Question 34-1 : The type of hydraulic fluid which has the greatest resistance to cavitation is ? [ Registration lift off ]
Synthetic fluid
.cavitation occurs when a liquid moves within tubing or pipes at very fast speeds causing the absolute pressure of the liquid to drop drastically this process occurs with little loss of heat if the absolute pressure drops below the vapour pressure of the liquid cavitation will form this phenomenon is more serious in viscous liquids than in thin liquids .cavitation causes separation of gases that are within the liquid such as air or water vapour from the liquid itself bubbles would form then collapse .in the case of a liquid entering the suction side of a pump the pressure would be low for the liquid to move from one place to another it would have to expend energy thus causing a further decrease in pressure .the hydraulic fluid used will be synthetic because of the high temperatures involved and the lesser risk of cavitation compared other fluids mineral oil or vegetable oil based fluids
Question 34-2 : Filtration in a hydraulic system is usually ensured by ?
Filters in both the pressure and return lines
Question 34-3 : The relationship between pressure force and area is ?
Force = pressure x area
Question 34-4 : In a commercial transport aeroplane the landing gear normal operating system is usually ?
Hydraulically driven
Question 34-5 : Generally on modern jet transport aircraft how can the landing gear be extended if there is a complete hydraulic system failure ?
Mechanically
Question 34-6 : The type of brake unit found on most transport aeroplanes is a ?
Multiple disk brake
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Question 34-7 : The reason for fitting thermal plugs to aeroplane wheels is that they ?
Release air from the tyre in the event of overheating
Tyres are fitted with thermal plug to release air from the tyre in the event of overheating after a landing or a rejected take off with overweight and overspeed conditions the tyres and brakes are extremely hot and thermal plug can malfunction on the video you can see a tyre explosion .vdo834
Question 34-8 : Thermal plugs are installed in ?
Wheel rims
Tyres are fitted with thermal plug to release air from the tyre in the event of overheating after a landing or a rejected take off with overweight and overspeed conditions the tyres and brakes are extremely hot and thermal plug can malfunction on the video you can see a tyre explosion .vdo834
Question 34-9 : In a hydraulic braking system an accumulator is pre charged to 1200 psi if an electrically driven hydraulic pump is started and provides a system pressure of 3000 psi the pressure gauge which is connected to the gas section of the accumulator will read ?
3000 psi
The question states the pressure gauge is connected to the gas section of the accumulator .thus if the electrically driven hydraulic pump is started and provides a system pressure of 3000 psi you will read a pressure of 3000 psi
Question 34-10 : The modern anti skid processes are based on the use of a computer whose input data is .1 idle wheel speed measured .2 braked wheel speed measured .3 brake temperature measured .4 desired idle wheel train slipping rate.5 tire pressure.the combination regrouping all the correct statements is ?
1 2 and 4
3 steps during the landing roll .1 if the wheels are not braked at all they all follow kinematics that is the speed of the airplane and wheel radius of course directly determine their angular speed and deceleration if we would use only spoilers and thrust reversers we would have pure kinematic deceleration of the wheels and hence no slipping of course we presume that runway surface conditions are ideal in this case all wheels are on their 'idle' speed all the time in the sense that they are not being braked externally by the brakes they just 'naturally' decelerate together with the airplane idling all the time ..2 but if the brakes are applied during landing roll that means that at first moment none of the wheels is idle any more now they are not just decelerating with the airplane they are having an additional deceleration from brakes being applied on them that means that there is some small physical slipping at the contact area of the tire and the runway surface ..3 now the computer monitors the situation and has those braked wheels speed input now let's say for simplicity that one of the wheel for some reason gains such a high angular deceleration which would soon lead to blockage zero angular speed of that wheel computer prevents that by commanding servo on that wheel to reduce the brakes on that particular wheel from that moment on that particular wheel is idling at the desired wheel train slipping rate
Question 34-11 : When a landing gear wheel is hydroplaning its friction factor is around ?
0
Question 34-12 : From the following fuselage profile sort them from the worst to the best one concerning the pressurization . 818 ?
1 3 4 2
N°1 is clearly the weakest and would only be used on an unpressurised aircraft twin otter for example .n°2 is geometrically the strongest from a pressurisation point of view as the hoop stresses can be uniform on the whole cross section .n°3 'double bubble' type where two circles intersect connected via a floor not the best choice but clearly better than n°4 .n°4 the pressurization constraints will not be optimal on an oval format .this question also exists with the statement 'from the following fuselage profile sort them from the worst to the best one concerning the pressurization '.answer 1 4 3 2
Question 34-13 : The illumination of the green landing gear light indicates that the landing gear is ?
Locked down
Question 34-14 : The damping element in a landing gear shock absorber used on large aircrafts is ?
Oil and viscous liquid
Question 34-15 : 'nose wheel shimmy' may be described as ?
A possibly damaging vibration of the nose wheel when moving on the ground
Question 34-16 : The abs auto brake system is being disconnected after landing ?
By pilot action
Img837. 1 auto brake disarm light . illuminated amber . speed brake lever moved to down detent during rto or landing. manual brakes applied during rto or landing. thrust lever s advanced during rto or landing. except during first 3 seconds after touchdown for landing. landing made with rto selected. rto mode selected on ground. illuminates for one to two seconds then extinguishes. a malfunction exists in automatic braking system . extinguished . auto brake select switch set to off. autobrake armed .. 2 auto brake select switch .off autobrake system deactivated . 1 2 3 or max . selects desired deceleration rate for landing. switch must be pulled out to select max deceleration .rto automatically applies maximum brake pressure when thrust levers are retarded to idle at or above 90 knots .. 3 antiskid inoperative antiskid inop light .illuminated amber a system fault is detected by antiskid monitoring system .extinguished antiskid system operating normally
Question 34-17 : The purposes of the oil and the nitrogen in an oleo pneumatic strut are ?
The oil supplies the damping function and the nitrogen supplies the spring function
Question 34-18 : The highest load on the torsion link in a bogie gear is ?
Whilst turning on the ground with a small radius
Question 34-19 : The function of a fusible plug is to ?
Protect the tyre against explosion due to excessive temperature
Question 34-20 : Compared to a tyre fitted with an inner tube a tubeless tyre presents the following characteristics .1 high heating.2 valve fragility.3 lower risk of bursting.4 better adjustment to wheels.the combination containing all the correct statements is ?
3 and 4
Question 34-21 : An under inflated tyre will ?
Experience increased wear at the shoulders
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Question 34-22 : A scissor torsion link is a component found on landing gears its function is to ?
Prevent any rotation of the oleo strut in the landing gear shock absorber
The torque links prevent rotation about the vertical axis to maintain wheel alignment in the fore and aft direction throughout the vertical range of oleo travel in maintaining proper wheel alignment the torque links stabilize any torsional oscillations shimmy .by their design torque links have their maximum mechanical advantage and control when the oleo is compressed and minimum advantage when the oleo is fully extended . 671.sometime it doesn't work .vdo672
Question 34-23 : Associate the correct legend to each of the numbered diagrams . 841 ?
1 cantilever 2 fork 3 half fork 4 dual wheels
Question 34-24 : The function of an accumulator in a hydraulic brake system is ?
To supply a limited amount of brake energy in the event of failure of the hydraulic system normally supplying the brakes
Question 34-25 : A red or an amber light on an undercarriage position indicator signifies ?
At least one wheel is in the travelling or unlocked condition
Question 34-26 : In some aircraft there is a protection device to avoid the landing gear being inadvertently retracted on the ground it consists of ?
A latch located in the landing gear lever
Question 34-27 : Overcentre mechanisms in landing gear systems are used to ?
Lock the landing gear in the up and/or down positions
That naturally depends on the type of aircraft main undercarriage units are locked down by mechanical and overcentre geometric locks hook locks are generally used for the up position
Question 34-28 : The systems used for emergency extension of landing systems may comprise .1 compressed c0².2 compressed nitrogen.3 compressed oxygen.4 mechanical/manual system.5 freefall.the combination containing all of the correct statements is ?
2 4 5
Question 34-29 : The working principle of the anti skid system is ?
Reduction of the brake pressure at the slower turning wheels
Anti skid protection is provided to allow maximum braking efficiency which in turn minimizes landing distances if the pilot applies enough brake pedal force to cause slippage between the tires and the runway the wheel speed transducer data received by a control box will indicate a sudden deceleration for the slipping wheel the control box will determine the severity of the impending skid and send the appropriate current signal to the anti skid servo valve to reduce brake pressure accordingly dual servo valves reduce pressure for either brake independently .therefore a single wheel skid will result in the reduction of brake pressure at the skidding wheel only
Question 34-30 : Vle is the maximum ?
Flight speed with landing gear down
Question 34-31 : Vlo is the maximum ?
Speed at which the landing gear can be operated with full safety
Question 34-32 : What is the correct statement about rudder deflection and steering nose ?
When performing a rudder check during taxiing an additional pilot action is required to avoid deflection of the nose wheel
Revised ecqb03 september 2016 ..during taxiing if the pilots want to use rudder pedals to check rudder deflection without interfering with steering they have a pushbutton on either steering hand wheel on the a320 or the tiller must be physically held so as to prevent the aircraft from turning for b737 .the hand wheel controller tiller is only suitable at the beginning of the take off roll on the a320 the effectiveness of the hand wheel is diminished above 20 kt and is canceled above 80 kt on the b737 the hand wheel controller was to be used under 60 kt
Question 34-33 : To avoid the risk of tyre burst from overheating there is ?
A thermal plug that deflates the tyre at a specific temperature
Question 34-34 : Which of these statements about an anti skid system are correct or incorrect .1 in case of failure of an anti skid system the auto brake system takes over the regulation of the slip ratio.2 careful brake application by the pilot in case of anti skid failure can never achieve the same performance as ?
1 is incorrect 2 is correct
Ecqb03 september 2016 ..the 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance in case of failure of the anti skid system the auto brake system can not take over the 'regulation of the slip ratio' .careful brake application by the pilot in case of anti skid failure can never achieve the same performance as a properly functioning anti skid system .the anti skid system through various mechanisms compares the speed of the aircraft with the rotational speed of each main wheel if the speed of any wheel is too slow for the existing aircraft speed the brake on that wheel or wheels is released momentarily to allow the wheel speed to increase and prevent the wheel from skidding the system is fully automatic and is active from immediately after initial wheel spin up on landing during which time brake activation might or might not be inhibited down to a design limited minimum speed usually about 15 kt .anti skid systems are designed to minimise aquaplaning and the potential tyre damage which can occur when a wheel is locked or rotating at a speed which does not correspond to the speed of the aircraft anti skid removes the possibility of reverted rubber skids caused by locked wheels an anti skid system also greatly improves stopping distance on substandard surfaces such as gravel or grass and is particularly effective on surfaces contaminated with frozen contaminants such as ice or slush by ensuring maximum effective breaking
Question 34-35 : Which of these statements about an anti skid system are correct or incorrect .1 the 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance.2 careful brake application by the pilot in case of anti skid failure can achieve the same performance as a properly ?
1 is correct 2 is incorrect
Ecqb03 september 2016 ..the 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance in case of failure of the anti skid system the auto brake system can not take over the 'regulation of the slip ratio' .careful brake application by the pilot in case of anti skid failure can never achieve the same performance as a properly functioning anti skid system .the anti skid system through various mechanisms compares the speed of the aircraft with the rotational speed of each main wheel if the speed of any wheel is too slow for the existing aircraft speed the brake on that wheel or wheels is released momentarily to allow the wheel speed to increase and prevent the wheel from skidding the system is fully automatic and is active from immediately after initial wheel spin up on landing during which time brake activation might or might not be inhibited down to a design limited minimum speed usually about 15 kt .anti skid systems are designed to minimise aquaplaning and the potential tyre damage which can occur when a wheel is locked or rotating at a speed which does not correspond to the speed of the aircraft anti skid removes the possibility of reverted rubber skids caused by locked wheels an anti skid system also greatly improves stopping distance on substandard surfaces such as gravel or grass and is particularly effective on surfaces contaminated with frozen contaminants such as ice or slush by ensuring maximum effective breaking
Question 34-36 : On the diagram the landing gear element indicated by the number 11 is . 842 ?
Bogie beam
Question 34-37 : Which statement is correct concerning auto brake system ?
When using manual braking during taxiing the auto brake system remains armed
During rto or landing the auto brake system is automatically disconnected when using manual braking but not during taxiing .. 837. 1 auto brake disarm light . illuminated amber . speed brake lever moved to down detent during rto or landing. manual brakes applied during rto or landing. thrust lever s advanced during rto or landing. except during first 3 seconds after touchdown for landing. landing made with rto selected. rto mode selected on ground. illuminates for one to two seconds then extinguishes. a malfunction exists in automatic braking system . extinguished . auto brake select switch set to off. autobrake armed .. 2 auto brake select switch .off autobrake system deactivated . 1 2 3 or max . selects desired deceleration rate for landing. switch must be pulled out to select max deceleration .rto automatically applies maximum brake pressure when thrust levers are retarded to idle at or above 90 knots .. 3 antiskid inoperative antiskid inop light .illuminated amber a system fault is detected by antiskid monitoring system .extinguished antiskid system operating normally
Question 34-38 : Which of these statements about an anti skid system are correct or incorrect .1 the 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance.2 careful brake application by the pilot in case of anti skid failure can never achieve the same performance as a ?
1 is correct 2 is correct
The 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance in case of failure of the anti skid system the auto brake system can not take over the 'regulation of the slip ratio' .careful brake application by the pilot in case of anti skid failure can never achieve the same performance as a properly functioning anti skid system .the anti skid system through various mechanisms compares the speed of the aircraft with the rotational speed of each main wheel if the speed of any wheel is too slow for the existing aircraft speed the brake on that wheel or wheels is released momentarily to allow the wheel speed to increase and prevent the wheel from skidding the system is fully automatic and is active from immediately after initial wheel spin up on landing during which time brake activation might or might not be inhibited down to a design limited minimum speed usually about 15 kt .anti skid systems are designed to minimise aquaplaning and the potential tyre damage which can occur when a wheel is locked or rotating at a speed which does not correspond to the speed of the aircraft anti skid removes the possibility of reverted rubber skids caused by locked wheels an anti skid system also greatly improves stopping distance on substandard surfaces such as gravel or grass and is particularly effective on surfaces contaminated with frozen contaminants such as ice or slush by ensuring maximum effective breaking
Question 34-39 : Which of these statements about an anti skid system are correct or incorrect .1 in case of failure of an anti skid system the auto brake system takes over the regulation of the slip ratio.2 careful brake application by the pilot in case of anti skid failure can achieve the same performance as a ?
1 is incorrect 2 is incorrect
The 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance in case of failure of the anti skid system the auto brake system can not take over the 'regulation of the slip ratio' .careful brake application by the pilot in case of anti skid failure can never achieve the same performance as a properly functioning anti skid system .the anti skid system through various mechanisms compares the speed of the aircraft with the rotational speed of each main wheel if the speed of any wheel is too slow for the existing aircraft speed the brake on that wheel or wheels is released momentarily to allow the wheel speed to increase and prevent the wheel from skidding the system is fully automatic and is active from immediately after initial wheel spin up on landing during which time brake activation might or might not be inhibited down to a design limited minimum speed usually about 15 kt .anti skid systems are designed to minimise aquaplaning and the potential tyre damage which can occur when a wheel is locked or rotating at a speed which does not correspond to the speed of the aircraft anti skid removes the possibility of reverted rubber skids caused by locked wheels an anti skid system also greatly improves stopping distance on substandard surfaces such as gravel or grass and is particularly effective on surfaces contaminated with frozen contaminants such as ice or slush by ensuring maximum effective breaking
Question 34-40 : Which of these statements about an auto brake system are correct or incorrect .1 an auto brake system can function properly even when the anti skid system is inoperative.2 in the rto mode maximum anti skid braking is applied ?
1 is incorrect 2 is correct
Proper functioning of an auto brake system requires proper functioning of the anti skid system .in the rto rejected take off mode maximum anti skid braking is applied the 'regulation of slip ratio' function of an anti skid system ensures optimum braking performance using the rto mode provides the best stopping performance during a rejected take off the deceleration will not be constant it will increase as the speed decreases
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