<PAGE>   1
                  AGREEMENT TO TERMINATE SUBTENANT'S RIGHT OF
                       OCCUPANCY UNDER SUBLEASE AGREEMENT


     This Agreement To Terminate Subtenant's Right of Occupancy Under Sublease 
Agreement (this "Agreement") is entered into effective as of this 1st day of 
October, 1998 (the "Effective Date"), by and among SHASTA AVIATION CORP., 
d.b.a. CRESCENT HELICOPTERS ("Sublessor"), GLOBAL TURBINE SERVICES, INC. 
("Sublessee") and AMERICAN AIRCARRIERS SUPPORT, INCORPORATED ("Assignee").


                                    RECITALS


A.   Effective December 3, 1997, the Sublessor and Sublessee entered into the 
     Sublease Agreement attached hereto and incorporated herein as Exhibit A 
     (the "Sublease") for the premises described therein (the "Premises").

B.   Tenant accepted the condition of the Premises and has been in continuous 
     occupation of the Premises since the effective date of the Sublease.

C.   Tenant is selling its assets to Assignee, and has requested Sublessor to 
     consent to the assignment of the Sublease to Assignee, and to release 
     Sublessee from the continuing obligation to pay rent under the Sublease.

D.   Sublessor is not in default under the Sublease. Sublessee is current on 
     payment of rent under the Sublease.

E.   Sublessor desires to release Sublessee from its obligation to pay rent 
     under the Sublease, subject to the terms and conditions contained in this 
     Agreement.

F.   Assignor desires to assume the Sublessee subject to the terms and 
     conditions contained in this Agreement and the Sublease.


                                   AGREEMENT


     In consideration of the above recitals and the mutual promises contained 
in this Agreement, the receipt and sufficiency of which are hereby 
acknowledged, the parties agree as follows:

     1.   RELEASE OF SUBLESSOR. Sublessee hereby releases Sublessor from any 
and all conditions, covenants and obligations of Sublessor under the Sublease 
and agrees not to institute any action or suit in law or equity against 
Sublessor or to institute, prosecute or in any way aid in the institution or 
prosecution of any claim, demand, action or cause of action against Sublessor 
arising out of the Sublease or the Premises.
<PAGE>   2

     2.     ASSUMPTION BY ASSIGNEE.  Assignee hereby assumes the Sublease and
all of Sublessee's obligations under the same as of the Effective Date hereof,
and accepts the terms and conditions of the Sublease. Assignee agrees to begin
paying rent no later than the Effective Date.

     3.     SECURITY DEPOSIT.  Sublessor acknowledges Sublessee's assignment of
the security deposit to Assignee, which shall continue to be subject to the 
terms and conditions described in the Sublease. The Parties acknowledge that 
Sublessor shall retain the security deposit in satisfaction of Assignor's 
requirement to provide a security deposit under the Sublease.

     4.     VACATION OF PREMISES.  Sublessee agrees to remove any personal 
assets or assets not being sold to Assignee no later than the Effective Date.

     5.     INDEMNITY.  Sublessee shall indemnify, defend and hold the 
Sublessor harmless from and against any and all claims, losses, damages, 
injuries, liabilities and all costs, including attorneys fees, court costs and 
expenses and liabilities incurred in or from any such claim, arising from 
Sublessee's use or occupancy of the Premises during the term of the Sublease as 
modified by this Agreement, or arising from any act, negligence or the failure 
to act of Sublessee, or any of its agents, contractors, employees, invitees or 
guests. Sublessee, upon notice from sublessor, shall defend Sublessor at 
Sublessee's expense by counsel reasonably satisfactory to Sublessor. Sublessee, 
as a material part of the consideration of Sublessor, hereby waives all claims 
in respect thereof against Sublessor.

     6.     CONDITIONS PRECEDENT TO RELEASE OF SUBLESSEE.  Sublessor's release
of Sublessee's obligation to pay rent under the Sublease, as further described 
in this Section 6 of this Agreement, is expressly conditioned upon and subject 
to satisfaction of the following conditions:

            (a)    Assignee assuming the Sublease and all obligations thereof 
after the date hereof.

     7.     RELEASE OF SUBLESSEE.  Subject to Sublessee's compliance with the 
covenants and conditions contained in this Agreement and the satisfaction of 
the conditions contained in Section 6, and except as to the following 
conditions, effective as of the Effective Date, the Sublessor hereby releases 
Sublessee from any further obligation(s) to pay rent or to reimburse sublessor 
for operating, maintenance and common area operating expenses that relate to 
the period after such date.

     Sublessee is not released from its covenants under the Sublease other than 
for the payment of rent and the reimbursement or payment of operating, 
maintenance and common area maintenance expenses. Sublessee is not released 
from any other covenants under the Sublease, including, but not limited to, 
payment for claims relating to environmental contamination of the Premises, 
claims for payment for work performed on the Premises, claims relating to 
Sublessee's use or occupancy of the Premises, or Sublessee's failure to 
properly maintain the Premises, which claims arose during the term of the 
Sublease.
<PAGE>   3
     8.  ATTORNEYS' FEES. In the event of any controversy, claim or action being
filed or instituted between the parties to this Agreement to enforce the terms
and conditions of this Agreement or arising from the breach of any provision
hereof, the prevailing party will be entitled to receive from the other party
all costs, damages, and expenses, including reasonable attorneys' fees, incurred
by the prevailing party, whether or not such controversy or claim is litigated
or prosecuted to judgment, including all costs and reasonable attorneys fees
incurred as a result of any appeal. The prevailing party will be that party who
was awarded judgment as a result of trial or arbitration, or who receives a
payment of money from the other party in settlement of claims asserted by that
party.

     9.  COUNTERPARTS. This Agreement may be executed in any number of
counterparts and once so executed by all parties thereto, each such counterpart
shall be deemed to be an original instrument but all such counterparts together
shall constitute but one agreement.

     10. SURVIVAL. The terms and provisions hereof shall survive the termination
of the Lease and shall remain in full force and effect thereafter.

     11. BINDING EFFECT. This Agreement and shall be for the benefit of and bind
the parties hereto and their respective heirs, legal representatives, successors
and assigns.

     12. FURTHER ACTS. Except as otherwise provided herein, in addition to the
acts and deeds recited herein and contemplated to be performed, executed and/or
delivered by the parties, the parties hereby agree to perform, execute and/or
deliver or cause to be performed, executed and/or delivered any and all such
further acts, deeds and assurances as any party hereto may reasonably require to
consummate the transaction contemplated hereunder.

     13. ENTIRE AGREEMENTS. This Agreement and the other documents to be
executed by the parties hereunder, embody the entire agreement relative to the
subject matter hereof, and there are no oral agreements existing relative to
the subject matter hereof which are not expressly set forth herein or in the
documents to be executed hereunder and covered hereby, and in the case of any
conflicts between any such documents, this Agrement shall control. This
Agreement may be modified only in writing when signed by all the parties hereto.

     14. WAIVER. No covenant, term or condition or the breach thereof shall be
deemed waived, except by written consent of the party against whom the waiver is
claimed, and any waiver of the breach of any covenant, term or condition shall
not be deemed to be a waiver of any other covenant, term or condition herein.
Acceptance by a party of any performance by another party after the time the
same shall have become due shall not constitute a waiver by the first party of
the breach or default of any such covenant, term or condition unless otherwise
expressly agreed to by the first party in writing.

     15. INCORPORATION OF RECITALS. The foregoing recitals are incorporated into
and made an integral part of this Agreement.

<PAGE>   4
EXECUTED effective the date first set forth above.

                                 SUBLESSOR

                  
                                 SHASTA AVIATION CORP.,
                                 an Idaho corporation



                                 By:   /s/ Dean H. Shealy
                                     ------------------------------------
                                       Dean H. Shealy, President



                                 SUBLESSEE

                                 GLOBAL TURBINE SERVICES, INC.,
                                 a ___________________ corporation
                                   

                                 By:   /s/ Mike Evans
                                      ------------------------------------

                                 Its:  President
                                      ------------------------------------



                                 ASSIGNEE

                                 AMERICAN AIR CARRIERS SUPPORT, INCORPORATED,
                                 a Delaware corporation



                                 By:    Karl Brown
                                      ------------------------------------

                                 Its:   President
                                      ------------------------------------
<PAGE>   5
                               SUBLEASE AGREEMENT


THIS AGREEMENT, entered into on October 1, 1997 by and between SHASTA AVIATION
CORP., dba CRESCENT HELICOPTERS, hereinafter called the SUBLESSOR, and GLOBAL
TURBINE SERVICES INC., hereinafter called SUBLESSEE or TENANT:


                                   WITNESSETH

1.   AGREEMENT TO LEASE:

     Subject to the approval of Broward County, Florida, a political 
     subdivision of the State of Florida, SUBLESSOR does this day lease unto 
     SUBLESSEE, and said SUBLESSEE, does hire and take as tenant under said 
     SUBLESSOR, that portion of SUBLESSEES premises known as the NORTHEAST and 
     NORTHWEST HANGARS, including concrete pad and land to the south of the two 
     Hangars together with designated tie downs and other land and open areas 
     as shown on Exhibit "A" attached hereto and incorporated herein by 
     reference. The SUBLESSEE Premises specifically excludes the Jet Fuel
     Facility including ingress and egress thereto, and land east of the 
     north/south taxiway to the west of the NORTHWEST HANGAR as shown on 
     Exhibit "A".

2.   MASTER LEASE:

     SUBLESSEE hereby acknowledges that the Premises and SUBLESSOR'S rights 
     thereto are subject to the Master Lease with Broward County, a copy of 
     which is on file in the offices of Broward County Aviation Department, 
     Division of Airports and SUBLESSOR'S offices, and SUBLESSEE hereby 
     represents that it is familiar with the provisions of same and said Master 
     Lease is incorporated herein by reference. SUBLESSEE acknowledges that (a) 
     it will comply with each and every provision of the Master Lease in 
     accordance with the terms hereof as such provisions relate to the 
     Premises, except as such provisions are supplemented or amended by this 
     Sublease Agreement; (b) any and all rights and reservations of Broward 
     County under the Master Lease as such rights or reservations may apply to 
     the leased Land described in the Master Lease or SUBLESSOR shall likewise 
     apply to the Premises and SUBLESSEE under this Sublease Agreement; and (c) 
     any remedy which Broward County may have against SUBLESSOR or the leased 
     premises under the Master Lease shall become a remedy of SUBLESSOR and 
     Broward County against SUBLESSEE and the Premises under this Sublease 
     Agreement. The foregoing shall in no manner limit SUBLESSOR's right to 
     require SUBLESSEE to comply with SUBLESSEE's obligations under this 
     Sublease Agreement or SUBLESSEE's obligations, as limited by this 
     Agreement, under the Master Lease.

3.   LEASE TERM:

     The term of this Lease is for FOUR (4) years commencing December 15, 1997 
     and continuing through December 14, 2001, subject to and conditioned upon 
     the approval of Broward County Florida, and the fulfillment of all terms 
     and conditions of this lease. Furthermore, the SUBLESSOR does hereby grant 
     SUBLESSEE an additional TWO YEAR NINE AND ONE HALF MONTHS Option to Lease 
     said premises commencing December 15, 20001 and continuing through 
     September 30, 2004, at the rental amounts specified below. Such option to 
     be exercised by SUBLESSEE providing SUBLESSOR notice


                                       1
<PAGE>   6
     in writing of intent to exercise the option no later than 180 days prior to
     the end of the initial lease term (December 14, 2001).

     RENTAL AMOUNT:

     The agreed total base annual rental amount for year one shall be $96,000 or
     $8,000 per month plus any applicable sales or use tax or other sums imposed
     by law on such payments. It is recognized that, for purposes of any rental
     increases imposed on SUBLESSOR by Broward County, SUBLESSEE shall occupy
     50% of the total premises leased by SUBLESSOR and will be responsible to
     pay, as additional rent, 50% of any such Broward County imposed rental
     increase. Therefore, 50% of the final rent increase resulting from the
     revaluation of the premises in August 1997, which is currently being
     negotiated with Broward County (estimated to be between $500 and $2,200 per
     month), will be added to the base monthly rent of $8,000 retroactive to
     December 15, 1997. It is further agreed that 50% of any rent increase
     resulting from the re-evaluation of the premises by Broward County as of
     August 2002 will be added to the then monthly rental rate paid by SUBLESSEE
     during the option period if said option has been exercised by SUBLESSEE. In
     addition, at the time of percentage Consumer Price Index (CPI) increases
     (if any) imposed by Broward County on SUBLESSOR, SUBLESSEE'S annual rental
     amount will be increased by a dollar amount equal to 50% of that CPI
     percentage increase. Base monthly rent will also increase beginning the
     second year (December 15, 1998) as well as at the beginning of each year
     thereafter including each option year by an amount of $500 per month. All
     rents are due monthly in advance on the first calendar day of each month
     payable to: CRESCENT HELICOPTERS, 7750 Pines Blvd., Pembroke Pines, FL
     33024. The first lease payment due December 15, 1997 will be for both the
     first and last month's base lease payments amounting to $16,000. A 10%
     penalty fee will be incurred by the SUBLESSEE for any payments not received
     by the SUBLESSOR by the seventh calendar day of the applicable month.

5.   DEPOSIT:

     Receipt is hereby made in the amount of $8,500 from SUBLESSEE. Upon
     acceptance of this lease, such deposit shall belong to the SUBLESSOR and
     applied as a Security Deposit for the period of said Lease. Said Security
     Deposit shall secure the performance of the SUBLESSEE'S obligation
     hereunder and shall constitute a fund from which any liens incurred by
     SUBLESSEE or damages caused by SUBLESSEE and suffered by SUBLESSOR shall be
     paid. Any Deposit remaining upon termination shall be returned to the
     SUBLESSEE. SUBLESSEE shall not have the right to apply the Security Deposit
     in payment of monthly rent.

6.   LESSEE'S OBLIGATIONS:

     (A)           SUBLESSEE herein to the absolute and complete exclusion of 
                   SUBLESSOR herein, shall be solely responsible for the 
                   performance of any and all maintenance upon the interior and
                   exterior of premises including maintenance and repair of the 
                   tie down areas, maintenance of the landscaping, cutting grass
                   areas including grass around tie down areas, the payment of 
                   any and all liability, fire and personal property insurance
                   premiums, and 100% of said hangar's metered utilities. In 
                   addition, tenant A shall pay 50% of the water bill which is a
                   joint use water bill for the entire premises. 
     (B)           SUBLESSEE shall be solely responsible for the maintenance and
                   repair of all equipment, doors, windows, electrical, plumbing
                   and HVAC equipment and any and all other related equipment.

                                       

                                       2
<PAGE>   7


     (G)  SUBLESSEE shall accept the premises in "as is" condition including 
          acknowledgment by SUBLESSEE of an acceptable Phase II environmental 
          inspection having been completed on the premises as of __________
          199_, a copy of which is attached and as such made a part of this
          lease. SUBLESSEE shall also be responsible for any and all
          improvements to the premises, with any improvement costing more than
          $1,000 requiring the written approval of SUBLESSOR. All SUBLESSEE
          improvements shall at the end of the lease term become the property of
          the SUBLESSOR unless said improvements are removed by SUBLESSEE and
          the premises are put back to it's original condition as determined
          solely by SUBLESSOR.
 
7.   SUBLESSOR'S OBLIGATIONS:

     (A)  SUBLESSOR shall be responsible for the maintenance on the roof, 
          exterior structural walls and foundation of any buildings located on
          the Premises.

8.   SUB-LETTING:

     SUBLESSEE shall not assign this lease nor sublet the premises, or any part
     thereof, without the written consent of the SUBLESSOR, nor shall SUBLESSEE
     allow the premises, or any part thereof, to be used for any other purpose
     than is legally permitted by Broward County or any other governing body.

9.   PERSONAL PROPERTY:

     All personal property placed or moved into the premises above described by
     the SUBLESSEE, shall be at risk of the SUBLESSEE or OWNER thereof, and the
     SUBLESSOR shall not be liable for any damage to said personal property, or
     to the SUBLESSEE, or to any other party for any reason whatsoever.

10.  COMPLIANCE WITH RULES AND REGULATIONS:

     SUBLESSEE shall promptly comply with all statutes, ordinances, rules,
     orders, regulations and requirements of the Federal, State and Local
     Governments, Broward County Aviation Department, and of any and all of
     their departments, bureaus and agencies applicable to said premises.

11.  COMPLIANCE WITH RULES AND REGULATIONS: NON-PAYMENT OF RENT, RIGHT OF 
     RE-ENTRY:

     (A)  Time shall be of the essence within the terms and conditions of this 
          Lease. THE PROMPT PAYMENT OF THE RENT FOR SAID PREMISES UPON THE DATES
          NAMED, AND THE FAITHFUL OBSERVANCE OF THE RULES AND REGULATIONS AND
          TERMS OF THIS LEASE ARE THE CONDITIONS UPON WHICH THIS LEASE IS MADE
          AND ACCEPTED. Any material failure on the part of the SUBLESSEE herein
          to comply with the terms, conditions, rules or regulations now in
          existence, or which may be hereinafter required by Broward County,
          Florida, to whom this Lease is subservient, or the failure to pay rent
          within Seven calendar days after the same is due and payable, shall,
          at the option of the SUBLESSOR, work a forfeiture of this said
          contract and of all rights of the SUBLESSEE hereunder, and, thereupon,
          the SUBLESSOR, it's agent or attorneys, shall have the right to enter
          said premises and remove therefrom all persons and/or personal
          property located therein, forcibly or otherwise.
     (B)  If the SUBLESSEE shall abandon or vacate the subject premises before
          the end of the term of this Lease, or any extension thereof, or if
          said SUBLESSEE shall suffer the rent or any other sums of money due
          SUBLESSOR to be in arrears, then, and in such event, the SUBLESSOR.


                                       3
<PAGE>   8
          may, at its option, forthwith cancel this Lease or SUBLESSOR may enter
          said premises by force or otherwise, without being liable in any way
          therefor, and relet the premises with or without any furniture, tools,
          or equipment, that may be therein, at such price and upon such terms
          and for such duration of time as the SUBLESSOR may determine, and
          revive the rent therefor, applying the same to the payment of the rent
          or other moneys due by these presents, and if the full rental or other
          sums of money due SUBLESSOR herein provided shall not be realized by
          SUBLESSOR over and above the expenses to the SUBLESSOR in such
          releting, the said SUBLESSEE shall pay any deficiency.

12.  ATTORNEY'S FEES AND COSTS:

     The parties hereto agree, jointly and severally, to pay to the prevailing
     party a reasonable attorney's fee, suit costs, and all other costs
     connected with the enforcement of any and all terms of this Lease
     Agreement.

13.  TIMELY PAYMENT OF RENT, UTILITIES, TAXES AND INSURANCE.

     (A)  SUBLESSEE agrees that they will pay all charges for rent, insurance,
          utilities etc. on said premises, and should said charges herein
          provided for at any time become due and unpaid for a period of Seven
          (7) Calendar days after the same shall become due and owing, the
          SUBLESSOR may, at its option, consider the said SUBLESSEE to be
          tenants at sufferance and shall have the right to immediately reenter
          upon said premises and the entire rent for the remainder of this Lease
          Agreement shall be at once due and payable and may forthwith be
          collected by distress and otherwise, plus reasonable attorney's fees
          and any other costs and expenses connected with the enforcement of the
          terms and conditions of any portion of this Lease Agreement.
     (B)  SUBLESSEE agrees that they will pay any and all applicable sales 
          taxes, personal property taxes, which may be levied against the 
          property herein now or in the future during the course of this Lease 
          Agreement or any extension thereof.

14.  RIGHT OF INSPECTION AND ENTRY:

     The SUBLESSOR, or any of its agents, shall have the right to enter said 
     premises during all reasonable hours to examine the same, to make such 
     repairs, additions or alterations as may be deemed necessary for the 
     safety, comfort or preservation thereof, of said building, or to exhibit 
     said premises, and to put or keep upon the doors thereof a notice "FOR 
     RENT" at any time the SUBLESSEE is in default of this sublease agreement 
     as well as within 180 days before the expiration of this Sublease.

15.  ACCEPTANCE AND RETURN OF PREMISES:

     SUBLESSEE hereby accepts the premises in the condition they are in at the 
     beginning of this Lease and agrees to maintain said premises in at least 
     the same condition, order and repair as they are at the time commencement 
     of said term, excepting only reasonable wear and tear.


                                       4
<PAGE>   9
16.  LIMITATION OF LANDLORD'S LIABILITY:

     SUBLESSOR shall not be liable for any damages or injury by any cause, which
     may be sustained by the SUBLESSEE herein or any persons or for any other
     damage or injury resulting from carelessness, negligence or improper
     conduct on the part of any other tenant or agent, or employee, or entity.

17.  DEFAULT AND REMEDIES:

     A.  DEFAULT. The occurrence of any of the following shall constitute a
         material default and breach of this Lease by SUBLESSEE:
          (1) Any failure by SUBLESSEE to pay Minimum Rent or Percentage Rent or
              any other monetary sums required to be paid hereunder, where such
              failure continues for three (3) days after written notice by
              SUBLESSOR to SUBLESSEE:
          (2) The failure to occupy or the abandonment or vacation of the
              Premises by SUBLESSEE;
          (3) The repudiation of this Lease by SUBLESSEE, any action by
              SUBLESSEE which renders performances by SUBLESSEE of its
              obligations under this Lease impossible, or any action by
              SUBLESSEE which demonstrates an intent by SUBLESSEE not to perform
              an obligation under this Lease or not to continue with the
              performance of obligations under this Lease;
          (4) A failure by SUBLESSEE to observe and perform any other provisions
              of this Lease to be observed or performed by SUBLESSEE, where such
              failure continues for fifteen (15) days after written notice
              thereof by SUBLESSOR to SUBLESSEE; provided, however, that if the
              nature of the default is such that the same cannot reasonably be
              cured within said fifteen (15) day period, SUBLESSEE shall not be
              deemed to be in default if SUBLESSEE shall within such period
              commence such cure and thereafter diligently prosecute the same to
              completion;
          (5) The making by SUBLESSEE of any general assignment or general
              arrangement for the benefit of creditors, the filing by or against
              SUBLESSEE of a petition to have SUBLESSEE adjudged  bankrupt or of
              a petition for reorganization or arrangement under any law
              relating to bankruptcy (unless, in the case of a petition filed
              against SUBLESSEE, the same is dismissed within sixty (60) days),
              the appointment of a trustee or receiver to take possession of
              substantially all of SUBLESSEE'S assets or of SUBLESSEE'S interest
              in this Lease, where possession is not restored to SUBLESSEE
              within thirty (30) days, or the attachment, execution or other
              judicial seizure of substantially all of SUBLESSEE'S assets
              located at the Premises or of SUBLESSEE'S interest in this Lease,
              where such seizure is not discharged within thirty (30) days.
     B.  NOTICE. SUBLESSEE shall pay SUBLESSOR the sum of One Hundred and
         No/100ths dollars ($100.00) in addition to any other obligations
         hereunder for the cost of sending each Notice to Default. 
     C.  REMEDIES. In the event of any such material default or breach by
         SUBLESSEE, SUBLESSOR may at any time thereafter, without limiting
         SUBLESSOR in the exercise of any right of remedy at law or in equity
         which SUBLESSOR may have by reason of such default or breach:
         (1)  Maintain this Lease in full force and effect and recover the Rent
              and other monetary charges as they become due (or alternatively,
              if SUBLESSOR exercises the right to accelerate the Rent due
              hereunder as set forth in Section 17D below, recover all Rent and
              other monetary charges due as a result of acceleration), without
              terminating SUBLESSEE'S right to possession irrespective of
              whether SUBLESSEE shall have


                                       5
<PAGE>   10
               abandoned the Premises. In the event SUBLESSOR elects not to
               terminate this Lease, SUBLESSOR shall nevertheless have the right
               to attempt to re-let the Premises at such rent and upon such
               conditions and for such a term, and to do all acts necessary to
               maintain or preserve the Premises as SUBLESSOR deems reasonable
               and necessary without being deemed to have elected to terminate
               this Lease, including removal of all persons and property from
               the Premises; such property may be removed and stored in a public
               warehouse or elsewhere at the cost of and for the account of
               SUBLESSEE, and if SUBLESSEE does not pay for storage, then sold
               at public auction; the proceeds of such sale shall first be
               applied to payment of the expenses of such sale, second to
               amounts due SUBLESSOR and the balance, if any, to SUBLESSEE. In
               the event any re-letting occurs, SUBLESSEE'S right to possession
               of the Premises under this Lease shall terminate automatically
               upon the new SUBLESSEE taking possession of the Premises, but
               SUBLESSEE shall nevertheless be responsible for damages, more
               particularly described in Sections 17C.(2)a through 17C.(2)e.
               Notwithstanding that SUBLESSOR fails to elect to terminate the
               Lease initially, SUBLESSOR may at any time during the term of
               this Lease elect to terminate this Lease by virtue of such
               previous default of SUBLESSEE.
          (2)  Terminate SUBLESSEE'S right to possession by any lawful means
               and SUBLESSEE shall immediately surrender possession of the
               Premises to SUBLESSOR. In such event SUBLESSOR shall be entitled
               to recover from SUBLESSEE all damages incurred by SUBLESSOR by
               reason of SUBLESSEE'S default, including without limitation
               thereto the following:
                   a.) the worth at the time of award of any unpaid Rent which
                       had been earned at the time of such termination; plus
                   b.) the worth at the time of award of the amount by which the
                       unpaid Rent which would have been earned after
                       termination until the time of award exceeds, the amount
                       of such rental loss that could have been reasonably
                       avoided; plus
                   c.) the amount by which the unpaid Rent for the balance of
                       the term after the time of award exceeds the amount of
                       such rental loss that could be reasonably avoided; plus
                   d.) any other amount necessary to compensate SUBLESSOR for
                       all the detriment proximately caused by SUBLESSEES
                       failure to perform its obligation under this Lease or
                       which in the ordinary course of events would be likely to
                       result therefrom including costs and expenses incurred by
                       SUBLESSOR in making the Premises ready for a new
                       SUBLESSEE; plus
                   e.) at SUBLESSOR'S election, such other amounts in addition
                       to or in lieu of the foregoing as may be permitted from
                       time to time by applicable law of the State where the
                       Premises are located. Upon any such re-entry, SUBLESSOR
                       shall have the right to make any reasonable repairs,
                       alterations or modifications to the Premises, which
                       SUBLESSOR in its sole discretion deems reasonable and
                       necessary. As used in Section 17C.(2)a. above, the "worth
                       at the time of award" is computed by allowing interest at
                       the rate of one percent (1%) per month from the date of
                       default. The term Rent, means the rent to be paid
                       pursuant to Paragraph 4 and all other monetary sums
                       required to be paid by SUBLESSEE pursuant to the terms of
                       this Lease.
     D.  ACCELERATION OF RENT. In the event of any such material default or
         breach by SUBLESSEE, SUBLESSOR may, at its election and without
         limiting SUBLESSOR'S other rights and remedies, accelerate the payment
         of all Rent and other monetary sums payable by 


                                       6
<PAGE>   11
             SUBLESSEE for the balance of the term and upon any such elections 
             such sums shall be immediately due and payable in full.
     E.      SPECIAL DAMAGES. In addition to the damages for breach of this 
             Lease described in Paragraph 17C. and 17D. SUBLESSEE agrees that 
             SUBLESSOR shall be entitled to receive from SUBLESSEE any and all
             costs in connection with SUBLESSEE'S default hereunder, including
             without limitation, administrative costs of SUBLESSOR associated 
             with SUBLESSEE'S default, costs of repairing and/or remodeling the
             Premises for new SUBLESSEES and leasing commissions for any leasing
             agent engaged to re-let the Premises. 
     F.      LATE CHARGES. SUBLESSEE hereby acknowledges that late payment by
             SUBLESSEE to SUBLESSOR of Rent and other sums due hereunder will 
             cause SUBLESSOR to incur costs not contemplated by this Lease, the
             exact amount of which are unknown and will be extremely difficult
             to ascertain other than such late charges which may be imposed on
             SUBLESSOR by the terms of any mortgage or trust deed covering the
             Premises. Accordingly, if any installment of Rent or any other sums
             due from SUBLESSEE shall not be received by SUBLESSOR or 
             SUBLESSOR'S designee within seven (7) days after such amount shall
             be due, SUBLESSEE shall pay to SUBLESSOR in addition to any late 
             charges incurred by SUBLESSOR under any mortgage or deed of trust
             covering the Premises, a late charge equal to ten percent (10%) of
             the amount(s) past due and additionally all such installments of 
             Rent or other sums due shall bear interest from the seventh day 
             forward at the rate of One percent (1%) per month until paid in 
             full. The parties hereby agree that such late charges represents 
             fair and reasonable estimate of the costs SUBLESSOR will incur by
             reason of late payment by SUBLESSEE. Acceptance of such late charge
             by SUBLESSOR shall in no event constitute a waiver of SUBLESSEE'S 
             default with respect to such overdue amount, nor prevent SUBLESSOR
             from exercising any of the rights and remedies granted hereunder. 
     G.      DEFAULT BY SUBLESSOR. SUBLESSOR shall not be in default unless 
             SUBLESSOR fails to perform obligations required of SUBLESSOR within
             a reasonable time, but in no event later that thirty (30) days 
             after written notice by SUBLESSEE to SUBLESSOR and to the holder of
             any mortgage or deed of trust covering the Premises furnished to 
             SUBLESSEE in writing, specifying wherein SUBLESSOR has failed to 
             perform such obligations; provided, however, that if the nature of
             SUBLESSOR'S obligation is such that more than thirty (30) days are
             required for performance, then SUBLESSOR shall not be in default if
             SUBLESSOR commences performance within such thirty (30) day period
             and thereafter diligently prosecutes the same to completion; 
             provided, further, that in the event that SUBLESSOR has defaulted 
             in the payments of a monetary obligation and SUBLESSEE has advanced
             monies to pay such obligation. SUBLESSOR shall pay SUBLESSEE 
             interest on such monies advanced at a rate of one percent (1%) per
             month until paid in full. 
     H.      BANKRUPTCY. 
             (1.)      CHAPTER 7. In the event that SUBLESSEE shall become a 
                       debtor in a case filed under Chapter 7 of the Bankruptcy
                       Code, and SUBLESSEE'S trustee or SUBLESSEE shall elect to
                       assume this Lease for the purpose of assigning the same
                       or otherwise, such election and assignment may be made 
                       only if the provisions of Sections 17H.(2), 17H.(3), and
                       17H.(5) are satisfied. If SUBLESSEE or SUBLESSEE'S 
                       trustee shall fail to elect to assume this Lease within
                       sixty (60) days after the filing of such petition or such
                       additional time as provided by the court within such 60-
                       day period, this Lease shall be deemed to have been 
                       rejected. Immediately thereupon SUBLESSOR shall be 
                       entitled to possession of the Premises without further 
                       obligation to SUBLESSEE or SUBLESSEE'S trustee and this
                       Lease, upon the election of SUBLESSOR, shall terminate 
                       but SUBLESSOR'S right to be compensated for



                                       7

<PAGE>   12
               damages (including, without limitation, damages pursuant to this 
               Paragraph 17) in any such proceeding shall survive whether or 
               not the Lease is terminated.
          (2.) CHAPTER 11. In the event that SUBLESSEE shall become a debtor in 
               a case filed under Chapter 11 of the Bankruptcy Code, or in a 
               case filed under Chapter 7 of the Bankruptcy Code which is 
               converted to Chapter 11, SUBLESSEE'S trustee or SUBLESSEE, as 
               debtor-in-possession, must elect to assume this Lease within 
               sixty (60) days from the date of the filing of the petition 
               under Chapter 11 or conversion thereto, or SUBLESSEE'S trustee 
               or the debtor-in-possession shall be deemed to have rejected 
               this Lease. Immediately thereupon SUBLESSOR shall be entitled to 
               possession of the Premises without further obligation to 
               SUBLESSEE or SUBLESSEE'S trustee and this Lease, upon the 
               election of SUBLESSOR, shall terminate, but SUBLESSOR'S right to 
               be compensated for damages (including, without limitation, 
               damages pursuant to this Paragraph 17) in any such proceeding 
               shall survive whether or not the Lease is terminated.
                    Should SUBLESSEE'S trustee, or SUBLESSEE or debtor-in-
               possession elect to assume this lease, it can do so only if:
               a.)  SUBLESSEE'S trustee or the debtor-in-possession has cured 
                    all defaults under this Lease, or has provided SUBLESSOR 
                    with Assurance (as defined below) that it will cure all 
                    defaults susceptible of being cured by the payment of money 
                    on the date of such assumption, and that it will cure all 
                    other defaults under this Lease which are susceptible of 
                    being cured by the performance of any act within fifteen 
                    (15) days from the date of such assumption.
               b.)  SUBLESSEE'S trustee or the debtor-in-possession has
                    compensated or has provided SUBLESSOR with Assurance that 
                    within ten (10) days from the date of such assumption that 
                    it will compensate SUBLESSEE for any actual pecuniary loss 
                    incurred by SUBLESSEE arising from the default of 
                    SUBLESSEE, SUBLESSEE'S trustee, or the debtor-in-possession 
                    indicated in any statement of actual pecuniary loss sent 
                    by SUBLESSOR to SUBLESSEE'S trustee or the 
                    debtor-in-possession.
               c.)  SUBLESSEE'S trustee or the debtor-in-possession has 
                    provided SUBLESSOR with Assurance of future performance of 
                    each of the obligations under this Lease of SUBLESSEE, 
                    SUBLESSEE'S trustee or the debtor-in-possession, and if 
                    SUBLESSEE'S trustee or the debtor-in-possession has 
                    provided such assurance, SUBLESSEE'S trustee or the 
                    debtor-in-possession shall also deposit with, or provide 
                    Assurance as defined below to SUBLESSOR, as security for 
                    the timely payment of Rent hereunder, an amount equal to 
                    six (6) monthly installment payments of the Rent, provided 
                    all terms and provisions of this Lease shall have been 
                    complied with. The obligations imposed upon SUBLESSEE'S 
                    trustee or the debtor-in-possession by this paragraph shall 
                    continue with respect to SUBLESSEE or any assignee of this 
                    Lease after the completion of bankruptcy proceedings.
               d.)  Such assumption will not breach or cause a default under 
                    any provision of any other lease, mortgage, financing 
                    agreement or other agreement by which SUBLESSOR is bound 
                    relating to the Premises. For purposes of this Paragraph 
                    17H, SUBLESSOR and SUBLESSEE acknowledge that "Assurance" 
                    shall mean no less than: SUBLESSEE'S trustee or the 
                    debtor-in-possession has and will continue to have 
                    sufficient unencumbered assets after the payment of all 
                    secured obligations and administrative expenses to assure 
                    SUBLESSOR that sufficient funds will be available to 
                    fulfill the obligations of SUBLESSEE under this Lease and 
                    there shall have been deposited with SUBLESSOR, or the 
                    Bankruptcy Court


                                       8
<PAGE>   13
                      shall have entered an order segregating sufficient cash
                      payable to SUBLESSOR and/or SUBLESSEE'S trustee or
                      debtor-in-possession shall have been granted a valid and
                      perfected first lien and security interest and/or mortgage
                      in property of SUBLESSEE, SUBLESSEE'S trustee of the
                      debtor-in-possession, acceptable as to value and kind to
                      SUBLESSOR, to secure to SUBLESSOR the obligation of
                      SUBLESSEE'S trustee or the debtor-in-possession to cure
                      the defaults under this Lease, monetary and/or
                      non-monetary, within the time periods set forth above.
          (3). SUBSEQUENT PETITIONS. In the event that this Lease is assumed in 
               accordance with Paragraph 17H(2) and thereafter SUBLESSEE is
               liquidated or files or has filed against it a subsequent petition
               under Chapter 7 or Chapter 11 or the Bankruptcy Code, SUBLESSOR
               may, at it's option, terminate this Lease and all rights of
               SUBLESSEE hereunder by giving SUBLESSEE notice of its election to
               so terminate within thirty (30) days after the occurrence of
               either of such events.
          (4). ADEQUATE ASSURANCES. If SUBLESSEE'S trustee or the 
               debtor-in-possession has assumed the Lease pursuant to the terms
               and provisions of Sections 17H(1), 17H(2) and 17H(3) for the
               purposes of assigning (or thereafter elects to assign) this
               Lease, this Lease may be so assigned only if the proposed
               assignee has provided adequate assurance of future performances
               of all of the terms, covenants and conditions of this Lease to be
               performed by SUBLESSEE. SUBLESSOR shall be entitled to receive
               all cash proceeds of such assignment. As used herein, "adequate
               assurance of future performance" shall mean and include all such
               requirements as set forth in Section 365 of Title II, U.S. Code
               (as may be amended) are met, and further that no less than each
               of the following conditions has been satisfied.
               a). The proposed assignee has furnished SUBLESSOR with either 
                   (i) a current financial statement audited by a certified
                   public accountant indicating a net worth and working capital
                   in amounts which SUBLESSOR reasonably determines to be
                   sufficient to assure the future performance by such assignee
                   of SUBLESSEE'S obligations under this Lease, or (ii) a
                   guarantee or guarantees, in form and substance satisfactory
                   to SUBLESSOR, from one or more persons with a net worth which
                   SUBLESSOR reasonable determines to be sufficient to secure
                   the SUBLESSEE'S obligations hereunder, and has also furnished
                   information with respect to the proposed assignee's
                   management ability, expertise and experience in SUBLESSEE'S
                   business and SUBLESSOR has reasonably determined that the
                   proposed assignee has the management expertise and experience
                   to operate the business conducted on the Premises.
               b). SUBLESSOR has obtained all consents or waivers from others 
                   required under any lease, mortgage, financing arrangement or
                   other agreement by which SUBLESSOR is bound, in order to
                   permit SUBLESSOR to consent to such assignment without
                   violating the terms of any such agreement.
               c). The proposed assignment will not release or impair any 
                   guaranty of the obligations of SUBLESSEE (including the
                   proposed assignee) under this Lease.
          (5). USE AND OCCUPANCY CHARGES. When, pursuant to the Bankruptcy 
               Code, SUBLESSEE'S trustee or the debtor-in-possession shall be
               obligated to pay reasonable use and occupancy charges for the use
               of the Premises, such charges shall not be less than the Base
               Rent plus Broward County valuation rental increase, CPI
               increases, and other charges due hereunder. No acceptance by
               SUBLESSOR of said use and occupancy charges, or of Rent hereunder
               shall constitute a waiver of any of the provisions of this
               Paragraph 17H, or any of SUBLESSOR'S rights thereunder.


                                       9
<PAGE>   14
          (6)  NO TRANSFER IN BANKRUPTCY WITHOUT CONSENT. Neither the whole nor 
               any portion of SUBLESSEE'S interest in this Lease or its estate 
               in the Premises shall pass to any trustee, receiver, or assignee 
               for the benefit of creditors, or any other person or entity, or 
               otherwise by operation of law under the laws of any state having 
               jurisdiction of the person or property of SUBLESSEE unless the 
               requirements and conditions of this Paragraph 17H, are truly met 
               or unless SUBLESSOR shall have otherwise consented to such 
               transfer in writing. No acceptance by SUBLESSOR of installment 
               payments or Rent or any other payments from any such trustee, 
               receiver, assignee, person or other entity shall be deemed to 
               constitute such consent by SUBLESSOR nor shall it be deemed a 
               waiver of SUBLESSOR'S rights under this Paragraph 17H including 
               the right to terminate this Lease for any transfer of 
               SUBLESSEE'S interest under this Lease without such consent.

18.  PERSONS AND PARTIES BOUND HEREBY:

     This contract shall be binding upon the SUBLESSOR, it's heirs,
     administrators or legal representatives, and of the SUBLESSEE, individually
     or corporately, jointly and severally.

19.  TIME OF PERFORMANCE HEREUNDER:

     It is understood and agreed by and between the parties hereto that time is 
     of the essence of this contract and this applies to all terms and 
     conditions contained herein.

20.  NOTICE:

     It is understood and agreed by and between the parties hereto that written 
     notice mailed or hand delivered to the premises leased hereunder shall 
     constitute sufficient notice to the SUBLESSEE to comply with the terms of 
     this Lease Agreement. As to the SUBLESSOR, all notices shall be sent to: 
     Crescent Helicopters, 7750 Pines Blvd., Pembroke Pines, FL 33024.

21.  CHARGES AS RENT:

     It is understood and agreed by and between the parties hereto that any 
     charges against the SUBLESSEE by the SUBLESSOR for services or for work 
     done on the premises by order of the SUBLESSEE or otherwise accruing under
     this contract shall be considered as rent due and shall be included in 
     any lien for rent due and unpaid.

22.  REQUIRED INSURANCE:  

     SUBLESSEE, at it's sole expense, shall maintain a Comprehensive General 
     Liability Insurance Policy in an amount not less that $1,000,000 and 
     listing Crescent Helicopters, and Larry D. Stevens and Dean H. Shealy, as 
     "ADDITIONAL INSURED". SUBLESSEE shall also maintain fire and extended 
     coverage insurance upon the Premises and any contents owned by SUBLESSOR 
     in an amount equal to no less than 100% of the replacement cost. Such 
     insurance shall include standard extended coverage, vandalism, malicious 
     mischief, and water damage coverage and shall name Broward County, 
     SUBLESSOR and any mortgagee of SUBLESSOR as additional insured and co-loss 
     payee thereunder. Evidence of the above insurance must be delivered to 
     SUBLESSOR prior to occupancy. SUBLESSEE


                                       10

<PAGE>   15
     will continue to provide SUBLESSOR with satisfactory evidence that such
     insurance is maintained throughout the SUBLESSEE term.

23.  WASTE DISPOSAL:

     SUBLESSEE shall not suffer the disposal of any human or chemical waste in,
     on or about the demised premises except in approved containers, or fashion,
     and in areas specifically approved by Landlord for such purpose. All
     government requirements relative to the storage and disposal of hazardous
     chemicals, fuel, oil, etc., shall be strictly adhered to at all times.

24.  MAINTENANCE OF GROUNDS:

     SUBLESSEE, at their sole expense, shall maintain the demised premises,
     including lawn and shrubbery, in at least as good condition as the same
     presently exists.

25.  USE:

     SUBLESSEE shall occupy the premises for Aircraft Service and Maintenance
     only. Any other use must be approved by Crescent Helicopters and Broward
     County Aviation Dept. SUBLESSEE is expressly restricted from conducting any
     helicopter activities on the premises including but not limited to
     equipment and parts sales, charters and contracts. SUBLESSEE is also
     restricted from performing any aircraft or aircraft parts stripping and/or
     painting activities on the Premises. Restrictions on SUBLESSEE activities
     as specified above also apply to anyone subletting or renting from
     SUBLESSEE.

26.  HOLD HARMLESS:

     SUBLESSEE shall indemnify and hold forever harmless SUBLESSOR and Broward
     County, against any and all claims of every kind or character arising out
     of the acts or omissions of SUBLESSOR, its directors, officers, agents, or
     employees or failure of SUBLESSOR to perform or comply with any of the
     terms hereof or otherwise caused by SUBLESSOR, its directors, officers,
     agents, or employees on said premises (except to the extent that such
     claims may be attributable to the negligence or willful misconduct of the
     agents or employees of SUBLESSOR) whether such claims shall arise from or
     be based upon injuries to persons (including death) or damage to property
     provided SUBLESSEE shall give SUBLESSOR prompt notice of any claims, damage
     or loss, or action in respect thereto, and an opportunity reasonably to
     investigate and defend against any claim or action based upon alleged
     negligent conduct of SUBLESSOR, its duly authorized director, officers,
     agents or employees.

27.  BINDING EFFECT:

     The party executing this Sublease Agreement on behalf of SUBLESSOR and
     SUBLESSEE respectively has the authority to bind the respective parties to
     this Sublease Agreement.

28.  ENTIRE AGREEMENT:

     The foregoing constitutes the entire agreement between the parties and may
     be modified only by a writing signed by both parties.


                                       11
<PAGE>   16

IN WITNESS WHEREOF, the parties hereto have executed this instrument for the 
purpose expressed, the day and year above written.


<TABLE>
<S>                                                         <C>
SUBLESSOR:                                                  SUBLESSEE:
----------                                                  ----------

SHASTA AVIATION CORPORATION                                 GLOBAL TURBINE SERVICES, INC.
DBA CRESCENT HELICOPTERS




BY:                                                         BY:
   ---------------------------------------------               --------------------------------------------


NAME:  DEAN H. SHEALY                                       NAME:
                                                                 ------------------------------------------


TITLE:  President                                           TITLE:
                                                                  -----------------------------------------


Signed, sealed and delivered in the presence of:            Signed, sealed and delivered in the presence of:


------------------------------------------------            ------------------------------------------------
Witness                                                     Witness
</TABLE>


     In Witness whereof, the parties have made and executed this Agreement:


BROWARD COUNTY through its BOARD OF COUNTY COMMISSIONERS, signing by and 
through its Chairman or Vice Chairman, _______________________, authorized to 
execute same by Board Action on the ______ day of _______________, 1996.


GLOBAL TURBINE SERVICES, INC., signing by and through its ____________________

duly authorized to execute same and SHASTA AVIATION, dba CRESCENT HELICOPTERS,

signing by and through its ____________________ duly authorized to execute same.


                                     COUNTY
                                     ------

<TABLE>
<S>                                                  <C>
ATTEST:                                              BROWARD COUNTY, through its


                                                     BOARD OF COUNTY COMMISSIONERS


-----------------------------------------            ----------------------------------------

County Administrator and Ex-Officio Clerk                      day of                  , 1996
                                                     ---------        ----------------

of the Board of County Commissioners                 Approved as to form by Office of County Attorney

of Broward County, Florida                           Broward County, Florida
</TABLE>

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