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The alternators when connected are usually connected ?

Deepen > EASA

exemple reponse 132

Other study patent: Telepilote theorique examen 27

The capacity of an accumulator is ?

exemple reponse 133
The capacity of an accumulator The quantity of electricity that battery can supply during discharge. a battery's capacity the quantity of electricity that it can supply during discharge the more electrolyte electrode material there in cell greater capacity of cell a small cell has less capacity than a larger cell with same chemistry they develop same open circuit voltage because of chemical reactions within cells capacity of a battery depends on discharge conditions such as magnitude of current (which may vary with time) allowable terminal voltage of battery temperature other factors the available capacity of a battery depends upon rate at which it discharged if a battery discharged at a relatively high rate available capacity will be lower than expected.

The moving part in an AC generator is usually referred to as the ?

exemple reponse 134
The moving part in an ac generator usually referred to as The quantity of electricity that battery can supply during discharge. a battery's capacity the quantity of electricity that it can supply during discharge the more electrolyte electrode material there in cell greater capacity of cell a small cell has less capacity than a larger cell with same chemistry they develop same open circuit voltage because of chemical reactions within cells capacity of a battery depends on discharge conditions such as magnitude of current (which may vary with time) allowable terminal voltage of battery temperature other factors the available capacity of a battery depends upon rate at which it discharged if a battery discharged at a relatively high rate available capacity will be lower than expected.

  • exemple reponse 135
    The purpose of bonding metallic parts of an aircraft to Provide safe distribution of electrical charges currents. the single earth return uses aircraft structure as a return path if component not electrical it does not need a return path but still requires bonding to equalise potential difference in event of static build up this why answer provide a single earth electrical devices false.

  • exemple reponse 136
    A constant speed drive aims at ensuring That electric generator produces a constant frequency. the single earth return uses aircraft structure as a return path if component not electrical it does not need a return path but still requires bonding to equalise potential difference in event of static build up this why answer provide a single earth electrical devices false.

  • exemple reponse 137
    When a persistent underexcitation fault detected on an ac generator connected to aircraft mains with another ac generator protection device opens The exciter control relay generator breaker the tie breaker. A control relay a 'magnetic switch' which can isolate a circuit so in effect same as a 'breaker' an 'exciter breaker' an 'exciter control relay' are in effect same thing an exciter breaker (exciter control relay) will isolate power to voltage regulator the generator breaker will isolate generator from bus bar the tie breaker will isolate two different bus bars from each other or can connect two generators to same bus bar in most cases you will want to keep bus bars connected so that you can use all your services so you will trip generator breaker to isolate generator from bus bar the exciter breaker so you effectively shut down that generator if you have 2 generators supplying same single bus bar then you will trip tie breaker to isolate generator the generator exciter breakers to isolate shut down generator.

  • exemple reponse 138
    A test to assess state of charge of a lead acid battery would involve Comparing 'on loa 'off loa battery voltages. A control relay a 'magnetic switch' which can isolate a circuit so in effect same as a 'breaker' an 'exciter breaker' an 'exciter control relay' are in effect same thing an exciter breaker (exciter control relay) will isolate power to voltage regulator the generator breaker will isolate generator from bus bar the tie breaker will isolate two different bus bars from each other or can connect two generators to same bus bar in most cases you will want to keep bus bars connected so that you can use all your services so you will trip generator breaker to isolate generator from bus bar the exciter breaker so you effectively shut down that generator if you have 2 generators supplying same single bus bar then you will trip tie breaker to isolate generator the generator exciter breakers to isolate shut down generator.

  • Question 27-8

    The advantages of grounding negative pole of aircraft structure are 1 weight saving 2 easy fault detection 3 increase of short circuit risk 4 reduction of short circuit risk 5 circuits are not single wired lines the combination regrouping all correct statements Comparing 'on loa 'off loa battery voltages. the fuselage used as an earth return electrical components on an aircraft which means that you only need one length of cable (the battery will be connected its negative pole) this saves weight space as you don't need two cables to complete a circuit statement 3 increase of short circuit risk not an advantage statement 5 circuits are not single wired lines wrong correct answer '1 2 4' the most correct one even if we are not totally agree with.

  • Question 27-9

    When an 'open circuit' occurs in an electrical supply system Loss of continuity will prevent its working components from functioning. short circuit (open circuit) fault as most common failure of aircraft electrical power supply system when an 'open circuit' occurs components connected on circuit cease to operate.

  • Question 27-10

    An ac generator driven a csd unit Requires a voltage controller to maintain constant voltage under load. The csd (constant speed drive) a hydro mechanical unit fitted between engine gearbox the generator its function to maintain a constant generator speed regardless of engine speed for a three phase generator to maintain 400hz this would be 8000 rpm although generator speed remains constant electrical load will vary according to services selected to maintain a steady output voltage strength of field (excitation) controlled the voltage regulator.

  • Question 27-11

    Consider variable pitch propeller of a turbo prop during deceleration When braking propeller supplies negative thrust absorbs engine power. when braking it means when you move power lever in reverse or beta range in 'reverse' pitch position engine/propeller turns in same direction as in normal (forward) pitch position but propeller blade angle positioned to other side of flat pitch in reverse pitch air pushed away from airplane rather than being drawn over it reverse pitch results in braking action rather than forward thrust of airplane.

  • Question 27-12

    The correct formula to calculate total displacement of a multi cylinder piston engine the Piston area x piston stroke x number of cylinders. when braking it means when you move power lever in reverse or beta range in 'reverse' pitch position engine/propeller turns in same direction as in normal (forward) pitch position but propeller blade angle positioned to other side of flat pitch in reverse pitch air pushed away from airplane rather than being drawn over it reverse pitch results in braking action rather than forward thrust of airplane.

  • Question 27-13

    When changing power on engines equipped with constant speed propeller engine overload avoided Increasing rpm before increasing manifold pressure. A small trick propeller´s control the bravest the first to enter (increase rpm before increase map) the last to leave (decrease map before decrease rpm.

  • Question 27-14

    The blade angle of a constant speed propeller Increases with increasing true air speed. When it refers to blade angle it refers to angle between chord line the direction of propeller rotation the important bit in this question that it a constant speed prop you are correct in that angle of attack does decrease as forward speed increases so thrust decreases as well therefore rpm would increase csu would sense increase in rpm would then increase blade angle to reduce rpm down to correct speed restore lost thrust.

  • Question 27-15

    A propeller blade twisted so as to Keep local angle of attack constant along blade. The angle of attack the angle between blade chord line the relative airflow trouble is relative airflow different along blade the blade rotating so bit nearest hub has a small speed at right angles to way aircraft going but bit near tip moving rapidly across aircraft flight path to put real numbers on to this a 10 ft blade doing 3000rpm will have a tip speed of about 300mph so if aircraft going forward at 300mph relative airflow hitting tip at 45deg off aircraft centre line thus if you want tip to have same angle of attack as root you have to twist blade 45deg along its length the speed past tip will now be more like 440mph in total so if angle of attack the chord length were same you would get a lot more lift (thrust) out toward tip but only reason why you might not want extra thrust because it might bend blade and if that worries you you can taper blade reducing chord length blade design always a compromise but if you want best efficiency (least fuel consumption) in cruise you will twist blade so all sections reach their most efficient angle of attack at same time.

  • Question 27-16

    A pilot can actuate feathering system Pulling propeller control lever rearwards. by pulling propeller control lever fully rearwards you will feather propeller (to minimize drag in event of an engine failure example) in normal flight you will pull or push propeller control lever to adjust blade pitch the different phases of flight (climb cruise descent) .

  • Question 27-17

    When increasing true airspeed with a constant engine rpm angle of attack of a fixed pitch propeller Pulling propeller control lever rearwards. With fixed propellers throttle controls rpm variations in forward speed affect angle of attack which varies in line with amount of airflow into propeller disc if you increase speed angle of attack reduces if you slow down it increases affecting lift/drag ratio meaning that a fixed pitch propeller gets less efficient as you move away from its optimum speed which usually set cruise.

  • Question 27-18

    A pressure relief valve in an oil system that does not seat correctly could result in Pulling propeller control lever rearwards. To prevent too high a pressure a pressure release valve (prv) fitted it comprises a stainless steel ball bearing a spring the ball forced the spring against an oil port when oil pressure sufficiently high ball if forced off its seat oil allowed to bypass this restriction thus making sure that pressure never gets too high if pressure relief valve not hermetic there will be a leak the pressure decreases.

  • Question 27-19

    In case of engine failure during flight blades of a constant speed propeller in a single engine aeroplane not fitted with feathering system Move in lowest pitch position the centrifugal force and/or spring force. In event of a problem causing engine to stop propeller goes to minimum pitch in order to reduce drag permits pilot to try to restart engine(if possible) with less drag you will have less propeller torque allowing a windmilling start a constant speed propeller system will make use of centrifugal force oil or gas pressure or a spring to reduce pitch.

  • Question 27-20

    For take off correct combination of propeller pitch 1 and propeller lever position 2 at brake release Move in lowest pitch position the centrifugal force and/or spring force. Pushing propeller control lever fully forward selects max rpm in order to achieve this propeller goes to a fine pitch this also called low pitch! high pitch would be a coarse pitch position .

  • Question 27-21

    For piston engines mixture ratio the ratio between Mass of fuel mass of air entering cylinder. Pushing propeller control lever fully forward selects max rpm in order to achieve this propeller goes to a fine pitch this also called low pitch! high pitch would be a coarse pitch position .

  • Question 27-22

    Variations in mixture ratios carburettors are achieved the adjustment of Mass of fuel mass of air entering cylinder. Pushing propeller control lever fully forward selects max rpm in order to achieve this propeller goes to a fine pitch this also called low pitch! high pitch would be a coarse pitch position .

  • Question 27-23

    As altitude increases mixture ratio of a piston engine should be adjusted to Reduce fuel flow in order to compensate the decreasing air density. Pushing propeller control lever fully forward selects max rpm in order to achieve this propeller goes to a fine pitch this also called low pitch! high pitch would be a coarse pitch position .

  • Question 27-24

    When applying carburettor heating The mixture becomes richer. When you apply carburettor heating air (which will mix with fuel in carburettor) passes around muffler (or exhaust pipe) in order to be heated to avoid risks of icing the air's density decreases as air heated what generates a mixture (mixture) richer.

  • Question 27-25

    When pilot moves mixture lever of a piston engine towards a lean position Amount of fuel entering combustion chamber reduced. When you apply carburettor heating air (which will mix with fuel in carburettor) passes around muffler (or exhaust pipe) in order to be heated to avoid risks of icing the air's density decreases as air heated what generates a mixture (mixture) richer.

  • Question 27-26

    When altitude increases without adjustment of mixture ratio piston engine performance affected because of a A decrease of air density with a fuel flow which becomes too high. When you apply carburettor heating air (which will mix with fuel in carburettor) passes around muffler (or exhaust pipe) in order to be heated to avoid risks of icing the air's density decreases as air heated what generates a mixture (mixture) richer.

  • Question 27-27

    A rich mixture setting has to be used during climb segments this results in a Lower cylinder head temperature. To obtain best torque during climb you will have to decrease fuel entering in carburettor in order to compensate decreasing of air density a rich mixture will not permit to deliver best available power but it permits a lower cylinder head temperature.

  • Question 27-28

    Maximum exhaust gas temperature egt of a piston engine theoretically associated with a Fuel to air ratio of 5. Egt relative to temperature of charge as it burns within cylinder cht measures temperature of engine cylinder the highest egt achieved at a ratio of 15 parts of air to one part of fuel if ratio reduced ie rich charge temperature reduces due to excess fuel being left in cylinder if ratio greater than 15 1 ie lean or weak charge cooled excess air to appreciate why cht increases with lean mixtures we must consider speed at which fuel burns ie its flame rate lean mixtures burn slower than rich mixtures this means more heat transferred to engine components with lean mixtures example if you move a lighted match quickly under you hand no problem but move it slowly you will burn your hand! slow burning lean mixtures will increase cht.

  • Question 27-29

    For a given type of oil oil viscosity depends on Fuel to air ratio of 5. Egt relative to temperature of charge as it burns within cylinder cht measures temperature of engine cylinder the highest egt achieved at a ratio of 15 parts of air to one part of fuel if ratio reduced ie rich charge temperature reduces due to excess fuel being left in cylinder if ratio greater than 15 1 ie lean or weak charge cooled excess air to appreciate why cht increases with lean mixtures we must consider speed at which fuel burns ie its flame rate lean mixtures burn slower than rich mixtures this means more heat transferred to engine components with lean mixtures example if you move a lighted match quickly under you hand no problem but move it slowly you will burn your hand! slow burning lean mixtures will increase cht.

  • Question 27-30

    The fuel temperature at which under standard conditions vapour ignites in contact with a flame and extinguishes immediately the Fuel to air ratio of 5. Egt relative to temperature of charge as it burns within cylinder cht measures temperature of engine cylinder the highest egt achieved at a ratio of 15 parts of air to one part of fuel if ratio reduced ie rich charge temperature reduces due to excess fuel being left in cylinder if ratio greater than 15 1 ie lean or weak charge cooled excess air to appreciate why cht increases with lean mixtures we must consider speed at which fuel burns ie its flame rate lean mixtures burn slower than rich mixtures this means more heat transferred to engine components with lean mixtures example if you move a lighted match quickly under you hand no problem but move it slowly you will burn your hand! slow burning lean mixtures will increase cht.

  • Question 27-31

    Pre ignition refers to condition that may arise when The mixture ignited abnormal conditions within cylinder before spark occurs at plug. Egt relative to temperature of charge as it burns within cylinder cht measures temperature of engine cylinder the highest egt achieved at a ratio of 15 parts of air to one part of fuel if ratio reduced ie rich charge temperature reduces due to excess fuel being left in cylinder if ratio greater than 15 1 ie lean or weak charge cooled excess air to appreciate why cht increases with lean mixtures we must consider speed at which fuel burns ie its flame rate lean mixtures burn slower than rich mixtures this means more heat transferred to engine components with lean mixtures example if you move a lighted match quickly under you hand no problem but move it slowly you will burn your hand! slow burning lean mixtures will increase cht.

  • Question 27-32

    A fuel strainer fuel filter when fitted to a carburettor will be positioned Upstream of needle valve. A fuel strainer a fuel filter the fuel need to be filtered before entering carburettor .

  • Question 27-33

    The working cycle of a four stroke engine Induction compression power exhaust. A fuel strainer a fuel filter the fuel need to be filtered before entering carburettor .

  • Question 27-34

    Specific fuel consumption defined as Mass of fuel required to produce unit power unit time. A fuel strainer a fuel filter the fuel need to be filtered before entering carburettor .

  • Question 27-35

    The purpose of contact breaker to Control primary circuit of magneto. A fuel strainer a fuel filter the fuel need to be filtered before entering carburettor .

  • Question 27-36

    Under normal running conditions a magneto draws primary current From a self contained electro magnetic induction system. A fuel strainer a fuel filter the fuel need to be filtered before entering carburettor .

  • Question 27-37

    The air in a piston engine turbo supercharger centrifugal compressor Enters eye of impeller leaves at a tangent to periphery. the air in a piston engine turbo supercharger centrifugal compressor enters eye of impeller leaves at a tangent to periphery.

  • Question 27-38

    The power of a piston engine which will be measured a friction brake Enters eye of impeller leaves at a tangent to periphery. the air in a piston engine turbo supercharger centrifugal compressor enters eye of impeller leaves at a tangent to periphery.

  • Question 27-39

    The power output of a piston engine can be calculated Enters eye of impeller leaves at a tangent to periphery. the air in a piston engine turbo supercharger centrifugal compressor enters eye of impeller leaves at a tangent to periphery.

  • Question 27-40

    The power of a piston engine decreases during a climb with a constant power lever setting because of decreasing Enters eye of impeller leaves at a tangent to periphery. Howarthson note in this question 'with a constant power lever setting' so as you climb power will be decreasing because air becoming less dense so manifold absolute pressure will be decreasing.


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