<PAGE>


                         ASSIGNMENT AND ASSUMPTION OF LEASES

               This Agreement is made and entered into to be effective as of 
the _____ day of October, 1997 (the "Effective Date"), by and between Gerald 
G. Mercer (aka Jerry G. Mercer) ("Assignor"), and AirNet Systems, Inc., an 
Ohio corporation ("Assignee").

                                Preliminary Statements
                                ----------------------

               A.   Assignor is the tenant under those certain Leases 
described as follows:

                    (a)  Fuel Farm Lease Agreement between the City of 
Columbus and P.D.Q. Air Service, Inc., dated August 15, 1984, the tenant's 
interest in which was subsequently assigned to Assignor.  A Memorandum of 
said lease is recorded at Official Records Vol. 5954, page E-09, Recorder's 
Office, Franklin County, Ohio.

                    (b)  Lease Agreement between the City of Columbus and 
Jerry G. Mercer dated October 4, 1984, as modified by (i) Modification #1 
dated June 11, 1985, (ii) Modification #2 dated June 11, 1986, (iii) 
Modification #3 dated May 15, 1987, (iv) Modification #4 dated August 17, 
1989 and (v) Modification #5 dated December 15, 1994.  A Memorandum of said 
lease is recorded at Official Record Vol. 5317, page I12, and a Modification 
is recorded at Official Record Vol. 6394, page A14, both in the Recorder's 
Office, Franklin County, Ohio.

               B.   The Leases demise certain real property and improvements 
described more particularly therein and in EXHIBIT A, attached hereto.  The 
real property is located on the south side of International Gateway Drive in 
Columbus, Ohio and is generally known as 3939 International Gateway Drive, 
Columbus, Ohio (herein called the "Property").  The permanent tax parcel 
number for the Property is 010-200806.

               C.   Assignor desires to assign all of its right, title and 
interest in, to and under the Leases and the leasehold estates in the 
Property created thereby to Assignee, and Assignee desires to accept such 
assignment and assume the Leases.

<PAGE>

                                   AGREEMENT

     NOW THEREFORE, in consideration of the premises as described in the 
foregoing Preliminary Statements and of the mutual promises herein set forth, 
the parties do hereby agree as follows:

     1.   ASSIGNMENT.  Assignor hereby assigns and transfers to Assignee, 
effective as of the Effective Date hereof, all of Assignor's right, title and 
interest in, to and under the Leases and the leasehold estates in the 
Property created thereby, including the rights-of-first refusal to lease 
additional property contained therein.

     2.   ASSUMPTION.  Assignee hereby assumes the Leases as of the Effective 
Date hereof, and agrees to perform and observe all of the covenants and 
conditions therein contained on the tenant's part to be performed and 
observed from and after the Effective Date hereof.

     3.   INDEMNIFICATION.  Assignor agrees to indemnify and hold Assignee 
harmless against any loss or liability arising from or in connection with 
Assignor's failure to perform and observe any of the covenants and conditions 
of the Leases to be performed and observed by the tenant therein prior to the 
Effective Date of this assignment.

               [The remainder of this page 2 has intentionally been
               left blank.  The signatures appear on the following
               page 3.]

                                       2

<PAGE>

                    IN WITNESS WHEREOF, the parties have executed and 
delivered this Agreement to be effective as of October ____, 1997, regardless 
of the actual dates of execution by the parties.

Signed and acknowledged
in the presence of the
following two (2) 
witnesses as to each signature:

As to (i):

                              (i)
-------------------------        -----------------------
  (witness signature)                 Gerald G. Mercer

------------------------
    (printed name)

and

------------------------
  (witness signature)

------------------------
    (printed name)

As to (ii) and (iii):         AIRNET SYSTEMS, INC.

                              By:
-------------------------        -----------------------
  (witness signature)                 (signature)

                                   Eric P. Roy
-------------------------     --------------------------
    (printed name)                (printed name)

and                           Its Executive Vice-President

------------------------
  (witness signature)

------------------------
    (printed name)

                                       3

<PAGE>


STATE OF OHIO
FRANKLIN COUNTY, ss:

     The foregoing instrument was acknowledged before me this ____ day of 
October, 1997 by Gerald G. Mercer.

                                        ------------------------
                                        Notary Public

STATE OF OHIO
FRANKLIN COUNTY, ss:

     The foregoing instrument was acknowledged before me this _____ day of 
October, 1997, by Eric P. Roy, Executive Vice-President of AirNet Systems, 
Inc., an Ohio corporation, on behalf of the corporation.

                                        ------------------------
                                        Notary Public


                           CONSENT AND AGREEMENT OF LESSOR
                           -------------------------------

     The undersigned, the Lessor under the Leases identified in the foregoing 
Assignment and Assumption of Leases, hereby indicates its consent to said 
assignment.

                                        COLUMBUS MUNICIPAL 
                                          AIRPORT AUTHORITY

                                        By:
                                           ---------------------




This Instrument Prepared By:
     Gary E. Davis, Esq.
     Vorys, Sater, Seymour and Pease
     52 East Gay Street
     Columbus, Ohio  43215

                                       4

<PAGE>

   LIST OF EXHIBITS AND SCHEDULES TO LEASEHOLD INTEREST PURCHASE AGREEMENT
           DATED OCTOBER 31, 1997 BY AND BETWEEN GERALD G. MERCER
                            AND AIRNET SYSTEMS, INC.


  Exhibit
  -------

Exhibit A       Description of the Leased Premise




NOTES: AirNet Systems, Inc., hereby agrees to furnish supplementary a copy of 
any omitted Exhibits and Schedules to the Securities and Exchange Commission 
upon request.