Primary Aircraft Applications

Exhibit 4.3

SUPPLEMENTAL INDENTURE TO BE DELIVERED
BY GUARANTOR

     SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of August 24, 2004, among Dunlop Standard Aerospace (US) Inc., Dunlop Standard Aerospace (US) Legal Inc., Standard Aero, Inc., Dunlop Aerospace Parts, Inc., Standard Aero (San Antonio) Inc., Standard Aero (Alliance) Inc., Standard Aero Canada, Inc., 3091781 Nova Scotia Company, 3091782 Nova Scotia Company, 3091783 Nova Scotia Company, Standard Aero Limited, Not FM Canada Inc. (each a “Guarantor” and collectively the “Guarantors”), each a direct or indirect subsidiary of Standard Aero Holdings, Inc. (or its permitted successor), a Delaware corporation (the “Company”), the Company and Wells Fargo Bank, National Association, as trustee under the indenture referred to below (the “Trustee”).

WITNESSETH

     WHEREAS, the Company has heretofore executed and delivered to the Trustee an indenture (the “Indenture”), dated as of August 20, 2004 providing for the issuance of an unlimited amount of 8¹/4% Senior Subordinated Notes due 2014 (the “Notes”);

     WHEREAS, the Indenture provides that under certain circumstances the Guarantors will execute and deliver to the Trustee a supplemental indenture pursuant to which the Guarantors will unconditionally guarantee all of the Company’s Obligations (as defined in the Indenture) under the Notes and the Indenture on the terms and conditions set forth herein (the “Subsidiary Guarantee”); and

     WHEREAS, pursuant to Section 9.01 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, the Guarantors 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 will have the meanings assigned to them in the Indenture.

     2. Agreement To Guarantee. Each Guarantor hereby agrees as follows:

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3. Execution And Delivery Of Subsidiary Guarantees.

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4. Guarantor May Consolidate, etc. on Certain Terms.

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5. Releases.

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     6. No Recourse Against Others. No past, present or future director, officer, employee, incorporator, stockholder or agent of any Guarantor, as such, will have any liability for any Obligations of the Company or any Guarantor under the Notes, any Subsidiary 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 SEC that such a waiver is against public policy.

     7. NEW YORK LAW TO GOVERN. THIS SUPPLEMENTAL INDENTURE WILL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

     8. Counterparts. The parties may sign any number of copies of this Supplemental Indenture. Each signed copy will 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 will not affect the construction hereof.

     10. The Trustee. The Trustee will 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 the Guarantors and the Company.

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     IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed and attested, all as of the date first above written.

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