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ATPL 21 AIRCRAFT GENERAL KNOWLEDGE – AIRFRAME AND SYSTEMS |
| 21.03 HYDROMECHANICS: BASIC PRINCIPLES |
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1
The purpose of the blow-in-doors at the air inlets is to:
Provide the engine with additional air at high power settings and low air speeds. |
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2
In order to enable a fire to be controlled as quickly as possible, the fire detectors are located in the highest risk compartments. theses compartments are : 1. the main landing gear wheel wells 2. the fuel tanks 3. the oil tanks 4. the auxiliary power unit 5. around the engines the combination regrouping all the correct statements is:
1,4,5 |
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3
In transport aeroplanes overheat detection systems are installed in the:
Landing gear bays / wheel wells. |
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4
The indication of the fire detection systems is performed by a:
Warning light and a warning bell (or aural alert). |
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5
Turbine blade stages may be classed as either "impulse" or "reaction". in an impulse blade section :
The pressure drops across the nozzle guide vanes and remains constant across the rotor blades . |
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6
The primary purpose of the bleed valves fitted to axial flow compressors is to :
Reduce the likelihood of compressor stall. |
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7
The fan in a high by- pass ratio turbo-jet engine produces:
The greater part of the thrust. |
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8
At constant fuel flow, if engine compressor air is bled off for engine anti-icing or a similar system, the turbine temperature:
Will rise. |
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9
A reverse thrust door warning light on the flight deck instrument panel illuminates when:
The reverser doors are unlocked. |
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10
In a single spool gas turbine engine, the compressor rpm is :
The same as turbine rpm. |
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11
When the combustion gases pass through a turbine the :
Pressure drops. |
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12
The primary reason for a limitation being imposed on the temperature of gas flow is to :
Ensure that the maximum acceptable temperature at the turbine blades is not exceeded. |
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13
In a gas turbine engine, compressor blades, which are not rigidly fixed in position when the engine is stationary, take up a rigid position when the engine is running due to :
The resultant of aerodynamic and centrifugal forces. |
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14
If air is tapped from a gas turbine hp compressor, the effect on the engine pressure ratio (epr) and the exhaust gas temperature (egt) is that :
Epr decreases and egt increases. |
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15
A "fan" stage of a ducted-fan turbine engine is driven by:
The low pressure turbine. |
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16
In a free turbine engine:
There is no mechanical connection between the compressor and the power output shaft. |
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17
Continuous loop fire detector systems operate on the principle that an increase in temperature produces :
A decrease in resistance |
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18
On an aircraft provided with resistance and capacitance variation type fire detection loops, a fire alarm is initiated by a temperature increase detected:
At any isolated point of the loops or else generally on all the loops |
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19
On a multi-engined aircraft a fire detection system includes :
A warning light for each engine and a single alarm bell common to |
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20
In a gas turbine engine, the maximum gas temperature is attained:
Within the combustion chamber. |
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21
Concerning the centrifugal compressor, the compressor diffuser is a device in which the:
Pressure rises and velocity falls. |
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22
When a continuous element of a fire detection system is heated: 1. its resistance decreases. 2. its resistance increases. 3. the leakage current increases. 4. the leakage current decreases. the combination regrouping all the correct statements is :
1, 3 |
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23
In a compressor stage of a jet engine, the sequence is:
Rotor - stator |
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24
The accessory units driven by the accessory gearbox of a turbo-jet engine are the : 1. tacho-generator n1 2. tacho-generator n2 3. thrust reverser pneumatic motors 4. ac generator and its constant speed unit (csd) 5. oil pumps 6. hydraulic pumps 7. high pressure fuel pumps the combination regrouping all the correct statements is :
1, 4, 5, 6, 7. |
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25
The wing of an aircraft in flight, powered by engines located under the wing, is subjected to a bending moment which causes its leading edge, from the wing root to the wing tip, to operate in:
Compression, then in tension. |
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26
In the axial flow compressor of a turbo- jet engine, the flow duct is tapered. its shape is calculated so as to:
Maintain a constant axial speed in cruising flight. |
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27
In the stator of a turbine, the speed v and static pressure ps vary as follows:
V increases, ps decreases. |
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28
A fault protection circuit in a fire detection system will:
Inhibit the fire detector when the detection line is connected to ground. |
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29
In a fire detection system with single-loop continuous components (with no fault protection), if the line is accidently grounded:
The fire alarm is triggered. |
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30
When a wire type fire system is tested:
The wiring and the warning are tested. |
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31
In flight the wing of an aircraft containing fuel is subjected to vertical loads that produce a bending moment which is:
Highest at the wing root |
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32
The maximum zero fuel mass: 1 is a limitation set by regulation. 2 is designed for a maximum load factor. 3 is due to the maximum bending moment at wing root. 4 requires to empty external tanks first. 5 requires to empty internal tanks first. the correct combination of true statements is :
1,2,3 |
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33
The compressor surge effect during acceleration is prevented by the :
Fuel control unit (f.c.u.). |
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34
For a fan jet engine, the by-pass ratio is the:
External airflow mass divided by the internal airflow mass |
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35
A gaseous sensor/responder tube fire sensor is tested by
Heating up the sensor with test power connection. |
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36
A stage in an axial compressor:
Is made of a rotor disc followed by a row of stator blades |
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37
When a bimetallic strip is used as a switch in a fire detection loop, a fire alarm is triggered after a delay. the purpose of this delay is to:
Avoid false alarms in case of vibrations |
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38
The disadvantages of axial flow compressors compared to centrifugal flow compressors are : 1 - expensive to manufacture 2 - limited airflow 3 - greater vulnerability to foreign object damage 4 - limited compression ratio the combination of correct answers is :
01-mar |
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39
On a non-stressed skin type wing, the wing structure elements which take up the vertical bending moments mx are:
The spars. |
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40
An impulse turbine is a turbine in which the expansion takes place:
Fully in the stator. |