ERAU Flashcards
What is a light twin?
a small multi‐engine airplane with a maximum certificated takeoff weight of 6,000 pounds or less.
What is Vsse?
Safe,intentionalone‐engine inoperativespeed.Originallyknownassafesingle enginespeed,itistheminimumspeedtointentionallyrenderthecriticalengine
inoperative
What is Vmc?
Minimumcontrolspeedwiththecriticalengineinoperative.Theminimumspeedat
whichdirectionalcontrolcanbemaintainedunderaveryspecificsetofcircumstances
outlinedin14CFRPart23,AirworthinessStandards
Markedwitharedradiallineonmostairspeedindicators.
• VMConlyaddressesdirectionalcontrol.Thereisnorequirementthattheairplanebe
capableofclimbingatthisairspeed.
What does the blue radial mark on the AS indicator?
Vyse
What is accelerate stop distance?
therunwaylengthrequiredtoacceleratetoaspecifiedspeed
(eitherVRorVLOF,asspecifiedbythemanufacturer),experienceanenginefailure,and
bringtheairplanetoacompletestop.
What is accelerate go distance?
Thehorizontaldistancerequiredtocontinuethetakeoffand
climbto50’AGL.,assuminganenginefailureoccursatVRorVLOF,asspecifiedbythe
manufacturer
What will yield minimum rate of sink if below absolute ceiling?
Vyse
What are the requirements for an aircraft with a weight under 6000 pounds and a Vso of 61 or less?
Thesingle‐enginerateofclimbat5,000’MSLmustsimplybedeterminedwiththe—
- Criticalengineinoperativeanditspropellerintheminimumdragposition
- Remainingengine(s)atnomorethanmaximumcontinuouspower
- Landinggearretracted
- Wingflapsretracted
- Climbspeednotlessthan1.2VS1
Can be negative
What are the requirements for an aircraft with a weight over 6000 pounds or a Vso of 61 or more?
maintainasteadyclimbgradientofatleast1.5percent
atapressurealtitudeof5,000ft.withthe—
1. Criticalengineinoperativeanditspropellerintheminimumdragposition
2. Remainingengine(s)atnomorethanmaximumcontinuouspower
3. Landinggearretracted
4. Wingflapsretracted
5. Climbspeednotlessthan1.2VS1
What happens when an engine fails to the aircraft?
AsymmetricalthrustwillcauseayawingmomentaroundtheC.G.towardsthe
inoperativeengine
Theyawingmomentfromabovewillcausethewingwiththeoperating
enginetomovefasterthroughtheairastheairplaneyaws.Thiscausesafaster
velocityofairoverthewingwiththeoperativeenginemeaningmoreliftonthat
wingandresultsinarolltowardstheinoperativeengine.
–Inducedflow(acceleratedslipstream)overthewingfromtheoperating
engineandlackofinducedflow(acceleratedslipstream)overtheinoperative
enginecausesasymmetricalliftonthewings,resultinginarollingmomentaround
theC.G.towardstheinoperativeengine
Which engine is critical in a conventional twin?
Left
What are the four factors that determine that the left engine is critical?
P-factor
Accelerated slipstream
Spiraling slipstream
Torque
Why does P-factor make the left engine critical?
P‐factoriswherethedescendingpropellerbladecreatesmorethrustthanthe
ascendingblade.Thiscausesasymmetricalthrustoneachsideofthepropeller.Tofigure
outtheeffectontheairplane,theformulaTHRUSTxArm=Momentcanbeused.This
meansthatthelongerthearmfromtheC.G.tothethrust,thelargertheyawingmoment
willbe.
Becausethedescendingpropellerbladeontherightwingenginehasalongerarm(A2)
thanthedescendingpropellerbladeontheleftwingengine(A1),theairplanewillhavea
greateryawingmomenttotheleftiftheleftenginefailsthaniftherightenginefails.
Why does accelerated slipstream make the left engine critical?
Thepropellerswillaccelerateairoverthewings.Morelift
isproducedwherethepropellersacceleratetheairoverthewing.JustasP‐factorcauses
asymmetricalthrustforward,italsoproducesthesameeffectintheasymmetricalairflow
behindthepropeller.
Whenoneenginefails,theacceleratedslipstreamcausesarolltowardstheinoperative
engine.TofigureouttheeffectontheairplanetheformulaLIFTxArm=Momentcan
beused.JustlikeP‐factor,thearmtotherightengineislongerthanthearmtotheleft
engine.Thismeansthatiftheleftenginefails,therollmomentwillbegreatertotheleft
thaniftherightenginefails
Why does torque make the left engine critical?
Astheengineandpropellerrotateinonedirection,they,inturn,trytorotate
theairplaneintheotherdirection.ThisisduetoNewton’sthirdlawwhichstates,“For
everyactionthereisanequalandoppositereaction.”Thisforcealsoactswhenanengine
failsbecausethereisstillasecondoperatingengine
Iftheleftenginefails,theyawingmomentfromtherightengine(thrust)andthetotal
torquewillbothworktogethertoyawandrolltheairplanetotheleft.
What does spiraling slipstream make left critical?
Iftheleftenginefailsthespiralslipstreamwillnothitthetailatall,resultinginno
additionalyawingforce.Iftherightenginefailsthespiralslipstreamwillhittheleftsideof
thetailcausingayawtotheleftintheoppositedirectionoftheyawtotherightcausedby
thefailedengine.Thisyawfromthespiralslipstreamwillhelpopposetheyawfromthe
failedengine
What is Vmc?
Asairspeedisdecreased,therudderbecomeslesseffective.Therefore,morerudder
deflectionwillberequiredtomaintaindirectionalcontrol.Eventually,anairspeedwillbe
reachedwherefullrudderdeflectionwillberequiredtomaintaindirectionalcontrol.At
thispoint,anyfurtherdecreaseinairspeedwillleadtolossofdirectionalcontrol.Itisthis
airspeedatwhichtheairplanereachesVMC
What is Vmc technically?
Minimumcontrolspeedwiththecriticalengineinoperative.
2. Theminimumspeedatwhichdirectionalcontrolcanbemaintainedunderavery
specificsetofcircumstancesasoutlinedin14CFRPart23.
What factors are meet when determining Vmc based on 23.149?
. Mostunfavorableweight‐(notnecessarilymaximumgrossweight)
- Mostunfavorablecenterofgravityposition
- Theairplaneairborneandthegroundeffectnegligible
- Maximumavailabletakeoffpowerinitiallyoneachengine
- Theairplanetrimmedfortakeoff
- Flapsinthetakeoffposition
- Landinggearretracted
- Allpropellercontrolsintherecommendedtakeoffposition.
What must be meet when recovering from Vmc?
Therudderpedalforcerequiredtomaintaincontrolmustnotexceed150pounds.
- Itmustnotbenecessarytoreducepoweroftheoperativeengine(s).
- Theairplanemustnotassumeanydangerousattitude.
- Itmustbepossibletopreventaheadingchangeofmorethan20degrees.
What are four ways to recognize vmc?
Loss of directional control
Stall warning horn
Buffeting before stall
Rapid decay of control effectiveness
What two things are done to recover from Vmc?
Reduce power (reducing asymmetrical thrust) Pitch down (Increase forward airspeed making rudder more effective)
Why does Vmc decrease with density altitude?
sduetothefactthatasdensityaltitude
increasesenginepowerwilldecrease.Thedecreaseinenginepowerresultsinless
asymmetricalthrust,meaningtheyawingfromafailedenginewillbeless
What happens to stall speed with density altitude?
It remains constant
Due to the changes in Vmc and stall speeds what will happen at higher altitudes?
A stall will happen before yaw making it difficult to recover from
What are two things that will cause Vmc to decrease?
Anything that will move CG forward
Anything allowing less rudder to be used
How does power affect Vmc?
Themorepower(thrust)ontheoperatingengine,themorerudderisneededtostopthe
resultingyaw.Usingmorerudderleaveslessavailabletothepilot=VMCspeedincreasesas
powerontheoperatingengineisincreased
How does density altitude increase Vmc?
Asdensityaltitudeincreases,temperatureincreases,pressuredecreases,and/orhumidity
increasestheoutputoftheengineorthrustcreatedbytheenginedecreases.Theless
thrustthatiscreated,thelessrudderinputneededtoopposetheyaw.
How does CG location affect Vmc?
TheC.G.locationchangesthelengthofthearmtotherudder:thelongerthearm,themore
effectivetherudder;themoreeffectivetherudder,thelowerVMC.AstheC.G.moves
forward,VMCdecreases;astheC.G.movesaft,VMCincreases
How does gear postion affect Vmc?
Keel, stabilizing effect
Also moves CG fo forward with nose gear moving forward
(POH says gear and fuel burn do not significantly affect Vmc)
What affect will a windmilling prop have on Vmc?
Awindmillingpropellercreatesmoredragthanafeatheredpropeller.Thisextradragadds
totheyawingfromafailedenginetomakethetotaleffectworse.
What affect will flaps down have on Vmc?
Keel effect
More lift from flaps down will also increase drag counteracting some of the yaw lowering Vmc
What affect will weight have on Vmc?
The more weight the more lift required, then when the plane turns it is split into horizontal and vertical lift. The more weight the more the horizontal component is able to counter yaw
What is true of angle of attack on the rudder?
Theangleofattackontherudderdetermineshowmuchforcetheruddercancreate.Itis
dependentontheangleoftherelativewindtothechordlineoftherudder.Thelargerthe
angleofattack,thelargertheforceproducedbytherudder.Whentheairplaneisbanked,
rudderforceswillactbothintheverticalandhorizontaldirections.
When will a zero slide slip condition occur?
therelativewindisdirectlyparalleltothelongitudinalaxisoftheairplane.Thiscondition
resultsintheminimumamountdragpossiblewhenanengineisfailed
Why is Vmc lowered with 2-3 degrees of bank?
Theangleofattackontherudderislargermakingitmoreeffective.
2. Theamountofrudderneededandusedislessthaninthe0°ofbankscenariosinceit
ismoreeffective.Also,thehorizontalcomponentofliftisnowhelpingtoopposethe
yawfromtheinoperativeengine(meaninglessrudderwillberequired).`
What happens to Vmc with 0 degrees of bank?
Therelativewind,comingfromtheleftofthenose,willcausetheairplanetobeinaslip.
Thiscauses theangleofattackontheruddertobesmalland,therefore,makesitless
effective.
What happens with 8 degrees of bank towards the operative engine?
Thedirectionoftherelativewindwillcreatealargeangleofattackontherudder.This
makesitmoreeffectiveresultingislessrudderinputneededbythepilot.Also,thegreater
amountofhorizontalliftmeansthatlessrudderwillbeneededtomaintainheading.This
resultsinalowerVMC.
What will happen from a bank towards the inop engine?
Bankingtowardstheinoperativeenginewillcausethehorizontalliftfromthewingstoadd
totheyawfromtheinoperativeengine.Therelativewindwillcreateafuselageliftthat
opposestheyaw.Theangleoftherelativewindwiththerudderwillcreateasmallangleof
attackmakingtherudderlesseffective.
How does ground effect affect Vmc?
Thereductioninthrustrequiredmeansthattheairplanewillhaveextrathrust.Theextra
thrustonagoodenginewillcauseagreateramountofyaw.
Increases Vmc
What forces act on the prop to bring it to a high pitch and feathered position and low RPM?
Nitrogen
Hub Spring
counterweights
What can effect the time it takes for the engine to unfeather?
The temperature of the oil
What is the feathering lock operated by?
Centrifugal force
When will the engine feather?
When there is no oil pressure and the speed is above 950 RPM
What is used to move hydraulic fluid?
12 volt reversible pump
Where is the landing gear pump?
Behind the baggage compartment aft bulkhead
How long does landing gear extension and retraction take?
6-7 seconds
What happens once the hydraulic pump is activated?
It moves hydraulic fluid from one side to the other which moves a picton
What is max emergency extension speed?
100
Thisspeedisslowtoallowthenosewheeltogoforwardintotheoncomingair.
Thereisalsoalargespringtohelpassistthenosewheeltoextendforward
What do the squat switches do?
Says if aircraft is airborne or on ground
Left prevents retraction
Right activates stall warning horn and maintenance time
How is the gear held up?
Hydraulic pressure
How is gear locked down?
Down lock hook
When do the three green lights turn on?
When the down limit switches are depressed
When does the red WARN GEAR UNSAFE light illuminate?
When any down limit switches are not depressed or up limit switches are not depressed
What are possible problems if a landing gear light does not turn on?
Thegearisnotlockeddown.
- Anannunciatorlightbulbisburnedout.
- Thereisamalfunctionintheindicatingsystem
What happens when the gear is retracted?
- Gear pump start, pumps fluid to retract side
- Down-locks disengage
- Red light comes on
- Landing gear retracted with hydraulic actuators
- Will continue to build up pressure until pressure switch is engaged
- Up limit switch turns off light
What happens when gear is extended?
- Selector down
- Gear push fluid opposite way
- Landing gear extend assisted by gravity and springs
- Up limit switch not depressed light on
- Operate until all three down limit switches are depressed
- Down limit switches will cause light to turn off and green lights to turn on
When will the gear warning horn go off?
LandinggearisnotDown‐and‐LockedandtheMPisbelow14”ononeorboth
engines.
Thisisaccomplishedbymicro‐switchespositionedonthethrottlequadrantnearthe
throttlesthemselves(notfromaMPindication).Becausethepositioningofthe
micro‐switchesarecriticaltotheaccuracyofhornactuation,anyvariationinthe
locationoftheseswitcheswillcausethegearhorntosoundataMPhigherorlower
than14”,asappropriate.
2. Flapsareextendedtothe2ndor3rdnotchandthelandinggearisnotdownand
locked.
3. IftheGearSelectorswitchisintheUPpositionwhentheairplaneisontheground.
When can you mute the horn?
When not intending to land and when caused by throttles
How does the emergency gear extension work?
Through a pressure relief valve
What does the thermal relief valve do?
thevalvewillopentorelievepressureasaresultof
temperatureandpressurechangesastheairplaneclimbsordescends
What does the high pressure control valve do?
–ifthepressureswitchfailstoshutoffthepumpwhenthe
landinggearisbeingretracted,thisvalvewillopentopreventthegearpumpfrom
buildingexcessivepressureinthehydraulicsystem
What does the low pressure relief valve do?
ifthepumpfailstoshutoffwhenthegearisbeinglowered,
thisvalvewillopenuptopreventanydamagetothegearpumporsystem
Why is the overcenter joint important?
Keeps gear down and locked in event of side load
What kind of ailerons does the semi have?
Frise differential ailerons
Forms a slot so that air flows more smoothly at higher angle of attacks
up 23 down 17
What are the flap positions?
1, 10, 25, 40
What does the scupper drain do?
Remove excess fuel
What kind of alternators are there?
Bekt driven 14 volts 70 amp
What does the alternator control unit do?
A viltage regulator that maintains 14 volts in the system, over voltage relay to take off alt if volt exceeds 17
What kind of battery does it have?
12 volts 35 amp
Where is the battery?
Nose compartment
What are the electrical busses?
BATMAN Battery buss Avionics 1 Tie bus Main Bus Avionics 2 Non-essential bus
What kind of heater is it?
Janitorial combustion heater
Where does the heater get fuel from?
left fuel tank
How does the heater work?
Theheaterdrawsin
outsideairandusesasparkplugandfueltomakea“highvelocitywhirlingflame”.
The
heatfromthisflamewillheatairmovingaroundashroudaroundtheheaterandthenpush
warmairintothecabin.
When plane is in the air there is ram air and a fan for on the ground
Why do you turn the heater fan switch?
Thiswillallowtheheatertocooldownafteruse
