AMENDED AND RESTATED FIRST NON-NEGOTIABLE PROMISSORYNOTE

Exhibit 10.6

EXECUTION VERSION

AMENDED AND RESTATED FIRST NON-NEGOTIABLE PROMISSORY NOTE

ABX Air, Inc., a Delaware corporation (the “Maker”), for value received, hereby unconditionally promises to pay to DHL Express (USA), Inc., an Ohio corporation (the “Holder”), as successor to Airborne, Inc., a Delaware corporation, the principal sum of $31,000,000, plus all accrued but unpaid interest thereon, at 12:00 noon New York time on or before August 15, 2028 (the “Payment Date”), at the offices of DPWN Holdings (USA), Inc. (“DPWN Holdings”), 1200 South Pine Island Road, Suite 3000, Plantation, FL 33321, or to make such payment at such other place as may otherwise be directed in writing by the Holder from time to time in accordance with the terms of this Amended and Restated First Non-Negotiable Promissory Note (this “Note”). The terms and conditions of this Note are set forth below.

Terms and Provisions

Section 1. Payments. All payments to be made by the Maker hereunder shall be made without set-off or counterclaim, in United States dollars in immediately available funds at the office of DPWN Holdings or such other place as may be designated by the Holder in writing from time to time. Whenever any payment hereunder shall be stated to be due on a day that is not a Business Day (as defined in Section 10), such payment shall be made on the next succeeding Business Day.

Section 2. Interest.

(a) This Note shall bear interest from the date hereof at a rate of five percent (5%) per annum. Prior to the Payment Date, accrued interest shall be payable in immediately available funds on each December 1^st and June 1^st, commencing on June 1, 2009. Interest shall be computed on the basis of a year of 365/366 days for actual days elapsed. Accrued interest also shall be payable on demand in respect of any past due amounts and upon payment in full of this Note on the Payment Date. Interest shall accrue and be paid by the Maker in arrears. Anything in this Note to the contrary notwithstanding, the Holder shall not be permitted to charge or receive, and the Maker shall not be obligated to pay, interest in excess of the maximum rate from time to time permitted by applicable law.

(b) Any principal, interest or any other amount hereunder which is not paid when due (whether as stated, by acceleration or otherwise) shall, to the extent permitted by law, thereafter bear interest at a rate of two percent (2%) per annum above the rate described above.

Section 3. Prepayment. The Maker may at any time and from time to time, with two (2) Business Days prior written notice to the Holder, prepay in immediately available funds, this Note in whole or in part without premium or penalty; provided that such prepayment is accompanied by the payment of all unpaid interest accrued to the date of prepayment and any other amounts due under this Note; and provided, further, that, except for required prepayments called for under Section 8(b), each partial prepayment shall be in an amount not less than $100,000 or a whole multiple thereof (or, if less, the remaining outstanding principal amount thereof). Amounts prepaid may not be re-borrowed.

Section 4. Repayment on a Change of Control. The Maker shall give the Holder written notice in the event of a Change of Control (as defined below) that occurs after the date hereof at or prior to its consummation prior to the Payment Date. Upon receipt of such notice, the Holder shall have 60 days to demand in writing the repayment in full of this Note, including all accrued but unpaid interest, and the Maker hereby unconditionally agrees that it shall, on the second (2^nd) Business Day following the receipt of such demand from the Holder, pay to the Holder, in immediately available funds, an amount equal to the entire outstanding principal amount of this Note, plus all accrued but unpaid interest thereon.

For purposes of this Note, a “Change of Control” means the occurrence of any of the following after the date of this Note: (i) during any period of two (2) consecutive years, individuals who at the beginning of such period constituted the directors of ATSG (as defined in Section 10) (together with any new directors whose election by such directors or whose nomination for election by the stockholders of ATSG was approved by a vote of a majority of the directors of ATSG then still in office who were either directors at the beginning of such period or whose election or nomination for election was previously so approved), cease for any reason to constitute a majority of the directors of ATSG then in office, (ii) (A) any merger, consolidation or other business combination of ATSG with or into any other entity, or any other similar transaction, whether in a single transaction or series of related transactions where (1) the stockholders of ATSG, immediately prior to such transaction in the aggregate, cease to own at least fifty percent (50%) of the voting securities of the entity surviving or resulting from such transaction (or the ultimate parent thereof) (such ownership being based solely on the voting securities of ATSG owned by such stockholders immediately prior to such event) or (2) any Person (as defined in Section 10) becomes the beneficial owner of more than fifty percent (50%) of the voting securities of the entity surviving or resulting from such transaction (or the ultimate parent thereof) with ATSG or (B) a change in the ownership of the Maker such that ATSG (or the ultimate parent thereof) fails directly or through one or more Subsidiaries to (1) own legally and beneficially at least 51%, on a fully diluted basis, of the issued and outstanding voting securities of the Maker or (2) have the power to direct or cause the direction of the management and policies of the Maker, (iii) any transaction or series of related transactions after which in excess of fifty percent (50%) of ATSG’s (or the ultimate parent thereof) voting power is held by any Person or group (within the meaning of Regulation 13D under the Securities Exchange Act of 1934), or (iv) any sale, transfer, lease, assignment, conveyance, exchange, mortgage or other disposition of all or substantially all of the assets, property or business of ATSG and its Subsidiaries, taken as a whole, other than (A) in connection with the granting of any security interest or other lien pursuant to the Senior Credit Facility (provided, however, that if any secured party takes possession or control of any material portion of such pledged assets, for any purpose other than to perfect its security interest in such pledged asset, a Change of Control shall be deemed to have occurred) or (B) any transaction in the ordinary course of business involving the sale and leaseback of any aircraft (provided, however, that such transaction does not involve all or substantially all of the aircraft of ATSG and its Subsidiaries, taken as a whole). Without limiting the generality of the foregoing, a “Change of Control” shall not include any transaction consummated before the date of this Note.

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Section 5. Representations and Warranties. The Maker hereby represents and warrants to the Holder that (i) the Maker is duly organized, validly existing and in good standing under the laws of its jurisdiction of organization, has the full power and authority to make, deliver and perform this Note and its obligations hereunder on the terms and conditions hereof, (ii) the execution, delivery and performance of this Note have been duly authorized by the Maker, and this Note has been duly executed and delivered on behalf of the Maker, (iii) no consent or authorization of, filing with, notice to or other act by or in respect of, any Governmental Authority (as defined in Section 10) or any other Person is required in connection with the debt hereunder or with the execution, delivery, performance, validity or enforceability of this Note, except for consents, authorizations, filings and notices that have been obtained or made and are in full force and effect, (iv) this Note constitutes a legal, valid and binding obligation of the Maker enforceable against it in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the enforcement of creditors’ rights generally and by general equitable principles (whether enforcement is sought by proceedings in equity or at law), (v) the execution, delivery and performance of this Note will not violate any requirement of law or any of the applicable articles or certificates of incorporation, bylaws or similar organizational documents of the Maker or its Subsidiaries and (vi) no Event of Default (as defined below) has occurred and is continuing.

Section 6. Events of Default. If:

(a) the Maker fails to pay the principal amount in accordance with the terms of this Note;

(b) the Maker fails to pay any interest on this Note or any fee or any other amount (other than an amount referred to in clauses (a) or (h) of this Section 6) payable under this Note, when and as the same shall become due and payable, and such failure shall continue unremedied for a period of thirty (30) days;

(c) the Maker fails to observe or perform in any material respect any covenant, condition or agreement contained in this Note, and such default shall continue for a period of sixty (60) days after notice is given by the Holder to comply with such covenant, condition or agreement;

(d) any representation or warranty made by the Maker in or in connection with this Note or any amendment or modification hereof or waiver hereunder proves to have been incorrect in any material respect when made and such defect shall continue for a period of sixty (60) days after notice is given by the Holder to comply with such representation or warranty;

(e) by virtue of a default by the Maker or, as applicable, any of its Affiliates or Subsidiaries under the Senior Credit Facility, the entire indebtedness outstanding under the Senior Credit Facility has been accelerated by the holders of such indebtedness, and, thereby, such indebtedness becomes immediately due and payable in advance of the regularly scheduled maturity date for such indebtedness;

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(f) the Maker or any of its Affiliates or Subsidiaries commences any case, proceeding or other action (i) under any existing or future law of any jurisdiction, domestic or foreign, relating to bankruptcy, insolvency, reorganization or relief of debtors, seeking to have an order for relief entered with respect to it, or seeking to adjudicate it bankrupt or insolvent, or seeking reorganization, arrangement, adjustment, winding-up, liquidation, dissolution, composition or other relief with respect to its debts, or (ii) seeking appointment of a receiver, trustee, custodian or other similar official for any substantial part of its assets, or the Maker makes a general assignment for the benefit of its creditors;

(g) there shall be commenced against the Maker or any of its Subsidiaries any case, proceeding or other action of a nature referred to in paragraph (f) above which (i) results in the entry of an order for relief for any such adjudication or appointment or (ii) remains undismissed, undischarged or unbonded for a period of sixty (60) days; or

(h) the Maker fails to make any payment to the Holder in accordance with Section 8(b) of this Note on the date that the first payment made in connection with any transaction contemplated by Section 8(b) of this Note is made;

then, and in any such event (each, an “Event of Default”), the Holder may, by notice of default given to the Maker in writing (including by facsimile transmission), declare any unpaid principal, accrued but unpaid interest and all other amounts payable under this Note to be immediately due and payable without presentment, demand, protest or other notice of any kind on the part of the Holder. Any cure periods provided for in this Section 6 shall be available from time to time in respect of subsequent failures or deficiencies so long as this Note remains outstanding.

Section 7. Ranking. The obligations of the Maker in respect of this Note shall rank pari passu with all other unsecured debt of the Maker that is not expressly subordinated to the indebtedness outstanding hereunder.

Section 8. Covenants. Until the principal of and interest and all other amounts due on this Note have been paid in full, the Maker covenants and agrees with the Holder that:

(a) Intentionally Omitted.

(b) Restricted Payments.

(i) ATSG, its Subsidiaries and Affiliates shall not purchase or otherwise acquire, directly or indirectly, the issued and outstanding shares of common stock or other equity interests of ATSG, unless, concurrently therewith, the Maker prepays the principal outstanding balance of this Note in the amount of Twenty Cents ($0.20) for each dollar expended by ATSG and its Subsidiaries and Affiliates for the purchase or other acquisition of such stock or other equity interests.

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(ii) ATSG, its Subsidiaries and Affiliates shall not declare, make or pay, directly or indirectly, any dividend or other distribution to the stockholders of ATSG (other than a dividend or other distribution (including, without limitation, a stock split) paid solely in capital stock of ATSG) unless, concurrently therewith, the Maker prepays the principal outstanding balance of this Note in the amount of Twenty Cents ($0.20) for each dollar that ATSG and its Subsidiaries and Affiliates pays or distributes to ATSG’s stockholders in the form of a dividend or other distribution.

(c) Limitations on Asset Sales. ATSG shall not, and shall not permit any of its Subsidiaries to, sell, lease, convey, transfer or otherwise dispose, whether in a single transaction or a series of related transactions, of any property or asset, including (subject to this Section 8(c)) the capital stock of any Subsidiary (any such event, an “Asset Sale”), unless the consideration received from such Asset Sale is at least equal to the fair market value of the property, asset or capital stock sold as determined in good faith (taking into account any assumption of indebtedness in connection with such disposition, if any) by resolution of the Board of Directors of ATSG or the applicable Subsidiary thereof; provided, however, that a board resolution shall not be required for any bona fide arm’s-length (i) Asset Sale made in the ordinary course of business consistent with past practice, (ii) sale-leaseback transaction or (iii) Asset Sale involving aggregate consideration of less than $10,000,000. Notwithstanding anything to the contrary in this Section 8(c), neither (A) the granting by ATSG or its Subsidiaries of a security interest, mortgage, collateral assignment, pledge or other lien on any property or asset nor (B) the enforcement by the holder of any security interest, mortgage, collateral assignment, pledge or other lien on any property or asset of ATSG and/or its Subsidiaries shall violate the terms of this Section 8(c) or result in an Event of Default.

(d) Intentionally Omitted.

(e) Notices. The Maker hereby covenants that so long as any principal, interest or other amount remains outstanding and unpaid under this Note, the Maker shall notify the Holder promptly (and in any event, within three (3) Business Days) upon the occurrence of any Event of Default of which it has knowledge.

(f) Financial Statements. The Maker shall furnish to the Holder:

(i) as soon as available, but in any event not later that ninety (90) days after the end of each fiscal year of the Maker, a copy of the audited consolidated balance sheet of ATSG and its consolidated Subsidiaries as at the end of such year and the related audited consolidated statements of income and of cash flows for such year prepared in accordance with GAAP, setting forth in each case in comparative form the figures for the previous year and certified by independent certified public accountants of nationally recognized standing; and

(ii) as soon as available, but in any event not later than forty-five (45) days after the end of each of the first three quarterly periods of each fiscal year of the Maker, the unaudited consolidated balance sheet of ATSG and its consolidated Subsidiaries as at the end of such quarter and the related unaudited consolidated statements of income and of cash flows for such quarter and the portion of the fiscal year through the end of such

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quarter prepared in accordance with GAAP, setting forth in each case in comparative form the figures for the previous year, certified by the chief executive officer, president or chief financial officer of the Maker, but in any event, with respect to financial matters, the chief financial officer of the Maker (each a “Responsible Officer”) as being fairly stated in all material respects (subject to normal year-end audit adjustments and the omission of footnotes); provided, however, that no such certification shall be required with respect to any such period for which the Maker is required to file such financial statements pursuant to the Securities Exchange Act of 1934, as amended.

(g) Certificates; Other Information. The Maker shall furnish to the Holder:

(i) concurrently with the delivery of the financial statements referred to in clause (f)(i) of this Section 8, a certificate of the independent certified public accountants reporting on such financial statements stating that in making the examination necessary therefor no knowledge was obtained of any Event of Default, except as specified in such certificate; provided, however, that no such certification shall be required with respect to any such period for which the Maker is required to file such financial statements pursuant to the Securities Exchange Act of 1934, as amended;

(ii) concurrently with the delivery of any financial statements pursuant to clause (f) of this Section 8, a certificate of a Responsible Officer stating that, to the best of such Responsible Officer’s knowledge, the Maker during such period has observed or performed in all material respects all of its covenants and other agreements, and satisfied in all material respects every condition contained in this Note to be observed, performed or satisfied by it, and that such Responsible Officer has obtained no knowledge of any Event of Default except as specified in such certificate; and

(iii) promptly, such additional financial and other information as the Holder may from time to time reasonably request.

Section 9. Fees and Expenses. The Maker agrees to pay all of the Holder’s reasonable costs and out-of-pocket expenses (including fees and disbursements of counsel) arising after the date hereof in connection with the enforcement of, and preservation of rights under, this Note; provided, however, in connection with any legal action, Holder shall not be entitled to such costs or expenses if Holder does not prevail. The Maker agrees to indemnify the Holder for, and to hold the Holder harmless from, any loss (exclusive of any consequential, special, exemplary, punitive or lost profit damages) or expense (including, for avoidance of doubt, fees and disbursements of counsel) which the Holder may sustain or incur as a consequence of default by the Maker in payment of any principal of or interest or any other amount on this Note.

Section 10. Definitions. As used in this Note, the following terms shall have the following meanings:

“Affiliates” means, with respect to any specified Person, any other Person that, directly or indirectly, controls, is controlled by or is under common control with, such specified Person. For purposes of this definition, “control” (including, with correlative meanings, the

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terms “controlled by” and “under common control with”), as used with respect to any Person, means the possession, directly or indirectly, of the power to direct or cause the direction of the management or policies of such Person, whether through the ownership of voting securities, by contract or otherwise.

“ATSG” means Air Transport Services Group, Inc., a Delaware corporation.

“Business Day” means any day other than a Saturday or Sunday or a day on which national banking institutions in the City of New York, New York are authorized or obligated by law or executive order to be closed.

“GAAP” means generally accepted accounting principles in the United States of America as in effect from time to time.

“Governmental Authority” means any foreign, federal, state, provincial or local government or any agency, authority, subdivision or instrumentality of any of the foregoing, including any court, tribunal, department, bureau, commission or board, or any quasi-governmental or private body exercising any regulatory, taxing, inspecting or other governmental authority.

“Legal Requirement” means any statute, ordinance, code, law, rule, regulation, order or other requirement, standard or procedure enacted, adopted or applied by any Governmental Authority (including judicial decisions applying common law or interpreting any other Legal Requirement) applicable to a Person, its business and its operations.

“Payment Date” means the earlier of (i) August 15, 2028 or (ii) the date on which all sums under this Note become immediately due and payable.

“Person” means a natural person, corporation, partnership, limited partnership, limited liability company, trust or unincorporated organization or similar entity, or a Governmental Authority.

“Senior Credit Facility” means the Credit Agreement, dated as of December 31, 2007, among ABX Holdings, Inc., now known as ATSG, the Maker, CHI Acquisition Corp., the Lenders from time to time party thereto, SunTrust Bank, as Administrative Agent, Regions Bank, as Syndication Agent, and Fifth Third Bank and Merrill Lynch Commercial Finance Corp., as Co-Documentation Agents, including any notes, guarantees, collateral and security documents, instruments and agreements executed in connection therewith (including Hedge Agreements related to the Indebtedness, as defined in and incurred thereunder), and in each case as amended, restated or refinanced from time to time, including any agreement extending the maturity of, refinancing, replacing or otherwise restructuring (including increasing the amount of borrowings or other Indebtedness outstanding or available to be borrowed thereunder) all or any portion of the Indebtedness under such agreements, and any successor or replacement agreement or agreements with the same or any other agents, creditor, lender or group of creditors or lenders.

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“Subsidiary” means, with respect to any Person, another Person (i) of which greater than fifty percent (50%) of the capital stock, voting securities, other ownership or equity interests having voting power under ordinary circumstances to elect directors or similar members of the governing body of such corporation or other entity (or, if there are no such voting interests, greater than fifty percent (50%) of the equity interests) are owned or controlled, directly or indirectly, by such first Person or (ii) of which such first Person is a general partner or similar controlling member or otherwise has the ability to designate a majority of the members of the board of directors or other controlling body thereof.

Section 11. Governing Law; Venue. This Note shall be governed by and construed and enforced in accordance with the laws of the State of New York. The Maker and the Holder, by accepting this Note, irrevocably and unconditionally: (i) agree to be subject to, and hereby consents and submits to, the exclusive jurisdiction of the United States District Court for the Southern District Court of New York located in the borough of Manhattan in the City of New York, or if such court does not have jurisdiction, the Supreme Court of the State of New York, New York County, for the purposes of any suit, action or other proceeding arising out of this Note or any of the transactions contemplated hereby, (ii) agree not to commence any legal proceedings related hereto except in such courts, (iii) to the extent such party is not otherwise subject to service of process in the State of New York, appoint The Corporation Trust Company (or any successor thereof), as such party’s agent in the State of New York for acceptance of legal process, (iv) agree that service made on any such agent set forth in (iii) above shall have the same legal force and effect as if served upon such party personally within such state and (v) agree that a final judgment in any such action or proceeding shall be conclusive and may be enforced in other jurisdictions by suit on the judgment or in any other manner specified by law.

Section 12. Successors and Assigns; Assignment. This Note shall inure to the benefit of, and be binding upon, the Holder and the Maker and their respective successors and permitted assigns. Except as expressly provided herein, this Note may not be transferred or assigned by either the Maker or the Holder without the prior written consent of the other; provided that the Holder may transfer and assign this Note to DHL Worldwide Express B.V. or any of its controlled Affiliates without the Maker’s prior consent.

Section 13. Entire Agreement. This Note, the letter agreement dated March 16, 2009 between the Maker and DPWN Holdings and its Subsidiaries, and the Guaranty, dated as of May 8, 2009, by and between ATSG and the Holder constitute the full and entire understanding and agreement between the Holder and the Maker with regard to the subjects hereof.

Section 14. Severability. In case any provision of this Note shall be invalid, illegal or unenforceable in any jurisdiction, such provision shall be ineffective to the extent of such invalidity, illegality or unenforceability without affecting or impairing the validity, legality and enforceability of the remaining provisions hereof, and any such invalidity, illegality or unenforceability shall not invalidate or render illegal or unenforceable such provision in any other jurisdiction.

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Section 15. Amendment and Waiver. Subject to applicable law, this Note may only be amended pursuant to a written agreement executed by each of the Maker and either (x) DPWN Holdings or its successor entity or (y) any subsequent permitted Holder pursuant to Section 12, and no waiver of compliance with any provision or condition of this Note, and no consent provided for in this Note shall be effective unless evidenced by a written instrument executed by each of the Maker and either (A) DPWN Holdings or its successor entity or (B) any subsequent permitted Holder pursuant to Section 12. No waiver of any term or provision of this Note shall be construed as a further or continuing waiver of such term or provision or any other term or provision.

Section 16. Delays or Omissions. It is agreed that no delay or omission to exercise any right, power or remedy accruing to any party, upon any breach, default or noncompliance by another party under this Note, shall impair any such right, power or remedy, nor shall it be construed to be a waiver of any such breach, default or noncompliance, or any acquiescence therein, or of any similar breach, default or noncompliance thereafter occurring.

Section 17. Notices. All notices, requests, claims, demands and other communications under this Note shall be in writing and shall be deemed to have been duly given to the Holder or the Maker if delivered in person or sent by overnight delivery (providing proof of delivery) to such party at the following addresses (or at such other address for the Holder or the Maker as shall be specified by like notice) on the date of delivery, or if by facsimile, upon confirmation of receipt:

Section 18. Titles and Subtitles. The titles of the sections and subsections of this Note are for convenience of reference only and are not to be considered in construing this Note.

Section 19. Mutilated, Destroyed or Missing Notes. If a mutilated Note is surrendered to the Maker or the Maker receives evidence to its satisfaction of the destruction, loss or theft of this Note, the Maker shall issue a replacement Note. If reasonably required by the Maker, an indemnity bond must be supplied by the Holder that is sufficient in the reasonable judgment of the Maker to protect the Maker from any loss it may suffer if this Note is replaced. The Maker may charge for any reasonable expenses in replacing this Note.

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Section 20. Waiver of Presentment, Demand and Dishonor. The Maker hereby waives presentment, demand, protest or other notice or formality of any kind with respect to this Note except as demand or notice is expressly provided for in this Note.

Section 21. Confidentiality. The Holder covenants and agrees that, except as required by the provisions of any Legal Requirement for which the Holder is obligated, the Holder shall use commercially reasonable efforts not to disclose any information provided to it hereunder.

Section 22. Reduction of Principal Amount. The Holder acknowledges that the principal amount set forth in this Note may be reduced pursuant to the terms of the ACMI Agreement.

Section 23. Prior Note. This Note, issued on May 8, 2009, supersedes and replaces in its entirety that certain First Non-Negotiable Promissory Note issued on August 15, 2003 in the original principal amount of $92,948,714 (the “Prior Note”). Immediately prior to the execution and delivery of this Note, (i) the unpaid principal balance of the Prior Note was $92,275,656, (ii) the Maker made a payment in the aggregate amount of $15,000,000 to the Holder which was applied to the unpaid principal balance of the Prior Note, and (iii) the Holder irrevocably and permanently forgave an aggregate outstanding principal amount of $46,275,656. Accordingly, (i) the original principal balance of this Note as of the date hereof is $31,000,000 and (ii) this Note continues the obligations of the Maker to the Holder under the Prior Note, as amended and restated hereby, only to the extent of the unpaid principal balance of $31,000,000.

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IN WITNESS WHEREOF, the Maker has caused this Note to be duly executed and delivered by its duly authorized officer as of the date first written above.