Exhibit 4.6

EXECUTION VERSION

AAR CORP.

2.25 % Convertible Senior Notes due 20 16

Registration Rights Agreement

February  11 , 2008

MERRILL LYNCH & CO.

Merrill Lynch, Pierce, Fenner & Smith

                                                                    Incorporated

as Representative of the several Purchasers

4 World Financial Center

New York, New York  10080

Ladies and Gentlemen:

AAR CORP., a Delaware corporation (the “Company”), proposes to issue and sell to the Purchasers (as defined herein) upon the terms set forth in the Purchase Agreement (as defined herein) its 2.25 % Convertible Senior Notes due 20 16 (the “Securities”).  As an inducement to the Purchasers to enter into the Purchase Agreement and in satisfaction of a condition to the obligations of the Purchasers thereunder, the Company agrees with the Purchasers for the benefit of Holders (as defined herein) from time to time of the Registrable Securities (as defined herein) as follows:

1.                                        Definitions.

(a)                                   Capitalized terms used herein without definition shall have the meanings ascribed to them in the Purchase Agreement.  As used in this Agreement, the following defined terms shall have the following meanings:

“Affiliate” of any specified person means any other person which, directly or indirectly, is in control of, is controlled by, or is under common control with such specified person.  For purposes of this definition, control of a person means the power, direct or indirect, to direct or cause the direction of the management and policies of such person whether by contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

“Closing Date” means the Initial Closing Time as defined in the Purchase Agreement.

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“Commission” means the United States Securities and Exchange Commission, or any other federal agency at the time administering the Exchange Act or the Securities Act, whichever is the relevant statute for the particular purpose.

“Common Stock” means the Company’s common stock, par value $1.00 per share, together with any associated share purchase rights.

“DTC” means The Depository Trust Company.

“Effectiveness Period” has the meaning assigned thereto in Section 2(b)(i) hereof.

“Effective Time” means the time at which the Commission declares the Shelf Registration Statement effective or at which the Shelf Registration Statement otherwise becomes effective.

“Electing Holder” has the meaning assigned thereto in Section 3(a)(iii) hereof.

“Exchange Act” means the United States Securities Exchange Act of 1934, as amended.

“FINRA Rules” means the Rules of the Financial Industry Regulatory Authority, as amended from time to time.

“Holder” means any person that is the record owner of Registrable Securities (and includes any person that has a beneficial interest in any Registrable Security in book-entry form).

“Indenture” means the Indenture, dated as of February  11 , 2008, between the Company and U.S. Bank National Association, as trustee, as amended and supplemented from time to time in accordance with its terms.

“Issuer Free Writing Prospectus” has the meaning assigned thereto in Section 2(d) hereof.

“Liquidated Damages” has the meaning assigned thereto in Section 7(a) hereof.

“Managing Underwriters” means the investment banker or investment bankers and manager or managers that shall administer an underwritten offering, if any, conducted pursuant to Section 6 hereof.

“Notice and Questionnaire” means a Notice of Registration Statement and Selling Securityholder Questionnaire substantially in the form of Appendix A hereto.

The term “person” means an individual, partnership, corporation, limited liability company, trust or unincorporated organization, or a government or agency or political subdivision thereof.

“Prospectus” means the prospectus (including, without limitation, any preliminary prospectus, any final prospectus and any prospectus that discloses information previously omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430B under the Securities Act) included in the Shelf Registration Statement, as amended or

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supplemented by any prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by the Shelf Registration Statement and by all other amendments and supplements to such prospectus, including all material incorporated by reference in such prospectus and all documents filed after the date of such prospectus by the Company under the Exchange Act and incorporated by reference therein.  Any information included in the Prospectus that was omitted from the Shelf Registration Statement at the time it became effective but that is deemed to be part of and included in the Shelf Registration Statement pursuant to Rule 430B(f) is referred to as the “Rule 430B Information.”

“Purchase Agreement” means the purchase agreement, dated as of February  5 , 2008, between the Purchasers and the Company relating to the Securities.

“Purchasers” means the Purchasers named in Schedule A to the Purchase Agreement.

“Registrable Securities” means all or any portion of the Securities issued from time to time under the Indenture in registered form and the shares of Common Stock issuable upon conversion of such Securities; provided, however, that a Security or a share of Common Stock ceases to be a Registrable Security when it is no longer a Restricted Security.

“Registration Default” has the meaning assigned thereto in Section 7(a) hereof.

“Restricted Securities” means any Securities or shares of Common Stock issuable upon conversion thereof except any such Securities or shares of Common Stock where (i) a Shelf Registration Statement with respect to such Securities or shares of Common Stock shall have become effective under the Securities Act and such Securities or shares of Common Stock shall have been disposed of pursuant to such Shelf Registration Statement, (ii) such Securities or shares of Common Stock shall have been sold to the public pursuant to Rule l44 (or any similar provision then in force, but not Rule 144A) under the Securities Act , (iii) one year has passed since the issue date of the Securities or (iv) such Securities or shares of Common Stock shall have ceased to be outstanding.

“Rules and Regulations” means the published rules and regulations of the Commission promulgated under the Securities Act or the Exchange Act, as in effect at any relevant time.

“Securities Act” means the United States Securities Act of 1933, as amended.

“Shelf Registration” means a registration effected pursuant to Section 2 hereof.

“Shelf Registration Statement” means a “shelf” registration statement filed under the Securities Act providing for the registration of, and the sale on a continuous or delayed basis by the Holders of, all of the Registrable Securities pursuant to Rule 415 under the Securities Act and/or any similar rule that may be adopted by the Commission, filed by the Company pursuant to the provisions of Section 2 of this Agreement, including the Prospectus contained therein, any amendments and supplements to such registration statement, including post-effective amendments, and all exhibits and all material incorporated by reference in such registration statement.

“Suspension Period” has the meaning assigned thereto in Section 2(c) hereof.

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“Trust Indenture Act” means the Trust Indenture Act of 1939, or any successor thereto, and the rules, regulations and forms promulgated thereunder, as the same shall be amended from time to time.

“Underwritten Offering” means a registration in which Registrable Securities are sold to one or more underwriters for reoffering to the public.

The term “underwriter” means any underwriter of Registrable Securities in connection with an offering thereof under a Shelf Registration Statement.

(b)           Wherever there is a reference in this Agreement to a percentage of the “principal amount” of Registrable Securities or to a percentage of Registrable Securities, shares of Common Stock shall be treated as representing the principal amount of Securities that was surrendered for conversion or exchange in order to receive such number of shares of Common Stock.

2.                                        Shelf Registration.

(a)                                   Subject to Section 2(e) of this Agreement, the Company shall, no later than six months of the Closing Date, file with the Commission a Shelf Registration Statement or designate an existing Shelf Registration Statement filed with the Commission relating to the offer and sale of the Registrable Securities by the Holders from time to time in accordance with the methods of distribution elected by such Holders and set forth in such Shelf Registration Statement and, thereafter, shall use its reasonable best efforts to cause such Shelf Registration Statement to be declared or otherwise become effective under the Securities Act no later than six months of the Closing Date; provided, however, that the Company may, upon written notice to all Holders, postpone having the Shelf Registration Statement become effective for a reasonable period not to exceed 90 days if the Company possesses material non-public information, the disclosure of which would have a material adverse effect on the Company and its subsidiaries taken as a whole, if a pending transaction that would be material to the Company and its subsidiaries, taken as a whole, could be materially adversely affected as a result, or if the Company is unable to file financial statements required to be included in a shelf registration statement as a result of a pending litigation; provided, further, however, that no Holder shall be entitled to be named as a selling securityholder in the Shelf Registration Statement or to use the Prospectus forming a part thereof for resales of Registrable Securities unless such Holder is an Electing Holder.

(b)                                  Subject to Section 2(e) of this Agreement, the Company shall use its reasonable best efforts:

(i)                                      to keep the Shelf Registration Statement continuously effective under the Securities Act in order to permit the Prospectus forming a part thereof to be usable by Holders until the earlier of (1) the date on which all of the Securities and the shares of Common Stock issued and issuable upon conversion thereof have been sold pursuant to the Shelf Registration Statement, (2) the date on which all of the outstanding Securities and shares of Common Stock issued and issuable upon conversion thereof and held by Holders who are not Affiliates of the Company may be freely transferred immediately

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pursuant to the second sentence of Rule 144(b)(1)(i) (as such rule shall become effective on February 15, 2008) or any successor rule thereto , (3) one year after the issue date of the Securities and (4) the date on which there are no outstanding Registrable Securities (such period being referred to herein as the “Effectiveness Period”) .

(ii)                                   after the Effective Time of the Shelf Registration Statement, promptly upon the request of any Holder of Registrable Securities that is not then an Electing Holder, to take any action reasonably necessary to enable such Holder to use the Prospectus forming a part thereof for resales of Registrable Securities, including, without limitation, any action necessary to identify such Holder as a selling securityholder in the Shelf Registration Statement; provided, however, that nothing in this subparagraph shall relieve such Holder of the obligation to return a completed and signed Notice and Questionnaire to the Company in accordance with Section 3(a)(ii) hereof; and

(iii)                                if at any time the Securities, pursuant to Article 4.2 of the Indenture, are convertible into securities other than Common Stock, to cause, or to cause any successor under the Indenture to cause, such securities to be included in the Shelf Registration Statement no later than the date on which the Securities may then be convertible into such securities.

The Company shall be deemed not to have used its reasonable best efforts to keep the Shelf Registration Statement effective during the requisite period if the Company voluntarily takes any action that would result in Holders of Registrable Securities covered thereby not being able to offer and sell any of such Registrable Securities during that period, unless such action is (A) required by applicable law and the Company thereafter promptly complies with the requirements of paragraph 3(j) below or (B) permitted pursuant to Section 2(c) below.

(c)                                   The Company may suspend the use of the Prospectus for a period not to exceed 30 days in any 90-day period or an aggregate of 90 days in any 12-month period (each, a “Suspension Period”) if the Board of Directors of the Company shall have determined in good faith that because of valid business reasons (not including avoidance of the Company’s obligations hereunder), including the acquisition or divestiture of assets, pending corporate developments, public filings with the Commission and similar events, it is in the best interests of the Company to suspend such use, and prior to suspending such use the Company provides the Holders with written notice of such suspension, which notice need not specify the nature of the event giving rise to such suspension.

(d)                                  The Company represents and agrees that, unless it obtains the prior consent of the Holders of a majority of the Registrable Securities that are registered under the Shelf Registration Statement at such time or the consent of the Managing Underwriter in connection with any underwritten offering of Registrable Securities, it will not make any offer relating to the Securities that would constitute an “issuer free writing prospectus,” as defined in Rule 433 (an “Issuer Free Writing Prospectus”), or that would otherwise constitute a “free writing prospectus,” as defined in Rule 405, required to be filed with the Commission.  Each Holder represents and agrees that, unless it obtains the prior consent of the Company and any such Managing Underwriter, it will not make any offer relating to the Securities that would constitute a “free writing prospectus,” as defined in Rule 405, required to be filed with the

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Commission.  The Company represents that any Issuer Free Writing Prospectus or a “free writing prospectus”will not include any information that conflicts with the information contained in the Shelf Registration Statement or the Prospectus and, any Issuer Free Writing Prospectus or a “free writing prospectus”, when taken together with the information in the Shelf Registration Statement and the Prospectus, will not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading.

(e)                                   The Company’s obligations pursuant to Sections 2 and 3 of this Agreement shall be suspended during any period in which Holders that are not Affiliates of the Company (and have not been Affiliates of the Company during the preceding three months) (i) do not hold any Registrable Securities or (ii) may freely transfer their Registrable Securities immediately pursuant to Rule 144 (or any similar provision then in force) under the Securities Act, including Rule 144(b)(1)(i) (as such rule shall become effective on February 15, 2008).

3.             Registration Procedures .  In connection with the Shelf Registration Statement, the following provisions shall apply subject to Section 2(e) of this Agreement:

(a)                                   Not less than 30 calendar days prior to the Effective Time of the Shelf Registration Statement, the Company shall mail the Notice and Questionnaire to the Holders of Registrable Securities.  No Holder shall be entitled to be named as a selling securityholder in the Shelf Registration Statement as of the Effective Time, and no Holder shall be entitled to use the Prospectus forming a part thereof for resales of Registrable Securities until such Holder has returned a completed and signed Notice and Questionnaire to the Company; provided, however, to be included in the Registration Statement as of the Effective Time, Holders of Registrable Securities shall have at least 28 calendar days from the date on which the Notice and Questionnaire is first mailed to such Holders to return a completed and signed Notice and Questionnaire to the Company.

(i)                                      After the Effective Time of the Shelf Registration Statement, the Company shall, upon the request of any Holder of Registrable Securities that is not then an Electing Holder, promptly send a Notice and Questionnaire to such Holder.  From and after the Effective Time of the Shelf Registration Statement, the Company shall (A) use reasonable best efforts, within 15 Business Days after receipt, to prepare and file with the Commission (x) any Exchange Act report, (y) a supplement to the Prospectus or, if required by applicable law, a post-effective amendment to the Shelf Registration Statement and (z) any other document required by applicable law, so that the Holder delivering such Notice and Questionnaire is named as a selling securityholder in the Shelf Registration Statement and is permitted to deliver the Prospectus to purchasers of such Holder’s Registrable Securities in accordance with applicable law, and (B) if the Company shall file a post-effective amendment to the Shelf Registration Statement, use its reasonable best efforts to cause such post-effective amendment to become effective under the Securities Act as promptly as is practicable; provided, however, that if a Notice and Questionnaire is delivered to the Company during a Suspension Period, the Company shall not be obligated to take the actions set forth in this clause (ii) until the termination of such Suspension Period; provided further, the Company shall not be obligated to file more than one post-effective amendment in any 90-day period.  Notwithstanding the

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foregoing, if the Registrable Securities are converted as provided under the Indenture, the Company shall use its reasonable best efforts to file the Exchange Act filing, prospectus supplement, post-effective amendment or other document within 10 Business Days of the end of the Conversion Reference Period, as defined in the Indenture; provided, however, that the Company shall not be obligated to take the actions set forth in this sentence during a Suspension Period.

(ii)                                   The term “Electing Holder” shall mean any Holder of Registrable Securities that has returned a completed and signed Notice and Questionnaire to the Company in accordance with Section 3(a)(i) or 3(a)(ii) hereof.

(b)                                  The Company shall furnish to each Electing Holder, prior to the Effective Time, a copy of the Shelf Registration Statement initially filed with the Commission, and shall furnish to such Holders, prior to the filing thereof with the Commission, copies of each amendment thereto and each amendment or supplement, if any, to the Prospectus included therein, and shall use its reasonable best efforts to reflect in each such document, at the Effective Time or when so filed with the Commission, as the case may be, such comments as such Holders and their respective counsel reasonably may propose.

(c)                                   The Company shall promptly take such action as may be necessary so that (i) each of the Shelf Registration Statement and any amendment thereto and the Prospectus forming a part thereof and any amendment or supplement thereto (and each report or other document incorporated therein by reference in each case) complies in all material respects with the Securities Act and the Exchange Act and the respective rules and regulations thereunder, (ii) each of the Shelf Registration Statement and any amendment thereto does not, when it becomes effective, including any Rule 430B Information, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading and (iii) each of the Prospectus forming a part of the Shelf Registration Statement, and any amendment or supplement to such Prospectus, does not at any time during the Effectiveness Period include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(d)                                  The Company shall promptly advise each Electing Holder, and shall confirm such advice in writing if so requested by any such Electing Holder:

(i)                                      when a Shelf Registration Statement and any amendment thereto has been filed with the Commission and when a Shelf Registration Statement or any post-effective amendment thereto has become effective, in each case making a public announcement thereof by release made to Reuters Economic Services and Bloomberg Business News;

(ii)                                   of any request by the Commission for amendments or supplements to the Shelf Registration Statement or the Prospectus included therein or for additional information;

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(iii)                                of the issuance by the Commission of any stop order suspending the effectiveness of the Shelf Registration Statement or the initiation of any proceedings for such purpose;

(iv)                               of the receipt by the Company of any notification with respect to the suspension of the qualification of the securities included in the Shelf Registration Statement for sale in any jurisdiction or the initiation of any proceeding for such purpose; and

(v)                                  of the occurrence of any event or the existence of any state of facts that requires the making of any changes in the Shelf Registration Statement or the Prospectus included therein so that, as of such date, such Shelf Registration Statement and Prospectus do not contain an untrue statement of a material fact and do not omit to state a material fact required to be stated therein or necessary to make the statements therein (in the case of the Prospectus, in light of the circumstances under which they were made) not misleading (which advice shall be accompanied by an instruction to such Holders to suspend the use of the Prospectus until the requisite changes have been made).

(e)                                   The Company shall use its reasonable best efforts to prevent the issuance, and if issued to obtain the withdrawal at the earliest possible time, of any order suspending the effectiveness of the Shelf Registration Statement.

(f)                                     The Company shall furnish to each Electing Holder, without charge, at least one copy of the Shelf Registration Statement and all post-effective amendments thereto, including financial statements and schedules, and, if such Electing Holder so requests in writing, all reports, other documents and exhibits that are filed with or incorporated by reference in the Shelf Registration Statement.

(g)                                  The Company shall, during the Effectiveness Period, deliver to each Electing Holder, without charge, as many copies of the Prospectus (including each preliminary prospectus) included in the Shelf Registration Statement and any amendment or supplement thereto as such Electing Holder may reasonably request; and the Company consents (except during a Suspension Period or during the continuance of any event or the existence of any state of facts described in Section 3(d)(v) above) to the use of the Prospectus and any amendment or supplement thereto by each of the Electing Holders in connection with the offering and sale of the Registrable Securities covered by the Prospectus and any amendment or supplement thereto during the Effectiveness Period.

(h)                                  Prior to any offering of Registrable Securities pursuant to the Shelf Registration Statement, the Company shall (i) register or qualify or cooperate with the Electing Holders and their respective counsel in connection with the registration or qualification of such Registrable Securities for offer and sale under the securities or “blue sky” laws of such jurisdictions within the United States as any Electing Holder may reasonably request, (ii) keep such registrations or qualifications in effect and comply with such laws so as to permit the continuance of offers and sales in such jurisdictions for so long as may be necessary to enable any Electing Holder or underwriter, if any, to complete its distribution of Registrable Securities pursuant to the Shelf Registration Statement, and (iii) take any and all other actions necessary or

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advisable to enable the disposition in such jurisdictions of such Registrable Securities; provided, however, that in no event shall the Company be obligated to (A) qualify as a foreign corporation or as a dealer in securities in any jurisdiction where it would not otherwise be required to so qualify but for this Section 3(h) or (B) file any general consent to service of process in any jurisdiction where it is not as of the date hereof so subject.

(i)                                      Unless any Registrable Securities shall be in book-entry only form, the Company shall cooperate with the Electing Holders to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be sold pursuant to the Shelf Registration Statement, which certificates, if so required by any securities exchange upon which any Registrable Securities are listed, shall be penned, lithographed or engraved, or produced by any combination of such methods, on steel engraved borders, and which certificates shall be free of any restrictive legends and in such permitted denominations and registered in such names as Electing Holders may request in connection with the sale of Registrable Securities pursuant to the Shelf Registration Statement.

(j)                                      Upon the occurrence of any event or the existence of any state of facts contemplated by paragraph 3(d)(v) above, the Company shall promptly prepare a post-effective amendment to any Shelf Registration Statement or an amendment or supplement to the related Prospectus or file any other required document so that, as thereafter delivered to purchasers of the Registrable Securities included therein, the Prospectus will not include an untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.  If the Company notifies the Electing Holders of the occurrence of any event or the existence of any state of facts contemplated by paragraph 3(d)(v) above, the Electing Holders shall suspend the use of the Prospectus until the requisite changes to the Prospectus have been made.

(k)                                   Not later than the Effective Time of the Shelf Registration Statement, the Company shall provide a CUSIP number for the Registrable Securities that are debt securities.

(l)                                      The Company shall use its reasonable best efforts to comply with all applicable Rules and Regulations, and to make generally available to its securityholders as soon as practicable, but in any event not later than eighteen months after (i) the effective date (as defined in Rule 158(c) under the Securities Act) of the Shelf Registration Statement, (ii) the effective date of each post-effective amendment to the Shelf Registration Statement, and (iii) the date of each filing by the Company with the Commission of an Annual Report on Form 10-K that is incorporated by reference in the Shelf Registration Statement, an earning statement of the Company and its subsidiaries complying with Section 11(a) of the Securities Act and the applicable Rules and Regulations (including, at the option of the Company, Rule 158).

(m)                                Not later than the Effective Time of the Shelf Registration Statement, the Company shall cause the Indenture to be qualified under the Trust Indenture Act; in connection with such qualification, the Company shall cooperate with the Trustee under the Indenture and the Holders (as defined in the Indenture) to effect such changes to the Indenture as may be required for such Indenture to be so qualified in accordance with the terms of the Trust Indenture Act; and the Company shall execute, and shall use all reasonable efforts to cause the Trustee to execute, all documents that may be required to effect such changes and all other forms and

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documents required to be filed with the Commission to enable such Indenture to be so qualified in a timely manner.  In the event that any such amendment or modification referred to in this Section 3(m) involves the appointment of a new trustee under the Indenture, the Company shall appoint a new trustee thereunder pursuant to the applicable provisions of the Indenture.

(n)                                  In the event of an underwritten offering conducted pursuant to Section 6 hereof, the Company shall, if requested, promptly include or incorporate in a prospectus supplement or post-effective amendment to the Shelf Registration Statement such information as the Managing Underwriters reasonably agree should be included therein and to which the Company does not reasonably object and shall make all required filings of such prospectus supplement or post-effective amendment as soon as practicable after it is notified of the matters to be included or incorporated in such prospectus supplement or post-effective amendment.

(o)                                  The Company shall enter into such customary agreements (including an underwriting agreement in customary form in the event of an underwritten offering conducted pursuant to Section 6 hereof) and take all other appropriate action in order to expedite and facilitate the registration and disposition of the Registrable Securities, and in connection therewith, if an underwriting agreement is entered into, cause the same to contain indemnification provisions and procedures substantially identical to those set forth in Section 5 hereof with respect to all parties to be indemnified pursuant to Section 5 hereof.

(p)                                  The Company shall:

(i)                                      (A) make reasonably available for inspection by the Electing Holders, any underwriter participating in any disposition pursuant to the Shelf Registration Statement, and any attorney, accountant or other agent retained by such Electing Holders or any such underwriter all relevant financial and other records, pertinent corporate documents and properties of the Company and its subsidiaries, and (B) cause the Company’s officers, directors and employees to supply all information reasonably requested by such Electing Holders or any such underwriter, attorney, accountant or agent in connection with the Shelf Registration Statement, in each case, as is customary for similar due diligence examinations; provided, however, that all records, information and documents that are designated in writing by the Company, in good faith, as confidential shall be kept confidential by such Electing Holders and any such underwriter, attorney, accountant or agent, unless such disclosure is made in connection with a court proceeding or required by law, or such records, information or documents become available to the public generally