EXHIBIT 4.1.1

                            SUPPLEMENTAL INDENTURE

     SUPPLEMENTAL INDENTURE (this "Supplemental Indenture"), dated as of 
January 22, 1999 among PATS, Inc., Patrick Aircraft Tank Systems, Inc., PATS 
Support, Inc., PATS Aircraft and Engineering Corporation and Flight Refueling, 
Inc. (each a "Guarantor"), a subsidiary of DeCrane Aircraft Holdings, Inc. 
(or its permitted successor), a Delaware corporation (the "Issuer"), the 
other Guarantors (as defined in the Indenture referred to herein) and State 
Street Bank and Trust Company, as trustee under the Indenture referred to 
below (the "Trustee").

                             W I T N E S S E T H 

     WHEREAS, the Issuer has heretofore executed and delivered to the Trustee 
an indenture (the "Indenture"), dated as of October 5, 1998 providing for the 
issuance of an aggregate principal amount of up to $100 million of 12% Senior 
Subordinated Notes due 2008 (the "Notes");

     WHEREAS, the Indenture provides that under certain circumstances each 
Guarantor shall execute and deliver to the Trustee a supplemental indenture, 
pursuant to which each Guarantor shall unconditionally guarantee all of the 
Issuer's Obligations under the Notes and the Indenture on the terms and 
conditions set forth herein (the "Note Guarantee"); and

     WHEREAS, pursuant to Section 9.06 of the Indenture, the Trustee is 
authorized to execute and deliver this Supplemental Indenture.

     NOW THEREFORE, in consideration of the foregoing and for other good and 
valuable consideration, the receipt of which is hereby acknowledged, each 
Guarantor and the Trustee mutually covenant and agree for the equal and 
ratable benefit of the Holders of the Notes as follows;


     1.  CAPITALIZED TERMS. Capitalized terms used herein without definition 
shall have the meanings assigned to them in the Indenture.

     2.  AGREEMENT TO GUARANTEE. Each Guarantor hereby agrees as follows:

     (a) Along with all Guarantors named in the Indenture, to jointly and 
severally Guarantee to each holder of a Note authenticated and delivered by 
the Trustee and to the Trustee and its successors and assigns, irrespective of 
the validity and enforceability of the Indenture, the Notes or the 
obligations of Issuer hereunder or thereunder, that:

          (i)  the principal of an interest on the Notes will be promptly paid
     in full when due, whether at maturity, by acceleration, redemption or 
     otherwise, and interest on the overdue principal of and interest on the 
     Notes, if any, is lawful, and all other obligations of the Issuer to the 
     Holders or the Trustee hereunder or thereunder will be promptly paid in 
     full or performed, all in accordance with the terms hereof and thereof; 
     and

         (ii)  in case of any extension of time of payment or renewal of any 
     Notes or any of such other obligations, that same will be promptly paid 
     in full when due or performed in accordance with the terms of the 
     extension or renewal, whether at stated maturity, by acceleration or 
     otherwise. Failing 



     payment when due of any amount so guaranteed or any 
     performance so guaranteed for whatever reason, the Guarantors shall be 
     jointly and severally obligated to pay the same immediately.

     (b)  The obligations hereunder shall be unconditional, irrespective of 
the validity, regularity or enforceability of the Notes or the Indenture, the 
absence of any action to enforce the same, any waiver or consent by any 
Holder of the Notes with respect to any provisions hereof or thereof, the 
recovery of any judgment against Issuer, any action to enforce the same or 
any other circumstance which might otherwise constitute a legal or equitable 
discharge or defense of a guarantor.

     (c)  The following is hereby waived: diligence, presentment, demand of 
payment, filing of claims with a court in the event of insolvency or 
bankruptcy of the Issuer, any right to require a proceeding first against the 
Issuer, protest, notice and all demands whatsoever.

     (d)  This Note Guarantee shall not be discharged except by complete 
performance of the obligations contained in the Notes and the Indenture.

     (e)  If any Holder or the Trustee is required by any court or otherwise 
to return to the Issuer, the Guarantors, or any Custodian, trustee, 
liquidator or other similar official acting in relation to either the Issuer 
or the Guarantors, any amount paid by either to the Trustee or such Holder, 
this Note Guarantee, to the extent theretofore discharged, shall be 
reinstated in full force and effect.

     (f)  Each Guarantor shall not be entitled to any right of subrogation in 
relation to the Holders in respect of any obligations guaranteed hereby until 
payment in full of all obligations guaranteed hereby.

     (g)  As between the Guarantors, on the one hand, and the Holders and the 
Trustee, on the other hand, (x) the maturity of the obligations guaranteed 
hereby may be accelerated as provided in Article 6 of the Indenture for the 
purposes of this Note Guarantee, notwithstanding any stay, injunction or 
other prohibition preventing such acceleration in respect of the obligations 
guaranteed hereby, and (y) in the event of any declaration of acceleration of 
such obligations as provided in Article 6 of the Indenture, such obligations 
(whether or not due and payable) shall forthwith become due and payable by 
the Guarantors for the purpose of this Note Guarantee.

     (h)  The Guarantors shall have the right to seek contribution from any 
non-paying Guarantor so long as the exercise of such right does not impair the 
rights of the Holders under the Guarantee.

     (i)  Pursuant to Section 11.03 of the Indenture, after giving effect to 
any maximum amount and any other contingent and fixed liabilities that are 
relevant under any applicable Bankruptcy or fraudulent conveyance laws, and 
after giving effect to any collections from, rights to receive contribution 
from or payments made by or on behalf of any other Guarantor in respect of 
the obligations of such Guarantor under its Note Guarantor not constituting a 
fraudulent transfer or conveyance.

     3.  EXECUTION AND DELIVERY. Each Guarantor agrees that the Note 
Guarantees shall remain in full force and effect notwithstanding any failure 
to endorse on each Note a notation of such Note Guarantee.

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     4.    GUARANTOR MAY CONSOLIDATE ETC. ON CERTAIN TERMS.

     (a)   No Guarantor may consolidate with or merge with or into (whether 
or not such Guarantor is the surviving Person), another corporation, Person 
or entity whether or not affiliated with such Guarantor unless:

           (i)   subject to Section 5(a) hereof, the Person formed by or 
     surviving any such consolidation or merger (if other than such 
     Guarantor) assumes all the obligations of such Guarantor pursuant to a 
     supplemental indenture in form and substance reasonably satisfactory to 
     the Trustee, under the Notes, the Indenture and the Registration Rights 
     Agreement;

           (ii)  immediately after giving effect to such transaction, no 
     Default or Event of Default exists; and

           (iii) Issuer would, at the time of such transaction and after 
     giving pro forma effect thereto and if such transaction had occurred at 
     the beginning of the applicable four-quarter period, be permitted to 
     incur at least $1.00 of additional Indebtedness pursuant to the Fixed 
     Charger Coverage Ratio test set forth in Section 4.09 of the Indenture 
     by virtue of the Issuer's pro forma Cash Flow Coverage Ratio, 
     immediately after giving effect to such transaction, to incur at least 
     $1.00 of additional Indebtedness pursuant to the Cash Flow Coverage 
     Ratio test set forth in Section 4.07 of the Indenture;

PROVIDED THAT, the requirements of clause (iii) of this Section 4(a) will not 
apply in the case of a consolidation with or merger with or into the Issuer 
or another Guarantor.

     (b)   In case of any such consolidation, merger, sale or conveyance and 
upon the assumption by the successor Person, by supplemental Indenture 
executed and delivered to the Trustee in the form of Exhibit E to the 
Indenture or otherwise satisfactory in form to the Trustee, of the Note 
Guarantee and the due and punctual performance of all of the covenants and 
conditions of the Indenture to be performed by each Guarantor, such successor 
Person shall succeed to and be substituted for each Guarantor with the same 
effect as if it had been named herein as a Guarantor. All the Note Guarantees 
so issued shall in all respects have the same legal rank and benefit under 
the Indenture as the Note Guarantees theretofore and thereafter issued in 
accordance with the terms of the Indenture as though all of such Note 
Guarantees had been issued at the date of the execution hereof.

     (c)   Except as set forth in Articles 4 and 5 of the Indenture, and 
notwithstanding clauses (a) and (b) above, nothing contained in the Indenture 
or in any of the Notes shall prevent any consolidation or merger of a 
Guarantor with or into the Issuer or another Guarantor, or shall prevent any 
sale or conveyance of the property of a Guarantor as an entirety or 
substantially as an entirety to the Issuer or another Guarantor.

     5.    RELEASES.

     (a)   In the event of a sale or other disposition of all of the assets 
of any Guarantor, by way of merger, consolidation or otherwise, or a sale or 
other disposition of all of the capital stock of any Guarantor, such 
Guarantor (in the event of a sale or other disposition, by way of such a 
merger, consolidation or otherwise, of all of the capital stock of such 
Guarantor) or the corporation acquiring the property (in the event of a sale 
or other disposition of all of the assets of such Guarantor) will be released 
and relieved of any obligations under its Note Guarantee;


                                     3


PROVIDED that the Net Proceeds of such sale or other disposition are applied 
in accordance with the applicable provisions of the Indenture, including 
without limitation Section 4.10 of the Indenture. Upon delivery by the Issuer 
to the Trustee of an Officers' Certificate and an Opinion of Counsel to the 
effect that such sale or other disposition was made by the Issuer in 
accordance with the applicable provisions of the Indenture, including, 
without limitation, Section 4.10 of the Indenture, the Trustee shall execute 
any documents reasonably required in order to evidence the release of any 
Guarantor from its obligations under its Note Guarantee.

     (b)     Any Guarantor not released from its obligations under its Note 
Guarantee shall remain liable for the full amount of principal of and 
interest on the Notes and for the other obligations of any Guarantor under 
the Indenture as provided in Article 11 of the Indenture.

     6.      NO RECOURSE AGAINST OTHERS. No past, present or future director, 
officer, employee, incorporator, stockholder or agent of each Guarantor, as 
such, shall have any liability for any obligations of the Issuer or any 
Guarantor under the Notes, any Note Guarantees, the Indenture or this 
Supplemental Indenture or for any claim based on, in respect of, or by reason 
of, such obligations or their creation. Each Holder of the Notes by accepting 
a Note waives and releases all such liability. The waiver and release are 
part of the consideration for issuance of the Notes. Such waiver may not be 
effective to waive liabilities under the federal securities laws and it is 
the view of the Commission that such a waiver is against public policy.

     7.      NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW 
YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT 
WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE 
EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE 
REQUIRED THEREBY.

     8.      COUNTERPARTS. The parties may sign any number of copies of this 
Supplemental Indenture. Each signed copy shall be an original, but all of 
them together represent the same agreement.

     9.      EFFECT OF HEADINGS. The Section headings herein are for 
convenience only and shall not affect the construction hereof.

     10.     THE TRUSTEE. The Trustee shall not be responsible in any manner 
whatsoever for or in respect of the validity or sufficiency of this 
Supplemental Indenture or for or in respect of the recitals contained herein, 
all of which recitals are made solely by each Guarantor and the Issuer.

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                                       SIGNATURES

Dated as of January 22, 1999

                                       DECRANE AIRCRAFT HOLDINGS, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       AEROSPACE DISPLAY SYSTEMS, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       AUDIO INTERNATIONAL, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       AVTECH CORPORATION

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       CORY COMPONENTS, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       DETTMERS INDUSTRIES, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO

                                       5


                                       ELSINORE AEROSPACE
                                       SERVICES, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       ELSINORE ENGINEERING, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       HOLLINGSEAD INTERNATIONAL INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       TRI-STAR ELECTRONICS
                                       INTERNATIONAL, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       PATS, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       PATRICK AIRCRAFT TANK SYSTEMS, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       PATS SUPPORT, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO

                                       6


                                       PATS AIRCRAFT AND ENGINEERING
                                       CORPORATION

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


                                       FLIGHT REFUELING, INC.

                                       BY: /s/ John R. Hinson
                                           ----------------------------
                                           Name:  John R. Hinson
                                           Title: CFO


STATE STREET BANK AND TRUST COMPANY

BY: /s/ Steven Cimalore
    -------------------------------
    Name:  Steven Cimalore
    Title: Vice President

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