**EXHIBIT 4.2****FIRST SUPPLEMENTAL INDENTURE**          **THIS FIRST SUPPLEMENTAL INDENTURE**(this “Supplemental Indenture”), dated as of October25, 2005, is made by and among Argo-Tech Corporation, a Delaware corporation (the“Company”), Argo-Tech Corporation (Aftermarket), a Delaware corporation(“Aftermarket”), Argo-Tech Corporation (HBP), a Delaware corporation (“HBP”),Argo-Tech Corporation (OEM), a Delaware corporation (“OEM”), Argo-Tech Corporation CostaMesa, a California corporation (“Costa Mesa”) and Durodyne, Inc., an Arizona corporation(“Durodyne,” and together with Aftermarket, HBP, OEM and Costa Mesa, the “SubsidiaryGuarantors”), and BNY Midwest Trust Company, an Illinois trust company organized under the lawsof the State of Illinois (the “Trustee”), as Trustee.**RECITALS:**     A. The Company, the Subsidiary Guarantors, and the Trustee are parties to an Indenture datedas of June 23, 2004 (the “Indenture”).     B. Pursuant to the Indenture, the Company issued and the Trustee authenticated and deliveredan aggregate principal amount of $250,000,000 of the Company’s 91/4% Senior Notes due 2011.     C. Section 9.2 of the Indenture provides, among other things, that with the written consent ofthe Holders of at least a majority in principal amount of the Securities then outstanding (the“Requisite Consents”), the Company, the Subsidiary Guarantors and the Trustee may amend theIndenture or the Securities, subject to certain exceptions specified in Section 9.2 of theIndenture.     D. On October 6, 2005, the Company mailed a Consent Solicitation Statement (as amended,modified, or supplemented, the “Solicitation Statement”) to each Holder.     E. The Company has obtained the Requisite Consents to amend the Indenture in certain respects(the “Proposed Amendments”).     F. This Supplemental Indenture has been duly authorized by all necessary corporate action onthe part of the Company and the Subsidiary Guarantors.     G. The Company has delivered, or caused to be delivered, to the Trustee an Officers’Certificate and an Opinion of Counsel meeting the requirements of Section 9.6 of the Indenture.     **NOW THEREFORE**, each party agrees for the benefit of the other parties and for the equal andratable benefit of all Securityholders, as follows:
 

 
**AGREEMENT:**     **Section 1. Definitions.**Capitalized terms used in this Supplemental Indenture and nototherwise defined herein have the meanings given to them in the Indenture.     **Section 2. Amendments.**     **2.1 Amendment of Certain Sections of the Indenture.**Subject to Section 3.1 hereof, theIndenture is hereby amended in the following respects: (a) Section 3.3 of the Indenture is hereby amended to read in itsentirety as follows:     SECTION 3.3. Limitation on Restricted Payments. The Company shall not, and shall not permitany of its Restricted Subsidiaries, directly or indirectly, to: (1) declare or pay any dividend or make any distribution (whether made in cash,securities or other property) on or in respect of its Capital Stock (including anypayment in connection with any merger or consolidation involving the Company or any ofits Restricted Subsidiaries) except: (a) dividends or distributions payable in Capital Stock of theCompany (other than Disqualified Stock) or in options, warrants or other rightsto purchase such Capital Stock of the Company; and  (b) dividends or distributions payable to the Company or aRestricted Subsidiary (and if such Restricted Subsidiary is not a Wholly-OwnedSubsidiary, to its other holders of common Capital Stock on a pro rata basis); (2) purchase, redeem, retire or otherwise acquire for value any Capital Stock ofthe Company or any direct or indirect parent of the Company held by Persons other thanthe Company or a Restricted Subsidiary (other than in exchange for Capital Stock of theCompany (other than Disqualified Stock));  (3) purchase, repurchase, redeem, defease or otherwise acquire or retire for value,prior to scheduled maturity, scheduled repayment or scheduled sinking fund payment, anySubordinated Obligations or Guarantor Subordinated Obligations (other than thepurchase, repurchase, redemption, defeasance or other acquisition or retirement ofSubordinated Obligations or Guarantor Subordinated Obligations purchased inanticipation of satisfying a sinking fund obligation, principal installment or finalmaturity, in each case due within one year of the date of purchase, repurchase,redemption, defeasance or other acquisition or retirement); or  (4) make any Restricted Investment in any Person;
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(any such dividend, distribution, purchase, redemption, repurchase, defeasance, other acquisition,retirement or Restricted Investment referred to in clauses (1) through (4) shall be referred toherein as a “Restricted Payment”), if at the time the Company or such Restricted Subsidiary makessuch Restricted Payment: (a) a Default shall have occurred and be continuing (or wouldresult therefrom); or  (b) the Company is not able to Incur an additional $1.00 ofIndebtedness pursuant to the first paragraph under Section 3.2 after givingeffect, on a pro forma basis, to such Restricted Payment; or  (c) the aggregate amount of such Restricted Payment and all otherRestricted Payments declared or made subsequent to the Issue Date (excludingthe Restricted Payments permitted by clauses (1), (2), (3), (4), (7), (8),(9)(a), (9)(c), (9)(d), (9)(e), 9(g) and (11) of the following paragraph only)would exceed the sum of: (i) 50% of Consolidated Net Income for the period(treated as one accounting period) from the beginning of the firstfiscal quarter commencing after the date of this Indenture to the endof the most recent fiscal quarter ending prior to the date of suchRestricted Payment for which financial statements are in existence (or,in case such Consolidated Net Income is a deficit minus 100% of suchdeficit);  (ii) 100% of the aggregate Net Cash Proceedsreceived by the Company from the issue or sale of its Capital Stock(other than Disqualified Stock) or other capital contributionssubsequent to the Issue Date (other than Net Cash Proceeds receivedfrom an issuance or sale of such Capital Stock to a Subsidiary of theCompany or an employee stock ownership plan, option plan or similartrust to the extent such sale to an employee stock ownership plan orsimilar trust is financed by loans from or Guaranteed by the Company orany Restricted Subsidiary unless such loans have been repaid with cashon or prior to the date of determination);  (iii) the amount by which Indebtedness of theCompany or its Restricted Subsidiaries is reduced on the Company’sbalance sheet upon the conversion or exchange (other than by aSubsidiary of the Company) subsequent to the Issue Date of anyIndebtedness of the Company or its Restricted Subsidiaries convertibleor exchangeable for Capital Stock (other than Disqualified Stock) ofthe Company (less the amount of any cash, or the fair market value ofany other property, distributed by the Company upon such conversion orexchange); and
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 (iv) the amount equal to the net reduction inRestricted Investments made by the Company or any of its RestrictedSubsidiaries in any Person resulting from: (A) repurchases or redemptions ofsuch Restricted Investments by such Person, proceeds realizedupon the sale of such Restricted Investment to an unaffiliatedpurchaser, repayments of loans or advances or other transfers ofassets (including by way of dividend or distribution) by suchPerson to the Company or any Restricted Subsidiary; or  (B) the redesignation of UnrestrictedSubsidiaries as Restricted Subsidiaries (valued in each case asprovided in the definition of “Investment”) not to exceed, inthe case of any Unrestricted Subsidiary, the amount ofInvestments previously made by the Company or any RestrictedSubsidiary in such Unrestricted Subsidiary,which amount in each case under this clause (iv) was included in thecalculation of the amount of Restricted Payments; *provided, however*,that no amount will be included under this clause (iv) to the extentit is already included in Consolidated Net Income.     The provisions of the preceding paragraph shall not prohibit: (1) any purchase, repurchase, redemption, defeasance or other acquisition orretirement of Capital Stock, Disqualified Stock, Subordinated Obligations of theCompany or Guarantor Subordinated Obligations of any Subsidiary Guarantor made byexchange for, or out of the proceeds of the substantially concurrent sale of, CapitalStock of the Company (other than Disqualified Stock and other than Capital Stock issuedor sold to a Subsidiary or an employee stock ownership plan or similar trust to theextent such sale to an employee stock ownership plan or similar trust is financed byloans from or Guaranteed by the Company or any Restricted Subsidiary unless such loanshave been repaid with cash on or prior to the date of determination); *provided,however*, that the Net Cash Proceeds from such sale of Capital Stock will be excludedfrom clause (c)(ii) of the preceding paragraph;  (2) any purchase, repurchase, redemption, defeasance or other acquisition orretirement of Subordinated Obligations of the Company or Guarantor SubordinatedObligations of any Subsidiary Guarantor made by exchange for, or out of the proceeds ofthe substantially concurrent sale of, Subordinated Obligations of the Company or anypurchase, repurchase, redemption, defeasance or other acquisition or retirement ofGuarantor Subordinated Obligations made by exchange for or out of the proceeds of thesubstantially concurrent sale of Guarantor Subordinated Obligations that, in each case,is permitted to be Incurred
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   pursuant to Section 3.2 and that in each case constitutes Refinancing Indebtedness;  (3) any purchase, repurchase, redemption, defeasance or other acquisition orretirement of Disqualified Stock of the Company or a Restricted Subsidiary made byexchange for or out of the proceeds of the substantially concurrent sale ofDisqualified Stock of the Company or such Restricted Subsidiary, as the case may be,that, in each case, is permitted to be Incurred pursuant to Section 3.2 and that ineach case constitutes Refinancing Indebtedness;  (4) so long as no Default or Event of Default has occurred and is continuing, anypurchase or redemption of Subordinated Obligations or Guarantor SubordinatedObligations of a Subsidiary Guarantor from Net Available Cash to the extent permittedunder Section 3.5 below;  (5) dividends paid within 60 days after the date of declaration if at such date ofdeclaration such dividend would have complied with this provision;  (6) so long as no Default or Event of Default has occurred and is continuing, (a) the purchase, redemption or other acquisition, cancellation orretirement for value of Capital Stock, or options, warrants, equityappreciation rights or other rights to purchase or acquire Capital Stock of theCompany or any Restricted Subsidiary or any parent of the Company held by anyexisting or former directors, employees or officers of the Company or Holdingsor any Subsidiary of the Company or their assigns, estates or heirs, in eachcase in connection with the repurchase provisions under employee stock optionor stock purchase agreements or other agreements to compensate employees;*provided*that such redemptions or repurchases pursuant to this clause shall notexceed $3.5 million in the aggregate during any calendar year (with amounts notbeing used in any calendar year being carried forward to subsequent calendaryears; *provided*that the aggregate amount in any calendar year may not exceed$10.0 million);  (b) the purchase, redemption or other acquisition, cancellation orretirement for value of Capital Stock of the Company, any Restricted Subsidiaryor Holdings held by any existing or former directors, employees or officers ofthe Company or Holdings or any Subsidiary of the Company or their assigns,estates or heirs, made by exchange for Subordinated Obligations of the Companyin connection with the repurchase provisions of the Company’s Employee StockOwnership Plan and Trust Agreement, as amended, as in effect on the Issue Dateand only to the extent of amounts mandatorily required to be purchased,redeemed, acquired, cancelled or retired by such Employee Stock Ownership Planand Trust Agreement, as amended, as in effect on the Issue Date; and
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 (c) loans or advances to employees or directors of the Company orHoldings or any Subsidiary of the Company the proceeds of which are used topurchase Capital Stock of the Company or Holdings, in an aggregate principalamount not in excess of $1.0 million at any one time outstanding; *provided,however*, that the Company and its Subsidiaries shall comply in all materialrespects with all applicable provisions of the Sarbanes-Oxley Act and the rulesand regulations promulgated in connection therewith relating to such loans andadvances; (7) so long as no Default or Event of Default has occurred and is continuing, thedeclaration and payment of dividends to holders of any class or series of DisqualifiedStock of the Company issued in accordance with the terms of this Indenture to theextent such dividends are included in the definition of “Consolidated InterestExpense”;  (8) repurchases of Capital Stock deemed to occur upon the exercise of stockoptions, warrants or other convertible securities if such Capital Stock represents aportion of the exercise price thereof;  (9) cash dividends or loans to Holdings in amounts equal to: (a) the amounts required for Holdings to pay any Federal, state orlocal income taxes to the extent that such income taxes are directlyattributable to the income of the Company and its Restricted Subsidiaries;  (b) to the extent of amounts actually received by the Company fromits Unrestricted Subsidiaries, the amounts required for Holdings to pay anyFederal, state or local income taxes to the extent that such income taxes aredirectly attributable to the income of such Unrestricted Subsidiaries;  (c) the amounts required for Holdings to pay franchise taxes andother fees required to maintain its legal existence;  (d) an amount not to exceed $0.5 million in any fiscal year topermit Holdings to pay its corporate overhead expenses Incurred in the ordinarycourse of business, and to pay salaries or other compensation of employees whoperform services for both Holdings and the Company;  (e) an amount not to exceed $57.6 million to enable Holdings toredeem all of the outstanding shares of Holdings’ Series A CumulativeExchangeable Redeemable Preferred Stock on the Issue Date;  (f) the amounts required to enable Holdings to effect anytransaction permitted under clause (6) of this paragraph, to the extentpermitted by such clause, in lieu of the Company or any Restricted Subsidiary;and  (g) an amount not to exceed $5.0 million in connection with theconsummation of the Agreement and Plan of Merger, dated September 13,
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   2005, by and among Holdings, V.G.A.T. Investors, LLC, Vaughn Merger Sub,Inc., the Company and GreatBanc Trust Company, as Trustee of the Argo-TechCorporation Employee Stock Ownership Plan and Trust. (10) the purchase, repurchase, redemption, defeasance or other acquisition orretirement for value of any Subordinated Obligation (i) at a purchase price not greaterthan 101% of the principal amount of such Subordinated Obligation in the event of aChange of Control in accordance with provisions similar to Section 3.10 or (ii) at apurchase price not greater than 100% of the principal amount thereof in accordance withprovisions similar to Section 3.5; *provided*that, prior to or simultaneously with suchpurchase, repurchase, redemption, defeasance or other acquisition or retirement, theCompany has made the Change of Control Offer or Asset Disposition Offer, as applicable,as provided in such covenant with respect to the Securities and has completed therepurchase or redemption of all Securities validly tendered for payment in connectionwith such Change of Control Offer or Asset Disposition Offer; and  (11) Restricted Payments in an amount not to exceed $5.0 million.     The amount of all Restricted Payments (other than cash) shall be the fair market value on thedate of such Restricted Payment of the asset(s) or securities proposed to be paid, transferred orissued by the Company or such Restricted Subsidiary, as the case may be, pursuant to suchRestricted Payment. The fair market value of any cash Restricted Payment shall be its face amountand any non-cash Restricted Payment shall be determined conclusively by the Board of Directors ofthe Company acting in good faith whose resolution with respect thereto shall be delivered to theTrustee, such determination to be based upon an opinion or appraisal issued by an accounting,appraisal or investment banking firm of national standing if such fair market value is estimated ingood faith by the Board of Directors of the Company to exceed $20.0 million. Not later than thedate of making any Restricted Payment, the Company shall deliver to the Trustee an Officers’Certificate stating that such Restricted Payment is permitted and setting forth the basis uponwhich the calculations required by this Section 3.3 were computed, together with a copy of anyfairness opinion or appraisal required by this Indenture. (b) Section 3.11 of the Indenture is hereby amended to read in itsentirety as follows:          SECTION 3.11. SEC Reports. Notwithstanding that the Company may not be subject to thereporting requirements of Section 13 or 15(d) of the Exchange Act, to the extent permitted by theExchange Act, the Company shall file with the SEC, and make available to the Trustee and theregistered Holders of the Securities, the annual reports and the information, documents and otherreports (or copies of such portions of any of the foregoing as the SEC may by rules and regulationsprescribe) that are specified in Sections 13 and 15(d) of the Exchange Act within the time periodsspecified therein. In the event that the Company is not permitted to file such reports, documentsand information with the SEC pursuant to the Exchange Act, the Company shall nevertheless makeavailable such Exchange Act information to the Trustee and the Holders of the Securities as if theCompany were subject to the reporting requirements of Section 13 or 15(d) of the Exchange Actwithin the time periods specified therein.
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     In addition, if at any time Holdings (1) Guarantees the obligations and liabilities of theCompany hereunder (there being no obligation of Holdings to do so), (2) holds no material assetsother than cash, Cash Equivalents, the Capital Stock of Argo Tracker Corporation, a wholly ownedsubsidiary of Holdings, and the Capital Stock of the Company or of any direct or indirect parententity of the Company that only engages in similar activities (and performs the related incidentalactivities associated with such ownership) and (3) complies with the requirements of Rule 3-10 ofRegulation S-X promulgated by the SEC (or any successor provision), the reports, documents andinformation required to be furnished to the Trustee and the registered Holders of the Securitiespursuant to this covenant may, at the option of the Company, be furnished by and be those ofHoldings rather than the Company.     If the Company has designated any of its Subsidiaries as Unrestricted Subsidiaries, then thequarterly and annual financial information required by the preceding paragraphs shall include areasonably detailed presentation, either on the face of the financial statements or in thefootnotes to the financial statements and in Management’s Discussion and Analysis of Results ofOperations and Financial Condition, of the financial condition and results of operations of theCompany and its Restricted Subsidiaries.     **2.2 Amendment of Certain Provisions of the Securities.**Subject to Section 3.1 hereof, theSecurities are hereby amended or are deemed to have been amended in the following respects: Theprovisions in the Securities corresponding to the provisions in the Indenture that are amended byvirtue of Section 2.1 hereof are correspondingly amended in the Securities to the same extent asthe Indenture is amended by Section 2.1 hereof.     **Section 3. Miscellaneous.**     **3.1 Effect of Supplemental Indenture.**Upon the execution and delivery of this SupplementalIndenture by the Company, the Subsidiary Guarantors, and the Trustee, the Indenture shall besupplemented in accordance herewith, and this Supplemental Indenture shall form a part of theIndenture for all purposes, and every Securityholder holding Securities that have been heretoforeor hereafter authenticated and delivered under the Indenture shall be bound thereby;provided, however, that Sections 2.1 and 2.2 hereof will not become operativeunless and until the Sale, as such term is defined in the Solicitation Statement that was providedto Securityholders in connection with the Company’s solicitation of consents (the“Solicitation”) of such Securityholders to the Proposed Amendments, is consummated and theother conditions to the Solicitation are satisfied or waived.     **3.2 Indenture Remains in Full Force and Effect.**Except as supplemented hereby, all provisionsof the Indenture shall remain in full force and effect.     **3.3 Indenture and Supplemental Indenture Construed Together.**This Supplemental Indenture isan indenture supplemental to and in implementation of the Indenture, and the Indenture and thisSupplemental Indenture shall henceforth be read and construed together.     **3.4 Confirmation and Preservation of the Indenture.**The Indenture as supplemented by thisSupplemental Indenture is in all respects confirmed and preserved.
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     **3.5 Conflict with Trust Indenture Act.**If any provision of this Supplemental Indenturelimits, qualifies, or conflicts with any provision of the Trust Indenture Act of 1939, as amended(the “Act”), that is required under such Act to be part of and govern any provision of thisSupplemental Indenture, the provision of such Act shall control. If any provision of thisSupplemental Indenture modifies or excludes any provision of the Act that may be so modified orexcluded, the provisions of the Act shall be deemed to apply to the Indenture as so modified or tobe excluded by this Supplemental Indenture, as the case may be.     **3.6 Trustee Not Responsible for Recitals.**The recitals contained herein shall be taken as thestatements of the Company and the Trustee assumes no responsibility for their correctness. TheTrustee makes no representation as to the validity or adequacy of this Supplemental Indenture.     **3.7 Certain Duties and Responsibilities of the Trustee.**In entering into this SupplementalIndenture, the Trustee shall be entitled to the benefit of every provision of the Indenturerelating to the conduct or affecting the liability of or affording protection to the Trustee,whether or not elsewhere herein so provided, including specifically the Trustee’s rights toindemnification contained in Section 7.7 of the Indenture.     **3.8 Separability Clause.**In case any provision of this Supplemental Indenture shall beinvalid, illegal, or unenforceable, the validity, legality, and enforceability of the remainingprovisions shall not in any way be affected or impaired thereby.     **3.9 Effect of Headings.**The Section and Subsection headings herein are for convenience onlyand shall not affect the construction hereof.     **3.10 Benefits of Supplemental Indenture.**Nothing in this Supplemental Indenture, theIndenture, or the Securities, express or implied, shall give to any Person, other than the partieshereto and thereto and their successors hereunder and thereunder, and the Securityholders, anybenefit of any legal or equitable right, remedy, or claim under the Indenture, this SupplementalIndenture, or the Securities.     **3.11 Successors and Assigns.**All covenants and agreements in this Supplemental Indenture bythe Company shall bind its successors and permitted assigns, whether so expressed or not.     **3.12 Governing Law.**THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED INACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK. EACH OF THE PARTIES HERETO AGREES TO SUBMIT TOTHE JURISDICTION OF THE COURTS OF THE STATE OF NEW YORK IN ANY ACTION OR PROCEEDING ARISING OUT OFOR RELATING TO THIS SUPPLEMENTAL INDENTURE.     **3.13 Counterparts.**This Supplemental Indenture may be executed in counterparts (including bymeans of facsimile signature pages), each of which shall be an original, but all such counterpartsshall together constitute one and the same instrument.
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*[Remainder of Page Blank – Signature Page Follows]*
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     **IN WITNESS WHEREOF**, the parties hereto have caused this Supplemental Indenture to be dulyexecuted as of the date and the year first written above.     **ARGO-TECH CORPORATION**  **ARGO-TECH CORPORATION (HBP)**  **ARGO-TECH CORPORATION (OEM)**  **ARGO-TECH CORPORATION**  **(AFTERMARKET)**  **ARGO-TECH CORPORATION COSTA MESA**  **DURODYNE, INC.**         By: /s/ Paul R. Keen        Name: Paul R. Keen      Title: Vice President             **BNY MIDWEST TRUST COMPANY**             By: /s/ J. Bartolini              Name: J. Bartolini       Title: Vice President