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When a turbo prop aeroplane decelerates during the intial part of the landing roll a constant speed propeller within the beta range ? Certificate > landing

exemple question 172
Produces negative thrust.


Most high bypass unmixed turbofan engines are equipped with a cold exhaust reverser fan reverser only in order to ?

exemple question 173
Most high bypass unmixed turbofan engines are equipped with a cold exhaust reverser fan reverser only in order to Save costs mass at expense of a reduction in available reverse thrust. High bypass turbofan engines are equipped with a cold exhaust reverser only 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 typical high bypass thrust reversers .


A booster or LP compressor in a twin spool turbofan ?

exemple question 174
A booster or lp compressor in a twin spool turbofan Rotates at same rotor speed as fan. If engine a twin spool turbofan it highly likely that there will be a hp compressor lp compressor a fan the lp comp the fan will be driven from same turbine on same shaft will therefore be at same speed .


exemple question 175
The function of swirl vanes round fuel nozzles to 1 increase air pressure at fuel nozzles 2 reduce average axial flow speed in order to stabilise flame front 3 generate a swirl of incoming air to enhance mixing of fuel with air the combination that regroups all of correct statements Rotates at same rotor speed as fan. If engine a twin spool turbofan it highly likely that there will be a hp compressor lp compressor a fan the lp comp the fan will be driven from same turbine on same shaft will therefore be at same speed .


exemple question 176
The take off of a jet aeroplane may be performed with 'reduced thrust' in order to Reduce maintenance costs. If engine a twin spool turbofan it highly likely that there will be a hp compressor lp compressor a fan the lp comp the fan will be driven from same turbine on same shaft will therefore be at same speed .


exemple question 177
In an ignition system during a normal start of a gas turbine engine igniter activation Should commence prior to fuel entering combustion chamber. If engine a twin spool turbofan it highly likely that there will be a hp compressor lp compressor a fan the lp comp the fan will be driven from same turbine on same shaft will therefore be at same speed .


exemple question 178
A gas turbine engine r at ground idle a period of time prior to shutdown to Prevent seizure of rotor blades in their seals. This allows to gas generator the power turbine discs more time to cool than if engines were immediately shut down the danger that rotor will cool (and will shrink) more rapidly than blades they could be seized in their seals.


8
The purpose of variable pass valves in a high bypass turbofan engine between lp compressor and hp compressor hpc to Prevent fan stall lp compressor stall during engine start low rotor speeds. A bypass valve another name a bleed valve it can also be called a blow off valve anti stall valve or an acceleration valve.


9
If a gas turbine engine fuel/oil heat exchanger located downstream of hp fuel pump internal leakage of heat exchanger will cause oil level to Prevent fan stall lp compressor stall during engine start low rotor speeds. The oil in fuel/oil heat exchanger (located in tanks) always at a higher pressure than fuel but question states located downstream of hp fuel pump so it a secondary fuel/oil heat exchanger in order to avoid fuel icing in fuel regulation system in this heat exchanger you will have high pressure fuel relatively low pressure oil so any internal leak will transfer fuel to oil system raising indicated oil level.


10
The compressor pressure ratio of an axial flow compressor primarily determined the Prevent fan stall lp compressor stall during engine start low rotor speeds. The oil in fuel/oil heat exchanger (located in tanks) always at a higher pressure than fuel but question states located downstream of hp fuel pump so it a secondary fuel/oil heat exchanger in order to avoid fuel icing in fuel regulation system in this heat exchanger you will have high pressure fuel relatively low pressure oil so any internal leak will transfer fuel to oil system raising indicated oil level.


11
In a theoretical gas turbine cycle combustion takes place at constant Prevent fan stall lp compressor stall during engine start low rotor speeds. The oil in fuel/oil heat exchanger (located in tanks) always at a higher pressure than fuel but question states located downstream of hp fuel pump so it a secondary fuel/oil heat exchanger in order to avoid fuel icing in fuel regulation system in this heat exchanger you will have high pressure fuel relatively low pressure oil so any internal leak will transfer fuel to oil system raising indicated oil level.


12
When a gas turbine engine accelerates from idle to take off thrust and compressor rpm too high in comparison with air inlet velocity this may result in Prevent fan stall lp compressor stall during engine start low rotor speeds. Like stall of a wing compressor stall caused a breakdown of airflow 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).


13
Which of following parameters remains constant in a divergent subsonic gas turbine engine intake Prevent fan stall lp compressor stall during engine start low rotor speeds. Like stall of a wing compressor stall caused a breakdown of airflow 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).


14
The most favourable conditions to apply flexible take off procedure are 1 high take off mass2 low take off mass3 high outside temperature4 low outside temperature5 high atmospheric pressure6 low atmospheric pressurethe combination grouping all correct answers Prevent fan stall lp compressor stall during engine start low rotor speeds. Like stall of a wing compressor stall caused a breakdown of airflow 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).


15
Assuming jet pipe not choked equation to calculate jet engine thrust t with mass flow m airspeed vv and jet velocity vj Prevent fan stall lp compressor stall during engine start low rotor speeds. Like stall of a wing compressor stall caused a breakdown of airflow 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).


16
Given p0 = static ambient pressure t0 = static ambient temperaturem = air mass flowvv = true air speedvj = jet efflux exhaust velocitypj = jet efflux exhaust static pressuretj = jet efflux exhaust static temperaturea = exhaust cross sectional areathe thrust t of a jet engine T = m(vj vv ) + a(pj p ). Thrust = air mass flow (jet exhaust velocity true air speed) + exhaust cross sectional area (jet exhaust static pressure static ambient pressure) thrust equal to change in momentum of air entering leaving (it measured the acceleration of air through engine).


17
The axial compressor of a gas turbine engine usually has more stages than its driving turbine because The power output of a turbine stage higher than power consumption of a compressor stage. Thrust = air mass flow (jet exhaust velocity true air speed) + exhaust cross sectional area (jet exhaust static pressure static ambient pressure) thrust equal to change in momentum of air entering leaving (it measured the acceleration of air through engine).


18
On a fadec gas turbine engine during normal flight power the fadec's sensors comes from The fadec power source(s) on engine. The fadec has its own independent power supply (generator) which separate from aircraft generator to ensure that fadec system has electrical power as long as engine running regardless of any problems or faults with aircraft system.


19
In a gas turbine combustion chamber Secondary air required cooling of inner casing. The combustion system's purpose to provide a smooth stream of uniformly heated gas with least loss of pressure the maximum release of heat the combustion chamber made from two tubes one the flame tube which inside air casing between two an air gap through which any air that does not go into combustion chamber passes (secondary air) air enters combustion chamber at around 500 ft/sec is diffused to around 80 ft/sec even at this speed slow flame (at 1/2 ft/sec) would be blown away so a region of low pressure created round it to keep it alright.


20
If there a single input data failure on a fadec gas turbine engine The engine continues to operate normally. The combustion system's purpose to provide a smooth stream of uniformly heated gas with least loss of pressure the maximum release of heat the combustion chamber made from two tubes one the flame tube which inside air casing between two an air gap through which any air that does not go into combustion chamber passes (secondary air) air enters combustion chamber at around 500 ft/sec is diffused to around 80 ft/sec even at this speed slow flame (at 1/2 ft/sec) would be blown away so a region of low pressure created round it to keep it alright.



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