-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 pmMBw1LUS8TfzbWzCh2Abw==

<SEC-DOCUMENT>0001185849-03-000001.txt : 20030523
<SEC-HEADER>0001185849-03-000001.hdr.sgml : 20030523
<ACCEPTANCE-DATETIME>20030523170900
ACCESSION NUMBER:		0001185849-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030522
FILED AS OF DATE:		20030523

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SISLOWSKI DAVID
		CENTRAL INDEX KEY:			0001185849

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12805
		FILM NUMBER:		03718689

	BUSINESS ADDRESS:	
		STREET 1:		C/O FRONTIER AIRLINES
		STREET 2:		7001 TOWER RD.
		CITY:			DENVER
		STATE:			CO
		ZIP:			80249

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FRONTIER AIRLINES INC /CO/
		CENTRAL INDEX KEY:			0000921929
		STANDARD INDUSTRIAL CLASSIFICATION:	AIR TRANSPORTATION, SCHEDULED [4512]
		IRS NUMBER:				841256945
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		7001 TOWER ROAD
		CITY:			DENVER
		STATE:			CO
		ZIP:			80249
		BUSINESS PHONE:		7203744200

	MAIL ADDRESS:	
		STREET 1:		7001 TOWER ROAD
		CITY:			DENVER
		STATE:			CO
		ZIP:			80249
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-05-22</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000921929</issuerCik>
        <issuerName>FRONTIER AIRLINES INC /CO/</issuerName>
        <issuerTradingSymbol>FRNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185849</rptOwnerCik>
            <rptOwnerName>SISLOWSKI DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>V.P. &amp; General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Employee Stock Option</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>5.15</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-04-01</value>
            <footnoteId id="F1"/>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>30000</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2004-04-01</value>
            <footnoteId id="F2"/>
        </exerciseDate>
        <expirationDate>
            <value>2013-04-01</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>30000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>30000</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Employee Stock Option</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>6.15</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-05-22</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>5000</value>
            </transactionShares>
            <transactionValue>
                <value>0</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2004-05-22</value>
            <footnoteId id="F2"/>
        </exerciseDate>
        <expirationDate>
            <value>2013-05-22</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>5000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>5000</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">Grant authorized by the action of the Company Board of Directores on May 22, 2003.</footnote>
        <footnote id="F2">1/5 of the options become exerciseable on the first anniversary of the Transaction Date, with an additional 1/5 becoming exercisable on each subsequent anniversary.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David S. Sislowski</signatureName>
        <signatureDate>2003-05-23</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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