereof that either or both of them may wish to
         carry, but in the event Authority or Tenant, as the case may be, shall
         procure or maintain any such insurance not required by this Sublease,
         the cost thereof shall be at the expense of the party procuring or
         maintaining the same.

5.6      ADDITIONAL INSUREDS

         All insurance required by this Article shall be procured and maintained
         in the name of Tenant and shall add Authority and the City of Tucson as
         additional insureds as their interests appear.

5.7      WAIVER OF SUBROGATION

         Each party hereto waives all claims for recovery from the other party
         for any loss or damage to any of its property on the Premises insured
         under valid and collectible insurance policies to the extent of any
         recovery collected from such policies. The parties agree that all
         material insurance policies shall be endorsed with a clause which
         waives subrogation against the other party.

5.8      INSURANCE BY AUTHORITY

         Authority may, upon written notice to Tenant, in the event that Tenant
         fails to timely provide proof of insurance as required by Section 5.4
         above, procure and maintain any or all of the insurance required of
         Tenant under this Article. In such event, all costs of such insurance
         procured and maintained by Authority on behalf of Tenant shall be the
         responsibility of Tenant and shall be fully reimbursed to Authority
         within ten (10) business days after Authority advises Tenant of the
         cost thereof.

5.9      CASUALTY TO PREMISES

         Authority may, but shall not be required to, maintain insurance against
         loss or damage to the Premises or the Building, but shall have no
         obligation to repair the Premises or the Building in the event of
         casualty or damage thereto. In the event that any such casualty renders
         the Premises unsafe or untenantable, this Sublease shall terminate
         unless Authority notifies Tenant, within 45 days of the date of the
         casualty, that Authority intends to repair the Premises, in which event
         this Sublease shall remain in full force and effect, although rent
         shall abate while the Premises are unusable.

                               ARTICLE VI - TAXES

6.1      TENANT'S RESPONSIBILITY

         Tenant shall pay before delinquency any and all taxes levied or
         assessed against the Premises, any levied or assessed against or by
         reason of personal property located in, on or about the Premises, any
         levied or assessed because of Tenant's right to possession of the
         Premises and improvements thereon, all applicable taxes levied or
         assessed by any government body as the result of Tenant's operations
         and all taxes which may be levied or assessed as the result of rentals
         payable under this Sublease. All such taxes and assessments for partial
         years shall be apportioned and adjusted on a time basis. Authority



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         shall, within five (5) days of receipt, forward to Tenant any notices
         received from the collecting agency regarding the collection or amount
         of such taxes.

6.2      PROTEST

         Tenant shall have the right at its own cost and expense to contest the
         amount or validity of any such tax or assessment and to bring or defend
         any actions involving the amount or validity of any such tax or
         assessment in its own name or in the name of Authority; provided that,
         if unsuccessful, Tenant shall pay and discharge any such tax or
         assessment so contested, together with any penalties, fines, interest,
         costs and expenses, including reasonable attorneys' fees, that may
         result from any such action by Tenant.

                    ARTICLE VII - RULES, REGULATIONS AND LAWS

7.1      COMPLIANCE WITH ALL APPLICABLE LAWS

         Tenant and all persons operating under the rights granted hereby shall
         observe and obey all reasonable and lawful rules and regulations with
         respect to the use of the Airport which have been or may in the future
         be adopted by Authority and shall further abide by all applicable laws,
         statutes, ordinances, rules, orders, and regulations of all governing
         bodies which are now in effect or which may hereafter be put into
         effect.

7.2      NON-DISCRIMINATION

         A.       NON-DISCRIMINATION COVENANTS

                  (1)      The Tenant for himself, his heirs, personal
                           representatives, subtenants, successors in interest,
                           and assigns, as a part of the consideration hereof,
                           does hereby covenant and agree, as a covenant running
                           with the land, that in the event improvements are
                           constructed, maintained, or otherwise operated on the
                           Premises for a purpose for which a Department of
                           Transportation ("DOT") program or activity is
                           extended or for another purpose involving the
                           provision of similar services or benefits, Tenant
                           shall maintain and operate such improvements and
                           services in compliance with all other requirements
                           imposed pursuant to Title 49, Code of Federal
                           Regulations, DOT, Subtitle A, Office of the
                           Secretary, Part 21, Nondiscrimination in
                           Federally-Assisted Programs of the Department of
                           Transportation-Effectuation of Title VI of the Civil
                           Rights Act of 1964, and as said Regulations may be
                           amended.

                  (2)      The Tenant for himself, his personal representatives,
                           successors in interest, and assigns, as a part of the
                           consideration hereof, does hereby covenant and agree,
                           as a covenant running with the land that: (1) no
                           person on the grounds of race, color, or national
                           origin shall be excluded from participation in,
                           denied the benefits of, or be otherwise subjected to



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                           discrimination in the use of said improvements, (2)
                           that in the construction of any improvements on,
                           over, or under such land and the furnishing of
                           services thereon, no person on the grounds of race,
                           color, or national origin shall be excluded from
                           participation in, denied the benefits of, or
                           otherwise be subject to discrimination, (3) that
                           Tenant shall use the Premises in compliance with all
                           other requirements imposed by or pursuant to Title
                           49, Code of Federal Regulations, Department of
                           Transportation, Subtitle A, Office of the Secretary,
                           Part 21, Non-discrimination in Federally-Assisted
                           Programs of the Department of
                           Transportation-Effectuation of Title VI of the Civil
                           Rights Act of 1964, and as said Regulations may be
                           amended.

                  (3)      Tenant shall furnish its accommodations and/or
                           services on a fair, equal and not unjustly
                           discriminatory basis to all users thereof and it
                           shall charge fair, reasonable and not unjustly
                           discriminatory prices for each unit or service,
                           PROVIDED THAT Tenant may be allowed to make
                           reasonable and nondiscriminatory discounts, rebates
                           or other similar type of price reductions to volume
                           purchasers.

                  (4)      Tenant assures that it will undertake an affirmative
                           action program as required by 14 CFR Part 152,
                           Subpart E, to insure that no person shall on the
                           grounds of race, creed, color, national origin, or
                           sex be excluded from participating in any employment
                           activities covered in 14 CFR Part 152, Subpart E.
                           Tenant assures that it will require that its covered
                           sub organizations provide assurances from their sub
                           organizations, as required by 14 CFR Part 152,
                           Subpart E, to the same effort.

         B.       NON-COMPLIANCE

                  Non-compliance with an provision of this Section shall
                  constitute a material breach hereof and in the event of such
                  non-compliance Authority shall have the right to terminate
                  this Sublease and the estate hereby created without liability
                  therefore or at the election of Authority or the United
                  States, either or both shall have the right to judicially
                  enforce these provisions.

         C.       SUBLEASES

                  Tenant agrees that it shall insert the provisions of this
                  Section in any sublease by which Authority grants a right or
                  privilege to any person, firm or corporation to render
                  accommodations and/or services to the public on the Premises
                  herein subleased.

7.3      COMPLIANCE WITH FAR PART 77

         Tenant shall comply with the notification and review requirements
         covered in Part 77 of the Federal Aviation Regulations in connection
         with any improvements or modification or alteration of improvements on
         the Premises.



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7.4      FAR PART 107; AIRPORT ACCESS

         Tenant and all persons operating under the rights granted hereunder
         shall comply with Part 107 of the Federal Aviation Regulations with
         respect to aircraft operations and airport security at the Airport.
         Tenant shall at all times take all reasonable steps to control, police
         and regulate the use of the Premises and of the Airport premises to
         prevent unauthorized persons and the general public from obtaining
         access to the Airport. Such steps by Tenant shall include, but not be
         limited to, steps requested by Authority and those required under
         Federal Regulations. Tenant must secure the Premises so that there is
         no inadvertent or purposeful unauthorized entry in or upon the Airport
         by people, vehicles, or animals.

7.5      STATE AND FEDERAL AVIATION REGULATIONS

         Tenant will conduct its operations and activities on the Airport so as
         to conform to all applicable regulations of the Federal Aviation
         Administration and the Aeronautics Division of the Arizona Department
         of Transportation.

7.6      EXCLUSIVE RIGHTS PROHIBITED

         It is understood and agreed that nothing herein contained shall be
         construed to grant or authorize the granting of an exclusive right
         within the meaning of Section 49 U.S.C. 40103(e).

7.7      ENVIRONMENTAL LAWS

         Tenant, at its own expense, shall ensure that Tenant and Tenant's
         agents, employees, invitees, and sublessee comply with all present and
         hereafter enacted Environmental Laws, and any amendments thereto,
         affecting Tenant's operation on the Premises.

         A.       DEFINITIONS

                  (1)      "Environmental Laws" means any laws, regulations and
                           ordinances (whether enacted by the local, state,
                           federal government, or by the Authority) now in
                           effect or hereafter enacted that deal with the
                           regulation or protection of the environment
                           (including the ambient air, ground water, surface
                           water, and land use, including sub-strata land), or
                           with the generation, storage, disposal or use of
                           chemicals or substances that could be detrimental to
                           human health or the environment.

                  (2)      "Extremely Hazardous Substances" means any substance
                           or material designated by the United States
                           Environmental Protection Agency as an "extremely
                           hazardous substance" under Section 302(a)(2) of the
                           Superfund Amendment and Reauthorization Act ("SARA")
                           (42 U.S.C. ss. 11002(a)(2)).



                                       10
<PAGE>   15

                  (3)      "Hazardous Material" means all substances, materials
                           and wastes that are, or that become, regulated under,
                           or that are classified as hazardous or toxic under
                           any environmental law (including, but not limited to,
                           Extremely Hazardous Substances and Toxic Chemicals).

                  (4)      "Release" means any releasing, spilling, leaking,
                           pumping, pouring, emitting, emptying, discharging,
                           injecting, escaping, leaching, disposing, or dumping.

         B.       SUPERFUND

                  The parties acknowledge that the subject Premises is located
                  within a Superfund designated site. The Landlord shall not
                  hold the Tenant liable hereunder for any responsibility
                  arising out of any environmental issues and/or liability
                  issues existing prior to the date of the commencement of the
                  Original Lease. Tenant shall not be liable or responsible
                  hereunder for any prior or existing conditions relating to
                  environmental issues regarding the Premises. Any liability
                  and/or responsibility of the Tenant hereunder pertaining to
                  the Premises shall be limited to any actions or events in
                  violation of the provisions of this section arising subsequent
                  to the date of Tenant's occupancy of the Premises.

         C.       COMPLIANCE

                  (i) Compliance with Environmental Laws Generally. Tenant shall
                      not cause or permit any Hazardous Material to be used,
                      generated, manufactured, produced, stored, brought upon,
                      or released, on, under or about the Premises, or
                      transported to and from the Premises, by Tenant, its
                      agents, employees, contractors, invitees, sublessees or
                      any third party in violation of any Environmental Law,
                      provided that, in no circumstances shall Tenant cause or
                      permit any Extremely Hazardous Substance or Toxic Chemical
                      to be used, generated, manufactured, produced, stored,
                      brought upon, or Released, on, under or about the
                      Premises, or transported to and from the Premises.

                  (ii) Cleanup. Without limiting the foregoing, if the presence
                      of any Hazardous Material on, under or about the Premises
                      caused or permitted by Tenant results in any contamination
                      of the Premises, Tenant shall promptly take all actions at
                      its sole cost and expense as are necessary to return the
                      Premises to the condition existing prior to the
                      introduction of any such Hazardous Material to the
                      Premises; provided that Authority's approval of such
                      actions shall first be obtained, which approval shall not
                      be unreasonably withheld so long as such actions would not
                      potentially have any material adverse effect on the
                      Premises. In the event Tenant shall fail timely to
                      commence or cause to be commenced or fail diligently to
                      prosecute to completion such actions as are necessary to
                      return the Premises to the conditions existing prior to
                      the introduction of any Hazardous Material to the
                      Premises, Authority may, but



                                       11
<PAGE>   16

                      shall not be obligated to, cause such action to be
                      performed, and all costs and expenses (including,
                      without limitation, attorneys' fees) thereof or
                      incurred by Authority in connection therewith shall
                      be paid by Tenant.

                  (iii) Governmental Submittals. Tenant shall, at Tenant's own
                      cost and expense, make all submissions to, provide all
                      information to, and comply with all requirements of any
                      governmental authority having jurisdiction (the
                      "Government") under the Environmental Laws. Should the
                      Government determine that a site characterization, site
                      assessment and/or a cleanup plan be prepared or that a
                      cleanup should be undertaken because of any release of
                      hazardous materials at the Premises which occur during the
                      term of this Sublease, then Tenant shall, at Tenant's own
                      cost and expense, prepare and submit the required plans
                      and financial assurances, and carry out the approved plans
                      in accordance with all requirements of the Government.

                  (iv) Information Sharing. Tenant shall provide to Tucson
                      Airport Authority a copy of any and all information,
                      reports, and applications submitted to the Government as
                      described in Paragraph X.6B.(4), whether such submittal is
                      routine or in response to a release or threatened release
                      of any Hazardous Material, and whether the impetus for
                      such submittal is generated by Tenant, or by an inquiry or
                      action by the Government or another third party. At no
                      cost or expense to Authority, Tenant shall promptly
                      provide all information requested by Authority to
                      determine the applicability of the Environmental Laws to
                      the Premises, or to respond to any governmental
                      investigation or to respond to any claim of liability by
                      third parties which is related to environmental
                      contamination. Tenant shall immediately notify Authority
                      of any correspondence or communication from any
                      governmental entity regarding the application of
                      Environmental Laws to the Premises or Tenant's operation
                      of the Premises.

                  (v) Change in Use of Premises. Tenant shall immediately notify
                      Authority of any changes in Tenant's operation on the
                      Premises that will change or has the potential to change
                      Tenant's or Authority's obligations or liabilities under
                      the Environmental Laws.

         D.       INDEMNITY

                  Tenant shall indemnity, defend and hold harmless Authority,
                  its successors and assigns, its employees, agents and
                  attorneys from and against any and all liability, loss,
                  damage, expense, penalties and costs (including legal and
                  investigation fees or costs) arising from or related to any
                  claim or action for injury, liability, breach or warranty or
                  representation, or damage to persons or property and any and
                  all claims or actions brought by any party or governmental
                  body, alleging or arising in connection with (i) contamination
                  of, or adverse effects on, the environment



                                       12
<PAGE>   17

                  (whether known, alleged, potential, or threatened), or (ii)
                  alleged or potential violation of any Environmental Law or
                  other statute, ordinance, rule, regulation, judgment or order
                  of any government or judicial entity which are brought as a
                  result (whether in part or in whole) of any activity or
                  operation on or Release from the Premises (caused by any
                  person or entity other than Authority) during the term of this
                  Sublease or any previous sublease of the Premises by Tenant or
                  its owners or related entities. This obligation includes but
                  is not limited to all costs and expenses related to
                  investigation and/or cleaning up the Premises and all land,
                  soil, and underground or surface water as required under the
                  law. Tenant's obligations and liabilities under this paragraph
                  shall continue so long as Authority bears any liability or
                  responsibility under the Environmental Laws for any action
                  that occurred on the Premises during the term of the Sublease.
                  This indemnification of Authority by Tenant includes, without
                  limitation, costs incurred in connection with any
                  investigation of site conditions or any cleanup, remedial,
                  removal or restoration work required by any federal, state, or
                  local governmental agency or political subdivision because of
                  Hazardous Material located on the Premises or present in the
                  soil or ground water on, under or about the Premises. The
                  parties agree that Authority's right to enforce Tenant's
                  Promise to indemnify is not an adequate remedy at law for
                  Tenant's violation of any provision of this paragraph;
                  Authority shall have all the rights and remedies set forth in
                  this Sublease as well as all other rights and remedies
                  provided by law.

         E.       SUBTENANTS

                  Tenant shall insert the provisions of this section in any
                  lease agreement or contract by which it grants a right or
                  privilege to any person, firm or corporation under this
                  Sublease.

                         ARTICLE VIII - SUPERIOR RIGHTS

8.1      AGREEMENTS WITH UNITED STATES

         This Sublease shall be subordinate to the provisions and requirements
         of any existing or future agreement between Authority and the United
         States, relative to the development, operation or maintenance of the
         Airport. In the event that the Authority, after the date of this
         Sublease, enters into an agreement with the United States that
         materially limits Tenant's rights to use and occupy the Premises
         hereunder, the Authority will give Tenant notice and a copy of the
         agreement.

8.2      RIGHTS OF GOVERNMENT DURING WAR OR NATIONAL EMERGENCY

         This Sublease and all the provisions hereof shall be subject to
         whatever right the United States Government now has or in the future
         may have or acquire, affecting the control, operation, regulation and
         taking over of the Airport or the exclusive or non-exclusive use of the
         Airport by the United States during the time of war or national
         emergency.



                                       13
<PAGE>   18

         Tenant and Authority recognize that during the time of war or national
         emergency the City of Tucson, owner of the Airport, has the right to
         enter into agreements with the United States government for military or
         naval use of part or all of the Airport. If any such agreement is
         executed by the City of Tucson, the provisions of this Sublease,
         insofar as they are inconsistent with the provisions of any agreement
         so made by the City of Tucson with the United States government, shall
         be subject to the terms of such agreement and Tenant shall have no
         claim against Authority or the City of Tucson for any loss or damage
         sustained by Tenant because of the making of such agreement by the City
         of Tucson. In such event, however, the amounts, if any, payable from
         the City of Tucson or the United States for improvements placed on the
         Premises by Tenant shall be paid to Tenant if this Sublease is in
         effect at the time of such taking.

8.3      RIGHTS OF AUTHORITY

         Authority reserves the right to further develop or improve the landing
         area of the Airport as it sees fit, regardless of the desires or view
         of Tenant and without interference or hindrance.

         Authority reserves the right, but shall not be obligated to Tenant, to
         maintain and keep in repair the landing area of the Airport and all
         publicly-owned facilities of the Airport, together with the right to
         direct and control all activities of Tenant in this regard.

8.4      AGREEMENTS WITH CITY OF TUCSON

         This Sublease is subject to the existing lease between Authority and
         the City of Tucson and to the provisions of any existing or future
         agreement between the City of Tucson and Authority.

8.5      SUPERFUND CONSENT DECREE

         The Premises are part of a site, as more particularly defined in the
         below-described Consent Decree (the "Site"), that is the subject of
         that certain Civil Action No. 99--313 TUC WDB, United States of America
         v. Tucson Airport Authority, City of Tucson, United States Air Force,
         General Dynamics Corp., McDonnell Douglas Corporation, in the United
         States District Court for the District of Arizona, brought pursuant to
         Sections 106 and 107 of the Comprehensive Environmental Response,
         Compensation, and Liability Act, 42 U.S.C. ss.ss.9606 and 9607. The
         United States Environmental Protection Agency ("EPA") has selected
         certain remedial actions to be carried out on the Site (including the
         Premises) pursuant to that certain "Record of Decision, Tucson
         International Superfund Site, Tucson, Arizona, Airport Property - Soils
         and Shallow Groundwater Zone, Burr-Brown Property - Soils, Former
         West-Capt Property - Soils" signed on September 30, 1997 (the "ROD").
         The City, the Authority and certain other parties (collectively, the
         "Settling Defendants") and EPA have entered into that certain Consent
         Decree, which was lodged with the United States District Court in the
         above-



                                       14
<PAGE>   19

         described action on June 17, 1999 (the "Consent Decree"), which grants
         EPA certain access, enforcement, and other rights with respect to the
         Site, and imposes on Settling Defendants certain obligations regarding
         implementation of the remedial action selected in the ROD. This
         Sublease is subject to the Consent Decree and the rights and
         obligations of the parties thereto, including the obligation of
         Settling Defendants to undertake the remedial actions described therein
         with respect to the Site, and the right of the EPA to access the Site
         to inspect and enforce compliance with the Consent Decree.

8.6      ABATEMENT OF OBLIGATION TO CONSTRUCT OR REBUILD

         Inasmuch as this Sublease contains certain provisions concerning
         repairs, replacement and rebuilding of damaged or destroyed buildings,
         construction of buildings, quiet enjoyment and other related causes
         applicable to the parties to this Sublease, and inasmuch as the
         Premises constitute a portion of a public Airport, it is agreed that
         the parties hereto shall not be required to repair, replace, rebuild or
         construct any building or portion of any building so long as the
         obligated party is prevented from so doing by action of the United
         States government or any agency or department thereof.

                 ARTICLE IX - RESERVATION OF AVIGATION EASEMENT

9.1      EASEMENT

         There is hereby reserved to Authority for the use and benefit of
         aircraft using the Airport a right of flight for the passage of
         aircraft in the airspace above the uppermost surface of the Premises,
         together with the right to cause such noise as may be inherent in the
         operation of any aircraft now known or hereafter used for navigation of
         or flight in said airspace, or landing at, or taking off from, or
         operating on the Airport.

9.2      STRUCTURES; ELEVATION LIMIT

         Tenant, by accepting this Sublease, expressly agrees for itself, its
         successors and assigns that it will not erect nor permit the erection
         of any structure or object, nor permit the growth of any tree on the
         Premises above the mean sea level elevation of 2460 feet. In the event
         the aforesaid covenants are breached, Authority reserves the right to
         enter upon the Premises and to remove the offending structure or object
         and cut the offending tree, all of which shall be at the expense of
         Tenant.

9.3      PURPOSES

         Tenant, by accepting this Sublease agrees for itself, its successors
         and assigns that it will not make use of the Premises in any manner
         which might interfere with the landing and taking off of aircraft from
         the Airport or otherwise constitute a hazard. In the event the
         aforesaid covenant is breached, Authority reserves the right to enter
         upon the Premises and cause the abatement of such interference at the
         expense of Tenant.


                                       15
<PAGE>   20

                       ARTICLE X - ASSIGNMENT AND SUBLEASE

10.1     CONSENT OF AUTHORITY

         Tenant shall not sublease the Premises or any portion thereof, or
         assign or sell this Sublease or any interest therein without first
         obtaining written consent from Authority which consent shall not be
         unreasonably withheld. For this purpose, any change in ownership or
         control of Tenant shall be considered an assignment of rights
         hereunder. Tenant shall furnish the Authority with a copy of any
         sublease or assignment entered into with respect to this Sublease or
         the Premises or any portion thereof.

10.2     CONTINUING RESPONSIBILITY OF TENANT

         If it is a complete assignment or sublease of the entire Premises it
         shall be in writing and provide that the subtenant or assignee assumes
         and agrees to perform all of the terms, covenants and agreements which
         Tenant has agreed to perform under this Sublease, and that Tenant's
         subtenant or assignee shall become jointly and severally liable with
         Tenant, or any successor in interest of Tenant, for the performance of
         the terms and covenants of this Sublease. A sublease for less than the
         entire Premises shall be in writing and shall recite that it is subject
         and subordinate to all the terms and provisions of this Sublease.
         Neither the execution of such sublease or assignment, the Authority's
         consent to the same, nor the acceptance of rent by Authority from
         Tenant's subtenant or assignee shall release or in any manner affect
         Tenant's liability to Authority hereunder.

10.3     SUBJECT TO THIS SUBLEASE

         Any sublease between Tenant and a subtenant shall be in writing and
         shall provide that said sublease is subject to all the provisions of
         this Sublease.

                       ARTICLE XI - DEFAULTS AND REMEDIES

11.1     DEFAULT BY TENANT

         Tenant shall be in default under this Sublease upon the occurrence of
         any of the following "Events of Default":

                  A.       Tenant shall fail to pay when due any installment of
                           rent payable pursuant to this Sublease and such
                           failure shall continue unremedied for a period of ten
                           (10) days; provided that Tenant shall not be entitled
                           to the benefit of more than one (1) grace period of
                           ten (10) days under this paragraph A(1) within any
                           calendar year.

                  B        Tenant or any of Tenant's agents, employees, guests,
                           invitees, or subtenants, shall use Premises for any
                           unlawful or illegal purpose or for any purpose other
                           than those permitted under Section 4.1.



                                       16
<PAGE>   21

                  C.       Tenant shall fail to observe or perform any other
                           covenant, agreement or obligation hereunder and such
                           failure shall not be remedied within thirty (30) days
                           (or such additional time as is reasonably required in
                           the opinion of Authority to correct any such failure,
                           if Tenant has instituted corrective action and is
                           diligently pursuing the same) after Authority shall
                           have given Tenant written notice specifying which
                           covenant, agreement or obligation Tenant has failed
                           to observe or perform; provided that Tenant shall not
                           be entitled to the benefit of more than two (2) grace
                           periods of thirty (30) days (or more if permitted)
                           under this paragraph within any calendar year.

                  D.       There is commenced by or against Tenant any case
                           under the Bankruptcy Code (Title 11 of the United
                           States Code) or any other bankruptcy, arrangement,
                           reorganization, receivership, custodianship or
                           similar proceeding under any federal, state or
                           foreign law, and with respect to any such case or
                           proceeding that is involuntary, such case or
                           proceeding is not dismissed with prejudice within
                           sixty (60) days of such filing.

                  E.       Tenant makes a general assignment for the benefit of
                           creditors or applies for, consents to, or acquiesces
                           in the appointment of a trustee, receiver, or other
                           custodian for Tenant or the property of Tenant or any
                           part thereof, or in the absence of such application,
                           consent, or acquiescence, a trustee, receiver or
                           other custodian is appointed for Tenant or the
                           property of Tenant or any part thereof, and such
                           appointment is not discharged within sixty (60) days

                  F.       Any action is commenced against Tenant to foreclose
                           any lien or mortgage or other rights of Tenant in or
                           to the Premises.

                  Tenant abandons, deserts or vacates the Premises for seven (7)
                  consecutive days or more.

11.2     REMEDIES OF AUTHORITY

         If Tenant shall be in default hereunder as set forth above, the
         Authority may exercise any of the following remedies.

         A.       TERMINATION

                  Authority may, at its election, give Tenant written notice of
                  its intention to terminate this Sublease on a date which shall
                  not be earlier than ten (10) days after such notice is given.
                  If all defaults have not been cured on or before the date
                  specified in the notice, Tenant's rights to possession of the
                  Premises shall cease, and with or without re-entry by
                  Authority, this Sublease and the term hereof shall terminate,
                  and Authority may then re-enter and take possession of the
                  Premises as provided below with respect to reentry without
                  termination. Any such



                                       17
<PAGE>   22

                  termination must be express, and neither notice to pay rent or
                  to deliver up possession of the Premises given pursuant to
                  law, nor any proceeding instituted by Authority, nor the
                  failure by Tenant for any period of time to pay any of the
                  rent herein reserved, shall of itself operate to terminate
                  this Sublease.

                  (i) Damages. Notwithstanding the termination of this Sublease
                      or any re-entry by Authority upon such termination, Tenant
                      shall continue to be liable for and Authority shall be
                      entitled to recover as damages:

                           (a)      the sum of all rent that is due and owing as
                                    of the date of termination and all other
                                    sums then owing by Tenant hereunder;

                           (b)      all rent that would otherwise continue to
                                    accrue during the remaining term hereof or,
                                    at the election of Authority, the discounted
                                    present value of the sum of all rentals
                                    remaining to be paid for the remaining term
                                    of this Sublease, calculated by the
                                    Authority in its reasonable discretion; and

                           (c)      the reasonable costs incurred by Authority
                                    in re-letting the Premises and the
                                    reasonable costs to Authority necessary to
                                    place the Premises in condition for
                                    re-letting.

                  (ii) Credit. Any rent, income, receipts, profits or other
                       monies received or derived by Authority from any
                       re-letting or other use of the Premises after the
                       termination of this Sublease shall, so long as Tenant
                       shall continue to be liable for the payment of rent
                       hereunder, be credited against such rent as received and
                       collected.

         B.       REENTRY WITHOUT TERMINATION

                  As an alternative remedy, Authority may, without terminating
                  this Sublease, and after giving Tenant ten (10) days written
                  notice, re-enter the Premises and take possession thereof
                  pursuant to any legal proceedings or notice required by law,
                  in which event Tenant shall remain liable for the payment of
                  all rent and the performance of all conditions contained in
                  this Sublease.

                  (i)      Reentry. Upon any such re-entry of the Premises by
                           Authority, Authority may expel Tenant and those
                           claiming through or under Tenant and remove their
                           property and effects (forcibly, if necessary) without
                           being guilty in any manner of trespass and without
                           any liability therefor and without prejudice to any
                           remedies of Authority in the event of default by
                           Tenant, and without liability for any interruption of
                           the conduct of the affairs of Tenant or those
                           claiming through or under Tenant which may result
                           from such entry. Tenant hereby irrevocably appoints
                           Authority as the agent and attorney-in-fact of Tenant
                           to remove all of Tenant's property whatsoever
                           situated upon the



                                       18
<PAGE>   23

                           Premises and to place such property in storage in any
                           warehouse or other suitable place in Tucson, Arizona,
                           for the account of and at the expense of Tenant and
                           Tenant hereby exempts and agrees to save harmless
                           Authority from any costs, loss or damage whatsoever
                           arising or occasioned by any such removal and storage
                           of such property by Authority or its duly authorized
                           agents in accordance with the provisions herein
                           contained. Nothing in this provision shall restrict
                           the right of the Tenant to utilize any and all
                           personal property as collateral for funding and make
                           such property subject to a Uniform Commercial Code
                           filing. Nothing in this Lease shall be construed to
                           give the Landlord a superior right to that of a
                           lender using such personal property of the Tenant as
                           collateral with rights superior to that of the
                           Landlord.

                  (ii)     Reletting. After such re-entry, Authority shall use
                           reasonable diligence to re-let the Premises, or any
                           part or parts thereof, for such period or periods and
                           upon such term or terms and at such reasonable rental
                           or rentals and upon such other conditions as
                           Authority may deem advisable, with the right to make
                           alterations and repairs to the Premises. Tenant
                           hereby irrevocably appoints Authority as the agent
                           and attorney-in-fact of Tenant to enter upon and
                           re-let the Premises and to incur any necessary
                           expenses in doing so, all to be reimbursed by Tenant.
                           Tenant agrees that no acts of Authority in effecting
                           such re-letting shall constitute a termination of
                           this Sublease, irrespective of the period for which
                           such re-letting is made or the terms and conditions
                           of such re-letting or otherwise.

                  (iii)    Credit. Tenant shall receive a credit against such
                           rental in the amount of the proceeds, if any, of such
                           re-letting. Tenant's obligations, in addition to
                           rent, for which it shall remain liable include, but
                           shall not be limited to, all repossession costs,
                           brokerage commissions, legal expenses, attorneys'
                           fees, expenses of employees, removal costs,
                           alteration costs and expenses of preparation for
                           re-letting, and any other amounts expended pursuant
                           to action taken under this paragraph.

11.3     REMEDIES CUMULATIVE

         All rights, options and remedies of Authority contained in this
         Sublease shall be construed and held to be cumulative, and no one of
         them shall be exclusive of the other, and Authority shall have the
         right to pursue any one or all of such remedies or any other remedy or
         relief which may be provided by law, whether or not stated in this
         Sublease (including but not limited to any right of "self help" or
         similar remedy in order to minimize any damages, expenses, penalties
         and related fees or costs).

11.4     NO WAIVER

         No waiver of any Event of Default of Tenant hereunder shall be implied
         from any acceptance by Authority of any rent or other payments due
         hereunder or any omission by Authority to take any action on account of
         such default if such default persists or is repeated, and no express
         waiver shall affect an Event of Default in a manner other than as
         specified in said waiver. The consent or approval by Authority to or of
         any act by Tenant requiring Authority's consent or approval shall not
         be deemed to waive or render unnecessary Authority's consent or
         approval to or of any subsequent similar acts by Tenant.



                                       19
<PAGE>   24

11.5     NOTICE

         Any default notice tendered to Tenant hereunder shall be deemed to be
         sufficient if it is sent as provided in Section 14.8 and is reasonably
         calculated to put Tenant on inquiry as to the nature and extent of such
         default.

11.6     INTEREST

         All amounts due the Authority hereunder shall accumulate interest at a
         rate of 12% per annum or the maximum amount allowed by law, whichever
         is less.

                       ARTICLE XII - TERMINATION BY TENANT

12.1     TERMINATION EVENTS

         Tenant may terminate this Sublease at any time upon thirty (30) days
         written notice to Authority upon or after the happening or continuation
         of any of the following events:

                  A.       The inability of Tenant to use, for a period of
                           thirty (30) consecutive days, any portion of the
                           rights, licenses, services or privileges of Tenant
                           hereunder because of any law, rule, regulation or
                           other action or failure to act on the part of any
                           United States governmental authority having
                           jurisdiction thereof.

                  B.       The default by Authority in the performance of any
                           covenant or agreement herein required to be performed
                           by Authority and the failure of Authority to remedy
                           such default for a period of thirty (30) days after
                           receipt of written request or demand from Tenant to
                           remedy the same.

                  C.       The assumption by the United States government or any
                           authorized agency thereof of the operation or control
                           of the Airport or any part thereof, in such manner as
                           to substantially restrict Tenant for a period of at
                           least thirty (30) consecutive days from conducting
                           any of its operation on the Premises.

12.2     CURE

         If any of the foregoing reasons for termination by Tenant cease to
         exist prior to a termination, then the right to terminate for such
         reason shall cease.



                                       20
<PAGE>   25

12.3     NO WAIVER

         No waiver by Tenant of Authority's default of any of its obligations
         hereunder shall be construed to be or act as a waiver by Tenant of any
         subsequent default by Authority.

          ARTICLE XIII - SURRENDER OF POSSESSION, CONDITION OF PREMISES

13.1     SURRENDER

         Upon the expiration or earlier termination of this Sublease or any
         extensions thereof Tenant shall forthwith surrender the Premises to
         Authority.

13.2     GOOD CONDITION

         The Premises shall be returned to Authority in as good condition as at
         the time of occupancy by Tenant, except as otherwise provided in this
         Sublease, ordinary wear and tear excepted.

13.3     REMOVAL OF PROPERTY

         Tenant, and Tenant's subtenants, may remove any and all personal
         property, including portable buildings, signs, trade fixtures,
         machinery and equipment from the Premises prior to expiration of this
         Sublease; provided, however, that Tenant shall repair any damage caused
         by such removal. Title to any property remaining in the Premises after
         expiration or termination of this Sublease shall vest in Authority and
         Authority shall have the right and option to remove the same, restore
         the Premises and recover from Tenant the costs and expenses of doing
         so.

                           ARTICLE XIV - MISCELLANEOUS

14.1     NOTIFICATION OF CHANGES

         Tenant shall promptly notify Authority of any change in Tenant's name
         or address or a change in ownership.

14.2     SUCCESSORS AND ASSIGNS BOUND

         All the terms, covenants and conditions of this Sublease shall extend
         to and bind the successors and assigns of the respective parties
         hereto.

14.3     ARTICLE HEADINGS

         The article headings contained herein are for convenience and reference
         and are not intended to define or limit the scope of any provisions of
         this Sublease.


                                       21
<PAGE>   26

14.4     SEVERABILITY

         If any term or condition of this Sublease shall be deemed to be invalid
         or unenforceable, all other terms and conditions shall remain in full
         force and effect.

14.5     APPLICABLE LAW

         The terms and conditions of this sublease shall be interpreted in
         accordance with the laws of the State of Arizona.

14.6     CONSTRUCTION OF SUBLEASE

         Authority and Tenant agree that each party and its counsel have
         reviewed and revised this Sublease and that any rule of construction to
         the effect that ambiguities are to be resolved against the drafting
         party shall not apply in the interpretation of this Sublease. No remedy
         or election given by any provisions of this Sublease shall be deemed
         exclusive unless so indicated, but each shall, whenever possible, be
         cumulative with all other remedies in law or equity. Each provision
         hereof shall be deemed both a covenant and a condition and shall run
         with the land for the duration of the leasehold term or any extensions
         thereof. Whenever the content of any provision shall require it, the
         singular number shall be held to include the plural number and vice
         versa. The form of this Sublease contemplates that Tenant will be an
         entity and not one or more natural persons. If Tenant is one or more
         natural persons, then all pronouns referring to Tenant shall be deemed
         to be appropriately changed to fit those circumstances.

14.7     COSTS AND ATTORNEYS' FEES

         A.       AUTHORITY'S REVIEW

                  Tenant shall pay the expenses (including reasonable attorneys'
                  fees and the fees of other consultants) incurred by Authority
                  in reviewing any of the documents (including subleases, plans
                  and specifications of any improvements to be constructed by
                  Tenant, and documents created pursuant to Section ) for which
                  Authority's approval is required by the terms hereof.

         B.       ENFORCEMENT OF RIGHTS

                  The non-prevailing party shall promptly pay to the prevailing
                  party, upon demand, all costs and other expenses paid or
                  incurred by the prevailing party (including, without
                  limitation, reasonable attorney's fees) in enforcing or
                  exercising its rights or remedies created by, connected with
                  or provided for in this Sublease, whether or not any action or
                  proceeding is brought (including, without limitation, all such
                  costs, expenses and fees incurred in connection with any
                  bankruptcy, receivership, or other court proceedings [whether
                  at the trial or the appellate level]).


                                       22
<PAGE>   27

14.8     NOTICES

         A.       TO AUTHORITY

                  Notices to Authority in connection with this Sublease shall be
                  sufficiently served if physically delivered or sent by
                  certified mail, postage prepaid, addressed to Authority at the
                  address shown for it on the cover page of this Lease, with a
                  coy to Property Manager.

         B.       TO TENANT

                  Notices to Tenant in connection with this Sublease shall be
                  sufficiently served if physically delivered or sent by regular
                  mail, postage prepaid, addressed to Tenant at the address
                  shown for it above, provided that notice of utility
                  interference shall be sufficiently served if Authority gives
                  said notice to the current supervisor of Tenant's operations
                  on the Premises.

         C.       TIMING

                  Service of any notice or demand by physical delivery shall be
                  deemed complete upon the date of delivery. Service of any
                  notice or demand by certified mail shall be deemed complete at
                  the expiration of three (3) days after the date of the
                  certified mailing if mailed within the continental United
                  States.

         D.       CHANGE IN ADDRESS

                  Each party may change its address to such other addresses as
                  such party may designate to the other in writing from time to
                  time.

14.9     AUTHORITY TO EXECUTE

         Each party represents and warrants to the other that it has the right
and authority to enter into this Sublease.



                                       23
<PAGE>   28

         IN WITNESS WHEREOF the parties have executed this Sublease as of the
day and year first above written.

                                        TUCSON AIRPORT AUTHORITY, INC.,
                                             an Arizona nonprofit corporation


                                   By:
                                        -------------------------------------
                                   Its:
                                        -------------------------------------
                                        "AUTHORITY"



                                        AAS-COMPLETE CONTROLS, INC.
                                             an Arizona Corporation

                                   By:
                                        -------------------------------------
                                        Micah Chapman
                                        President
                                        "TENANT"



                                       24
<PAGE>   29

                                    EXHIBIT A

                              [DIAGRAM OF PREMISES]



<PAGE>   30

                                    EXHIBIT B


USE OF PREMISES




TENANT:             AMERICAN AIR CARRIERS SUPPORT - COMPLETE CONTROLS, INC.



USE OF PREMISES:    MAINTENANCE, REPAIR AND OVERHAUL FACILITY
                    SPECIALIZING IN FLIGHT CONTROL SURFACES -STORAGE OF
                    AIRPLANE PARTS



<PAGE>   31

                                    EXHIBIT C

                                  RENT SCHEDULE

                        YEAR             MONTHLY RENT

                        2000             $9,114.00
                        2001             $9,114.00
                        2002             $9,478.56
                        2003             $9,857.01
                        2004             $10,252.02
                        2005             $10,662.10
                        2006             $11,088.50
                        2007             $11,532.14
                        2008             $11,993.43
                        2009             $12,473.17