In addition to providing 'customer' bleed for aeroplane systems air may be bled from compressors of a turbofan engine to increase stall margin ?
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One reason to fit a tip shroud to a turbine blade is to ?
The most important oil system instrument indication during gas turbine engine start is ?
Turbine blade stages may be classed as either 'impulse' or 'reaction' in an impulse turbine stage The pressure drops across stator blades remains constant across rotor blades. nozzle guide vanes = stator the pressure drops across stator blades remains constant across rotor blades. 
When a gas turbine engine fitted with can type combustion chambers A total of only two igniters are usually fitted since chambers are inter connected. Most gas turbine engines only have two igniters typically located diagonally opposed in fact engine would probably start quite readily with only one operating however because there are only two another means of passing starting flame between combustion chambers has to be found this the interconnector. 
The purpose of gas turbine engine trending To enhance maintenance planning detect anomalies. Engine trending performance analysis monitoring diagnostics permit to enhance maintenance planning to detect anomalies. 
The flexible take off mode 1 can be used only if engines are recent2 reduces engine wear3 can be used in situations where take off can be executed without need full engine power4 can only be used with an auto throttlethe combination that regroups all of correct statements To enhance maintenance planning detect anomalies. Engine trending performance analysis monitoring diagnostics permit to enhance maintenance planning to detect anomalies. Question 35-8
Concerning flexible take off mode temperature selected in fms Higher than ambiant airfield temperature in order to achieve a reduced power setting. extract from boeing fcom (flight crew operations manual) assumed temperature reduced thrust regulations permit use of up to 25% takeoff thrust reduction operation with assumed temperature reduced thrust use of assumed temperature reduced thrust not allowed with anti skid inoperative or on runways contaminated with standing water ice slush or snow use of assumed temperature reduced thrust not recommended if potential windshear conditions exist a takeoff thrust less than full rated thrust may be achieved using an assumed temperature that higher than actual temperature. Question 35-9
One reason to fit a tip shroud to a turbine blade to Reduce blade vibrations limit marginal leaks. The shrouded blades form a band around perimeter of turbine which serves to reduce blade vibrations the shrouds improve airflow characteristics increase efficiency of turbine the shrouds also serve to cut down gas leakage around tips of turbine blades. Question 35-10
On a high pass ratio fan engine reverse thrust achieved reversing Only direction of fan airflow. On high bypass turbofan engines reverse thrust achieved reversing only direction of fan airflow in order to save costs mass it not impossible to reverse hot exhaust gas but it complex the gain in reverse thrust will be less than 20% an increase in maintenance costs a higher inflight consumption due to weight of system. Question 35-11
If an abortive start hung start occurs when starting a gas turbine engine correct action to Only direction of fan airflow. On high bypass turbofan engines reverse thrust achieved reversing only direction of fan airflow in order to save costs mass it not impossible to reverse hot exhaust gas but it complex the gain in reverse thrust will be less than 20% an increase in maintenance costs a higher inflight consumption due to weight of system. Question 35-12
Compressor surge may be controlled means of Only direction of fan airflow. On high bypass turbofan engines reverse thrust achieved reversing only direction of fan airflow in order to save costs mass it not impossible to reverse hot exhaust gas but it complex the gain in reverse thrust will be less than 20% an increase in maintenance costs a higher inflight consumption due to weight of system. Question 35-13
The use of igniters in a gas turbine engine required 1 throughout operating range of engine2 during engine acceleration3 on ground starts4 in flight relights5 during in flight turbulence6 under heavy rains or icing conditionsthe combination that regroups all of correct statements Only direction of fan airflow. Normally in flight no igniters are in use as combustion self sustaining during engine start for take off landing igniters are in use you have to use igniters in case of moderate or severe precipitation turbulence or icing or an in flight relight. Question 35-14
Vibration sensors are used in a gas turbine engine to indicate Imbalance of one or both of spools. Normally in flight no igniters are in use as combustion self sustaining during engine start for take off landing igniters are in use you have to use igniters in case of moderate or severe precipitation turbulence or icing or an in flight relight. Question 35-15
The fan of a turbo fan engine driven Imbalance of one or both of spools. Normally in flight no igniters are in use as combustion self sustaining during engine start for take off landing igniters are in use you have to use igniters in case of moderate or severe precipitation turbulence or icing or an in flight relight. Question 35-16
Regarding a jet engine i the maximum thrust increases as pressure altitude decreases ii the specific fuel consumption increases slightly as pressure altitude decreases at constant tas I correct ii correct. jet engines are more efficient at higher altitudes because less fuel needed a given thrust due to reduction in lift drag lower temperatures through inlet cause a significant reduction in specific fuel consumption up to tropopause specific fuel consumption the amount of fuel burnt per unit of thrust for jets it reduces with altitude up to tropopause. Question 35-17
One of causes of high oil temperature in a gas turbine engine at constant power setting Malfunction of heat exchanger. the fuel/oil heat exchanger located in tanks it cools oil heats fuel so if at constant power setting you have a high oil temperature it may come from a malfunction of heat exchanger. Question 35-18
Given following information about an aeroplane with a turbojet engine mass air flow 50 kg/s tas 90 m/s exhaust nozzle gas velocity 150 m/s exhaust nozzle static pressure1050 hpa ambient static pressure 1000 hpa cross sectional area of nozzle 0 10 m net engine thrust equals Malfunction of heat exchanger. Jaredleto the formula required to answer this question is total thrust = mass thrust + pressure thrust or t = m(vj vv) + a(pj p0) where m = mass air flow vj = exhaust velocity vv = tas a = exhaust cross section area pj = exhaust static pressure and p0 = static ambient pressure in this instance pressures are given in hpa need to be converted to n/sq m therefore t = 50 (150 90) + 0 1 (105000 100000) which gives answer of 3500 n. Question 35-19
A turbofan engine with an inlet air mass flow of 1000 kg/s and a bypass mass flow of 889 kg/s has a bypass ratio Malfunction of heat exchanger. 1000 889 = 111 889 / 111 = 8 01 bypass ratio = bypass mass flow / hp compressor mass flow. Question 35-20
Exhaust gas temperature sensing usually taken Between gas generator turbine the free power turbine. 1000 889 = 111 889 / 111 = 8 01 bypass ratio = bypass mass flow / hp compressor mass flow. Question 35-21
Flat rated jet engines are designed to provide constant maximum take off thrust up to a certain level of Between gas generator turbine the free power turbine. the term flat rating so called because of flat nature of thrust versus ambient temperature curve the curve shows that from lowest operating temperature possible to specified temperature engine produces full thrust above this temperature full thrust will not be permitted a 'flat rate turbofan engine controlled in such a way that at constant ambient air pressure there no variation of take off thrust with air temperature up to some specified temperature limit above that limit engine operates in such a way that either fan speed or compressor speed constant or turbine inlet temperature constant and in either case thrust then decreases with increasing temperature. Question 35-22
Engine temperature limitations of a gas turbine engine are usually imposed due to temperature limitations on Between gas generator turbine the free power turbine. the term flat rating so called because of flat nature of thrust versus ambient temperature curve the curve shows that from lowest operating temperature possible to specified temperature engine produces full thrust above this temperature full thrust will not be permitted a 'flat rate turbofan engine controlled in such a way that at constant ambient air pressure there no variation of take off thrust with air temperature up to some specified temperature limit above that limit engine operates in such a way that either fan speed or compressor speed constant or turbine inlet temperature constant and in either case thrust then decreases with increasing temperature. Question 35-23
For a fan jet engine by pass ratio the External airflow mass divided the internal airflow mass. bypass ratio = bypass mass flow / hp compressor mass flow by pass mass flow the external airflow hp compressor mass flow the internal airflow mass. Question 35-24
If main oil filter of a gas turbine engine becomes clogged oil to main bearings still assured Because oil filter bypass valve opens. bypass ratio = bypass mass flow / hp compressor mass flow by pass mass flow the external airflow hp compressor mass flow the internal airflow mass. Question 35-25
In a free turbine engine energy delivered the free turbine stages Is dependent on rotational speed of gas generator. julien35 from bristol book 'free power turbine engine the mechanical link between gas generator the propeller turbine removed so each element free to rotate at its optimum spee yes but read question carefully it talk about the energy delivered the free turbine stages if gas generator does not rotate free turbine stages will delivered 0 energy if free turbine stages deliver full thrust it possible only with a high rotational speed of gas generator so energy delivered the free turbine stages dependent on rotational speed of gas generator. Question 35-26
Which statement correct a gas turbine engine with a constant speed propeller and free power turbine when power setting increased i the hp spool speed increases ii the egt increases I correct ii correct. Hp spool speed egt gas generator speed all increase a gas turbine engine with a constant speed propeller free power turbine when power setting increased. Question 35-27
Which statement correct a gas turbine engine with a constant speed propeller and free power turbine when power setting increased i the gas generator speed increases ii the egt increases I correct ii correct. Hp spool speed egt gas generator speed all increase a gas turbine engine with a constant speed propeller free power turbine when power setting increased. Question 35-28
The bypass ratio i the ratio of bypass air mass flow to hp compressor mass flow ii can be determined from inlet air mass flow and hp compressor mass flow I correct ii correct. bypass ratio = bypass mass flow / hp compressor mass flow the bypass ratio can be determined from inlet air mass flow the bypass mass flow. Question 35-29
The bypass ratio i the ratio of inlet air mass flow to hp compressor mass flow ii can be determined from inlet air volume flow and hp compressor volume flow I incorrect ii incorrect. bypass ratio = bypass mass flow / hp compressor mass flow the bypass ratio can be determined from inlet air mass flow the bypass mass flow not volume. Question 35-30
Compressor stall in a gas turbine engine Can be caused an axial airflow velocity that low relative to rotor speed. like stall of a wing compressor stall caused a breakdown of airflow if your wing suitable high speed you fly at low speed large angle of attack stall most likely to occur a compressor stall most likely to occur when air flow stagnates in rear stages of compressor a compressor blade hitting oncoming airflow at an angle of attack that determined a combination of rotational speed the incoming airflow when incoming speed low angle of attack will be high when angle of attack gets too high blade stalls so when axial flow in a compressor backs up blades stall (pressure increase in rear stages this slows down flow) you can prevent this dumping some late stage air to atmosphere (via bleed valves). Question 35-31
The air flow passages between adjacent axial compressor rotor blades are divergent but absolute exit velocity higher than absolute entry velocity of rotor this because Part of compressor work delivered to air converted into kinetic energy. compression of hot gas in rotor followed an expansion before entering stator. Question 35-32
A twin spool gas turbine engine one in which Lp turbine drives lp compressor the hp turbine drives hp compressor. compression of hot gas in rotor followed an expansion before entering stator. Question 35-33
When combustion gases pass through a turbine Lp turbine drives lp compressor the hp turbine drives hp compressor. compression of hot gas in rotor followed an expansion before entering stator. Question 35-34
The most common extinguishing agent used in gas turbine engine fire protection systems A liquid halogenated extinguishing agent pressurized gas (typically nitrogen). compression of hot gas in rotor followed an expansion before entering stator. Question 35-35
When a part of a continuous loop fire detection system heated 1 its resistance decreases 2 its resistance increases 3 leakage current increases 4 leakage current decreases the combination regrouping all correct statements A liquid halogenated extinguishing agent pressurized gas (typically nitrogen). compression of hot gas in rotor followed an expansion before entering stator. Question 35-36
A fault protection circuit in a fire detection system will Inhibit fire detector when detection line connected to ground. A fault protection circuit in a fire detection system will inhibit fire detection when detection line connected to ground so if a fire detection system with no fault protection has single loop continuous components if line accidentally grounded alarm will be triggered. Question 35-37
In a fire detection system with single loop continuous components with no fault protection if line accidentally grounded The fire alarm triggered. A fault protection circuit in a fire detection system will inhibit fire detection when detection line connected to ground so if a fire detection system with no fault protection has single loop continuous components if line accidentally grounded alarm will be triggered. Question 35-38
When a continuous loop wire type fire detection system tested The wiring the warning are tested. A fault protection circuit in a fire detection system will inhibit fire detection when detection line connected to ground so if a fire detection system with no fault protection has single loop continuous components if line accidentally grounded alarm will be triggered. Question 35-39
Regarding fire detection ion detectors are used to detect The wiring the warning are tested. A fault protection circuit in a fire detection system will inhibit fire detection when detection line connected to ground so if a fire detection system with no fault protection has single loop continuous components if line accidentally grounded alarm will be triggered. Question 35-40
Smoke detector systems are installed in the Upper cargo compartments (class e). A fault protection circuit in a fire detection system will inhibit fire detection when detection line connected to ground so if a fire detection system with no fault protection has single loop continuous components if line accidentally grounded alarm will be triggered.
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