-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 SKZz7zj/nZFO8hYiuLJ/ngbY0fpqugWhx82UsSFkNV9yOlBs0FFmbyC1CsuZN41X
 +B7kSlnllC1ZisamMU7s9Q==

<SEC-DOCUMENT>0000001750-08-000015.txt : 20080717
<SEC-HEADER>0000001750-08-000015.hdr.sgml : 20080717
<ACCEPTANCE-DATETIME>20080717105014
ACCESSION NUMBER:		0000001750-08-000015
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080715
FILED AS OF DATE:		20080717
DATE AS OF CHANGE:		20080717

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AAR CORP
		CENTRAL INDEX KEY:			0000001750
		STANDARD INDUSTRIAL CLASSIFICATION:	AIRCRAFT & PARTS [3720]
		IRS NUMBER:				362334820
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0531

	BUSINESS ADDRESS:	
		STREET 1:		1100 N WOOD DALE RD
		CITY:			WOOD DALE
		STATE:			IL
		ZIP:			60191
		BUSINESS PHONE:		6302272000

	MAIL ADDRESS:	
		STREET 1:		1100 N WOOD DALE RD
		CITY:			WOOD DALE
		STATE:			IL
		ZIP:			60191

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALLEN AIRCRAFT RADIO INC
		DATE OF NAME CHANGE:	19700204

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CLARK JAMES JOHN
		CENTRAL INDEX KEY:			0001182639

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06263
		FILM NUMBER:		08956226

	BUSINESS ADDRESS:	
		STREET 1:		1100 N WOOD DALE RD
		CITY:			WOOD DALE
		STATE:			IL
		ZIP:			60191
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-07-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000001750</issuerCik>
        <issuerName>AAR CORP</issuerName>
        <issuerTradingSymbol>AIR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182639</rptOwnerCik>
            <rptOwnerName>CLARK JAMES JOHN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Group Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-07-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3534</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.28</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Jo-Ellen Kiddie, Power of Attorney</signatureName>
        <signatureDate>2008-07-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----