-----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,
 Kguz7SUtO+0MaQbW4PBXuxpwaebMOLqUYGBX7s/Y8XC6dxSxKuD8EPZuDTbHuKuJ
 ivtvZkSyrfE/+TCE1nu+pQ==

<SEC-DOCUMENT>0001140361-10-049914.txt : 20101216
<SEC-HEADER>0001140361-10-049914.hdr.sgml : 20101216
<ACCEPTANCE-DATETIME>20101216123736
ACCESSION NUMBER:		0001140361-10-049914
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101215
FILED AS OF DATE:		20101216
DATE AS OF CHANGE:		20101216

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ELECSYS CORP
		CENTRAL INDEX KEY:			0000914398
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPONENTS, NEC [3679]
		IRS NUMBER:				481099142
		STATE OF INCORPORATION:			KS
		FISCAL YEAR END:			430

	BUSINESS ADDRESS:	
		STREET 1:		15301 W. 109TH STREET
		CITY:			LENEXA
		STATE:			KS
		ZIP:			66219
		BUSINESS PHONE:		9136470158

	MAIL ADDRESS:	
		STREET 1:		15301 W. 109TH STREET
		CITY:			LENEXA
		STATE:			KS
		ZIP:			66219

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AIRPORT SYSTEMS INTERNATIONAL INC
		DATE OF NAME CHANGE:	19931103

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			TAYLOR ROBERT D
		CENTRAL INDEX KEY:			0001132091

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15057
		FILM NUMBER:		101255643

	MAIL ADDRESS:	
		STREET 1:		2440 S PLUMTHICKET DR
		CITY:			ANDOVER
		STATE:			KS
		ZIP:			67002
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000914398</issuerCik>
        <issuerName>ELECSYS CORP</issuerName>
        <issuerTradingSymbol>ESYS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001132091</rptOwnerCik>
            <rptOwnerName>TAYLOR ROBERT D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>846 N. MART-WAY COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OLATHE</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66061</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1336</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.44</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>232536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Todd Daniels, Attorney-in-Fact for Robert D. Taylor</signatureName>
        <signatureDate>2010-12-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----