The alternators when connected are usually connected ?
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The capacity of an accumulator is ?
The moving part in an AC generator is usually referred to as the ?
The purpose of bonding metallic parts of an aircraft to Provide safe distribution of electrical charges currents, prevent electrolytic corrosion between mating surfaces of similar metals, isolate all components electrically thus make static potential constant, provide a single earth electrical devices. 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. 
A constant speed drive aims at ensuring That electric generator produces a constant frequency, that starter motor maintains a constant rpm not withstanding acceleration of engine, that csd remains at a constant rpm not withstanding generator rpm, equal ac voltage from all generators. 
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, generator breaker the tie breaker, generator control relay the generator breaker, 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. 
A test to assess state of charge of a lead acid battery would involve Comparing 'on loa 'off loa battery voltages, checking level of electrolyte, checking discharge current of battery 'on loa, checking battery voltage 'off loa. Question Piston Engines 27 Answer 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 , 2, 4,, 2, 3, 2, 3, 5,, 3, 5. 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 Piston Engines 27 Answer 9
When an 'open circuit' occurs in an electrical supply system Loss of continuity will prevent its working components from functioning, load as indicated the ammeter will increase, fuse or cb should isolate circuit due to excess current drawn, component will operate normally, but will not switch off. 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 Piston Engines 27 Answer 10
An ac generator driven a csd unit Requires a voltage controller to maintain constant voltage under load, does not need a voltage controller since csd will ensure constant voltage, does not need a voltage controller since an ac generator voltage cannot alter under load, requires a voltage controller to maintain constant frequency. 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 Piston Engines 27 Answer 11
Consider variable pitch propeller of a turbo prop during deceleration When braking, propeller supplies negative thrust absorbs engine power, at zero power, propeller thrust zero the engine power absorbed nil, when feathered, propeller produces thrust absorbs no engine power, with propeller windmilling, thrust zero the propeller supplies 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 Piston Engines 27 Answer 12
The correct formula to calculate total displacement of a multi cylinder piston engine the Piston area x piston stroke x number of cylinders, piston area x piston stroke, cylinder volume x number of cylinders, cylinder length x cylinder diameter Question Piston Engines 27 Answer 13
When changing power on engines equipped with constant speed propeller engine overload avoided Increasing rpm before increasing manifold pressure, reducing rpm before reducing manifold pressure, adjusting fuel flow before manifold pressure, increasing manifold pressure before increasing rpm. 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 Piston Engines 27 Answer 14
The blade angle of a constant speed propeller Increases with increasing true air speed, only varies with engine rpm, decreases with increasing true air speed, independent of 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 Piston Engines 27 Answer 15
A propeller blade twisted so as to Keep local angle of attack constant along blade, avoid appearance of sonic phenomena, decrease blade tangential velocity from blade root to tip, allow a higher mechanical stress. 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 Piston Engines 27 Answer 16
A pilot can actuate feathering system Pulling propeller control lever rearwards, pushing propeller control lever forwards, pulling power levers rearwards, pushing power lever forwards. 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 Piston Engines 27 Answer 17
When increasing true airspeed with a constant engine rpm angle of attack of a fixed pitch propeller Reduces, increases, stays constant, stays constant because it only varies with engine rpm. 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 Piston Engines 27 Answer 18
A pressure relief valve in an oil system that does not seat correctly could result in Low oil pressure, high oil pressure, low oil temperature, excessive oil consumption. 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 Piston Engines 27 Answer 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, move in low pitch position oil pressure created the windmilling propeller, move in a certain pitch position depending on windmilling rpm, move in highest pitch position the aerodynamic 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 Piston Engines 27 Answer 20
For take off correct combination of propeller pitch 1 and propeller lever position 2 at brake release ( ) low (2) forward, ( ) high (2) forward, ( ) low (2) aft, ( ) high (2) aft. 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 Piston Engines 27 Answer 21
For piston engines mixture ratio the ratio between Mass of fuel mass of air entering cylinder, volume of fuel volume of air entering cylinder, volume of fuel volume of air entering carburettor, mass of fuel volume of air entering carburettor. Question Piston Engines 27 Answer 22
Variations in mixture ratios carburettors are achieved the adjustment of Fuel flow, air flow, fuel flow, air flow temperature, fuel flow air flow. Question Piston Engines 27 Answer 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, reduce fuel flow in order to compensate the increasing air density, increase mixture ratio, increase fuel flow in order to compensate the decreasing air pressure density. Question Piston Engines 27 Answer 24
When applying carburettor heating The mixture becomes richer, mixture becomes leaner, a decrease in rpm results from lean mixture, no change occurs in mixture ratio. 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 Piston Engines 27 Answer 25
When pilot moves mixture lever of a piston engine towards a lean position Amount of fuel entering combustion chamber reduced, volume of air entering carburettor reduced, amount of fuel entering combustion chamber increased, volume of air entering carburettor increased. Question Piston Engines 27 Answer 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, an increase of air density with a fuel flow which becomes too high, an increase of air density with a fuel flow which becomes too low, a decrease of air density with a fuel flow which becomes too low. Question Piston Engines 27 Answer 27
A rich mixture setting has to be used during climb segments this results in a Lower cylinder head temperature, higher efficiency, increase of power, higher torque. 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 Piston Engines 27 Answer 28
Maximum exhaust gas temperature egt of a piston engine theoretically associated with a Fuel to air ratio of5, cruising mixture setting, full rich setting, mixture ratio very close to idle cut out. 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 Piston Engines 27 Answer 29
For a given type of oil oil viscosity depends on Oil temperature, outside pressure, oil pressure, quantity of oil. Question Piston Engines 27 Answer 30
The fuel temperature at which under standard conditions vapour ignites in contact with a flame and extinguishes immediately the Flash point, fire point, combustion point, self ignition point. Question Piston Engines 27 Answer 31
Pre ignition refers to condition that may arise when The mixture ignited abnormal conditions within cylinder before spark occurs at plug, mixture ignited before piston has reached top dead centre, a rich mixture ignited the sparking plugs, sparking plug ignites mixture too early. Question Piston Engines 27 Answer 32
A fuel strainer fuel filter when fitted to a carburettor will be positioned Upstream of needle valve, between needle valve the metering jet, between metering jet the discharge nozzle, downstream of discharge nozzle. A fuel strainer a fuel filter. the fuel need to be filtered before entering carburettor. Question Piston Engines 27 Answer 33
The working cycle of a four stroke engine Induction, compression, power, exhaust, induction, power, compression, exhaust, induction, compression, expansion, power, compression, induction, power, exhaust. Question Piston Engines 27 Answer 34
Specific fuel consumption defined as Mass of fuel required to produce unit power unit time, maximum fuel consumption of aircraft, designed fuel consumption a given rpm, quantity of fuel required to run engine one minute at maximum operating conditions. Question Piston Engines 27 Answer 35
The purpose of contact breaker to Control primary circuit of magneto, connect secondary coil to distributor, connect battery to magneto, connect contact breaker condenser in series with primary coil. Question Piston Engines 27 Answer 36
Under normal running conditions a magneto draws primary current From a self contained electro magnetic induction system, from booster coil, from aircraft batteries via an inverter, directly from aircraft batteries. Question Piston Engines 27 Answer 37
The air in a piston engine turbo supercharger centrifugal compressor Enters eye of impeller leaves at a tangent to periphery, enters via diffuser is fed to impeller at optimum angle of attack, enters at periphery leaves via eye of impeller, enters at a tangent to rotor leaves via stator. the air in a piston engine turbo supercharger centrifugal compressor enters eye of impeller leaves at a tangent to periphery. Question Piston Engines 27 Answer 38
The power of a piston engine which will be measured a friction brake Brake horse power, frictional horse power, heat loss power, indicated horse power. Question Piston Engines 27 Answer 39
The power output of a piston engine can be calculated Torque times rpm, work times velocity, force times distance, pressure times arm. Question Piston Engines 27 Answer 40
The power of a piston engine decreases during a climb with a constant power lever setting because of decreasing Air density, engine temperature, humidity, temperature. 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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