Textron Cessna - Page 61

McCAULEYPROPELLERSYSTEMS
CONSTANTSPEEDCOMPOSITEOWNER/OPERATOR
INFORMATIONMANUAL
8.LightningStrikeInspectionRequirements
A.Ifdoubtexistsastotheoccurrenceofalightningstrike,thefollowingcriteriacanbeusedtoverifyany
suspicionofalightningstrike:
(1)Checkforburnsorsignsofarcingontheblades,hub,andspinner.
(2)Usingamagnetismdetector,checkallexposedsteelareasofpropellerformagnetism.Apositive
magneticindicationsuggeststhepropellerwasstruckbylightening.
NOTE:Anyacceptedindustrystandardmagneticdetectiondeviceispermittedtobeusedto
testformagnetismintheexposedsteelpartsofthepropeller.
(3)Lookforanysignsoflocalizedmeltingormetalow,particularlyonthepropellerblades.
(a)Checktheleadingedgeguardofeachpropellerbladefordiscolorationordisbond.
(4)Examineallareasofmissingpaintforsignsofalightningstrike.
(5)Ifpreliminaryinspectionsuggestsanactualstrike,acompletepropelleroverhaulistobe
accomplishedinaccordancewiththeapplicableMcCauleyoverhaulmanualbyanFAA
approvedPart145PropellerRepairStationorinternationalequivalentbypersonneltrainedto
overhaulMcCauleycompositepropellers.
9.PropellerOverspeedInspectionRequirements
A.ThefollowingareinspectioncriteriaforMcCauleypropellersinvolvedinanoverspeedcondition.
PercentageOverspeed
ActiontobeTaken
Upto,andincluding10%(110%
actual)
Generalexternalvisualinspection.
Nofurtheractionrequired.
AllC3400ModelSeries
Propellers
Morethan10%(morethan110%
actual)
ContactMcCauleyProductSupport
fordisposition.
10.NormalCriteriaforStaticBladeShakeandTwistofVariablePitchPropellers
A.BladeShake
(1)Bladeshakeisdenedasfollows:
(2)Thetendencyforthepropellerbladestowobbleslightlywhenthetipisphysicallymovedby
hand,leadedgetotrailedge,(RefertoFigure601)isknownasbladeshake.
(a)ThistendencyisanaturalresultofthefabricationofpartswithintheMcCauleyretention
system.Whileaccumulationoftolerancesismeasuredinthousandthsofaninch,itmust
berememberedthatboththepartscausingbladeshake,andthepivotpointaboutwhich
thebladerotates,arenearthebladeroot.Asaresult,verysmalldifferencesattheblade
rootwillbemagniedmanytimeswhenmeasuredatthetip.
(3)Normalbladeshakeisnocauseforconcern,asitdisappearsduringpropellerrotationduetothe
highcentrifugalforcesactingontheblades(15,000to20,000pounds.(66,723to89,000N)).
NOTE:TheMcCauleyC3400seriespropellersdonotrequireabladeshakecheck.The
uniquefeaturesofthecompositebladeandtheSpring-AntiBladeShakeresultsin
apropellerbladeinstallationthatdoesnotrequireabladeshakecheck.
B.BladeTwist
(1)TwoCategoriesofBladeTwistexist.Theyaredenedasfollows:
(2)Rotationalplayisdenedasthesumtotalofrotationalmovementapropellerbladeallowswhen
movedbyhandarounditsaxisofrotation(RefertoFigure601).
(a)Thismovementis,toalimiteddegree,considerednormalandshouldnotbecausefor
concern.Allbladesinapropellershouldhaveaboutthesameamountofrotationalplay.
(b)Ifthedifferenceinrotationalplaybetweentwobladesisbeyond1.0degree,uneveninternal
wearand/ordamageisthepossiblecause.
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