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EXHIBIT 10.80

                             GROUND LEASE AGREEMENT

                                     BETWEEN

                                       THE

                   METROPOLITAN WASHINGTON AIRPORTS AUTHORITY

                                       AND

                             ATLANTIC COAST AIRLINES

                                       TO

                     DESIGN, CONSTRUCT, OPERATE AND MAINTAIN

                        AN AIRCRAFT MAINTENANCE FACILITY

                                       AT

                     WASHINGTON DULLES INTERNATIONAL AIRPORT



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                                      INDEX

                             ATLANTIC COAST AIRLINES
                          AIRCRAFT MAINTENANCE FACILITY


ARTICLE  SUBJECT                                                                        PAGE

I                 Airport Premises . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2

II                Rights and Obligations of the Lessee . . . . . . . . . . . . . . . . . . . . . . .          2

III               Term of Lease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10

IV                Rental Fees and Other Charges . . . . . . . . . . . . . . . . . . . . . . . . . . .        12

V                 Establishment of Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25

VI                Schedule for Submitting Plans and Specifications . . . . . . . . . . . . .              29

VII               Title to the Facility, Fixed Improvements,
                    and Operating Facilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31

VIII              Certified Cost of Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33

IX                Maintenance of the Aircraft Maintenance Premises. . . . . . . . . . . . .               35

X                 Leasehold Mortgages  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39

XI                Assignment and Subletting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
64

XII               Termination by the Authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
68

XIII              Termination by the Lessee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71

XIV               Destruction and Improvements  . . . . . . . . . . . . . . . . . . . . . . . . . . . .      72

XV                Insurance and Indemnification . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    75

XVI               Performance Guarantee and Bonds  . . . . . . . . . . . . . . . . . . . . . . . .           79

XVII              Late Charges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
81



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                                                                                                           Page 2

ARTICLE  SUBJECT                                                                        PAGE

XVIII             Airport Rules and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    82

XIX               Copartnership  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82

XX                Participation in Lease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82

XXI               Taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 . . .             83

XXII              Signs  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 . . . .           83

XXIII             Quiet Enjoyment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
83

XXIV              Right of Inspection of Premises . . . . . . . . . . . . . . . . . . . . . . . . . . . .    84

XXV               Saving Provision  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
84

XXVI              Waiver of Performance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
84

XXVII             Certification of the Lessee's Status . . . . . . . . . . . . . . . . . . . . . . .         85

XXVIII   Notices  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85

XXIX              Environmental Matters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

XXX               Federal Requirements  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93


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Lease No. MWAA-LD-97-04
Page 1 of 97 Pages
         This Ground Lease Agreement  (hereinafter  referred to as the "Lease"),
entered  into by and  between the  Metropolitan  Washington  Airports  Authority
(hereinafter  referred to as the  "Authority")  and Atlantic Coast  Airlines,  a
California  corporation  qualified to transact  business in the  Commonwealth of
Virginia d.b.a United  Express  (hereinafter  referred to as the "Lessee").  The
Authority and the Lessee together are referred to as the "Parties."
                               W I T N E S S E T H
         WHEREAS, pursuant to the lease agreement,  dated March 2, 1987, between
the United States of America,  acting  through the Secretary of  Transportation,
and the  Authority,  the  Authority  controls  certain  real  property  known as
Washington  Dulles  International   Airport  (hereinafter  referred  to  as  the
"Airport")  and,  subject to the lease,  has full power and dominion  over,  and
discretion in the operation and development of the Airport; and
         WHEREAS,  the Lessee  desires to  construct,  operate  and  maintain an
aircraft  maintenance facility for the purpose of performing routine and special
maintenance  on its fleet of aircraft and aircraft  operated by other  scheduled
air carriers; and
         WHEREAS,  the Authority has an aircraft  maintenance site available for
         development  on the Airport;  and WHEREAS,  the Lessee has  submitted a
         proposal to design, construct, operate, and maintain such an
aircraft maintenance facility, and the Authority has accepted the Lessee's proposal to do so on the terms and
conditions expressed herein; and


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         WHEREAS,  the Lessee intends to utilize the proceeds of bonds issued by
the Industrial Development Authority of Loudoun County, Virginia, to finance the
development of the aircraft maintenance facility.
         NOW,  THEREFORE,   in  consideration  of  the  charges,   fees,  mutual
covenants, conditions, and agreements contained herein, the Parties hereto agree
as follows:

                          ARTICLE I - AIRPORT PREMISES
         For the  purpose  of  designing,  constructing,  financing,  operating,
maintaining,  repairing,  replacing,  renovating,  and  restoring,  an  aircraft
maintenance  facility that includes an aircraft  maintenance hangar with office,
shops,  and parts warehouse  storage,  a concrete  aircraft  parking apron,  and
automobile  parking area, the Authority  hereby demises and leases to the Lessee
and the Lessee hereby accepts and leases from the  Authority,  subject to all of
the terms  and  conditions  expressed  herein,  the plot of land on the  Airport
containing  5.64  acres  and  the  aircraft  maintenance  facility  and  related
improvements to be constructed thereon (hereinafter referred to as the "Aircraft
Maintenance  Premises") as shown on Drawing No.  2231-001,  attached  hereto and
made a part hereof as Exhibit A,  together with rights of ingress,  egress,  and
access from the North Service Road to the Aircraft Maintenance Premises.

                ARTICLE II - RIGHTS AND OBLIGATIONS OF THE LESSEE


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         A.       The   Authority   does  hereby   grant  unto  the  Lessee  the
                  nonexclusive   right  and  privilege  to  design,   construct,
                  finance,  operate,  maintain,  repair, replace,  renovate, and
                  restore,  an aircraft  maintenance  facility on the Airport on
                  behalf of the Authority, but not as the agent, representative,
                  or  partner  of  the  Authority.  The  Authority  may,  at its
                  discretion,  either  construct and operate  itself,  or permit
                  others to construct and operate,  other  aircraft  maintenance
                  facilities on the Airport.
         B.       The Authority does hereby grant unto Lessee the exclusive lease of the Aircraft Maintenance
                  Premises and the nonexclusive right to provide routine and special maintenance from the
                  Aircraft Maintenance Premises for the servicing of aircraft operated by the Lessee, aircraft
                  of other companies providing commercial air transportation of persons, property, and/or mail
                  pursuant to published schedules to and from the Airport and holding the necessary authority
                  from the appropriate Federal or state agencies to provide such air transportation services
                  (hereinafter referred to as "Scheduled Air Carriers") or Scheduled Air Carriers who have
                  executed an Airport Use Agreement and Premises Lease with the Authority (hereinafter referred
                  to as "Airlines").  The Lessee shall not have the right to perform maintenance services on
                                                       ---
                  private or corporate aircraft not used in the common carriage of passengers, cargo, or
                  freight, or aircraft used as a non-scheduled charter operation or air taxi (hereinafter
                  referred to as "General Aviation aircraft").


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         C.       The routine and special maintenance service (hereinafter referred to as "Aircraft Maintenance
                  Services") to be performed from the Aircraft Maintenance Premises shall include, but not be
                  limited to, the maintenance, servicing, testing, and modification of aircraft, including
                  without limitation the finishing, refitting, repairing, inspecting, installing, painting,
                  stripping, cleaning, rewiring, reprogramming, and replacing of components (including without
                  limitation, avionics, power plants, interiors, mechanical systems, navigation systems, and
                  communication systems); retrofitting, upgrading, refurbishing, reconfiguring, re-engining and
                  conversion of aircraft; the maintenance of such hanger, office and shop space and related
                  facilities necessary for, or related to, such activities; maintenance and repair of ground
                  support equipment including without limitation vehicles, tugs, baggage carts, special-purpose
                  vehicles and other airfield equipment; and undertaking of ground activity necessary for the
                  support of such activities.  Aircraft Maintenance Services shall also include the obtaining,
                  installing, storing, and operating of all necessary material, machinery, and equipment to
                  maintain, repair, store, and park vehicles and equipment used and necessary to support the
                  services permitted herein.  No other use may be made of the Aircraft Maintenance Premises
                  without the advanced written approval of the Authority.
         D.       The Authority  shall have the continuing  right to approve the
                  kind and scope of any  additional  activities  proposed  to be
                  conducted  on or from the  Aircraft  Maintenance  Premises  in
                  addition to those specifically referred to herein.


<PAGE>


         E.       No other commercial business or concession shall be operated on or from the Aircraft
                  Maintenance Premises unless authorized in advance by this Lease, or approved in writing by the
                  Authority.  The Lessee shall not use, or suffer or permit any person or party to use, the
                  Aircraft Maintenance Premises for any purpose not authorized under this Lease or by separate
                  written approval of the Authority.  All restrictions or requirements imposed by this Lease on
                  the Lessee shall be deemed to extend to the Lessee's agents, customers, tenants, employees,
                  contractors, subcontractors, and guarantors.  It shall be the Lessee's obligation to cause
                  these persons and parties to comply with the restrictions or requirements of this Lease.
         F.       The Lessee shall  provide,  at its own cost and  expense,  the
                  necessary  skilled  management  and  labor  to  ensure,  on  a
                  continuing basis  throughout the term of this Lease,  that the
                  Aircraft  Maintenance  Premises  is  operated  and  maintained
                  efficiently,  and in a manner  reasonably  satisfactory to the
                  Authority.


<PAGE>


         G.       The Lessee shall, at its own cost and expense, comply with all mandatory Federal, state, or
                  local laws, ordinances, rules or regulations including directives and regulations of the
                  Authority, now or hereafter in force, governing the establishment, maintenance, and operation
                  of the Aircraft Maintenance Premises.  All such ordinances, rules, or regulations shall be
                  applied in a nondiscriminatory manner, provided, provisions of future Authority directives and
                  rules and regulations, as applied to Lessee, shall not adversely affect Lessee's use of the
                  Aircraft Maintenance Premises as provided for by this Lease.  The Lessee shall obtain and pay
                  for all licenses and permits necessary for the establishment, maintenance, and operation of
                  the Aircraft Maintenance Premises by the Lessee, and shall pay all fees and charges applicable
                  to the Lessee and assessed under state, local, or Federal statutes or ordinances.


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         H.       For the purposes described in Article II hereof, and elsewhere herein, the Authority grants to
                  the Lessee, and the employees, customers, contractors, suppliers, service personnel,
                  licensees, guests, patrons, tenants, and invitees of the Lessee, without charge therefor, the
                  right of ingress to and egress from the Aircraft Maintenance Premises over the Airport roadway
                  system; PROVIDED, that such rights of ingress and egress shall at all times be exercised in
                  compliance with any and all regulations promulgated by lawful authority for the care,
                  operation, maintenance, and protection of the Airport and applicable to all users of the
                  Airport; AND PROVIDED FURTHER, that such rights of ingress and egress shall not be construed
                  to prohibit the Authority from establishing and assessing a reasonable fee or charge for the
                  privilege of entry upon the Airport when such a fee or charge is levied upon all users of the
                  Airport, nor to prohibit the Authority from assessing a fee or charge on persons conducting a
                  commercial business on the Airport; AND PROVIDED FURTHER, that in no event shall the Authority
                  prevent or impede access to the Aircraft Maintenance Premises.
         I.       The Lessee,  and the customers,  tenants,  and invitees of the
                  Lessee may make use of the runways and taxiways of the Airport
                  to gain  access to the  Aircraft  Maintenance  Premises  as is
                  permitted by the Authority's rules and regulations and subject
                  to the fees and charges  assessed  aircraft for the use of the
                  Airport.


<PAGE>


         J.       The Lessee shall abide by all airfield and other security related requirements established by
                  the Authority, which apply to the Lessee and employees, service personnel, guests, visitors,
                  contractors, patrons, and invitees of the Lessee.  The Authority is required by Federal
                  Aviation Regulations (FAR), Part 107, to, "adopt and put into use facilities and procedures
                  designed to prevent and deter persons and vehicles from unauthorized access to the "Air
                  Operations Area."  The Lessee understands that the Authority has met said requirements by
                  developing a security plan for the Airport, and the operations of the Lessee shall not
                  conflict with the security standards set forth in said plan.  The Lessee shall prepare and
                  submit for the Authority's approval, which approval shall not be unreasonably withheld, its
                  own plans to provide facilities and procedures designed to prevent and deter persons and
                  vehicles from unauthorized access to the Air Operations Area from and through any premises
                  controlled or used by the Lessee in accordance with the provisions of FAR, Part 107, and the
                  security plan for the Airport.  To meet the requirements of Part 107, the Lessee's security
                  procedures and facilities on the Aircraft Maintenance Premises shall insure positive control
                  which shall prevent the entrance of unauthorized persons and vehicles onto the Air Operations
                  Area of the Airport and shall include but not be limited to:
                  1.       Fencing and locked gates,
                  2.       Visible   identification    materials   for   persons
                           authorized to enter the Air Operations Areas,
                  3.       An  electronic  entry  control  system where gates or
                           doorways  cannot  reasonably  be controlled by locks,
                           and
                  4.  Other  facilities  and  procedures  as may  be  reasonably
required by the Authority.


<PAGE>




         K.       Prohibited Uses.  Lessee shall not use the Aircraft Maintenance Premises nor permit the same
                  ---------------
                  to be used by its customers, tenants, invitees, contractors, service personnel or employees to
                  provide services, facilities, commodities, or supplies made available through concessionaires
                  or other contractors under contract with the Authority to provide such services, facilities,
                  commodities, or supplies on the Airport ("Prohibited Uses"); provided, however, that Aircraft
                                                                               --------  -------
                  Maintenance Services, as defined in Article II.C. above, shall not be prohibited hereunder.
                  Prohibited Uses include, but are not limited to:  the providing of services, facilities,
                  commodities, or supplies now or hereafter made available through other concessionaires and
                  contractors on the Airport (other than Aircraft Maintenance Services), and the operation of
                  automobile or vehicle rental businesses, airline inflight kitchens, air cargo facilities, or
                  commercial vehicle parking for the general public.  Lessee shall not use the Aircraft
                  Maintenance Premises for the storage, transportation, disposal, discharge, or handling of any
                  hazardous substances, except for the storage, transportation, disposal, discharge, or handling
                  of such substances reasonably necessary for the conduct of Aircraft Maintenance Services.
                  Under no circumstances shall any use be made of, or conduct occur on, the Aircraft Maintenance
                  Premises, which use would cause the Aircraft Maintenance Premises or any part thereof to be
                  deemed a hazardous waste treatment, storage, or disposal facility requiring a permit, interim
                  status, or any other special authorization under any Environmental Laws.  Lessee agrees that
                  storage of aircraft fuel upon or within the Aircraft Maintenance Premises (except for fuel
                  brought on the same in fuel tanks of aircraft) is prohibited and that purchases of aircraft
                  fuel for delivery at the Airport shall be made only from service contractors authorized by the
                  Authority to deliver or sell such fuel.  All subleases involving any portion of the Aircraft
                  Maintenance Premises shall incorporate in substance the terms of this Lease.

                           ARTICLE III - TERM OF LEASE
         A.       The term of this Lease shall commence upon the date of execution by the Authority and shall
                  expire at the end of the Operating Period of the Lease.  The Operating Period of the Lease
                  shall extend for a period not to exceed twenty-six (26) years ten (10) months and twenty-one
                  (21) days from the date on which the Authority issues its occupancy permit or equivalent
                  stating that the Aircraft Maintenance Premises is ready for occupancy and use by the Lessee.
                  The Parties hereto shall establish this date in writing, and that date, when established,
                  shall begin the Operating Period.  There shall be no occupancy or use of the Aircraft
                  Maintenance Premises by Lessee for the conduct of Aircraft Maintenance Services prior to the
                  beginning of the Operating Period.



<PAGE>


                  In no event  shall  the  Operating  Period  exceed  80% of the
                  confirmed or adjusted  expected  useful  economic  life of the
                  Aircraft Maintenance  Premises. In this regard, the Lessee has
                  provided the Authority with a written appraisal, acceptable to
                  the Authority,  establishing the expected useful economic life
                  of the  Aircraft  Maintenance  Premises  at  thirty-three  and
                  six-tenths (33.6) years. Eighty percent (80%) of the 33.6 year
                  expected  useful  economic  life of the  Aircraft  Maintenance
                  Premises is the term of the  Operating  Period  stated in this
                  paragraph A.
         B.       In the event that Lessee does not comply with the schedule set forth in Article VI.C. hereof,
                  but subject to the conditions and extensions of time provided for herein, the Authority shall
                  have the option to terminate this Lease and all of Lessee's rights hereunder after such date
                  by giving sixty (60) days prior written notice of the termination to Lessee and by designating
                  any improvements on the Aircraft Maintenance Premises to be removed by Lessee.  Lessee shall
                  then, at its own expense, demolish and remove all Authority-designated improvements, including
                  the aircraft maintenance hangar building and any related improvements on the Aircraft
                  Maintenance Premises.  Upon such termination becoming effective, the Authority shall be hereby
                  relieved of its obligations hereunder and shall be free to lease the land to other parties.
         C.       Upon the  termination or expiration of this Lease,  the Lessee
                  shall  deliver  the  Aircraft   Maintenance  Premises  to  the
                  Authority  in  good   condition,   reasonable  wear  and  tear
                  excepted. Lessee shall pay to the Authority the costs, if any,
                  incurred by the  Authority to bring the  Aircraft  Maintenance
                  Premises up to such condition.


<PAGE>


D.       Lessee  understands  that  there  is  no  renewal  or  purchase  option
         contained   herein  or  otherwise  agreed  to  and  that  there  is  no
         expectation of any such renewal or purchase option.

                   ARTICLE IV - RENTAL FEES AND OTHER CHARGES
         In  consideration  of the rights and  privileges  granted  herein,  the
Lessee agrees to pay to the Authority an annual  ground  rental;  a service cost
fee; utility payments; and, if applicable,  a percentage and sublease rental fee
from the gross receipts  realized by the Lessee by virtue of providing  Aircraft
Maintenance  Services  and/or the sublease of space on the Aircraft  Maintenance
Premises to its customers as permitted by this Lease.  Except for the percentage
and sublease rental fee that is paid quarterly, all other payments shall be made
monthly,  commencing  at the beginning of the  Operating  Period and  continuing
monthly until the expiration of the term of this Lease, as follows:
         A.       Annual  Ground  Rental  - An  annual  ground  rental  shall be
                  prorated monthly and paid monthly in advance  beginning on the
                  first day of each calendar  month of the Operating  Period and
                  continuing   until  the  expiration  of  this  Lease.  If  the
                  Operating  Period  begins or this  Lease  terminates  on a day
                  other  than  the  first  day of the  month,  rental  shall  be
                  prorated  on a daily  basis for that  portion of the first and
                  last month.


<PAGE>


                  1.       The annual  ground  rental shall be calculated as the
                           appraised  market value of the land leased under this
                           Lease  times  a  seven  percent  (7%)  capitalization
                           ratio;  PROVIDED,  HOWEVER,  that  no  annual  ground
                           rental shall be charged for the land  comprising  the
                           aircraft  parking  apron on the Aircraft  Maintenance
                           Premises.
                  2.       For the initial five (5) years of the Operating Period, the Lessee shall pay an
                           annual ground rental of Sixty-Six Thousand Nine Hundred and Twelve Dollars
                           ($66,912.00) payable in monthly payments of Five Thousand Five Hundred and
                           Seventy-Six Dollars ($5,576.00)  This is calculated as (1) the initial appraised
                           market value of the land leased under this Lease at $4.85 per square foot, multiplied
                           by (2) the portion of the Aircraft Maintenance Premises to which the annual ground
                           rental applies (197,090 sq. ft.), multiplied by (3) the capitalization ratio of seven
                           percent (7%).


<PAGE>


                  3.       For the second and each of the subsequent five (5) year terms of the Operating
                           Period, the annual ground rental shall be adjusted to reflect any change in the
                           appraised market value of land leased under this Lease.  In this regard, land shall
                           be reappraised during the fifth, tenth, fifteenth, twentieth and twenty-fifth year of
                           the Operating Period to facilitate the rental adjustment.  Once the new appraised
                           market value of the land has been determined, the new annual ground rental shall be
                           calculated by multiplying 7% times the new appraised market value of the land leased
                           under this Lease to which the ground rental applies (i.e. the Aircraft Maintenance
                           Premises less the land area comprising the aircraft apron on the Aircraft Maintenance
                           Premises).  The new annual rental shall become effective and due on the first day of
                           the sixth year of the Operating Period and shall continue each and every month until
                           it is again adjusted on the first day of the eleventh, sixteenth, twenty-first and
                           twenty-sixth year of the Operating Period.  Notwithstanding the foregoing, however,
                           in no event shall the adjusted annual ground rental for any of the subsequent five
                           (5) year terms of the Operating Period be increased by more than thirty percent (30%)
                           above the annual ground rental for the immediately preceding five (5) year term of
                           the Operating Period.


<PAGE>


                  4.       The adjustments of the annual rental shall be determined by the Authority on the
                           basis of appraisals made by two (2) commercial real estate appraisers who are members
                           of the Master Appraisers Institute.  The Authority shall select one such appraiser
                           and the Lessee shall select the other, with the understanding that the fee due and
                           payable to the appraisers shall be made by the Authority and the Lessee respectively
                           to their selected appraiser.  The Aircraft Maintenance Premises shall be considered
                           as unimproved land for purpose of these appraisals.  Unimproved land shall mean land
                           with adjacent Airport infrastructure improvements, but without any leasehold
                           improvements, structures, or paving.  The appraised value shall be set at the
                           arithmetic average of the two (2) appraisals; PROVIDED, HOWEVER, that in the event
                           that such appraisals differ by more than twenty percent (20%),  the appraisers
                           selected by the Authority and Lessee shall select a third appraiser who shall
                           thereupon complete his appraisal of the Aircraft Maintenance Premises considering
                           such as unimproved land.  In the latter situation, the fair market value of the
                           Aircraft Maintenance Premises shall be computed by selecting the two (2) appraisals
                           which are closest in value, be they the two (2) highest or two (2) lowest appraisals,
                           discarding the third, and thereafter taking the arithmetic average of such appraised
                           values as in the situation where only two (2) appraisals were made.  The fee of the
                           third appraiser shall be borne equally by the Authority and the Lessee.
         B.       Service  Cost  Fee - An  annual  service  fee to  recover  the
                  allocated  costs of  services  provided  to the  Lessee by the
                  Authority  for  each  year of the  Operating  Period.  1.  The
                  service costs for the Airport shall consist of that portion of
                  the Airport's
                           annual  maintenance  and operating  costs for police,
                           fire/crash rescue,  maintenance of roads and grounds,
                           and  maintenance of the access  highway  allocated to
                           the  commercially  leased land areas of the  Airport,
                           other than the passenger


<PAGE>


                           terminals  and  airfield  buildings  and  areas.  See
                           Exhibit  B  for  the   service   cost  fees  for  the
                           commercially leased areas on the Airport for FY 1997.
                  2.       The service costs shall be established by the Authority annually to reflect the
                           latest fiscal year costs experienced by the Authority in providing these services to
                           the commercially leased areas of the Airport.  An Airport service cost per square
                           foot shall be calculated annually by dividing the total service costs experienced by
                           the Authority by the total commercially leased areas of the Airport subject to a
                           service cost fee.  The annual service cost fee for the Lessee shall then be
                           calculated as the product of the land area leased under this Lease and the service
                           cost per square foot for the commercially leased areas of the Airport.


<PAGE>


                  3.       The annual service cost fee shall be prorated on a monthly basis and paid monthly in
                           advance beginning on the first day of each calendar month of the Operating Period and
                           continuing on the first of each month until written notice is received from the
                           Authority establishing the new annual service fee.  The initial annual service fee
                           shall be Sixty-Two Thousand Six Hundred and Fifty-One Dollars ($62,651.00) payable in
                           monthly payments of Five Thousand Two Hundred and Twenty-One Dollars ($5,221)
                           beginning on the first day of the Operating Period.  If the Operating Period becomes
                           effective or terminates on a day other than the first day of the month, service costs
                           shall be prorated on a daily basis for that portion of the first and last month of
                           the Operating Period.
         C.       Percentage and Sublease Rent
                  1.       Lessee shall pay to the Authority percentage rent on the gross receipts received from
                           performing Aircraft Maintenance Services on aircraft of other Airlines and the
                           aircraft of Scheduled Air Carriers serving the Airport from the Aircraft Maintenance
                           Premises, except that percentage rent shall not be due for any Aircraft Maintenance
                           Services performed on behalf of United Airlines or any other code sharing partner,
                           any affiliate or subsidiary thereof or any successor thereto, nor for any affiliate,
                           subsidiary or successor to Lessee.  The percentage rent shall consist of eight
                           percent (8%) of the adjusted gross receipts derived by the Lessee from providing
                           Aircraft Maintenance Services.  Gross receipts shall be adjusted to first deduct the
                           acquisition cost for equipment acquired by the Lessee on behalf of its customer and
                           installed on the aircraft of its customer prior to applying the 8% fee (i.e., total
                           gross receipts received from a customer minus the cost of any equipment acquired on
                           behalf of the customer and included in gross receipts times 8% shall be the
                           percentage rent due the Authority).


<PAGE>


                  2.       The Lessee shall pay to the Authority percentage rent
                           on the gross receipts derived from performing  Ground
                           Support Equipment Maintenance Services related to the
                           maintenance  and repair of ground  support  equipment
                           such    as    vehicles,    tugs,    baggage    carts,
                           special-purpose    vehicles,   and   other   airfield
                           equipment  of other  Airlines.  The  percentage  rent
                           shall  consist  of eight  percent  (8%) of the  gross
                           receipts   received  for  Ground  Support   Equipment
                           Maintenance Services.


<PAGE>


                  3.       Subject to the provisions of Article X herein, the Lessee shall pay sublease rent for
                           approved subleases on the Aircraft Maintenance Premises to parties other than the
                           Lessee or its affiliates.  For the initial five (5) years of the Operating Period,
                           the sublease rent shall be initially established at $2.25 per square foot per year
                           times the amount of approved subleased space on the Aircraft Maintenance Premises
                           times the actual time, on a daily basis, that such sublease is in effect (i.e.,
                           sublease right is only for 3 hours per day, etc.) or eight percent (8%) of the
                           sublease rental paid to Lessee, whichever is the greater amount.  The sublease rent
                           based on percentage shall remain at 8% for the term of this Lease.  The sublease rent
                           based on a dollar rental per square foot shall be adjusted for each five (5) year
                           term of the Operating Period in accordance with the Index now known as the United
                           States Bureau of Labor Statistics, Consumer Price Index, all Urban Consumers,"
                           1982-1984 = 100 Base, All Items, U.S. City Average (hereinafter referred to as the
                           "Index").  Such adjustment shall be calculated by multiplying the sublease rent in
                           effect by the percentage increase in the Index from the Index most recently published
                           prior to the commencement of the five (5) year term of the Operating Period to the
                           Index most recently published prior to the date on which the adjustment becomes
                           effective.  Any resulting positive number shall be added to the applicable sublease
                           rent per square foot to determine the adjusted sublease rent.  In no event shall the
                           increase of the sublease rent be greater than thirty percent (30%) above the sublease
                           rent for the preceding five year term of the Operating Period.



<PAGE>


                           If such Index shall be discontinued with no successor
                           or comparable  successor  Index,  or if a substantial
                           change  is  made  in the  term  or  number  of  items
                           contained  in this Index,  or if the Index  ceases to
                           use 1982-1984 = 100 as the basis for calculation, the
                           Parties  shall  attempt  to agree  upon a  substitute
                           formula,  but if the Parties are unable to agree upon
                           a  substitute  formula,  then  the  matter  shall  be
                           determined  by  arbitration  in  accordance  with the
                           rules of the American  Arbitration  Association  then
                           prevailing.

                           The  percentage  and  sublease  rent for each quarter
                           shall  be due  and  payable  on or  before  the  15th
                           calendar day  following the close of each quarter for
                           the  previous  quarter's  activity.  The Lessee shall
                           submit a statement on or before the 15th calendar day
                           following the close of each quarter,  certified to be
                           true by the  signature of an  authorized  official of
                           the Lessee,  that  details the  Lessee's  total gross
                           receipts and the  calculation  of the  percentage and
                           sublease rent due the Authority. Certified statements
                           shall be required each quarter, regardless of whether
                           the Lessee has any gross receipts to report.


<PAGE>


         D.       Utility Service Payments - The Authority shall furnish to the Lessee all utilities (including,
                  ------------------------
                                                                                                          without
                                                                                                          limitation,
                                                                                                          electricity,
                                                                                                          gas,
                                                                                                          water,
                                                                                                          and
                                                                                                          sanitary
                                                                                                          sewer)
                                                                                                          required
                                                                                                          for
                                                                                                          the
                                                                                                          use
                                                                                                          and
                                                                                                          operation
                                                                                                          of the
                                                                                                          Aircraft
                                                                                                          Maintenance
                                                                                                          Premises
                                                                                                          as
                                                                                                          contemplated
                                                                                                          by
                                                                                                          this
                                                                                                          Lease.
                                                                                                          In
                                                                                                          addition
                                                                                                          to the
                                                                                                          annual
                                                                                                          ground
                                                                                                          rental,
                                                                                                          service
                                                                                                          cost
                                                                                                          fee,
                                                                                                          and
                                                                                                          percentage
                                                                                                          and
                                                                                                          sublease
                                                                                                          rent
                                                                                                          stated
                                                                                                          above,
                                                                                                          the
                                                                                                          Lessee
                                                                                                          shall
                                                                                                          pay
                                                                                                          the
                                                                                                          Authority
                                                                                                          as
                                                                                                          additional
                                                                                                          rent
                                                                                                          an
                                                                                                          amount
                                                                                                          necessary
                                                                                                          to pay
                                                                                                          for
                                                                                                          all
                                                                                                          utilities
                                                                                                          (electricity,
                                                                                                          gas,
                                                                                                          water,
                                                                                                          and
                                                                                                          sanitary
                                                                                                          sewage)
                                                                                                          furnished
                                                                                                          by the
                                                                                                          Authority
                                                                                                          to the
                                                                                                          Aircraft
                                                                                                          Maintenance
                                                                                                          Premises.
                                                                                                          Charges
                                                                                                          for
                                                                                                          utilities
                                                                                                          consumed
                                                                                                          by the
                                                                                                          Lessee
                                                                                                          shall
                                                                                                          be
                                                                                                          reasonably
                                                                                                          established
                                                                                                          by the
                                                                                                          Authority
                                                                                                          and be
                                                                                                          consistent
                                                                                                          with
                                                                                                          like
                                                                                                          charges
                                                                                                          assessed
                                                                                                          other
                                                                                                          users
                                                                                                          of the
                                                                                                          utilities
                                                                                                          on the
                                                                                                          Airport.

                  Utility  costs for the  Airport  consist  of system  costs and
                  invoice  costs.  System  costs  are  those  derived  from  the
                  maintenance and operation of the utility  distribution  system
                  and  invoice  costs  are the  Authority's  cost  of  acquiring
                  utilities from the utility  providers.  The system and invoice
                  costs are combined and divided by the previous  year's utility
                  consumption  to derive the utility rate for each utility.  The
                  utility rates are applied to Lessee's  metered  consumption to
                  derive the utility charges due the Authority.

                  Payment  for  utilities  shall  be made by the  Lessee  within
                  thirty  (30)  calendar  days from  receipt  of  billing by the
                  Authority.  The  utility  rates  may be  changed  periodically
                  during the term of this Lease.  The Authority agrees to notify
                  the Lessee in writing of changes in utility rates prior to the
                  effective date of such changes.


<PAGE>




         E.       Project Rental - With respect to the financing of the Aircraft Maintenance Premises, the Lessee
                  --------------
                  shall also pay Project Rental (i)  in the amount of the principal and interest on the bonds
                  ("Bonds") or the portion of the purchase price corresponding thereto, to be issued by the
                  Industrial Development Authority of Loudoun County, Virginia ("the IDA") or (ii)  if the Bonds are
                  secured by a letter of credit or similar credit enhancement (the "Credit Facility") that will be
                  drawn upon to pay principal and interest and the purchase price of the Bonds, in an amount equal
                  to the amount necessary to reimburse the issuer of the Credit Facility (the "Credit Facility
                  Provider"), or any guarantor of such obligations of the Lessee (the "Guarantor"), for draws under
                  the Credit Facility to pay principal and interest and the purchase price of the Bonds.  A pro rata
                  portion of the Project Rental that corresponds to the principal of the Bonds, or the portion of a
                  drawing under the Credit Facility that corresponds to principal on the Bonds, shall be allocable
                  to, and shall accrue in, for tax purposes, each year of the Operating Period during which Project
                  Rental is paid.  Such Project Rental shall be payable in the amounts and at the times necessary to
                  make all payments due to the IDA and the Credit Facility Provider and the Guarantor.  The
                  Authority hereby assigns the Project Rental to the IDA and the Credit Facility Provider and the
                  Guarantor and the Lessee is hereby directed to pay such Project Rental to or at the direction of
                  the IDA; provided, however, that as long as the Credit Facility remains outstanding or any amounts
                  are owed the Credit Facility Provider or the Guarantor (and the Credit Facility Provider has not
                  failed to pay a drawing in strict compliance therewith) the Lessee is directed to pay such amount
                  to, or as directed by, the Credit Facility Provider and Guarantor.  Except for the above
                  direction, the Authority shall not have any liability for the payment of any principal of,
                  interest on, or other costs due on the Bonds or amounts due the Credit Facility Provider or
                  Guarantor.  Notwithstanding any other provision contained herein to the contrary, any requirement
                  for the payment of Project Rental shall terminate upon the repayment in full of the Bonds, or
                  other satisfaction of the indebtedness thereunder, including, without limitation, pursuant to any
                  foreclosure or other remedial action by or on behalf of the holders of such Bonds; provided that
                  such obligation shall not terminate without the written consent of the Guarantor and the Credit
                  Facility Provider unless the Credit Facility has terminated and all amounts owed to the Guarantor
                  and the Credit Facility Provider have been paid in full.
         F.       Priority of Payment
                  1.       After  the  payment  of  those  costs  necessary  for
                           maintaining  and operating  the Aircraft  Maintenance
                           Premises in accordance with Article IX hereof, Lessee
                           shall  pay the  rental  fees  and  other  charges  in
                           accordance  with  this  Article  IV in the  following
                           order or priority:
                                    First       -    Utility Service Payments
                                    Second  -        Project Rental
                                    Third      -     Annual Ground Rental and Service Cost Fee
                                    Fourth    -      Percentage and Sublease Rent


<PAGE>


                  2.       In the event that  insufficient  funds are  available
                           during any  quarter to pay all of the rental fees and
                           other charges  required under this Article IV, Lessee
                           shall  provide  the  Authority,  within  thirty  (30)
                           calendar days  following the close of the quarter,  a
                           detailed  statement  of cash  flow  for the  previous
                           month setting forth in detail all income and expenses
                           for the prior quarter, the allocation of the funds in
                           accordance  with the priority set forth  herein,  and
                           the amount accrued and due the  Authority,  including
                           any late charges.
                  3.       The Authority may, at its option,  exercise its right
                           to claim the annual performance  guarantee,  provided
                           for under Article XVI herein,  should the Lessee fail
                           to pay utility  payments and/or rental fees and other
                           charges due the  Authority  and that are greater than
                           thirty  (30)  calendar  days  past  due.  The  annual
                           renewal  of  the   performance   guarantee  shall  be
                           considered as a cost  necessary  for the  maintenance
                           and operation of the Aircraft Maintenance Premises as
                           outlined in paragraph F.1. above.
                  4.       The priority of payments set forth in this  Paragraph
                           F.  shall  apply  only  during  the  period  that the
                           initial  financing  is in  place,  as the same may be
                           modified or amended (with  Authority  approval)  from
                           time to time.


<PAGE>


         G.       All  remittances due the Authority by the terms and conditions
                  of this  Lease  shall  be made  payable  to the  "Metropolitan
                  Washington  Airports Authority" and forwarded to: Metropolitan
                  Washington  Airports  Authority,  P.O.  Box 2143,  Merrifield,
                  Virginia  22116-2143.  The certified  statements shall also be
                  forwarded to the above address.  Each payment submitted to the
                  Authority  shall  include  a  statement  that  identifies  the
                  specific  type of payment  being  made  (i.e.,  ground  rental
                  payment,  service cost fee,  percentage  and sublease rent, or
                  utility payment),  the period of time the payment covers,  and
                  the number of this Lease.

                      ARTICLE V - ESTABLISHMENT OF FACILITY


<PAGE>


         The Lessee agrees to design,  construct,  finance,  operate,  maintain,
repair,  restore,  renovate,  and replace, an aircraft  maintenance facility and
related  improvements  comprising the Aircraft Maintenance Premises on behalf of
the  Authority,  but  not  as  the  agent,  representative,  or  partner  of the
Authority,  which  will  reasonably  conform  with the scope and  quality of the
aircraft  maintenance  facility and related improvements as described herein and
presented by the Lessee to the  Authority.  The  Lessee's  total  investment  in
Aircraft  Maintenance  Premises is  estimated  to be  approximately  Ten Million
Dollars  ($10,000,000.00).  The Authority shall construct a taxiway connector to
connect the airfield (Taxiway W-2) with the Aircraft Maintenance  Premises.  The
Lessee  agrees  that  the  taxiway  connector  is to be used in  common  by such
lessee(s)  and aircraft  operators  authorized by the  Authority.  The Authority
shall cut and remove  the trees  from the  Aircraft  Maintenance  Premises.  The
Aircraft   Maintenance   Premises  may  undergo   design   changes   during  the
pre-development and development periods, and, to the extent such changes are not
within the scope of the work as described  herein,  they shall be subject to the
separate  written  approval of the Authority,  as provided for under Article VII
herein.  The  Lessee's  obligations  shall  include,  but not be  limited to the
following:
         A.       The  construction of an aircraft  maintenance  hangar building
                  with approximately 65,000 square feet of gross interior hangar
                  space and approximately  25,000 square feet of office,  shops,
                  and warehouse storage space.
         B.       The construction of a concrete aircraft parking apron adjacent
                  to the aircraft  maintenance  hangar of  approximately  48,600
                  square feet in size.
         C.       The construction of suitable open equipment  storage areas and
                  an   automobile   parking   area   adjacent  to  the  aircraft
                  maintenance  hangar  for the  employees,  customers,  tenants,
                  contractors, service personnel, and invitees of the Lessee.
         D.       The  construction  of on-site  concrete  curbing and  gutters,
                  on-site concrete  sidewalks,  the connection of gutters to the
                  Airport storm drainage  system,  exterior  lighting,  security
                  fencing  and  gates,  and   landscaping,   all  as  considered
                  necessary  for  the   development  and  use  of  the  Aircraft
                  Maintenance Premises.


<PAGE>


         E.       Connection to the dual electrical  feeder system located along
                  the North  Service  Road at an  existing  manhole  in order to
                  ensure a continuous supply of power in the event of failure of
                  the  existing  feeder or in the event the feeder  must be shut
                  down for maintenance or repairs.
         F.       The  landscaping  of the  approximately  forty  (40) foot wide
                  setback between the eastern border of the Aircraft Maintenance
                  Premises  and the  western  edge of  North  Service  Road,  in
                  accordance with the Authority's Design Manual.
         G.       A  fire   suppression   system  to   comply   with  fire  code
                  requirements for the maintenance activity conducted within the
                  hangar.
         H.       The  installation  of a Best lock keying system on all primary
                  building  entrances and mechanical  room entrances for police,
                  security, fire protection, and maintenance access.
         I.       The plans and specifications applicable to the construction of
                  the  aircraft  maintenance  facility  must show the  following
                  items and shall be subject  to the  specific  approval  of the
                  Authority,  which will not be unreasonably withheld,  prior to
                  commencement  of any  work:  1. The  design  and  construction
                  detail of the mass and facade of the aircraft maintenance
                           hangar   building,   including  the  roof,   exterior
                           lighting,   windows,   the   foundation,   the  steel
                           structure, and exterior finish material. A listing of
                           the  specifications  and capacity of the  electrical,
                           plumbing,  water, sewage, heating,  ventilating,  and
                           air conditioning systems.


<PAGE>


                  2.       The pavement section details and specifications for the concrete aircraft parking apron.
                  3.       The pavement section details and specifications of the automobile parking area and the
                           access roadway connection to the Airport roadway system.
                  4.       Architectural and landscaping plans and the exterior sign plans.
                  5.       A storm water management plan, including runoff calculations.
                  6.       The fire suppression system design and specifications for the hangar.
         J.       The latest edition of the following codes and regulations shall apply to the construction of the
                  aircraft maintenance facility:
                  1.       The 1987 Uniform Building Code of Virginia which shall have priority in the event of a
                           conflict with any other applicable code.
                  2.       1987 Building Officials and Code Administration:
                           (a)      Basic Building Code
                           (b)      Basic Mechanical Code
                           (c)      Basic Plumbing Code
                  3.       National Electrical Code.
                  4.       National Fire Protection Association's National Fire Codes.
                  5.       Uniform Federal Accessibility  Standards as published
                           in the Federal Register on August 7, 1984.
                  6.  Applicable  Federal  Aviation  Administration  Regulations
(FAR) and Advisory Circulars (AC).


<PAGE>


                  7.       Metropolitan Washington Airports O&I No. 6-3-1B, Construction and Alterations to
                           Buildings.
                  To the extent of any inconsistency between the above codes and
                  regulations  and the plans and  specifications  as approved by
                  the  Authority,   the  approved  plans  (and  any  waivers  or
                  modifications  contained  in  the  plans,  as  approved)  will
                  control.

                             ARTICLE VI - SCHEDULE FOR SUBMITTING PLANS AND SPECIFICATIONS
         The Lessee shall obtain the Authority's  written approval,  which shall
not be  unreasonably  withheld,  of final  plans  and  specifications,  prior to
commencement  of construction  work on the Aircraft  Maintenance  Premises.  The
Lessee agrees to diligently pursue the design and construction of the facility.
         A.       The Lessee has submitted preliminary plans and specifications for the facility that are acceptable
                  to the Authority.
         B.       Lessee intends to submit major design  components for approval
                  in phases.  Such  components may include,  but are not limited
                  to, the  pre-engineered  building,  site work and  mechanical,
                  electrical  and plumbing  systems.  Review of any of the plans
                  for any major  design  component  submitted  to the  Authority
                  shall  be  completed  and  approved  or   disapproved  by  the
                  Authority   within  45   calendar   days.   Any   revision  or
                  resubmission of disapproved plans


<PAGE>


                  or components  shall be made within 30 days, and the Authority
                  shall  have  14 days  to  review  such  resubmitted  plans  or
                  components.  Each  plan or  component,  when  approved,  shall
                  entitle  Lessee to proceed  with  ordering the  materials  and
                  parts and  commencing  that portion of the work.  Lessee shall
                  submit final plans and  specifications for the entire facility
                  to the  Airport  Manager  for  approval  within 120 days after
                  execution of this Lease.
         C.       Subject to the ability of Lessee to obtain necessary permits and other governmental approvals and
                  subject to other circumstances beyond Lessee's reasonable control, the Lessee agrees to commence
                  construction of the aircraft maintenance facility and to totally erect and have the facility ready
                  for occupancy within fifteen (15) months after the date of commencement of the construction;
                  PROVIDED, that the total elapsed time from the commencement of the Lease Term to completion and
                  occupancy of the facility shall be no more than two (2) years unless the construction is
                  temporarily stopped, interrupted, or otherwise handicapped or prevented for reasons beyond the
                  control and without the fault or negligence of the Lessee including, but not limited to, acts of
                  God, fire, floods, windstorms, or tornadoes.  In such a case, the applicable period of time
                  required to complete construction shall be suspended for such time as may be deemed reasonable by
                  the Authority.


<PAGE>


         D.       The construction work to be performed by or for the Lessee shall be accomplished in substantial
                  accordance with plans and specifications approved by the Authority and shall be subject to the
                  Authority's inspection and approval, both during the work and after its completion.  The Authority
                  will not unreasonably delay or interfere with Lessee's construction schedule, and to that end, the
                  Authority and its inspectors will coordinate its inspection activities with the Lessee and its
                  construction manager and/or contractor.  Whenever possible, the Authority will conduct its
                  inspections at the same time as the architect's inspection of the construction progress so that
                  any issues that may arise can be handled jointly.  The Lessee shall redo or replace, at its own
                  expense, any work not in substantial accordance with plans and specifications approved by the
                  Authority.

            ARTICLE VII - TITLE TO THE FACILITY, FIXED IMPROVEMENTS,
                                    AND OPERATING FACILITIES



<PAGE>


         A.       Title to the aircraft maintenance facility and all fixed improvements on the Aircraft Maintenance
                  Premises constructed by the Lessee under this Lease, and to any and all subsequent alterations,
                  modifications, and enlargements completed during the term of this Lease, as approved by the
                  Authority, shall, subject to the requirements of the Bonds, vest in the Authority as they are
                  constructed.  The Lessee shall have the contractual obligation to construct the improvements, in
                  accordance with the plans and specifications approved by the Authority, to a quality level which
                  is commercially reasonable, conforms to industry standards for such facilities and therefore is
                  acceptable to the Authority and shall make such corrections to the work as the Authority
                  reasonably requests.
         B.       The Lessee  shall have no right  during the term of this Lease
                  to demolish, in whole or in part, any building,  structure, or
                  fixed  improvement  constructed under the terms and conditions
                  of this Lease except with the written consent of the Authority
                  and  any  leasehold  mortgagee(s)  with  an  interest  in  the
                  building,  structure,  or fixed  improvement to be demolished,
                  which may at the discretion of the Authority be conditioned on
                  the  obligation  of  the  Lessee  to  replace  the  same  by a
                  building,  structure,  or fixed improvement  acceptable to the
                  Authority.
         C.       The Lessee and its subtenants shall have the right to lease, encumber, or own and use such trade
                  equipment, furniture, operating facilities, and trade fixtures directly related to the operation
                  at the aircraft maintenance facility, and other trade personalty as may be deemed desirable in the
                  use of the aircraft maintenance facility.  The Lessee and any subtenant or secured party, to the
                  extent of their respective interests in such personalty, shall have the right at any time to
                  remove or replace any and all thereof; PROVIDED, that any damage caused to real property by such
                  removal or replacement shall be repaired to the satisfaction of the Authority by and at the
                  expense of the Lessee.


<PAGE>



                  ARTICLE VIII - CERTIFIED COST OF CONSTRUCTION
         A.       Certified Statement
                  The  Lessee  shall,   within  180  calendar   days   following
                  commencement  of the  Operating  Period,  submit  a  certified
                  statement for the total cost of  construction  of the aircraft
                  maintenance facility and all fixed improvements constructed on
                  the  Aircraft   Maintenance  Premises  to  the  Authority  for
                  approval and in sufficient itemized detail to clearly identify
                  the  actual  sums  expended.  The  certified  statement  shall
                  identify which costs of the aircraft maintenance facility have
                  been paid from proceeds of the Bonds.
         B.       Allowable Costs of Construction to Determine Certified Costs
                  Allowable  costs of  construction  to determine  the certified
                  costs  reported  under  paragraph  A. above shall  include all
                  costs, fees, and expenses paid,  incurred or to be incurred by
                  the Lessee on behalf of the  Authority,  but not as the agent,
                  representative,  or partner of the  Authority,  in  connection
                  with the design,  development,  financing, and construction of
                  the aircraft maintenance  facility.  The costs of construction
                  shall specifically include:


<PAGE>


                  1.       Amounts  paid for all  construction,  equipment,  and
                           material costs for the aircraft  maintenance facility
                           including  the hangar,  offices,  shops,  and storage
                           warehouse  and all  equipment  attached to and made a
                           permanent part of the facility,  the aircraft parking
                           apron, and all other fixed  improvements  made on the
                           Aircraft Maintenance Premises.
                  2.       Amounts  paid  by  Lessee  to  connect  the  Aircraft
                           Maintenance  Premises to the Airport  roadway  system
                           and to extend  utility  lines  servicing the Aircraft
                           Maintenance  Premises to the Authority-owned  utility
                           service lines.
                  3.       Amounts  paid   architects,   engineers,   attorneys,
                           accountants,  consultants, and others for the design,
                           development,   financing,  and  construction  of  the
                           aircraft maintenance facility.
                  4.       Premiums  paid for all  insurance  and payment  bonds
                           required during the construction period; and
                  5.       All costs,  fees,  and expenses,  excluding  Lessee's
                           overhead,  incurred in  obtaining  and  settling  for
                           construction money financing and permanent financing,
                           as well as the interest carry applicable thereto.


<PAGE>


         C.       Neither the Lessee nor any successor in interest to the Lessee under this Lease may claim, for
                  income tax purposes, depreciation or investment credit with respect to the aircraft
                  maintenance facility or any part thereof, and the Parties acknowledge that the Authority will
                  be the owner of the entire aircraft maintenance facility and the Aircraft Maintenance
                  Premises.  An election under Section 142(b)(1)(B) of the Internal Revenue Code of 1986, as
                  amended, shall be made at the time of execution of this Lease and a copy of the election shall
                  be delivered to the Authority and the IDA.  The Authority and the Lessee shall retain copies
                  of the election in their respective records for the Operating Period.  The Lessee shall cause
                  the IDA to retain copies of the election in its records for the Operating Period.  Any
                  publicly recorded document recorded in lieu of this Lease will state in effect that neither
                  Atlantic Coast Airlines (the "Lessee") nor any successor in interest to the Lessee under this
                  Lease, between the Authority and the Lessee may claim, for income tax purposes, depreciation
                  or investment credit with respect to the aircraft maintenance facility, or any part thereof.

                           ARTICLE IX - MAINTENANCE OF THE AIRCRAFT MAINTENANCE PREMISES
         A.       The Lessee, at its sole cost and expense, shall be responsible
                  to the  Authority  throughout  the term of this  Lease for the
                  maintenance of the aircraft maintenance facility and all fixed
                  improvements  located on the  Aircraft  Maintenance  Premises,
                  except to the extent of any damage caused by the Authority, or
                  its agents,  employees,  contractors,  and  licensees,  and in
                  particular:


<PAGE>


                  1.       Lessee shall perform, on a continuous basis, all general and structural maintenance
                           upon the aircraft maintenance hangar building and all other improvements constructed
                           on the Aircraft Maintenance Premises, including exterior and interior building
                           structure, installed and operating equipment, landscaping of the Aircraft Maintenance
                           Premises and the frontage on North Service Road described in Article V.F., pavement,
                           exterior and interior lighting, fencing, and connections to the Authority-owned
                           utility service lines and to the Authority roadway.  In addition, the Lessee shall
                           perform, on a continuous basis, complete recurring maintenance services, including
                           all necessary snow removal services, janitorial and custodial services, trash removal
                           services, and any and all other related services necessary to maintain the Aircraft
                           Maintenance Premises in good condition and appearance, normal wear and tear
                           excepted.  All such maintenance shall be subject to the general monitoring by the
                           Authority to ensure a continued high quality of appearance and structural condition.


<PAGE>


                  2.       Lessee  shall,  subject to the  provisions of Article
                           XIV herein,  take timely  action to repair,  replace,
                           rebuild,  and  paint  all or any  part  of the  fixed
                           improvements    constructed    upon   the    Aircraft
                           Maintenance  Premises which may be worn,  damaged, or
                           destroyed.  All repairs or  replacements  made by the
                           Lessee  shall be of  materials,  specifications,  and
                           workmanship   at   least   equal   to  the   original
                           improvement, equipment, or material.
                  3.       Lessee shall take such care as would be reasonably prudent with respect to all fixed
                           improvements constructed upon the Aircraft Maintenance Premises, including, but not
                           limited to:  the building exteriors and interiors, the operating mechanism of
                           windows, screens,  roofs, foundations, steelwork, columns, doors, partitions, floors,
                           ceilings, inside and outside paved and unpaved areas, the aircraft parking apron,
                           pavement markings, glass of every kind, fences, landscaping, and the utility,
                           mechanical, electrical, and other systems so that at the expiration of this Lease,
                           the foregoing shall be in good condition, except for reasonable wear and tear which
                           does not materially adversely affect the efficient or proper use of any part of the
                           premises or the improvements thereon.
                  4.       Lessee shall provide complete,  proper,  and adequate
                           sanitary handling and disposal,  off the Airport,  of
                           all  trash,  garbage,  and other  refuse  caused as a
                           result  of the  operation  and  use  of the  aircraft
                           maintenance  facility  and provide  suitable  covered
                           receptacles for all trash,  garbage, and other refuse
                           on the Aircraft Maintenance Premises.


<PAGE>


                  5.       Lessee shall comply with the Authority's storm water detention requirements as well
                           as any and all Federal and state regulations addressing storm water and ensure,
                           through proper controls, that the Authority's sewerage and drainage control systems
                           are protected from contamination from toxic or hazardous waste products abandoned or
                           disposed of on the Aircraft Maintenance Premises by the Lessee or its tenants.
                           Lessee shall perform routine maintenance service on the storm water detention pond
                           located adjacent to but outside of the Aircraft Maintenance Premises until such time
                           as it may be relocated by the Authority or another party under contract to the
                           Authority.  Such routine maintenance service shall include the periodic cleaning and
                           cutting of vegetation to permit the continued operation of the storm water detention
                           pond.

                           Contractors   authorized  by  the   Authority   under
                           contract  to provide  fueling,  defueling,  handling,
                           and/or  servicing of aircraft on the Airport shall be
                           liable  to  the   Authority   for  the   containment,
                           handling, and cleanup, if necessary,  of any toxic or
                           hazardous   waste   brought   on  to   the   Aircraft
                           Maintenance Premises.  The Lessee shall not be liable
                           to the  Authority  for the  actions of the  Authority
                           contractors on the Aircraft Maintenance Premises.


<PAGE>


                  6.       Lessee shall not materially alter, modify, remove, or
                           improve the Aircraft Maintenance Premises without the
                           prior  written  approval  of  the  Authority,   which
                           approval shall not be unreasonably  withheld.  In the
                           event that an alteration,  modification,  removal, or
                           improvement  is required  to be made to the  Aircraft
                           Maintenance  Premises in order to conform  with state
                           or Federal  regulations,  the Lessee  shall make such
                           alteration,  modification, removal, or improvement at
                           its sole expense.
         B.       The Authority  shall provide all  maintenance  service for the
                  taxiway connector to the Aircraft  Maintenance  Premises.  The
                  Lessee  shall  maintain  and repair all utility  service  line
                  extensions  and  connections  to the  Authority-owned  utility
                  service  lines,  and  the  roadway   connecting  the  Aircraft
                  Maintenance Premises to the Authority's roadway system.

                         ARTICLE X - LEASEHOLD MORTGAGES


<PAGE>


         A.       The Lessee shall have the unrestricted right, from time to time, to encumber, hypothecate, or
                  mortgage its interest in this Lease and the leasehold estate created hereby under one or more
                  "Leasehold Mortgage(s)" (as hereinafter defined) to a "Leasehold Mortgagee" (as hereinafter
                  defined) without the prior consent of the Authority upon the condition, however, that all
                  rights acquired under a Leasehold Mortgage shall be subject to all the covenants, conditions,
                  and restrictions set forth in this Lease that the Lessee is required to observe, pay, and
                  perform.  The right of the Lessee to grant a Leasehold Mortgage without having to obtain the
                  consent of the Authority shall also include the refinancing of such Leasehold Mortgage and all
                  renewals, modifications, consolidations, replacements, and extensions thereof upon the
                  condition, however, that all rights acquired under such Leasehold Mortgage shall be subject to
                  the covenants, conditions, and restrictions set forth in this Lease that the Lessee is
                  required to observe, pay, and perform.  In the event a Leasehold Mortgagee or any other party
                  succeeding to the rights of the Lessee under this Lease, whether through foreclosure,
                  acceptance of an assignment or deed in lieu of foreclosure, or any possession, surrender,
                  assignment, judicial action, or any other action taken by or on behalf of a Leasehold
                  Mortgagee, the Authority agrees that this Lease shall not terminate as a result of such
                  transfer, surrender, assignment, judicial or other action and the Authority shall recognize
                  such Leasehold Mortgagee or such other party as the Lessee under this Lease in accordance with
                  the terms and provisions hereof.  As used herein, the term "Leasehold Mortgagee" shall mean:
                  (i)  any life insurance company, trust company, bank, national banking association, federal or
                  state savings and loan association, state licensed branch or agency office of a foreign bank,
                  pension plan, real estate investment trust (as defined in Section 856 of the Internal Revenue
                  Code


<PAGE>


                  of 1986 as  amended),  or other  institutional  lender  or any
                  subsidiary  or  affiliate of any of the  foregoing,  including
                  specifically, without limitation, the Credit Facility Provider
                  and its  subsidiaries  and  affiliates  who are  institutional
                  lenders, or (ii) any  noninstitutional  lender approved by the
                  Authority  which holds a Leasehold  Mortgage.  As used herein,
                  the term "Leasehold Mortgage" shall mean any mortgage, deed of
                  trust, or any other real property security instrument by which
                  the Lessee may encumber,  hypothecate, or mortgage all or part
                  of the  Lessee's  interest in this Lease and in the  leasehold
                  estate created hereby.
         B.       Should the Lessee give a Leasehold  Mortgage  encumbering  its
                  leasehold estate to a Leasehold Mortgagee,  and if there shall
                  be  delivered  to  the  Authority  a  conformed   original  or
                  certified copy of the recorded Leasehold  Mortgage  containing
                  the name and address of the Leasehold Mortgagee,  it is agreed
                  by and between the Authority and the Lessee as follows:


<PAGE>


                  (1)      The   Authority   agrees  to  provide  the  Leasehold
                           Mortgagee  with a copy of any  notice of  default  or
                           similar   kind   of   notice   served   upon   Lessee
                           simultaneously  with the giving of such notice to the
                           Lessee. No default or event of default or termination
                           of this Lease or of the Lessee's  right to possession
                           of the Aircraft Maintenance Premises or any reletting
                           of the Aircraft Maintenance Premises by the Authority
                           predicated  on the giving of any notice to the Lessee
                           shall be complete unless like notice in writing shall
                           have  been  given  to  the  Leasehold  Mortgagee  and
                           Leasehold Mortgagee has been given the cure period as
                           provided  in   subsection   B(2)   below.   Upon  the
                           expiration  of any  applicable  cure  period  for the
                           Lessee,  the  Authority  will  notify  the  Leasehold
                           Mortgagee  of the  Lessee's  failure to  effectuate a
                           cure within said cure period.
                  (2)      In the event of any  default by the Lessee  under any
                           of  the  provisions  of  this  Lease,  the  Leasehold
                           Mortgagee  will  have a period  to cure  the  default
                           beginning  on the same day as the cure  period  given
                           Lessee for remedying such default or causing it to be
                           remedied, plus, in each case, the Leasehold Mortgagee
                           will have an  additional  period of thirty  (30) days
                           after the  expiration  of the  Lessee's  cure  period
                           (such  additional  period  being  herein  called  the
                           "Extended Grace Period").


<PAGE>


                  (3)      In the event  the  Lessee  defaults  under any of the
                           provisions of this Lease,  regardless of whether such
                           default  consists  of a  failure  to  pay  rent  or a
                           failure  to do any other  thing  which the  Lessee is
                           required to do hereunder,  the  Leasehold  Mortgagee,
                           without  prejudice  to any of its rights  against the
                           Lessee, shall have the right (but not the obligation)
                           to  make  good  such  default  hereunder  within  the
                           Extended Grace Period, and the Authority shall accept
                           such   performance  on  the  part  of  the  Leasehold
                           Mortgagee  as though the same had been  performed  by
                           the Lessee;  and for such purpose,  the Authority and
                           the Lessee hereby  authorize the Leasehold  Mortgagee
                           to  enter   upon  the   Airport   and  the   Aircraft
                           Maintenance  Premises  and  to  exercise  any  of the
                           Lessee's rights and powers under this Lease.


<PAGE>




                  (4)      The term  "Incurable  Default" as used herein means a
                           default  which  cannot  be  reasonably   cured  by  a
                           Leasehold  Mortgagee  such as, by way of  example,  a
                           default  arising  out  of the  causes  set  forth  in
                           Article XII,  A.3.,  4., 5., and 6. hereof.  The term
                           "Curable Default," as used herein,  means any default
                           which is not an  Incurable  Default.  In the event of
                           any  Curable  Default by the Lessee  under any of the
                           provisions of this Lease and prior to the  expiration
                           of the Extended Grace Period, the Leasehold Mortgagee
                           may, at its option,  (a) give the  Authority  written
                           notice  that it  intends to  undertake  the curing of
                           such  Curable  Default or cause the same to be cured,
                           or to exercise  its rights to acquire the interest of
                           the Lessee in this Lease by foreclosure or otherwise,
                           and (b) tender  payment of all rental  fees and other
                           charges (except Project Rental) then due and owing to
                           the Authority prior to the expiration of the Extended
                           Grace Period.  In the event the  Leasehold  Mortgagee
                           does not give such notice to the Authority and tender
                           such  payments to the  Authority,  the  Authority may
                           proceed to  exercise  the  remedies  available  to it
                           under   Article  XII,  B.  of  this  Lease,   subject
                           nevertheless  to the  provisions of  subsection  B(5)
                           below.   Upon  the  giving  of  such  notice  by  the
                           Leasehold Mortgagee, the Authority will not terminate
                           or take any action to  effectuate  a  termination  of
                           this Lease nor reenter,  take possession or relet the
                           Aircraft  Maintenance  Premises or otherwise  enforce
                           performance  of  this  Lease  for so  long as (a) the
                           Leasehold  Mortgagee is with reasonable due diligence
                           and in good faith  engaged in effecting a foreclosure
                           of the  Leasehold  Mortgage  or the  curing  of  such
                           Curable  Default  and (b) all  rental  fees and other
                           charges  (with the  exception of Project  Rental) due
                           and owing to the  Authority  are paid;  provided that
                           the  Leasehold  Mortgagee  shall not be  required  to
                           continue such  foreclosure  proceedings or cause such
                           rental  fees and other  charges to be paid after such
                           Curable  Default is cured. In the event the nature of
                           any such Curable  Default is such that the  Leasehold
                           Mortgagee  must  take   possession  of  the  Aircraft
                           Maintenance  Premises  in order to cure such  Curable
                           Default, or there is an official  restraint,  such as
                           judicial order or administrative  order applicable to
                           the   Leasehold    Mortgagee,    including    without
                           limitation,  an  automatic  stay,  the running of all
                           applicable cure periods (including the Extended Grace
                           Period)  shall be tolled  so long as rental  fees and
                           other charges (with the exception of Project  Rental)
                           due  and  owing  the   Authority  are  paid  and  the
                           Leasehold  Mortgagee  is  diligently   attempting  to
                           obtain  relief  from  such   judicial   restraint  to
                           exercise its remedies  under the Leasehold  Mortgage.
                           Nothing  herein  shall  preclude the  Authority  from
                           terminating this Lease with respect to any additional
                           default which may occur during the  aforesaid  period
                           of  forbearance  which  is not  remedied  within  the
                           period  of  cure,  if  any,  applicable  to any  such
                           additional   default,   except  that  the   Leasehold
                           Mortgagee  shall have the same  rights  specified  in
                           this Section with respect to any additional defaults.


<PAGE>




                  (5)      In the  event of  termination  of this  Lease for any
                           reason, or in the event the Lessee's interest in this
                           Lease  shall  be  sold,   assigned,   or  transferred
                           pursuant  to the  exercise  of any  remedy  under the
                           Leasehold   Mortgage,   or   pursuant   to   judicial
                           proceedings  or an  assignment  or  deed  in  lieu of
                           foreclosure, and in the event that within thirty (30)
                           days  thereafter  the  Leasehold  Mortgagee  (or  its
                           nominee or the  purchaser,  assignee,  or  transferee
                           from the Leasehold Mortgagee or the trustee under the
                           Leasehold  Mortgage)  shall have paid or  arranged to
                           the reasonable  satisfaction of the Authority for the
                           payment of, all rental fees and other  charges  (with
                           the  exception of Project  Rental) which but for such
                           termination would have become so due and payable from
                           the date of such  termination  through  the  sixtieth
                           (60th) day thereafter, and shall have arranged to the
                           reasonable  satisfaction  of the  Authority  for  the
                           curing  of any  Curable  Default  on the  part of the
                           Lessee,  then the Authority,  within thirty (30) days
                           after receiving a written request  therefor given any
                           time  prior  to such  sixtieth  (60th)  day and  upon
                           payment of all  reasonable  expenses  incurred by the
                           Authority in connection  with the  enforcement of its
                           rights   under  this  Lease   (including   reasonable
                           attorneys'  fees),  will  execute  and deliver to the
                           Leasehold   Mortgagee   or  its  nominee  or  to  the
                           purchaser,  assignee, or transferee,  as the case may
                           be, a new lease of the Aircraft Maintenance Premises.
                           Such  new  lease  shall  be for a term  equal  to the
                           remainder  of the term of this  Lease  before  giving
                           effect to such termination,  shall be subject only to
                           encumbrances  and other  matters  existing  as of the
                           date  hereof,   and  shall   contain  the   identical
                           covenants, agreements,  conditions and limitations as
                           this  Lease,   with  the   exception   that  (a)  the
                           provisions  of Article XI, E. of this Lease shall not
                           apply,  (b) the  provisions of Article IV, C.3. shall
                           be modified as set forth in  subsection  B(10) below,
                           and  (c) if the  lessee  under  the  new  lease  is a
                           Leasehold   Mortgagee   or  a   Leasehold   Mortgagee
                           Affiliate  (as  hereinafter  defined),  the new lease
                           shall be subject to the provisions of subsection B(8)
                           below.  Upon the  execution  and delivery of such new
                           lease, the new tenant may take all appropriate  steps
                           as may be  necessary  to remove the  Lessee  from the
                           Aircraft  Maintenance  Premises,  but  the  Authority
                           shall  not be  subjected  to any  liability  for  the
                           payment of any reasonable fees (including  reasonable
                           attorney's  fees),  costs or expenses  in  connection
                           therewith.  The new  lessee  shall pay all such fees,
                           costs and expenses or, on demand,  make reimbursement
                           therefor to the Authority.


<PAGE>




                  (6)      No surrender  (except a surrender upon the expiration
                           of the term of this Lease or upon  termination by the
                           Authority  pursuant and subject to the  provisions of
                           this  Lease) by the Lessee to the  Authority  of this
                           Lease,  or  any  part  thereof,  or  of  any  of  the
                           improvements thereon, or of any interest therein, and
                           no  termination  or  rejection  of this  Lease by the
                           Lessee shall be valid or effective  without the prior
                           written consent of the Leasehold Mortgagee, which may
                           be withheld in the Leasehold Mortgagee's absolute and
                           sole discretion.  The Authority agrees that,  without
                           the prior written consent of the Leasehold Mortgagee,
                           which will not be unreasonably  withheld, it will not
                           enter into any amendment, modification, or alteration
                           of this Lease with the Lessee which is either (a) not
                           contemplated  by or  provided  for in this  Lease (it
                           being  agreed  that  amendments  to  change  a notice
                           address or to reflect the new Annual Ground Rental as
                           recalculated  and set  pursuant  to  Article IV every
                           fifth  year   during  the  term  of  this  Lease  are
                           contemplated  by or  provided  for in this  Lease and
                           therefore permitted without the prior written consent
                           of  the   Leasehold   Mortgagee)  or  (b)  which  may
                           materially   and   adversely   affect  the  Leasehold
                           Mortgagee's  interest in this Lease (it being  agreed
                           that  amendments  to  change  this  Article  X, or to
                           change the term of this Lease,  or to  introduce  new
                           categories  of rental fees and other  charges due the
                           Authority  and  not  contemplated  by this  Lease  or
                           required by  Federal,  State,  or local  laws,  or to
                           change   the  use   provisions   of  this  Lease  may
                           materially   and   adversely   affect  the  Leasehold
                           Mortgagee  and  therefore  require the prior  written
                           consent of the Leasehold Mortgagee). Furthermore, any
                           cancellation,  surrender, amendment, modification, or
                           alteration  of this  Lease  requiring  the  Leasehold
                           Mortgagee's  prior  consent,  but  made  without  the
                           Leasehold Mortgagee's prior written consent, shall be
                           null and void  and of no force or  effect.  Provided,
                           however,  the Leasehold  Mortgagee shall give written
                           notice to the Authority within thirty (30) days after
                           receiving a proposed amendment ("Proposed Amendment")
                           to this Lease from the  Authority  of its decision to
                           grant  or  withhold   its  consent  to  the  Proposed
                           Amendment.  If the Leasehold  Mortgagee withholds its
                           consent  to the  Proposed  Amendment,  it shall  also
                           specify  in  such  notice  its  reasons  therefor  in
                           detail.  If the  Leasehold  Mortgagee  does  not give
                           notice of the granting or  withholding of its consent
                           to the Proposed Amendment within such thirty (30) day
                           period,  then the Leasehold Mortgagee shall be deemed
                           to have  granted its consent  and the  Authority  and
                           Lessee may execute such amendment to this Lease.

                           In  the  event  the  Authority   disagrees  with  the
                           Leasehold   Mortgagee's   decision  to  withhold  its
                           consent to the  Proposed  Amendment on the basis that
                           such consent was unreasonably withheld (hereinafter a
                           "Dispute"),  the Authority  may elect,  within thirty
                           (30)  days  after  its   receipt  of  the   Leasehold
                           Mortgagee's  denial  of the  Proposed  Amendment,  to
                           submit the  Dispute to the same  binding  arbitration
                           procedure  afforded  the  Leasehold  Mortgagee  under
                           subsections B(8)(b)(iii), (iv), (v), (vi), (vii), and
                           (viii) of this Article X.
                  (7)      The Authority  hereby  consents to the inclusion of a
                           provision   in  the   Leasehold   Mortgage   for  the
                           assignment  of rents from  subleases  of the Aircraft
                           Maintenance Premises to the Leasehold


<PAGE>


                           Mortgagee, effective upon any default under the Leasehold Mortgage.
                  (8)      (a)      If the Lessee is in default under a Leasehold Mortgage, this Lease may be
                                    assigned  (i) to a Leasehold  Mortgagee  (or
                                    any  subsidiary  or affiliate of a Leasehold
                                    Mortgagee  or of  the  parent  company  of a
                                    Leasehold  Mortgage  ("Leasehold   Mortgagee
                                    Affiliate")  by a deed or assignment in lieu
                                    of  foreclosure  of a Leasehold  Mortgage or
                                    (ii)  to  a   Leasehold   Mortgagee,   or  a
                                    Leasehold Mortgagee Affiliate,  in each case
                                    without  the consent of the  Authority,  but
                                    otherwise   subject  to  all  of  the  other
                                    covenants,  conditions, and restrictions set
                                    forth in this Lease. In addition, this Lease
                                    may be assigned (i) by a Leasehold Mortgagee
                                    or  a  Leasehold  Mortgagee  Affiliate  to a
                                    third   party   assignee   or  (ii)  to  any
                                    purchaser  pursuant to a foreclosure sale or
                                    sale  pursuant  to  power  of  sale  under a
                                    Leasehold   Mortgage  (such  assignee  under
                                    clause  (i) or (ii)  being  herein  called a
                                    "Proposed Assignee"),  in each case with the
                                    prior  written  consent  of  the  Authority,
                                    which  consent  shall  not  be  unreasonably
                                    withheld,  but  otherwise  subject to all of
                                    the   other   covenants,   conditions,   and
                                    restrictions set forth in this Lease.


<PAGE>


                                    (b)     (i)      With regard to a proposed assignment ("Proposed
                                                     Assignment") of this Lease by a Leasehold Mortgagee or
                                                     Leasehold Mortgagee Affiliate to a Proposed Assignee, such
                                                     Leasehold Mortgagee or Leasehold Mortgagee Affiliate shall
                                                     provide or cause to be provided to the Authority, in
                                                     writing by registered or certified mail:
                                                     (A)      the name and address of the Proposed Assignee;
                                                     (B)      a detailed description of the Proposed Assignee's
                                                              business and the specific business it will conduct
                                                              on the Aircraft Maintenance Premises; and
                                                     (C)      such reasonable financial information required by
                                                              the  Authority  so
                                                              that the Authority
                                                              can  evaluate  the
                                                              Proposed  Assignee
                                                              under         this
                                                              subsection B(8).


<PAGE>


                                            (ii)     The Authority shall give written notice to the Leasehold
                                                     Mortgagee and to the Proposed Assignee within thirty (30)
                                                     days after receiving all of the information required in
                                                     subsection B(8)(b)(i) above of its decision whether to
                                                     grant or withhold its consent to the Proposed Assignment.
                                                     If the Authority withholds its consent to the Proposed
                                                     Assignment, it shall also specify in such notice its
                                                     reasons therefor in detail.  If the Authority does not give
                                                     notice of the granting or withholding of its consent to the
                                                     Proposed Assignment within such thirty (30) day period,
                                                     then the Authority shall be deemed to have granted its
                                                     consent to the Proposed Assignment and this Lease may be
                                                     assigned to the Proposed Assignee.


<PAGE>




                                            (iii)    In the event the Leasehold Mortgagee disagrees with the
                                                     Authority's decision to withhold its consent to the
                                                     Proposed Assignment on the basis that such consent was
                                                     unreasonably withheld (hereinafter a "Dispute"), the
                                                     Leasehold Mortgagee may elect, within thirty (30) days
                                                     after its receipt of the Authority's denial of the Proposed
                                                     Assignment to submit the Dispute to binding arbitration as
                                                     provided herein.  Such arbitration shall be initiated by
                                                     either the Authority or the Leasehold Mortgagee within ten
                                                     (10) days after the Leasehold Mortgagee shall have sent
                                                     written notice (an "Arbitration Notice") of a demand to
                                                     arbitrate by registered or certified mail to the Authority
                                                     and to Judicial Arbitration and Mediation Services, Inc.
                                                     ("JAMS").  The dispute shall be determined by binding
                                                     arbitration before a retired judge from the highest court
                                                     of general jurisdiction of the Commonwealth of Virginia
                                                     (the "Arbitrator") under the auspices of JAMS.  The
                                                     Authority and the Leasehold Mortgagee shall, within ten
                                                     (10) days after the initiation of the arbitration, attempt
                                                     to agree on a retired judge from the JAMS panel to serve as
                                                     the Arbitrator.  If they are unable to so agree, JAMS will
                                                     provide a list of three (3) available judges, and each
                                                     party may strike one.  The remaining judge (or if there is
                                                     more than one judge remaining, one of the remaining judges
                                                     as selected by JAMS) will serve as the Arbitrator.  If JAMS
                                                     shall no longer exist or if JAMS fails or refuses to accept
                                                     submission of the Dispute, the Dispute shall be resolved by
                                                     binding arbitration before the American Arbitration
                                                     Association ("AAA") under the AAA's commercial arbitration
                                                     rules then in effect.


<PAGE>


                                            (iv)     The Arbitrator shall schedule a pre-hearing conference to
                                                     resolve procedural matters, arrange, for the exchange of
                                                     information, obtain stipulations, and narrow the issues.
                                                     The parties will submit proposed discoveries and schedules
                                                     to the Arbitrator at the pre-hearing conference.  The scope
                                                     and duration of discovery shall be within the sole
                                                     discretion of the Arbitrator.  The Arbitrator shall have
                                                     the discretion to order a pre-hearing exchange of
                                                     information by the parties, including, without limitation
                                                     production of requested documents, exchange of summaries of
                                                     testimonies of proposed witnesses, and examination by
                                                     depositions of parties and third-party witnesses.  This
                                                     discretion shall be exercised to limit the scope of
                                                     discovery to the amount of discovery which the Arbitrator
                                                     determines to be reasonable under the circumstances.
                                            (v)      The  Arbitration  shall  be
                                                     conducted     in    Loudoun
                                                     County, Virginia. Any party
                                                     may   be   represented   by
                                                     counsel or other authorized
                                                     representative. The parties
                                                     may offer such  evidence as
                                                     is relevant and material to
                                                     the Dispute. The Arbitrator
                                                     shall   be  the   judge  of
                                                     relevance and materiality.
                                            (vi)     In  rendering  a  decision,
                                                     the    Arbitrator     shall
                                                     determine  the  rights  and
                                                     obligations  of the parties
                                                     according       to      the
                                                     substantive  and procedural
                                                     laws of the Commonwealth of
                                                     Virginia  and the terms and
                                                     provisions of this Lease.


<PAGE>


                                            (vii)    The Arbitrator shall issue the award as soon as reasonably
                                                     possible following the conclusion of the arbitration
                                                     hearing, but in no event, any later than thirty (30) days
                                                     after the conclusion of the arbitration hearing.  The
                                                     Arbitrator's award shall be based on the evidence at the
                                                     hearing, including all logical and reasonable inferences
                                                     therefrom.  The Arbitrator may make any determination
                                                     and/or grant any remedy or relief that is just and
                                                     equitable.  The award must be based on, and accompanied by,
                                                     a written decision explaining the factual and legal basis
                                                     for the award.  The award shall be conclusive and binding,
                                                     and it may thereafter be confirmed as a judgment in any
                                                     court having jurisdiction.
                                            (viii)   The  Arbitrator  may  award
                                                     costs,  including,  without
                                                     limitation,      attorney's
                                                     fees,    and   expert   and
                                                     witness    costs   to   the
                                                     prevailing party, if any is
                                                     determined      by      the
                                                     Arbitrator      in      the
                                                     Arbitrator's    discretion.
                                                     The  Arbitrator's  fees and
                                                     costs  shall be paid by the
                                                     non-prevailing   party   as
                                                     determined      by      the
                                                     Arbitrator  in  his  or her
                                                     discretion.


<PAGE>






                                            (ix)     Commencing on the date that the Arbitration Notice shall
                                                     have been given, and continuing through and including the
                                                     date on which the Arbitrator shall issue the award with
                                                     respect to the Dispute (the "Award Date"), the obligation
                                                     to pay all rental fees and other changes due and owing
                                                     under this Lease for such period shall be suspended (the
                                                     "Suspended Rent").  If the decision of the Arbitrator shall
                                                     be that the Authority shall not have unreasonably withheld
                                                     its consent to the Proposed Assignment, then the Leasehold
                                                     Mortgagee shall pay the Suspended Rent to the Authority
                                                     within ten (10) days after the Award Date, together with
                                                     interest at the rate of eight percent (8%) per annum from
                                                     and after the date each portion of the Suspended Rent would
                                                     have otherwise been due and payable under this Lease.  In
                                                     the event the Arbitrator's award shall determine that the
                                                     Authority unreasonably withheld its consent to the Proposed
                                                     Assignment, then (A)  this Lease may be assigned to the
                                                     Proposed Assignee that was the subject of the Dispute and
                                                     (B)  no rental fees or other charges shall be due or owing
                                                     under the Lease for the period commencing on the date the
                                                     Arbitration Notice shall have been given and continuing
                                                     through and including (1)  the date on which the Proposed
                                                     Assignee that was the subject of the Dispute shall become
                                                     the Lessee under this Lease pursuant to an assignment
                                                     hereof or 30 days after the date of the Arbitrator's award,
                                                     whichever comes first, or (2)  if this Lease is not
                                                     assigned because the Authority unreasonably withheld its
                                                     consent to the Proposed Assignment to such Proposed
                                                     Assignee and through no fault of the Leasehold Mortgagee or
                                                     the Leasehold Mortgagee Affiliate, the date on which this
                                                     Lease is assigned with the consent of the Authority to a
                                                     subsequent Proposed Assignee.  All rental fees and other
                                                     charges payable hereunder shall once again commence to
                                                     accrue from and after the effective date of such assignment
                                                     (whether to the Proposed Assignee that was the subject of
                                                     the Dispute or a subsequent Proposed Assignee).
                                            (x)      Unless the Authority and a Leasehold Mortgagee otherwise
                                                     agree in writing, the Authority and a Leasehold Mortgagee
                                                     shall have no right to resolve a Dispute in a manner which
                                                     is contrary to the provisions of this subsection B(8)(b).
                                                     The parties shall at all times conduct themselves in
                                                     accordance with the terms of this subsection B(8)(b), and
                                                     all attempts to circumvent the terms of this subsection
                                                     B(8)(b) shall be absolutely null and void and of no force
                                                     or effect whatsoever.


<PAGE>




                                    (c)     The ultimate assignee of this Lease shall assume the Lessee's
                                            obligations under this Lease, including, without limitation, the
                                            payment of all rental fees and other charges (with the exception of
                                            Project Rental) as they become due, and an executed counterpart of
                                            such assumption shall be delivered to the Authority.  If the
                                            Leasehold Mortgagee (or a Leasehold Mortgagee Affiliate) shall be
                                            the assignee of this Lease, its liability under such assumption
                                            agreement shall be limited to the period of ownership of this
                                            Lease, provided that the party to whom this Lease is assigned by
                                            the Leasehold Mortgagee (or a Leasehold Mortgagee Affiliate) shall
                                            deliver to the Authority at the time of such assignment a like
                                            assumption agreement, but without limitation as to duration of
                                            liability.  Furthermore, the Authority expressly agrees that it
                                            shall look solely to the estate and property of a Leasehold
                                            Mortgagee (or a Leasehold Mortgagee Affiliate) created under this
                                            Lease for the collection or enforcement of any judgment (or other
                                            judicial process), requiring the payment of money or the
                                            performance of any obligation by a Leasehold Mortgagee (or such
                                            Leasehold Mortgagee Affiliate) as the lessee of the Aircraft
                                            Maintenance Premises in the event of any default or breach by a
                                            Leasehold Mortgagee (or such Leasehold Mortgagee Affiliate) as the
                                            lessee of the Aircraft Maintenance Premises with respect to any of
                                            the terms and provisions of this Lease to be observed or performed
                                            by it; and no other assets of the Leasehold Mortgagee (or a
                                            Leasehold Mortgagee Affiliate) shall be subject to levy, execution,
                                            or other judicial process for the satisfaction of the Authority's
                                            claim.
                  (9)      Notwithstanding  anything  contained in this Lease to
                           the  contrary,  during  such  period  of  time  as  a
                           Leasehold   Mortgagee   (or  a  Leasehold   Mortgagee
                           Affiliate)  shall be the Lessee under this Lease, the
                           Leasehold   Mortgagee   (or  a  Leasehold   Mortgagee
                           Affiliate)  shall not be required to operate and keep
                           open  for   business  any  portion  of  the  Aircraft
                           Maintenance  Premises,  provided  that the  Leasehold
                           Mortgagee (or the Leasehold  Mortgagee  Affiliate) is
                           using  reasonable  efforts  in  cooperation  with the
                           Authority to find a replacement lessee to operate the
                           Aircraft Maintenance Premises.


<PAGE>


                  (10)     Notwithstanding  anything  contained in this Lease to
                           the  contrary,  upon and after the  foreclosure  of a
                           Leasehold Mortgage or the conveyance or assignment of
                           this Lease and the leasehold estate created hereby to
                           the  Leasehold   Mortgagee  or  Leasehold   Mortgagee
                           Affiliate in lieu of foreclosure:  (a) the provisions
                           of  Article  XI,  E.,  appearing  on  page 66 of this
                           Lease,  which  limits  the  total  space  within  the
                           aircraft  maintenance  hangar  which  shall  be under
                           sublease at any one time,  shall  terminate and be of
                           no further force or effect, and (b) the provisions of
                           Article   IV.C.3.   pertaining   to  the  payment  of
                           percentage  and sublease rent shall apply only if any
                           lessee,   sublessee,  or  occupant  of  the  Aircraft
                           Maintenance Premises or any part thereof is providing
                           aircraft  maintenance  services  to third  parties or
                           subleasing space to third parties and not for its own
                           account.  Any airline  utilizing  all or a portion of
                           the Aircraft Maintenance Premises for the maintenance
                           and  servicing  of its own fleet  shall not be liable
                           for  percentage  and sublease  rent under this Lease.
                           Any  firm  providing  maintenance  services  to third
                           parties,   including   warranty  work   performed  by
                           manufacturers,  shall be subject to and liable to pay
                           percentage  rent and  sublease  rent if it  subleases
                           space to third  parties in  accordance  with  Article
                           IV.C.3.


<PAGE>


                  (11)     There  shall be no merger of the  Lessee's  leasehold
                           estate with the leasehold estate or fee estate in the
                           land upon which the Aircraft  Maintenance Premises is
                           located  by  reason  of the fact  that  the  Lessee's
                           leasehold  estate may be held  directly or indirectly
                           by or for the  account  of any  person who shall also
                           hold directly or indirectly  the greater  estate,  or
                           any interest in such greater estate,  nor shall there
                           by any such  merger by reason of the fact that all or
                           any  part of the  Lessee's  leasehold  estate  may be
                           conveyed or  mortgaged to a Leasehold  Mortgagee  who
                           shall also hold directly or  indirectly  such greater
                           estate,  or any part thereof,  in the land upon which
                           the Aircraft  Maintenance Premises are located or any
                           interest of the Authority under this Lease.
                  (12)     The provisions of Article X, Sections A and B are for
                           the  benefit  of,  and are to be  enforceable  by,  a
                           Leasehold Mortgagee.
                  (13)     In the event  that  there is more than one  Leasehold
                           Mortgage  encumbering  the leasehold  estate  created
                           hereby,  the most senior  Leasehold  Mortgagee  shall
                           have priority in terms of exercising  the rights of a
                           Leasehold  Mortgagee  pursuant to the  provisions  of
                           this Section.


<PAGE>


                  (14)     The   Authority   and  the  Lessee  hereby  agree  to
                           cooperate  in  including  in this Lease,  by suitable
                           amendment from time to time, any provision  which may
                           reasonably  be requested  by any  proposed  Leasehold
                           Mortgagee  for  the  purpose  of   implementing   the
                           Leasehold Mortgagee  protection  provisions contained
                           in this Lease and allowing such  Leasehold  Mortgagee
                           reasonable  means to protect and to preserve the lien
                           of the  Leasehold  Mortgage on the  occurrence  of an
                           event of default under this Lease.  The Authority and
                           the Lessee each agrees to execute and deliver (and to
                           acknowledge,  if necessary,  for recording  purposes)
                           any  agreement   necessary  to  effectuate  any  such
                           amendments;  provided,  however,  any such amendment,
                           shall not in any way affect  the term or rental  fees
                           and other  charges due the  Authority or grant to the
                           Lessee rights  prohibited  ("Prohibited  Uses") under
                           this Lease,  nor  otherwise in any  material  respect
                           adversely  affect any rights of the  Authority  under
                           this Lease,  or the rights  heretofore  granted other
                           lessees on the Airport by the Authority.

                     ARTICLE XI - ASSIGNMENT AND SUBLETTING


<PAGE>


         A.       Assignment and Sublease by Lessee.  Except as otherwise provided in this Lease, Lessee
                  ---------------------------------
                  covenants that it shall not assign, transfer, convey, sell, mortgage, pledge or encumber
                  (hereinafter collectively referred to as an "assignment") or sublet the Aircraft Maintenance
                  Premises or any part thereof, or any rights of the Lessee hereunder or allow the use of the
                  Aircraft Maintenance Premises by any other person without the prior written consent of the
                  Authority.  Such consent shall not be unreasonably withheld.  Provided, however, that without
                  such consent Lessee may assign its rights under this Lease to any corporation with which
                  Lessee may merge or consolidate or to any corporation with which there is common ownership.
                  Consent by the Authority to any type of transfer described in this Article or elsewhere in
                  this Lease shall not in any way be construed to relieve Lessee from obtaining further
                  authorization from the Authority for any subsequent transfer of any nature whatsoever.  If
                  Lessee fails to obtain prior written approval of any such assignment or sublease, the
                  Authority shall have the right to refuse to recognize the assignment or sublease and the
                  assignee or sublessee shall acquire no interest in this Lease or any rights to use the
                  Aircraft Maintenance Premises;
         B.       Notwithstanding any assignment, sublease or any other transfer
                  of the Aircraft  Maintenance Premises or any rights under this
                  Lease,  Lessee shall remain fully and primarily liable for the
                  payment of all rental fees and other charges due hereunder and
                  fully  responsible  for the  performance  of all of its  other
                  obligations  hereunder until expressly  released in writing by
                  the Authority, subject to the provisions of Article X herein.


<PAGE>


         C.       Lessee,  when  requesting  an  approval  of an  assignment  or
                  sublease  agreement under Paragraph A., shall include with its
                  request a copy of the proposed  agreement,  if prepared,  or a
                  detailed  summary of the material  terms and  conditions to be
                  contained  in  such  agreement.   Any  proposed  agreement  or
                  detailed   summary   thereof   shall   provide  the  following
                  information:
                  1.       The Premises to be assigned, sublet or used;
                  2.       The terms;
                  3.       If a sublease, the rentals and fees to be charged;
                  4.       If a sublease,  a provision that the subtenant  shall
                           use its  subleased  premises  for only the  permitted
                           usage herein unless  otherwise  authorized in writing
                           by the Authority,  that the term shall not exceed the
                           unexpired  term of this Lease,  and that the sublease
                           shall be subject to and subordinate to this Lease;
                  5.       All  other  material  terms  and  conditions  of  the
                           assignment or sublease  agreement  that the Authority
                           may reasonably require.
         D.       The  Authority  shall  provide  written  notice to the  Lessee
                  within   thirty  (30)   calendar   days  of  its  approval  or
                  disapproval  of  the  proposed  assignment  or  sublease.   If
                  approved,  Lessee shall submit a fully  executed  copy of such
                  agreement to the  Authority  within  thirty (30) days prior to
                  the commencement of the assignment or sublease.
         E.       Notwithstanding the Authority's approval of subleases, no more
                  than  forty-nine  percent  (49%) of the total space within the
                  aircraft maintenance hangar shall be under sublease at any one
                  time, subject to the provisions of Article X herein.


<PAGE>


         F.       If any transfer of Lessee's interest hereunder shall occur, whether or not prohibited by this
                  Article XI, the Authority may elect to collect the rental fees and other charges due pursuant
                  to Article IV hereof from any assignee, sublessee or other transferee of Lessee and in such
                  event shall apply the net amount collected to the rental fees and other charges payable by
                  Lessee hereunder, PROVIDED, HOWEVER, such action by the Authority shall not release Lessee
                  from this Lease or any of its obligations hereunder.  If any transfer of interest prohibited
                  by this Article XI shall occur without authorization of the Authority and the Authority
                  collects rental fees and other charges from any assignee, sublessee or transferee of Lessee
                  and applies the net amount collected in the manner described in the preceding sentence, such
                  actions by the Authority shall not be deemed to be a waiver of the covenant contained in this
                  Article or constitute acceptance of such assignee, sublessee or other transferee by the
                  Authority.


<PAGE>


         G.       The  Authority  may elect in an assignment or transfer of this
                  Lease to permit the  release of the Lessee from any and all of
                  its  obligations  hereunder and thereafter  look solely to the
                  assignee to perform  all  obligations  of this  Lease.  Such a
                  release  of  the  Lessee  by  the  Authority   shall  only  be
                  considered  if the  Authority is satisfied  with the financial
                  suitability of the assignee, the capability of the assignee to
                  perform all  obligations  of Lessee  under the Lease,  and the
                  absence of conflict with any other rights granted the assignee
                  or other parties on the Airport by the Authority.

                   ARTICLE XII - TERMINATION BY THE AUTHORITY
         A.       The Lessee shall be deemed to be in default hereunder upon the
                happening of any of the following events and subsequent  failure
                of the  Lessee to cure,  or  commence  and  diligently  continue
                thereafter reasonable efforts to cure, the default, condition or
                event within thirty (30)  calendar days after written  notice by
                the Authority to the Lessee and any Leasehold Mortgagee or other
                financing  party  identified  under this Lease:  1. The material
                failure of the Lessee to  perform,  keep,  or observe any of the
                material
                         terms,   requirements,   and  conditions  which  it  is
                         obligated  to  perform,  keep,  or  observe  under this
                         Lease,  including  the payment of rental fees and other
                         charges due the Authority  (excluding  Project  Rental)
                         and the  Lessee's  failure  to  enforce  provisions  of
                         tenant sublease agreements.
                2.       The conduct by the Lessee of business activities on the
                         Aircraft  Maintenance  Premises not  authorized by this
                         Lease or approved in writing by the Authority.
                3.       The  occurrence  of any act by the  Lessee  or  persons
                         acting through the Lessee which operates to deprive the
                         Lessee   permanently   of  the  rights,   powers,   and
                         privileges  necessary  for the  proper  conduct  of its
                         rights and obligations under this Lease.


<PAGE>


                  4.       The abandonment of the Aircraft  Maintenance Premises
                           by  the   Lessee  or   Lessee's   failure  to  pursue
                           completion  of  the  aircraft   maintenance  facility
                           within  the time  requirements  set forth in  Article
                           VI.C.
                  5.       Any event of insolvency of the Lessee, including, but
                           not  limited  to, an  assignment  for the  benefit of
                           creditors,  or the filing of a bankruptcy petition by
                           Lessee.
                  6.  Termination  by the Authority of the Lessee's  Airport Use
         Agreement  and  Premises  Lease.  B. If the Lessee is in default  under
         paragraph A. above, subject to the applicable provisions under
                  Article X, the Authority may exercise any of the following remedies that it, in its sole
                  discretion, shall elect:
                  1.       The Authority may terminate this Lease in its entirety or as to any portion of the
                           rights and premises covered hereby.  Upon termination
                           hereunder  in  its  entirety  by the  Authority,  all
                           rights,  powers,  and  privileges of the Lessee under
                           this  Lease  shall   cease,   and  the  Lessee  shall
                           immediately  vacate any and all space  occupied by it
                           under this Lease. A partial termination,  if elected,
                           shall be reasonably limited to the part of this Lease
                           affected by the default.
                  2.       If the  Lease  is  terminated  under  paragraph  A.4.
                           above,  Lessee shall, at the option of the Authority,
                           and at Lessee's  expense,  demolish and remove any or
                           all   improvements   on  the   Aircraft   Maintenance
                           Premises,  including the aircraft  maintenance hangar
                           building and other related improvements.


<PAGE>


                  3.       Upon  termination  as  provided  in  paragraph  B. 1.
                           above,  the Authority may by use of reasonable  means
                           reenter   and  take   possession   of  the   Aircraft
                           Maintenance Premises occupied by the Lessee, by legal
                           process,  and  expel,  oust,  and  remove any and all
                           parties who occupy any portion of the premises on the
                           Airport covered by this Lease,  and any and all other
                           parties  that may be  found  in or upon the  Aircraft
                           Maintenance Premises.
                  4.       The Authority may, contemporaneously with termination
                           hereunder,   designate   a   replacement   lessee  to
                           purchase,  and the Lessee shall sell,  its  leasehold
                           interest in the  Aircraft  Maintenance  Premises at a
                           cash price (the  "Leasehold  Purchase  Price") not to
                           exceed the  amount  outstanding  under any  Leasehold
                           Mortgages.


<PAGE>


                  The portion of the Leasehold  Purchase Price  attributable  to
                  costs that have been financed out of the proceeds of the Bonds
                  shall  be  paid  to or at the  direction  of the  IDA.  If the
                  Aircraft Maintenance Premises will be leased to another entity
                  that  assumes  the  Lessee's  obligation  to  pay  the  amount
                  outstanding  on  the  Bonds,  the  Leasehold   Purchase  Price
                  attributable  to costs  that  have  been  financed  out of the
                  proceeds of the Bonds shall be zero. If the Authority does not
                  initially  designate  a  replacement  lessee to  purchase  the
                  Lessee's interest,  the Lessee shall have the right,  provided
                  that the  Lessee  maintains  in good  condition  the  Aircraft
                  Maintenance  Premises for such  period,  within six (6) months
                  thereafter  to sell or  otherwise  transfer  its interest to a
                  third party ("Buyer") acceptable to the Authority on terms and
                  conditions  which  require  that the Buyer  assume  all of the
                  obligations of the Lessee under this Lease,  commencing on the
                  date of transfer of the  Lessee's  interest to the Buyer.  The
                  Authority's   approval  of  the  Buyer,  which  shall  not  be
                  unreasonably  withheld,  shall be  conditioned  on the  Lessee
                  first meeting all payment  obligations to the Authority  under
                  the terms of the  Lease  from the date of  termination  to the
                  date of transfer of the Lessee's interest to the Buyer. In the
                  event the Lessee is unable to sell or  otherwise  transfer its
                  interest within such period,  the Authority shall use its best
                  efforts to find a purchaser  and the Lessee shall be obligated
                  to  sell  its  interest  to any  purchaser  identified  by the
                  Authority at the Leasehold Purchase Price.
         C.       Any action or  forbearance  of action  taken by the  Authority
                  hereunder  shall  not be  deemed a  waiver  of any  claim  for
                  damages that the  Authority may have against the Lessee or the
                  Lessee's  assignees.  The Authority  shall also be entitled to
                  maintain  an action at law or in equity  against the Lessee or
                  Lessee's assignees for damages, specific performance, or other
                  remedies available under applicable law.

                    ARTICLE XIII - TERMINATION BY THE LESSEE
         This Lease shall be subject to  termination,  in its  entirety,  by the
Lessee,  upon the happening of any one or more of the  following  events and the
subsequent  failure of the Authority to remove or correct the  condition  within
the sixty (60) calendar days after written notice to the Authority:


<PAGE>


         A.       Any  act on the  part  of the  Authority,  the  lessor  of the
                  Authority,  or any party  claiming by,  through,  or under the
                  Authority,   which  prevents  or  substantially  and  directly
                  restricts the use of the Aircraft  Maintenance  Premises for a
                  period of at least 120 consecutive days.
         B.       Any acts of God, civil commotion,  acts of the military power,
                  damage to runways,  or other  similar  causes which operate to
                  prevent or  substantially  restrain  use of the  Airport for a
                  period of at least 120 consecutive days.

         In no event  shall the Lessee  terminate  this Lease  without the prior
written consent of the leasehold  mortgagee for so long as a leasehold  mortgage
remains outstanding with respect to the Aircraft  Maintenance  Premises.  In the
event this Lease is terminated for reasons set forth in this Article, the Lessee
shall have the same rights with respect to buyout of its  leasehold  interest in
the Aircraft  Maintenance Premises granted in Article XII herein, and shall also
be entitled to maintain an action at law or in equity  against the Authority for
damages, specific performance, or other remedies available under applicable law.

                   ARTICLE XIV - DESTRUCTION AND IMPROVEMENTS


<PAGE>


         A.       In the event that the Aircraft Maintenance Premises is damaged or destroyed, in whole or in part,
                  by fire, explosion, acts of God, or any other cause, the Lessee agrees, with due diligence, to
                  restore, repair, and rehabilitate any and all damage to the Aircraft Maintenance Premises as
                  nearly as possible to the value and character of the facilities existing immediately prior to
                  such damage or destruction.  If the Aircraft Maintenance Premises is not tenantable or usable by
                  the Lessee for fifty percent (50%) or more of the building space within the Aircraft Maintenance
                  Premises, the term of this Lease shall be extended for the time required to repair or restore the
                  Aircraft Maintenance Premises to a condition existing prior to the occurrence of the damage.  The
                  time of extension, if any, shall be computed from the date of destruction, fire, or damage to the
                  date that a certificate of occupancy is issued certifying that the damage involved has been
                  repaired and the facilities are ready for the use by the Lessee; PROVIDED, HOWEVER, any such
                  extension of the term of this Lease to repair damaged facilities on the Aircraft Maintenance
                  Premises shall not extend beyond June 6, 2037.  If all or a portion of the Aircraft Maintenance
                  Premises is not tenantable during a period of restoration, the Authority shall make an equitable
                  adjustment to the ground rental and service cost fee due the Authority in proportion to the
                  percentage of the building space within the Aircraft Maintenance Premises that remains fit for
                  occupancy or use.


<PAGE>


         B.       The Lessee shall have the right to cancel and terminate this Lease during the last five (5) years
                  of the Operating Period, if the Aircraft Maintenance Premises is damaged or destroyed by fire,
                  explosion, acts of God, or any other cause beyond the control of the Lessee, to an extent in
                  excess of fifty percent (50%) as determined by an independent adjuster, of the then fully
                  insurable replacement value thereof, or to a lesser extent should the Parties hereto agree that
                  continued use and operation of the Aircraft Maintenance Premises is not feasible.  In the event
                  this Lease is canceled or terminated as provided for under this paragraph B., the Lessee shall
                  pay all fees and other charges due the Authority, as provided for under Article IV herein, to the
                  date of cancellation or termination of this Lease and shall cause the distribution of insurance
                  proceeds in the following order:  (i) first, to pay amounts outstanding for any Bonds and/or
                  leasehold mortgages, (ii) second, to remove debris and restore the grounds on the Aircraft
                  Maintenance Premises, (iii) third, to pay, in cash, the Authority an amount equal to the
                  Authority's interest in the replacement value of the Aircraft Maintenance Premises, and (iv) the
                  balance, if any, to the Lessee.  The method of determining the Authority's interest in the
                  replacement value of the Aircraft Maintenance Premises shall be calculated as the expired or
                  amortized percentage of the Operating Period on the date the Lease is canceled or terminated
                  times the total amount of replacement insurance proceeds available prior to distribution.  (e.g.,
                  The Lease is canceled or terminated on the first day of the twenty-sixth year of the Operating
                  Period and the replacement insurance proceeds total $15,000,000.  Therefore the amount due the
                  Authority under this example, assuming a thirty (30) year Operating Period, would be
                  .833 x $15,000,000 = $12,500,000 assuming the sum under (i) and (ii) above is $2,500,000 or less).


<PAGE>


         C.       The insurance proceeds from the policies of insurance provided
                  by the  Lessee  shall  be  held  in  trust  by  the  Leasehold
                  Mortgagee  and used  for the  sole  purpose  of  repairing  or
                  replacing  the  damaged  or  destroyed  Aircraft   Maintenance
                  Premises,  or  distributed  as provided in  paragraph B. above
                  should the Lease be canceled or  terminated  and the  Aircraft
                  Maintenance Premises not restored.

                   ARTICLE XV - INSURANCE AND INDEMNIFICATION
         A.       The Lessee shall continuously  provide,  maintain in force and
                  effect,  and pay all  premiums  for  the  following  insurance
                  coverage from an insurance  company(s)  possessing a rating of
                  B+10 or higher  from the A.M.  Best  Company or an  equivalent
                  rating. The Metropolitan  Washington  Airports Authority shall
                  be named as an  additional  insured  on all  policies,  except
                  Worker's   Compensation   and,   if   required,   Professional
                  Liability:  1. Property Insurance for the Aircraft Maintenance
                  Premises


<PAGE>


                           Insurance  against loss or damage to all improvements
                           constructed  on  the  Aircraft  Maintenance  Premises
                           (including  all subsequent  alterations,  rebuilding,
                           replacements,  changes and additions  thereto made by
                           Lessee) by reason of fire,  wind,  smoke,  vandalism,
                           malicious mischief, riot, civil commotion and hazards
                           and risks included with so-called  "extended coverage
                           endorsements" or "all risk." Such policies shall name
                           the Lessee as the insured  and each shall  contain an
                           endorsement   in  favor  of  the  Authority  and  the
                           Lessee's   Leasehold   Mortgagee(s)   as   additional
                           insureds in a form  satisfactory to the Authority and
                           such Leasehold  Mortgagee(s).  The insurance shall be
                           issued in an aggregate amount which shall not be less
                           than the full  replacement  value (exclusive of paved
                           surfaces, excavation,  basements, and foundations) of
                           all improvements  erected on the Aircraft Maintenance
                           Premises. Each insurance policy shall be in such form
                           and  content  as  is  reasonably  acceptable  to  the
                           Authority and to the Lessee's Leasehold Mortgagee(s).
                           Such policies may be in the form of blanket coverage.
                           The policy or policies  of  insurance  shall  provide
                           that all proceeds of such insurance  shall be payable
                           to the Lessee or Leasehold Mortgagee, in trust, to be
                           used for the sole  purpose of  repairing or replacing
                           the damaged or destroyed improvements constructed and
                           installed  on the  Aircraft  Maintenance  Premises or
                           distributed as provided for under Article XIV herein.
                  2.       Commercial General Liability Insurance


<PAGE>


                           Insurance  identifying the Authority as an additional
                           insured,  and protecting the Authority and the Lessee
                           against  public  liability  in an  amount of not less
                           than  Ten  Million  Dollars  ($10,000,000)   combined
                           single   limit   (which   shall   include    umbrella
                           coverages).   Such  policy  or  policies  of  general
                           liability    shall    include     Premises-Operations
                           Liability,  Contractual  Liability,  Personal Injury,
                           and Broad  Form  Property  Damage to cover the entire
                           Aircraft  Maintenance  Premises and all activities of
                           the  Lessee,  its  tenants,  and  all  other  parties
                           authorized  by the  Lessee to use or  operate  on the
                           Aircraft Maintenance Premises.
                  3.       Comprehensive Automobile Liability Insurance
                           Insurance with a combined single limit of Ten Million
                           Dollars  ($10,000,000) for bodily injury and property
                           damage for each accident (including garage liability,
                           all automotive  equipment  owned,  operated,  leased,
                           hired, and non-owned).
                  4.       Worker's Compensation and Employer's Liability Insurance
                           Insurance  required  for the  selected  proponent  to
                           comply  with the laws of the State of  Virginia  with
                           All  States  Endorsement   Employer's   Liability  of
                           $1,000,000 for each accident/disease.
         B.       The insurance  protection  required  under this Lease shall be
                  written with insurance  companies licensed and qualified to do
                  business  in the  State  of  Virginia.  If in the  Authority's
                  opinion the minimum levels of insurance  herein  required have
                  become  inadequate  during the term of this Lease,  the Lessee
                  agrees to increase  such  minimum  levels of  insurance to the
                  reasonable amount requested by the Authority.


<PAGE>


         C.       Each policy or certificate issued by the insurer shall contain
                  an  agreement  by the  insurer  that  the  policy  will not be
                  canceled  without at least  thirty (30) days  advance  written
                  notice of  cancellation  to the  Authority and to the Lessee's
                  Leasehold  Mortgagee(s) and in no event shall such policies be
                  canceled by the Lessee without the  Authority's  prior written
                  consent unless proper replacement policies are then issued and
                  available.
         D.       All insurance  required to be provided and  maintained  may be
                  placed  under  the  Lessee's  so-called  "blanket   policies";
                  PROVIDED,  HOWEVER,  the insurer named in the blanket policies
                  must certify to the  Authority  and to the Lessee's  Leasehold
                  Mortgagee(s)   that  the  coverage   required  is   separately
                  identified  and is  provided  within the terms of the  blanket
                  policy for the Aircraft Maintenance Premises.
         E.       At least  ten (10) days  before  the  expiration  date of each
                  policy of insurance  required by this Lease,  the Lessee shall
                  pay the  premiums  for the  renewal of each of such  policy or
                  policies  and within such period the Lessee  shall  deliver to
                  the  Authority  the  renewal  certificates  of  the  fire  and
                  extended risk endorsement policies,  the general comprehensive
                  general  liability  policies,  and  comprehensive   automobile
                  liability  policies with an endorsement  thereon marked "paid"
                  and/or  a  duplicate  receipt  evidencing   advanced  payment.
                  Certificates  of  insurance  shall  be  sent  to  the  Airport
                  Manager,  Washington Dulles  International  Airport,  P.O. Box
                  17045, Washington, DC 20041.


<PAGE>


         F.       Indemnification.  Except as provided in Article XXIX herein, the Lessee shall assume all risks
                  ---------------
                  incident to, or in connection with, the occupancy and use of the Aircraft Maintenance Premises
                  under this Lease, and Lessee shall be solely responsible for all accidents or injuries to persons
                  or property caused by the occupancy and use of the Aircraft Maintenance Premises. The Lessee shall
                  indemnify, defend, and save harmless the Authority, its authorized officers, employees, agents,
                  and representatives from any and all claims, suits, civil, criminal or administrative proceedings,
                  losses, damages, or attorney fees, of whatsoever kind or nature, arising directly or indirectly
                  out of or incident to the use and occupancy of the Aircraft Maintenance Premises and improvements
                  constructed thereon or resulting from the act or omission of the Lessee, its agents, contractors,
                  subcontractors, tenants, and employees, guests, and contractors of tenants, except to the extent
                  caused by acts or failures to act by the Authority or its agents, employees, contractors, or
                  licensees.
         G.       The  Authority   shall  be  responsible   for  performing  any
                  mitigating  measures  required by law or  regulation,  if any,
                  because of the  existence of possible  wetlands  within and/or
                  adjacent to the Aircraft  Maintenance  Premises and  requiring
                  mitigation   because  of  the  construction  of  the  aircraft
                  maintenance facility.

ARTICLE XVI - PERFORMANCE GUARANTEE AND BONDS


<PAGE>


         The Lessee  shall  furnish to the  Authority  performance  and  payment
bonds.  The bonds,  at the option of the Lessee,  may be in the form of a surety
bond, letter of credit, postal money order, certified cashier's check payable to
the Authority,  or an irrevocable  letter of credit.  The bonds shall be sent to
the Airport Manager,  Washington Dulles International  Airport,  P.O. Box 17045,
Washington,  DC 20041.  These bonds shall be in the amount  indicated  below and
conditioned on the Lessee's performance as follows:
         A.       Performance Guarantee
                  A  performance  guarantee  in  a  penal  sum  of  One  Hundred
                  Seventy-Nine   Thousand  Five  Hundred   Sixty-Three   Dollars
                  ($179,563) conditioned on the full and faithful performance by
                  the Lessee of each and all of the covenants,  agreements,  and
                  understandings  as set forth in this  Lease.  The  performance
                  guarantee  may be an  annual  guarantee  but  must be  renewed
                  annually at least thirty (30)  calendar days in advance of its
                  date of expiration.  The performance guarantee amount shall be
                  adjusted  annually  so that it is in the  amount  equal to one
                  hundred percent (100%) of the annual ground rental and service
                  cost fee and  fifty  percent  (50%) of the  estimated  utility
                  costs  payable  to the  Authority.  This  guarantee  shall  be
                  submitted to the Authority within thirty (30) calendar days of
                  the commencement of the Operating Period.
         B.       Payment Bonds


<PAGE>


                  Payment bonds in the amount of one hundred  percent  (100%) of
                  the  contract  price,  including  the value of materials to be
                  incorporated  in  the  work,  for  the  aircraft   maintenance
                  facility.  The  payment  bonds  shall be incurred by all major
                  trade  subcontractors  and the Lessee  shall  ensure that such
                  payment bonds collectively total one hundred percent (100%) of
                  the contract price of the aircraft maintenance facility. These
                  payment  bonds  are to  assure  payment  to  the  construction
                  contractors supplying labor and materials. The Lessee shall be
                  required  to  promptly  clear  all  liens  filed  against  the
                  aircraft     maintenance     facility,     its    contractors,
                  subcontractors,  material men, and workmen  arising out of the
                  performance of the construction  work, and shall indemnify the
                  Authority against all claims arising out of the performance of
                  all such  construction  work.  These payment bonds shall be in
                  effect until the completion of construction  and the beginning
                  of the Operating Period.

                           ARTICLE XVII - LATE CHARGES
         A.       Without  waiving  any other right of action  available  to the
                  Authority  in the event of late  payment  of  rental  fees and
                  other charges due hereunder, late charges will be assessed for
                  all rental fees and  charges for which  payment is received by
                  the Authority  after the due date. Late charges may consist of
                  interest,  penalties,  and administrative charges as indicated
                  in paragraphs B., C., and D. below.
         B.       The interest  charge for late payment  shall be  calculated as
                  the product of the charges that are late and an interest  rate
                  per annum  which is four  percent  (4%) higher than the "prime
                  rate" as published in The Wall Street  Journal,  commencing on
                  the date that such charges were past due,  provided the Lessee
                  shall have had at least thirty (30) days advance notice of any
                  rental  fee or other  charges  due the  Authority  under  this
                  Lease.


<PAGE>


         C.       The  monthly   penalty  charges  for  late  payment  shall  be
                  calculated  as the  product of the unpaid  portion of accounts
                  more than ninety (90)  calendar  days past due and an interest
                  rate  of  six  percent  (6%)  per  annum  (or  as  established
                  periodically).
         D.       The   administrative   charge   of  $12  (or  as   established
                  periodically)  will be  assessed  for  each  month  for  every
                  account past due more than thirty (30) calendar days.

                  ARTICLE XVIII - AIRPORT RULES AND REGULATIONS
         The Lessee, while exercising the rights granted under this Lease, shall
observe and obey all lawful rules and regulations of the Metropolitan Washington
Airports  Authority not inconsistent  with the rights granted the Lessee by this
Lease and applied in a  nondiscriminatory  manner to other lessees of comparable
Airport property.

                           ARTICLE XIX - COPARTNERSHIP
         It is  mutually  understood  and agreed  that  nothing in this Lease is
intended  or shall be  construed  as in any way  creating  or  establishing  the
relationship of copartners  between the Parties hereto,  or as making the Lessee
an agent or  representative  of the  Authority  for any purpose or in any manner
whatsoever.

                       ARTICLE XX - PARTICIPATION IN LEASE
         The Lessee agrees that no member of the Authority Board of Directors or
employees of the Authority  shall be admitted to any share or part of this Lease
or to any benefit that may arise therefrom.



<PAGE>


                               ARTICLE XXI - TAXES
         Lessee shall comply with all applicable taxation laws, rules,  rulings,
and regulations  imposed by any jurisdiction  with authority to tax the Lessee's
income,  receipts,  sales,  purchases,  property and leasehold interest or other
interests arising from this Lease.  Nothing herein shall be construed to deny or
limit the Lessee's  right to contest in good faith the amount or validity of any
tax or assessment by appropriate means.
                              ARTICLE XXII - SIGNS
         The  Lessee  shall  not,  without  the prior  written  approval  of the
Authority,  not to be unreasonably  withheld,  erect,  maintain,  or display any
advertising,   signs,  posters,  or  similar  devices  at  or  on  the  Aircraft
Maintenance Premises;  PROVIDED, HOWEVER, that on those interior portions of the
aircraft maintenance facility which are not visible from the outside, the Lessee
may install directional and identification  signs necessary for the facility and
all such signs shall be exempt from the prior approval of the Authority.

                         ARTICLE XXIII - QUIET ENJOYMENT
         The Authority agrees that the Lessee and its subtenants shall peaceably
have and enjoy the Aircraft  Maintenance  Premises and all rights and privileges
granted  under this Lease  without  any  interruption  or  disturbance  from the
Authority as long as the Lessee pays all amounts due the  Authority and performs
all other obligations required under this Lease.


<PAGE>



                 ARTICLE XXIV - RIGHT OF INSPECTION OF PREMISES
         The Authority,  its authorized  representatives and agents,  shall have
the  right  to view any and all of the  Aircraft  Maintenance  Premises,  at any
reasonable  time during normal  business  hours for the purpose of inspecting or
performing any other act therein which may be necessary for the proper operation
of the Airport;  PROVIDED,  HOWEVER,  that the Authority  will exercise its best
efforts to not  interfere  with the  Lessee's  use of the  Aircraft  Maintenance
Premises.

                         ARTICLE XXV - SAVING PROVISION
         If any provision of this Lease or the  application  of any provision of
this Lease to any person or circumstance  shall be invalid or  unenforceable  to
any extent,  the remainder of this Lease or the application of such provision to
persons  or   circumstances   other  than  those  to  which  it  is  invalid  or
unenforceable,  shall not be affected  thereby and each  provision of this Lease
shall be valid and be enforced to the fullest extent of the law.

                      ARTICLE XXVI - WAIVER OF PERFORMANCE


<PAGE>


         The failure of either the Authority or the Lessee to insist, in any one
or  more  instances,  upon  a  strict  performance  by the  other  of any of the
provisions,   terms,  covenants,   reservations,   conditions,  or  stipulations
contained  in this Lease,  shall not be  considered  a waiver or  relinquishment
thereof, but the same shall continue and remain in full force and effect, and no
waiver by either Party of any provision, term, covenant, reservation, condition,
or  stipulation  hereunder  shall be deemed  to have  been made in any  instance
unless expressed in writing and agreed to by the Parties hereto.

              ARTICLE XXVII - CERTIFICATION OF THE LESSEE'S STATUS
         The  Authority  agrees to execute and deliver to the Lessee  and/or any
other  person or  entity  designated  by the  Lessee,  from  time to time,  upon
reasonable  written  notice by the  Lessee,  which  notice  shall state that the
Lessee  requires same in  connection  with a financing or other  undertaking,  a
statement in writing:
                  (i)      certifying  that this Lease is unmodified and in full
                           force and  effect  (or if there  have  been  material
                           modifications,  that the  Lease is in full  force and
                           effect as modified);
                  (ii)     stating  whether  the  Lessee  is in  default  in the
                           performance  of any of the  terms,  requirements,  or
                           conditions   contained  in  this  Lease  and  if  so,
                           specifying the nature of such default; and
                  (iii)    addressing such other reasonable matters as Lessee or
                           any lender of Lessee may request.

                            ARTICLE XXVIII - NOTICES
         Notice to the Authority,  Lessee,  and any other parties  designated by
the Lessee  provided for herein shall be sufficient  if sent by certified  mail,
postage prepaid, and


<PAGE>


addressed  to the  addresses  set out below or to such  other  address as may be
designated  by the party  involved to the other  parties in writing from time to
time:

         If to the Authority, as follows:

                  Airport Manager
                  Washington Dulles International Airport
                  P.O. Box 17045
                  Washington, DC   20041

         If to the Lessee, as follows:

                  Atlantic Coast Airlines
                  Corporate Counsel
                  515A Shaw Road
                  Sterling, VA   20164

         With copies to:




If to any  Leasehold  Mortgagee(s),  to such  address as such  mortgagee(s)  may
notify the Authority in writing from time to time.

                      ARTICLE XXIX - ENVIRONMENTAL MATTERS
         A.       Hazardous Substances, Spills, and Releases.


<PAGE>


                  1.       Lessee shall immediately notify the Authority upon becoming aware of:  (1)  any leak,
                           spill, release, discharge, or disposal at a reportable level or a level that could
                           reasonably be expected to pose a threat to human health or the environment
                           (collectively, a "Material Level") of a Hazardous Substance on, under, or adjacent to
                           the Aircraft Maintenance Premises or threat of or reasonable suspicion of any of the
                           same; and/or (2)  any notice or communication from a governmental agency or any other
                           person, directed to Lessee or any other person (of which Lessee has knowledge),
                           relating to such Hazardous Substances thereon, thereunder, or adjacent thereto or any
                           violation of any federal, state, or local Environmental Laws, with respect to the
                           Aircraft Maintenance Premises or activities thereon; and (3) any other event relating
                           to Hazardous Substances or Environmental Laws, which event could reasonably be
                           expected to injure the Aircraft Maintenance Premises, reduce the value of the
                           Aircraft Maintenance Premises, or impair the Lessee's ability to comply with any of
                           its obligations under this Lease.


<PAGE>




                  2.       In the event of a leak, spill, or release at a Material Level of a Hazardous
                           Substances on the Aircraft Maintenance Premises by the Lessee or the threat of or
                           reasonable suspicion of the same, Lessee shall (to the extent that the Lessee or the
                           Authority is so required under applicable law, including Environmental Laws)
                           immediately undertake all emergency response necessary to contain, clean-up, and
                           remove the Hazardous Substance and shall undertake within a reasonable time all
                           investigatory, remedial, and/or removal action necessary or appropriate to ensure
                           that any contamination by the Hazardous Substance is eliminated; provided, however,
                                                                                            --------  -------
                           that the Authority shall choose the waste disposal site and assume complete
                           responsibility for arranging for the disposal of any Hazardous Substance arising from
                           any Authority Environmental Responsibilities.  The Authority shall have the right to
                           approve all investigatory, remedial, and removal procedures and the company(ies)
                           and/or individuals conducting said procedures; provided, however, that in the case of
                                                                          --------  -------
                           an emergency, no such prior approval shall be required.  In all other cases the
                           Authority's approval shall be deemed given three business days after the receipt of
                           the Lessee's proposed investigatory, remedial, or removal procedures.  Within thirty
                           days following completion of such investigatory, remedial, and/or removal action,
                           Lessee shall provide the Authority with a certificate acceptable to the Authority,
                           stating that all such contamination has been eliminated as required by applicable
                           Environmental Laws.  The Lessee shall be responsible for any costs incurred under
                           this Article XXIX, except that the Authority shall be responsible for any costs
                           incurred by the Lessee under this Article, which costs arise from:  (i)  a condition
                           on the Aircraft Maintenance Premises, existing on the date the Lessee took possession
                           thereof, whether or not such condition was uncovered in an environmental audit or
                           assessment and which condition is not caused by the Lessee or its employees,
                           contractors, or agents; or (ii)  any contamination caused by the migration of
                           Hazardous Substances from any other property (not caused by the Lessee or any of its
                           tenants, or their employees or agents); or (iii)  a leak, spill or release of a
                           Hazardous Substance on the Aircraft Maintenance Premises caused by any action or
                           inaction of the Authority, its employees, contractors, or agent (collectively, the
                           "Authority Environmental Responsibilities").
         B.       Environmental Indemnification - Lessee


<PAGE>




                  Lessee  agrees  to  indemnify,  save,  and hold  harmless  the
                  Authority   from  and   against  all   removal,   remediation,
                  containment,  and other costs (whenever  incurred)  caused by,
                  arising out of, or in connection  with the handling,  storage,
                  discharge,    transportation,   or   disposal   of   Hazardous
                  Substances,  which  Hazardous  Substances  are on the Aircraft
                  Maintenance Premises and which handling,  storage,  discharge,
                  transportation  or  disposal  occurs  after  the date of legal
                  possession of the Aircraft  Maintenance Premises by the Lessee
                  and prior to the vacation of the Aircraft Maintenance Premises
                  by the Lessee;  provided,  however,  this indemnity shall also
                  cover any costs (whenever incurred) caused by, arising out of,
                  or in  connection  with,  the  handling,  storage,  discharge,
                  transportation,  or disposal of  Hazardous  Substances,  which
                  Hazardous Substances are on the Aircraft Maintenance Premises,
                  resulting from the acts or omissions of Lessee,  or any of its
                  tenants  thereof,  or  their  employees,   representatives  or
                  agents; provided,  further, this indemnity shall not cover any
                  costs    resulting    from   the    Authority    Environmental
                  Responsibilities.  Costs shall include, but not be limited to:
                  (a) claims of third parties,  including governmental agencies,
                  for damages, response costs, injunctions, or other relief; (b)
                  the cost,  expense, or loss to the Authority of any injunctive
                  relief,  including preliminary or temporary injunctive relief,
                  applicable  to  the  Authority  or  the  Aircraft  Maintenance
                  Premises;  (c)  the  expense,  including  fees  of  attorneys,
                  engineers,  consultants,  paralegals and experts, of reporting
                  to any agency of the State of Virginia or the United States as
                  required by applicable  Environmental  Laws and  responding to
                  the existence of said  Hazardous  Substances;  (d) any and all
                  expenses  or   obligations,   including   fees  of  attorneys'
                  engineers,  consultants, and paralegals,  incurred at, before,
                  and after any trial or appeal therefrom, or any administrative
                  proceeding  or appeal  therefrom  whether  or not  taxable  as
                  costs, including, without limitation, attorneys' and paralegal
                  fees,  witness fees (expert and otherwise),  deposition costs,
                  copying and  telephone  charges,  and other  expenses,  all of
                  which  shall be paid by Lessee  promptly  after the  Authority
                  incurs  the  obligation  to pay such  amounts.  Such  damages,
                  costs,  liabilities,  and expenses shall include those claimed
                  to be owed by any  regulating  and  administering  agency.  As
                  applied to this  Article  the  Aircraft  Maintenance  Premises
                  shall be deemed to include the soil and water table thereof.
         C.       Environmental Indemnification - Authority


<PAGE>


                  The Authority agrees to indemnify, save, and hold harmless the
                  Lessee from and against all removal, remediation, containment,
                  and other  costs  arising  in  connection  with the  Authority
                  Environmental  Responsibilities  caused by, arising out of, or
                  in   connection   with  the  handling,   storage,   discharge,
                  transportation,  or disposal  of  Hazardous  Substances.  Such
                  costs shall include but not be limited to: (a) claims of third
                  parties, including governmental agencies, for damage, response
                  costs, injunctions, or other relief; (b) the cost, expense, or
                  loss to the Lessee of the Aircraft Maintenance  Premises;  (c)
                  the  expense,   including   fees  of   attorneys,   engineers,
                  consultants,  paralegals,  and  experts,  of  reporting to any
                  agency  of the  State of  Virginia  or the  United  States  as
                  required by applicable  Environmental  Laws and  responding to
                  the existence of said  Hazardous  Substances;  (d) any and all
                  expenses  or   obligations,   including   fees  of  attorneys'
                  engineers,  consultants, and paralegals,  incurred at, before,
                  and after any trial or appeal therefrom or any  administrative
                  proceeding  or appeal  therefrom,  whether  or not  taxable as
                  costs, including, without limitation, attorneys' and paralegal
                  fees,  witness fees (expert and otherwise),  deposition costs,
                  copying and  telephone  charges,  and other  expenses,  all of
                  which shall be paid by the Authority promptly after the Lessee
                  incurs  the  obligation  to pay such  amounts.  Such  damages,
                  costs,  liabilities,  and expenses shall include those claimed
                  to be owed by any regulating and administering agency. As used
                  in this Article,  the Aircraft  Maintenance  Premises shall be
                  deemed to include the soil and water table thereof.
         D.       Definitions.  For purposes of this Article XXIX the  following
                  words  and  phrases   shall  have  the   following   meanings:
                  "Environmental  Law" shall mean any Federal,  state,  or local
                  law, rule,  regulation,  code, order,  ordinance,  statute, or
                  decision related to Hazardous Substances.



<PAGE>


                  "Hazardous  Substances" shall mean (i) any substances  defined
                  as  hazardous  materials,   pollutants,   contaminants,  toxic
                  substances or related materials as now or hereinafter  defined
                  in any applicable  Federal,  state, or local law,  regulation,
                  ordinance,  or directive,  including,  but not limited to, the
                  Resource  Conservation  and  Recovery  Act of 1976 (42  U.S.C.
                  Sections  6901  et.  seq.);  the  Comprehensive  Environmental
                  Response,  Compensation  and Liability Act of 1980, as amended
                  by SARA (42 U.S.C.  Section  9601,  et.  seq.);  the Hazardous
                  Materials  Transportation  Act (49 U.S.C.  Section  1801,  et.
                  seq.);  the Toxic  Substances  Control Act (15 U.S.C.  Section
                  2601, et. seq.);  the Resource  Conservation and Recovery Act,
                  as amended (42 U.S.C.  Sections  9601,  et.  seq.);  the Clean
                  Water Act (33 U.S.C.  Section 7412 et. seq.); as any such acts
                  may  be  amended,   modified,  or  supplemented;   (ii)  those
                  substances  listed or otherwise  identified in the regulations
                  adopted and publications issued, as may be amended,  modified,
                  or  supplemented,  pursuant  to any  of  the  above-referenced
                  statutes;  (iii) any friable asbestos,  airborne asbestos,  or
                  any   substance   the   presence  of  which  on  the  Aircraft
                  Maintenance Premises is prohibited by any Environmental Law of
                  any  governmental  authority  or  which  may  give  rise to an
                  assessment  of a  governmental  authority;  and (v) any  other
                  substance which by any  Environmental  Law of any governmental
                  authority   requires   special  handling  in  its  collection,
                  storage, treatment, or disposal.

                       ARTICLE XXX - FEDERAL REQUIREMENTS
         A.       Relationship to Federal Lease
                  This Lease shall be and remain  subordinate  to the provisions
                  of  the  lease  between  the  United   States   Department  of
                  Transportation  and the Authority (the "Federal  Lease").  The
                  Authority agrees to provide Lessee and any Leasehold Mortgagee
                  written  advance notice of any amendments to the Federal Lease
                  that  materially  affect the terms of this Lease.  At any time
                  after execution of this Lease, the United States Department of
                  Transportation,  or its  successor,  shall  have the  right to
                  declare this Lease to be superior to the Federal Lease.


<PAGE>


         B.       Other Government Agreements
                  This Lease shall be and remain  subordinate  to the provisions
                  of any existing or future agreements between the Authority and
                  the United States government or other governmental  authority,
                  relative to the operation or maintenance  of the Airport,  the
                  execution of which has been or will be required as a condition
                  to the granting of federal or other governmental funds for the
                  development of the Airport,  to the extent that the provisions
                  of any  such  existing  or  future  agreements  are  generally
                  required by the Untied States or other governmental  authority
                  of other civil airports  receiving  such funds.  The Authority
                  agrees to use its best efforts to notify  Lessee and Leasehold
                  Mortgagee  of any  provision  of which the  Authority  becomes
                  aware which would materially and adversely modify the material
                  terms of this Lease.
         C.       Federal Government's Emergency Clause
                  All  provisions  of this  Lease  shall be  subordinate  to the
                  rights of the United  States of America to operate the Airport
                  or any portion thereof during time of war or declared national
                  emergency in accordance with  established  lawful  procedures.
                  Such rights shall  supersede  any provision of this Lease that
                  is  inconsistent  with the  operation  of the  Airport  by the
                  United  States  of  America  during a time or war or  national
                  emergency.


<PAGE>


         D.       Nondiscrimination
                  Lessee for itself, its personal representatives, successors in
                  interest,  and assigns,  as part of the consideration  hereof,
                  does hereby agree as a covenant running with the land that (i)
                  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 discrimination in the use of
                  the Aircraft Maintenance Premises; (ii) in the construction of
                  any improvements  on, over, or under the Aircraft  Maintenance
                  Premises 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 be
                  otherwise subjected to discrimination.
         E.       Airport Certification
                  Lessee shall not operate the Aircraft  Maintenance Premises in
                  a manner that prevents or impairs the  Authority's  ability to
                  be in, and  maintain,  compliance  with FAA  regulation 14 CFR
                  Part 139, "Certification and Operations: Land Airports Serving
                  Certain Air  Carriers," and other  requirements  for obtaining
                  and  maintaining,  an Airport  Operating  Certificate from the
                  FAA.



<PAGE>


         IN WITNESS  WHEREOF,  the Parties hereto have executed this Lease as of
the day and year shown below.

         METROPOLITAN WASHINGTON AIRPORTS AUTHORITY



         By
                  James A. Wilding
                  General Manager and
                  Chief Executive Officer

         Date


         ATLANTIC COAST AIRLINES



         By


         Title


         Date

                             SECRETARY'S CERTIFICATE
         I, , certify that I am the  Secretary of the  corporation  named as the
Lessee herein; that who signed this Lease on behalf of the corporation, was then
of said  corporation;  that said Lease was duly signed for and on behalf of said
corporation  by authority of its  governing  body and is within the scope of its
corporate powers.

                                                                         (Corporate Seal)
                  (Secretary's Signature)



<PAGE>


COMMONWEALTH OF VIRGINIA)
                                     ) ss.:
COUNTY OF LOUDOUN              )

         I,                                                    , a notary public in and for the State and
            ---------------------------------------------------
County aforesaid, do certify that                                                       , whose name, as
                                  ------------------------------------------------------
                                        of                                                       , is signed
to the writing above, bearing date on the           day of                                    , has
acknowledged the same before me in my County aforesaid.

         Given under my hand and official seal this           day of                                    .



                  Notary Public


COMMONWEALTH OF VIRGINIA)
                                     ) ss.:
COUNTY OF LOUDOUN              )

         I,                                            , a notary public in and for the Commonwealth and
County aforesaid, do certify that                                                , whose name, as
                                               , of METROPOLITAN WASHINGTON AIRPORTS AUTHORITY, is signed to
the writing above, bearing date on the        day of
                               , has acknowledged the same before me in my County aforesaid.

         Given under my hand and official seal this           day of                             .

         My term of office expires on the           of                                .





                  Notary Public

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