Question 36-1 : Most transport aeroplanes are provided with protection against control jamming this means that ? [ Experience registration ]

Question 36-2 : A flight control surface actuator is said to be 'irreversible' when ?

There is no feedback to the pilot's controls of the aerodynamic forces acting on the control surface.

An irreversible flight control system is where there is not a direct mechanical linkage connection between the control lever in the cockpit and the flight control surface in an irreversible mechanical system the control lever in the cockpit moves a spool valve on a hydraulic power control unit pcu a mechanical linkage drives the spool the mechanical linkage will consist of a combination of bellcranks pushrods cable systems pogos summing linkages etc the design of a mechanical irreversible system is similar to the design of a reversible flight control system the main difference will be the spool forces are better defined than surface hinge moments also an artificial feel system is required for irreversible flight control systems because there is no feedback to the pilot's controls of the aerodynamic forces acting on the control surface

Question 36-3 : Given an aeroplane with irreversible primary flight controls how is control maintained if one hydraulic system is lost due to a hydraulic leak ?

The remaining systems will take over control.

Question 36-4 : Which of these statements about a gust lock system are correct or incorrect i irreversible flight controls should have a gust lockii there is no need for a gust lock on manual flight controls ?

I is incorrect ii is incorrect.

There is no need for a gust lock on irreversible flight controls because the hydraulic actuators will be in hydraulic lock therefore the control surface will not move 852look at the left and right ailerons of this airbus a330 irreversible flight controls they both are down and in locked postion as for the elevator manual flight controls means reversible flight controls you need a gust lock systems inside the aircraft and outside 848

Question 36-5 : The reason for a double switch on the elevator trim is ?

To reduce the probability of a trim runaway.

Question 36-6 : A flight control surface actuator is said to be 'reversible' when ?

There is feedback to the pilot's controls of the aerodynamic forces acting on the control surface.

Question 36-7 : For a jar25 aeroplane spoilers are ?

Upper wing surface devices their deflection can be symmetrical or asymmetrical.

Question 36-8 : Which of these statements regarding most gust lock systems is correct ?

When the gust lock is on there is protection to prevent take off.

Question 36-9 : The expression 'secondary flight control' applies to the 1 stabiliser2 rudder3 speed brake4 aileronthe combination that regroups all of the correct statements is ?

1 3.

In addition to the primary flight controls for roll pitch and yaw there are often secondary controls available to give the pilot finer control over flight or to ease the workload the most commonly available control is a wheel or other device to control stabiliser trim so that the pilot does not have to maintain constant backward or forward pressure to hold a specific pitch attitude other types of trim for rudder and ailerons are common on larger aircraft but may also appear on smaller ones many aircraft have wing flaps controlled by a switch or a mechanical lever or in some cases are fully automatic by computer control which alter the shape of the wing for improved control at the slower speeds used for takeoff and landing other secondary flight control systems may be available including slats spoilers and air brakes

Question 36-10 : Ruddertrim adjustment in an aeroplane with irreversible flight controls is ?

An adjustment of the zero force rudder position.

Your flight controls are subjected to aerodynamic forces light aircraft will always have trim for the elevator to reduce these forces but as you climb out at low speed and high power you will have to apply a lot of leg force and hold in a lot of rudder right rudder on most aircraft due to right hand rotation of the propeller if you had a rudder trim you would adjust it until the force was zerothe question is about a fully powered rudder control irreversible there is no mechanical connection between rudder pedals and rudder the pilot is provided with artificial feelforce and when trimmed this is adjusted to give zero force on the pedals a conventional trim tab would have no feedback to the pilot because of the design of irreversible controls

Question 36-11 : Which of these statements about trimming in a irreversible flight control system of a conventional aeroplane are correct or incorrect i the zero force position of the control column does not change when using the elevator trimii the zero force position of the control wheel changes when using the ?

I is correct ii is correct.

Irreversible system fully powered system the pilot has no direct connection to the control surface he has no feel so an artificial feel system must be included this system works in parallel to the irreversible servo control unitreversible system power assisted system similar to the power assisted steering for a car the pilot feel a part of the load he receives assistance from the hydraulic system to move the control surfacehere we are talking about an irreversible flight control systemon a conventional aeroplane using an irreversible flight control system eg b737 ng with variable incidence trimming tailplane the trim is achieved by changing the full elevator deflection the zero force position of the control column does not changefor the aileron trim a variable incidence wing system does not exist on commercial airplane you can not 'trim' the wing thus when trimmed the control wheel will be biased to the right or to the left artificially and the zero force position of the control wheel will change

Question 36-12 : Which of these statements about trimming in a irreversible flight control system of a conventional aeroplane are correct or incorrect i the zero force position of the control column changes when using the elevator trimii the zero force position of the control wheel does not change when using the ?

Question 36-13 : Which of these statements about trimming in a irreversible flight control system of a conventional aeroplane are correct or incorrect i the zero force position of the control column does not change when using the elevator trimii the zero force position of the control wheel does not change when using ?

I is correct ii is incorrect.

Irreversible system fully powered system the pilot has no direct connection to the control surface he has no feel so an artificial feel system must be included this system works in parallel to the irreversible servo control unitreversible system power assisted system similar to the power assisted steering for a car the pilot feel a part of the load he receives assistance from the hydraulic system to move the control surfacehere we are talking about an irreversible flight control systemon a conventional aeroplane using an irreversible flight control system eg b737 ng with variable incidence trimming tailplane the trim is achieved by changing the full elevator deflection the zero force position of the control column does not changefor the aileron trim a variable incidence wing system does not exist on commercial airplane you can not 'trim' the wing thus when trimmed the control wheel will be biased to the right or to the left artificially and the zero force position of the control wheel will change

Question 36-14 : Cabin pressure is controlled by ?

Question 36-15 : During level flight at a constant cabin pressure altitude which could be decreased even at this flight level the cabin outflow valves are ?

Partially open.

Cabin altitude is the pressure altitude inside the pressurized zone of the fuselage it is expressed in 'altitude' generally in feet rather than with a unit of pressure in hectopascal for example the cabin pressure is regulated like this constant inlet flow regulation by air conditioning valves variable output flow action of the relief valves 853

Question 36-16 : The cabin pressure is regulated by the ?

Outflow valve.

Cabin altitude is the pressure altitude inside the pressurized zone of the fuselage it is expressed in 'altitude' generally in feet rather than with a unit of pressure in hectopascal for example the cabin pressure is regulated like this constant inlet flow regulation by air conditioning valves variable output flow action of the relief valves 853

Question 36-17 : Cabin differential pressure means the pressure difference between ?

Cabin pressure and ambient air pressure.

Question 36-18 : Under normal conditions easa cs 25 the cabin pressure altitude is not allowed to exceed ?

8000 ft.

Pressurisation cs 25841 pressurised cabins a pressurised cabins and compartments to be occupied must be equipped to provide a cabin pressure altitude of not more than 2438 m 8000 ft at the maximum operating altitude of the aeroplane under normal operating conditions if certification for operation over 7620 m 25 000 ft is requested the aeroplane must be able to maintain a cabin pressure altitude of not more than 4572 m 15 000 ft in the event of any reasonably probable failure or malfunction in the pressurisation system

Question 36-19 : Cabin altitude is the ?

Cabin pressure expressed as altitude.

Cabin altitude is the pressure altitude inside the pressurized zone of the fuselage it is expressed in 'altitude' generally in feet rather than with a unit of pressure in hectopascal for example the cabin pressure is regulated like this constant inlet flow regulation by air conditioning valves variable output flow action of the relief valves

Question 36-20 : On a modern large pressurized transport aircraft the maximum cabin differential pressure is approximately ?

7 9 psi.

Question 36-21 : The 'cabin differential pressure' is ?

Cabin pressure minus ambient pressure.

Question 36-22 : The cabin rate of descent is ?

A cabin pressure increase.

As we climb the cabin altitude 'climbs' to 6000ft8000ft when the aircraft altitude climbs to fl260fl410the cabin pressure is reducing from ground pressure mean 1013 hpa to less than 750 hpa in cruising flightthus while descending cabin rate of descent is a cabin pressure increase

Question 36-23 : The maximum cabin differential pressure of a pressurised aeroplane operating at fl370 is approximately ?

9 psi.

Typically there will be two gauges in the cockpit one to show the cabin's rate of climb the small one looks like a vsi vertical speed indicator and the other with two needles one for the inner scale indicates cabin altitude in feet one for the outer scale indicates differential pressure between cabin and ambient in psi 855the value 9 psi must be known this is a common value on jet aircrafts

Question 36-24 : The purpose of the pack cooling fans in the air conditioning system is to ?

Supply the heat exchangers with cooling air during slow flights and ground operation.

Question 36-25 : In flight the cabin air for modern airplanes with jet engines is usually supplied by ?

Engine compressors.

Question 36-26 : In an aircraft air conditioning system the air cannot be treated for ?

Humidity.

Modern air conditioning systems will mix the hot and cold air in a more efficient manner thus humidity control systems are not required anymore today we do not treat the air for humiditywater is removed from the conditioned air by the water separator but it is not controlledmore over actual humidity treatements are responsible for the legionary disease and are therefore forbidden in such cases

Question 36-27 : In a cabin air conditioning system equipped with a bootstrap the mass air flow is routed via the ?

Secondary heat exchanger outlet to the turbine inlet of the cold air unit.

Bootstrap or turbo compressor uses a primary heat exchanger for pre cooling against the ambient air temperature the compressor section of the cooling turbine to boost pressure and temperature to provide a significant pressure drop a secondary heat exchanger which also uses outside air as a coolant to remove the unwanted temperature rises across the compressor and the expansion turbine wich extracts work from the air by driving the compressor 856the term bootstrap refers to a self sustaining process that proceeds without external help

Question 36-28 : Engine bleed air used for air conditioning and pressurization in turbo jet aeroplanes is usually taken from the ?

Compressor section.

If the engine has a fan then the air will be taken from the compressor not the fan section

Question 36-29 : In large modern aircraft in the air conditioning system reduction of air temperature and pressure is achieved by ?

An expansion turbine.

Bootstrap or turbo compressor uses a primary heat exchanger for pre cooling against the ambient air temperature the compressor section of the cooling turbine to boost pressure and temperature to provide a significant pressure drop a secondary heat exchanger which also uses outside air as a coolant to remove the unwanted temperature rises across the compressor and the expansion turbine wich extracts work from the air by driving the compressor 856the goal of a bootstrap system is to distribute suitable air to the cabin engine bleed air is compressed passed through a heat exchanger cooled and then across an expansion turbine

Question 36-30 : A turbo compressor air conditioning system bootstrap system will ?

Cause a pressure drop as well as an associated temperature drop in the charge air.

Img856the goal of a bootstrap system is to distribute suitable air to the cabin engine bleed air is compressed passed through a heat exchanger cooled and then across an expansion turbine

Question 36-31 : Cabin heating in a large jet transport aeroplane is obtained from ?

Hot air bled from the compressors.

Cabin heating in a large jet transport aeroplane is obtained from hot air bled from the compressors via a 'bootstrap' system bootstrap or turbo compressor uses a primary heat exchanger for pre cooling against the ambient air temperature the compressor section of the cooling turbine to boost pressure and temperature to provide a significant pressure drop a secondary heat exchanger which also uses outside air as a coolant to remove the unwanted temperature rises across the compressor and the expansion turbine wich extracts work from the air by driving the compressor 856the term bootstrap refers to a self sustaining process that proceeds without external help

Question 36-32 : The pack cooling fan provides ?

Cooling air to the primary and secondary heat exchanger during slow flight and ground operation.

Img857 858the ram air inlets have their deflector doors opened because the aircraft is on the ground 859

Question 36-33 : If the cabin altitude rises aircraft in level flight the differential pressure ?

Decreases.

Standard pressurisation profil 860if cabin altitude rises difference between the red line and the blue line will reduce the differential pressure decreases

Question 36-34 : During a normal pressurised climb after take off ?

Cabin pressure decreases more slowly than atmospheric pressure.

Question 36-35 : If the maximum operating altitude of an aeroplane is limited by the pressurized cabin this limitation is due to the maximum ?

Positive cabin differential pressure at maximum cabin altitude.

An aircraft may be able to operate at for example fl450 but in order to respect a positive cabin differential pressure cabin pressure minus ambient pressure it could be limited at a lower level90 psi is a comon value for maximum differential pressure on jet aircraftsit is a positive value cabin pressure at fl 390 = 10 psi 700 hpa ambient pressure at fl 390 = 3 psi 200 hpa differential pressure = cabin pressure ambient pressure = 10 3 = 7 psiin this example the aircraft may climb to a higher level until it will be limited by the 90 psi maximum differential pressure

Question 36-36 : Main cabin temperature is ?

Controlled automatically or by flight crew selection.

Question 36-37 : A warning device alerts the crew in case of an excessive cabin altitude this warning must be triggered on reaching the following altitude ?

10000 ft.

Pressurisation cs 25841 pressurised cabins a b 6 warning indication at the pilot or flight engineer station to indicate when the safe or pre set pressure differential and cabin pressure altitude limits are exceededappropriate warning markings on the cabin pressure differential indicator meet the warning requirement for pressure differential limits and an aural or visual signal in addition to cabin altitude indicating means meets the warning requirement for cabin pressure altitude limits if it warns the flight crew when the cabin pressure altitude exceeds 3048 m 10000 ft

Question 36-38 : In a turbo compressor air conditioning system bootstrap system the main water separation unit is ?

After the cooling turbine.

Question 36-39 : A turbo compressor air conditioning system bootstrap system includes two heat exchangers the primary exchanger p and the secondary exchanger s the functions of these heat exchangers are as follows ?

P precools the engine bleed air s cools air behind the pack's compressor.

Bootstrap or turbo compressor uses a primary heat exchanger for pre cooling against the ambient air temperature the compressor section of the cooling turbine to boost pressure and temperature to provide a significant pressure drop a secondary heat exchanger which also uses outside air as a coolant to remove the unwanted temperature rises across the compressor and the expansion turbine wich extracts work from the air by driving the compressor 856the term bootstrap refers to a self sustaining process that proceeds without external help

Question 36-40 : When air is compressed for pressurization purposes the percentage oxygen content is ?

Unaffected.