GUARANTY OF SUBLEASE

         This  Guaranty of Sublease  ("Guaranty")  is made and  effective  as of
April 28, 1998, by Fields Aircraft Spares Inc., a Utah corporation ("Guarantor")
in favor of Sunrise Medical HHG Inc., a California  corporation  ("Sublandlord")
with reference to the facts set forth below.

                                   RECITALS:
                                   ---------

         A. Sublandlord has entered into that certain  Sublease  ("Sublease") of
even date  herewith  with Fields  Aircraft  Spares,  Incorporated,  a California
corporation ("Subtenant"), for the lease of the premises ("Premises") consisting
of an  approximately  122,484 square foot industrial  building,  located at 4175
Guardian  Street,  Simi Valley,  California,  together with the surrounding real
property and improvements, as further described in the Sublease.

         B. As a  condition  to  entering  into the  Sublease,  Sublandlord  has
required that Guarantor  execute this Guaranty  guaranteeing  performance of all
the  covenants on  Subtenant's  part to be performed  pursuant to the  Sublease.
Guarantor's  agreement to provide this Guaranty is a material  consideration for
Sublandlord's decision to lease the Premises to Subtenant.

         NOW, THEREFORE, to induce Sublandlord to enter into the Sublease and in
consideration thereof, Guarantor agrees as set forth below.

1. Guarantor  unconditionally  guarantees to Sublandlord,  and to  Sublandlord's
successors  and  assigns,  the payment by  Subtenant of the rental and all other
charges which accrue under the Sublease in the manner and at the time prescribed
therein, and the full and punctual performance and observance,  by Subtenant, of
all the terms,  covenants and  conditions  contained in the Sublease.  Guarantor
waives  notice of any breach or default by  Subtenant.  Guarantor's  obligations
hereunder  shall  continue  in full  force and  effect  with  respect  to any of
Subtenant's  obligations  under the Sublease  which are not  performed  upon the
termination of this Sublease.

2. This  Guaranty is a  continuing  guaranty of all of  Subtenant's  obligations
under the  Sublease,  independent  of and in  addition  to any  other  guaranty,
previously or  subsequently  given to  Sublandlord,  and this Guaranty shall not
affect any of said guaranties.

3. Guarantor  hereby  expressly  waives and  relinquishes any and all rights and
remedies which  Guarantor may have or be able to assert by reason of the laws or
decisions of the State of  California  pertaining  to the rights and remedies of
sureties.

4.  Guarantor  waives any right to require  Sublandlord  to (a) proceed  against
Subtenant  or any  co-guarantor,  (b) proceed  against or exhaust  any  security
(including a security deposit) held by Sublandlord,  or (c) pursue any remedy in
Sublandlord's  power whatsoever.  Guarantor waives any defense it may acquire by
reason of Sublandlord's  election of any remedy against it or Subtenant or both,
including,  but without limitation,  the election by Sublandlord to exercise its
rights to occupy and operate the Premises under the Sublease.

5. Guarantor waives any defense based upon the legal disability of Subtenant, or
any  discharge,   release  or  limitation  of  the  liability  of  Subtenant  to
Sublandlord, or any restraint or



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stay  applicable  to  actions  against   Subtenant,   or  any  disaffirmance  or
abandonment of the Sublease by a trustee of Subtenant whether consensual,  or by
order of a court or other governmental authority, arising by operation of law or
any liquidation, reorganization,  receivership, bankruptcy, insolvency or debtor
relief  proceeding,  or any other cause.  Guarantor  further  waives any defense
based  upon  any  amendment,   modification,   renewal,  extension,  assignment,
subletting or other  alteration  (with or without the consent of Sublandlord) of
the  Sublease,  or the  term of the  Sublease  or  obligation  of  Subtenant  or
Sublandlord  under  the  Sublease,  or  any  other  documents  relating  to  the
transactions  described  therein;  any  defense  based  upon the  negligence  of
Sublandlord;  any  defense  based  upon the  forfeiture  or  termination  of the
Sublease by Sublandlord whether by expiration or default; any defense based upon
the failure of  Sublandlord  to file a claim in  bankruptcy  of  Subtenant;  all
rights of  subrogation,  all rights to enforce any remedy that  Sublandlord  may
have against  Subtenant,  and all rights to  participate in any security held by
Sublandlord for the performance and obligations of Subtenant under the Sublease,
except to the extent such  security  remains after  payment and  performance  of
Subtenant's  obligations  in full;  any defense based upon the impairment of any
subrogation  rights that  Subtenant  might have;  any defense  based upon death,
incapacity,  lack of authority or termination of existence or revocation  hereof
by any person or entity,  or persons or  entities,  or the  substitution  of any
party  hereto,  and any  defense  based upon or related to  Guarantor's  lack of
knowledge as to Subtenant's  financial  condition,  and any and all rights under
Section 2845 of the California Civil Code and any successor provision.

6. Guarantor waives all presentments,  demands, protests and notices of any kind
including  notice of  acceptance  of the  Guaranty  by  Sublandlord.  Any act of
Sublandlord,  or its successors or assigns,  consisting of a modification of the
Sublease,  a waiver of any of the terms or conditions  of the  Sublease,  or the
giving of any consent to any manner or thing  relating to the  Sublease,  or the
granting of any  indulgences  or  extensions  of time to  Subtenant,  are hereby
deemed  approved by Guarantor  and may be done without  notice to Guarantor  and
without releasing Guarantor from any of its obligations hereunder.

7.  Guarantor  assumes full  responsibility  for keeping  fully  informed of the
financial  condition  of  Subtenant  and  all  other   circumstances   affecting
Subtenant's  ability to perform its obligations to Sublandlord,  and agrees that
Sublandlord  shall have no duty to report to  Guarantor  any  information  which
Sublandlord receives about Subtenant's  financial condition or any circumstances
bearing on Subtenant's ability to perform.

8. The covenants and  obligations of Guarantor  hereunder are independent of the
Subtenant's  obligations  under the Sublease and are binding upon the  Guarantor
notwithstanding  the  fact  that  the  Guarantor  is not  the  signatory  to the
Sublease;  separate  action or actions  may be  brought  against  any  guarantor
hereon,  whether or not action is brought against  Subtenant or any co-guarantor
or Subtenant or any co-guarantor be joined in any such action or actions.

9. Any  indebtedness or other  obligations of Subtenant now or hereafter held by
Guarantor is hereby subordinated to Subtenant's obligations to Sublandlord,  and
such indebtedness or other obligations of Subtenant to Guarantor, if Sublandlord
so request,  shall be  collected,  enforced and received by Guarantor as Trustee
for  Sublandlord  and be paid over to  Sublandlord  on  account  of  Subtenant's
obligations to Sublandlord,  but without reducing or affecting in any manner the
liability of Guarantor under the other provisions of this Guaranty.

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<PAGE>


10. This Guaranty shall be  enforceable  by  Sublandlord in accordance  with the
laws of the State of California and shall be construed in accordance  therewith,
without  regard to  principles  of  conflicts of laws.  Guarantor  agrees to pay
attorney's  fees and all other  costs and  expenses  which  may be  incurred  by
Sublandlord in enforcement of this  Guaranty.  Until paid to  Sublandlord,  such
sums will bear  interest  from the date such costs and  expenses are incurred at
the maximum rate permitted by law.

11. No delay or failure on the part of Sublandlord to pursue any right or remedy
hereunder  or under the  Sublease  shall  constitute  a waiver of that  right or
remedy. All remedies of Sublandlord against Guarantor are cumulative.

12. The  obligations  and  promises  set forth herein shall be joint and several
undertakings of each of the persons executing this Guaranty as a Guarantor,  and
Sublandlord  may  proceed  hereunder  against  any one or  more of said  persons
without waiving its right to proceed  against any of the others.  The use of the
singular herein shall include the plural.

13. Guarantor  acknowledges  that its undertakings  given hereunder are given in
consideration of  Sublandlord's  entering into the Sublease and that Sublandlord
would not  consummate the Sublease were it not for the execution and delivery of
this Guaranty.

14. The provisions of this Guaranty will bind and benefit the heirs,  executors,
administrators,  legal representatives,  successors and assigns of Guarantor and
Sublandlord.

15.  Guarantor  individually  represents  and warrants that it has all requisite
power and authority to:

     15.1 execute deliver,  perform and be legally bound by this Guaranty on the
terms and conditions herein stated; and

     15.2 transact any other  business with  Sublandlord as necessary to fulfill
the terms of this Guaranty.

16. No provision  of this  Guaranty or  Sublandlord's  rights  hereunder  can be
waived or modified nor can Guarantor be released from its obligations  hereunder
except by a writing executed by Sublandlord.  No such waiver shall be applicable
except in the specific instance for which given.

17. The term "Subtenant" will mean both the named subtenant and any other person
or entity at any time  assuming,  subleasing  or  otherwise  becoming  primarily
liable  for  all  or  any  part  of  the  subtenant's   obligations.   The  term
"Sublandlord"  will mean both the sublandlord  named herein and any future owner
or holder of  Sublandlord's  interest in the Premises.  Sublandlord may, without
notice,  assign  this  Guaranty  in whole or in part  without  extinguishing  or
reducing the liability of the Guarantor.

                                       -3-
<PAGE>

18. All  notices  or other  communications  required  or  permitted  to be given
hereunder  shall be in writing and shall be considered  effective  upon personal
delivery  or upon the  earlier of (i) two (2)  business  days  after  deposit in
first-class United States mail, postage prepaid, registered or certified or (ii)
actual  receipt as shown by the return  receipt.  For  purposes  of notice,  the
addresses  of  Guarantor  shall be as set forth on the  signature  page  hereof;
provided, however, that any party shall have the right to change its address for
notice  hereunder to any other  location by giving  notice to the other party in
the manner set forth above.

         IN WITNESS  WHEREOF,  the  undersigned has executed this Guaranty as of
the day and year first above written.

                                                GUARANTOR

                                                FIELDS AIRCRAFT SPARES INC., a
                                                Utah corporation


Guarantor's Address:

341 A Street                                    By: /s/  Alan M. Fields
Fillmore, CA 93015                                 ----------------------------
                                                Name: Alan M. Fields
                                                Title: President & CEO


                                                By: /s/ L. J. Troyna
                                                   ----------------------------
                                                Name: L. J. Troyna
                                                Title: Chief Financial Officer





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