AS311 exam 1

77 flashcards · Other · by macauley dsouza

What type of compressor(s) does this engine have? A) Axial and centrifugal B) Axial only C) Centrifugal only D) Reverse flow axial
Axial only
By what method are turbine blades cooled? A) Bleed air from compressor section. B) Outside air that enters through gaps in turbine case. C) Liquid cooled by coolant and radiator. D) Turbine blades are not cooled because higher temperatures create a more efficient turbine.
Bleed air from compressor section.
What is the historical significance of this airplane? A) First commercial transport using a turbine-powered engine B) First turbocharged propeller airplane C) First commercial transport using a turbojet engine D) First British airplane to use a turbine-powered engine
First commercial transport using a turbine-powered engine
The Engine Alliance GP7200 turbofan is a dual-spool engine. What is the name of the component inside the yellow circle? A) N2 compressor B) N1 compressor C) N2 turbine D) N1 turbine
N2 compressor
This compressor component is machined out of a single piece of metal. What is its name and benefit(s)? A) Blisk. Decreased weight. B) Mixed flow compressor. Increased strength. C) Stator-rotor combination disc. Decreased weight. D) Combustor stator. Optimum airflow to combustor.
Blisk. Decreased weight.
What is the name and purpose of these components in an accessory gearbox? A) Radial drive shaft and bevel gear. Transfers energy between the engine and the accessory gearbox. B) Radial inflow turbine. Converts gas energy into rotational energy for the accessory gearbox. C) Planetary reduction gear. Changes engine RPM into optimum RPM for each component in the accessory gearbox. D) Staged gear reduction. Increases engine RPM to provide higher RPM for components in the accessory gearbox.
Radial drive shaft and bevel gear. Transfers energy between the engine and the accessory gearbox.
This engine is a two-shaft turbofan. What is the name of the 14-stage compressor section aft of the compressor fan? A) N1 low pressure compressor B) N1 high pressure compressor C) N2 low pressure compressor D) N2 high pressure compressor
N2 high pressure compressor
Why does the Pilatus PC12 have a divergent inlet duct? A) It decreases airflow velocity and increases static pressure. B) It increases airflow velocity and decreases static pressure. C) Divergent inlet ducts are not used in turboprop engine inlets. D) It decreases airflow velocity and decreases static pressure.
It decreases airflow velocity and increases static pressure.
What conditions lead to the highest propulsive efficiency? A) Exhaust gas velocity equal to aircraft speed B) Exhaust gas velocity greater than aircraft speed C) When the engine extracts all available energy from the fuel D) The highest possible propeller or compressor speed
Exhaust gas velocity equal to aircraft speed
Which of these aircraft made the first jet-propelled flight? A) Airplane 1 B) Airplane 2 C) Airplane 3 D) Airplane 4
Airplane 1
What type of combustor is present in this engine? A) Reverse flow B) Axial flow C) Through-flow D) Mixed flow
Reverse flow
What type of engine compresses the incoming airflow without the use of a moving compressor? A) Ramjet B) Rocket C) Turboprop D) Turbojet
Ramjet
According to Bernoulli's Principle, how does dynamic pressure (q) change as subsonic airflow passes through this duct from left to right? A) Dynamic pressure decreases B) Dynamic pressure increases C) Dynamic pressure does not change D) Dynamic pressure increases and then decreases
Dynamic pressure decreases
The Engine Alliance GP7200 is a dual-spool turbofan engine. What is the name and purpose of the component in the yellow circle? A) N1. Spin the low pressure compressor B) N2. Spin the high pressure compressor C) Ng. Spin the compressor fan. D) N1. Increase exhaust gas pressure
N1. Spin the low pressure compressor
Why does the turbofan with afterburner have a lower specific impulse than a turbofan without an afterburner? A) An afterburner increases fuel flow B) An afterburner decreases fuel flow C) A plain turbofan goes faster D) A plain turbofan decreases drag
An afterburner increases fuel flow
What is/are the purpose(s) of the holes in the combustor liner? A) Protects the combustor liner from excessive temperature and controls turbine inlet temperature. B) Allows fuel/air mixture to enter the combustor. C) Allows only fuel to enter the combustor. D) Allows the flame to propagate between combustion chambers and prevents excessive pressure.
Protects the combustor liner from excessive temperature and controls turbine inlet temperature.
Air pressure in this engine's intake during a ground runup (static operations) is... A) Less than ambient pressure B) Equal to ambient pressure C) Greater than ambient pressure D) Steadily increasing
Less than ambient pressure
The Pilatus PC-24 has a maximum cruising speed of approximately M 0.71. What design features should be present in the engine inlet? A) Fixed geometry and divergent shape. B) Variable geometry and divergent shape. C) Fixed geometry and convergent shape. D) Variable geometry and convergent shape
Fixed geometry and divergent shape.
What is the name and primary purpose of the blades in this image? A) Rotor blades. Increase the pressure of the inlet air. B) Stator blades. Increase the static pressure and direct the airflow onto the rotor blades. C) Rotor blades. Increase the temperature and velocity of the intake air. D) Inlet guide vanes. Direct the inlet air onto the stator and rotor blades.
Stator blades. Increase the static pressure and direct the airflow onto the rotor blades.
What is the name and purpose of the component indicated by the blue circle near the top of the image? A) Diffuser. Increase static pressure. B) Inlet guide vane. Provide uniform airflow velocity. C) Combustor. Burn fuel and air mixture. D) Air inlet. Provide air to compressor at optimum angle, velocity, and pressure.
Diffuser. Increase static pressure.
What is the name and purpose of this engine component if the engine RPM is 39,000? A) Accessory gearbox. Changes engine RPM into optimum RPM for each component B) Radial drive shaft. Transfers engine RPM directly to engine components without changing RPM C) Hydraulic drive valve. Converts hydraulic energy into mechanical energy to drive engine components. D) Flywheel. Engages at high RPM to convert engine RPM into optimum RPM for each component.
Accessory gearbox. Changes engine RPM into optimum RPM for each component
What is the name and purpose of the red blades at the top-right corner of the image? (*Hint: Airflow is from right to left*) A) Turbine inlet guide vanes. Direct airflow into the first stage turbine rotor. B) Compressor exit guide vanes. Direct air into the diffuser. C) Turbine exit vanes. Direct air into the exhaust section. D) Turbine rotor. Extract energy from the exhaust to spin the compressor.
Turbine inlet guide vanes. Direct airflow into the first stage turbine rotor.
What is the name and purpose of the component in the center of the yellow circle? A) Swirl vane. Mix fuel and air. B) Air holes. Provide cooling air for combustor. C) Interconnector. Allows flame to propagate to different combustor chambers. D) Double annular combustor. Connects multiple annular combustor chambers.
Swirl vane. Mix fuel and air.
This is a dual-spool turbojet engine. What is the name of the turbine section immediately aft of the combustor? A) N2 high pressure turbine B) N2 low pressure turbine C) N1 high pressure turbine D) Free power turbine
N2 high pressure turbine
If both airports are located at sea level, and considering density altitude, at which airport will a turbine-powered engine create the most thrust and why? KLAX 292153Z 26010KT 10SM CLR 27/15 A2990 RMK AO2 SLP125 T02670150 KACV 292153Z AUTO 27003KT 6SM BR OVC003 16/14 A3003 RMK AO2 SLP175 T01560139 A) KACV because the density altitude is lower than KLAX. B) KLAX because the density altitude is lower than KACV. C) KACV because the density altitude is higher than KLAX. D) KLAX because the density…
KACV because the density altitude is lower than KLAX.
What is the turbine section's primary purpose? A) Spin the compressor, propeller, and/or rotor B) Decrease the exhaust gas velocity C) Decrease the exhaust gas pressure D) Increase the exhaust gas pressure
Spin the compressor, propeller, and/or rotor
What type of engine is used in this aircraft? A) Turboprop B) Turboshaft C) Turbojet D) Turbofan
Turboshaft
What type of combustor is pictured? A) Reverse flow B) Axial flow C) Through-flow D) Mixed flow
Reverse flow
What is the name of the blades on the inside of this compressor case and what is the direction of airflow? A) Stator vanes or inlet guide vanes. Air flows from left to right. B) Rotor blades. Air flows from left to right. C) Variable rotor vanes. Air flows from right to left. D) Stator vanes. Air flows from right to left.
Stator vanes or inlet guide vanes. Air flows from left to right.
How is compressor bleed air used in the turbine section? A) Cooling of both turbine blades and turbine case. B) Heating of turbine blades to maintain optimum blade-tip-clearance. C) Heating of turbine case to maintain optimum blade-tip-clearance D) Cooling of turbine shaft to minimize friction and mechanical efficiency
Cooling of both turbine blades and turbine case.
What is the name and purpose of the stationary blades at the exit of the combustion chamber? A) Turbine inlet guide vanes. Control airflow into the turbine. B) Turbine rotor blades. Extract energy from the exhaust gas. C) Turbine stage. Provide rotational energy to the compressor. D) N1 turbine. Provide rotational energy to the low pressure compressor.
Turbine inlet guide vanes. Control airflow into the turbine.
The Aerion AS2 is a prototype supersonic business jet. What design features must be present on the engine inlet? A) Convergent-divergent duct B) Only a divergent duct C) Only a convergent duct D) Variable geometry inlet with a convergent-divergent duct
Convergent-divergent duct
What type of engine is present in this aircraft? A) Turboshaft B) Turboprop C) Turbojet or turbofan D) Auxiliary power unit
Turboshaft
Some compressor blades are twisted from root to tip. What is this called and what is its purpose? A) Stagger angle. Provides uniform air velocity. B) Profile tip. Provides uniform temperature. C) Camber. Provides uniform static pressure D) Washup. Decreases engine vibration.
Stagger angle. Provides uniform air velocity.
What is the name and purpose of "C" in the picture? A) N1 compressor. Increases static pressure B) N1 compressor. Increases airflow velocity and decreases static pressure C) N2 compressor. Decreases airflow velocity and increases total pressure (dynamic + static). D) N2 compressor. Increases both dynamic and static pressure to increase total pressure
N1 compressor. Increases static pressure
What is the name and purpose of the holes (circled in blue) on the top of the Eurofighter inlet? A) Boundary layer bleed. Removes low energy airflow from inlet air. B) Boundary layer diverter. Keeps fuselage boundary layer air separate from intake air. C) Bleed valve. Diverts airflow for use in other aircraft systems. D) Boundary layer jet. Introduces high energy airflow into the intake air.
Boundary layer bleed. Removes low energy airflow from inlet air.
What is the name and purpose of the movable door in this picture of a turboprop air inlet? A) Particle (inertial) separator. Protect the compressor from FOD and ice. B) Internal separator. Vary airflow that reaches compressor, thereby altering engine RPM. C) Waste gate. Control engine RPM by controlling engine airflow. D) Variable geometry inlet. Create shockwave to reduce airflow velocity to less than M 1.0
Particle (inertial) separator. Protect the compressor from FOD and ice.
What part of the combustion cycle (part of the engine) is represented by the line from Point 2 to Point 3? A) Turbine B) Compressor C) Exhaust D) Inlet
Compressor
What type of engine is pictured? A) Reciprocating B) Turboprop C) Turbine D) Rotary
Reciprocating
What condition may occur in a turbine engine if you fly above maximum manufacturer altitudes? A) Flameout due to lean mixture. B) Flameout due to rich mixture. C) Flameout due to excessive combustor back pressure. D) Flameout due to turbulent airflow entering the combustor.
Flameout due to lean mixture.
Calculate force (F)(lbs/in2) at the exhaust exit on a PT-6 turboprop engine given the following conditions: Tailpipe diameter: 5 in Exhaust gas pressure: 19 psi Atmospheric pressure: 6.5 psi
245
How much power (P)(ft-lbs/min) is required to lift a Pratt & Whitney 207D turboshaft engine (237 lbs) 8.3 feet into a Bell 429 using a hydraulic lift if the total time required is 22 seconds? **Round power to the nearest 1/10**
How much horsepower (Hp) is required to lift a Piper Meridian (3,417 lbs) 18 inches using a hydraulic lift if the total time required is 48 seconds? **Round answer to the nearest 1/10**
How much power (P)(ft-lbs/min) is required to lift a Cessna 172 onto a maintenance stand given the following conditions: Aircraft weight: 2,120 lbs. Maintenance stand height: 21 inches Time: 78 seconds
2,854
How much work (W)(ft-lbs) is required to lift a Pratt & Whitney 207D turboshaft engine (237 lbs) 8.3 feet into a Bell 429? **Round work to the nearest 1/10**
How much horsepower (Hp) is required to lift a Cessna 172 onto a maintenance stand given the following conditions: **Round all answers to the nearest 1/10** Aircraft weight: 2,120 lbs. Maintenance stand height: 21 inches Time: 78 seconds
You are on the runway in a Dassault Falcon 8x and have added power to begin the takeoff roll. Assuming the airplane has not started moving, what is the gross thrust (Fg) (lbs.) for one engine? Exhaust gas velocity: 375 knots (nautical miles per hour) Engine inlet diameter: 41 inches Engine flow rate: 621 ft/s
8,558
A GE90 Turbofan engine produces 90,000 lbs of thrust during takeoff at 140 mph. How much thrust horsepower (Thp) does this engine produce? A) 36,000 Thp B) 33,600 Thp C) 225,000 Thp D) 89,458 Thp
What must be true of the turbine section in the turboshaft engine in this MD500? A) There must be a free power turbine. B) There must be a high pressure (N2) turbine. C) There must be a radial inflow turbine. D) There must be at least 2 stages in the N1 turbine.
There must be a free power turbine.
What type of engine is present in this Talos missile? A) Rocket B) Ramjet C) Turbojet D) Pulsejet
Ramjet
Why does the turbofan with afterburner have a lower specific impulse than a turbofan without an afterburner? A) An afterburner increases fuel flow B) An afterburner decreases fuel flow C) A plain turbofan goes faster D) A plain turbofan decreases drag
An afterburner increases fuel flow
In what type of engine is this turbine usually found? A) Auxiliary power units B) Small turboprop or turboshaft engines C) Small turbofan engines D) This is not a turbine
Auxiliary power units
Outside air is directed through the compressor case in a series of ducts. What is the purpose of this cooling air? A) Shrinks the compressor case to maintain optimum compressor blade tip clearance. B) Expands the compressor case to maintain optimum compressor blade tip clearance. C) Shrinks the stator blades to maintain optimum stator blade tip clearance. D) Expands the rotor blades to maintain optimum rotor blade tip clearance.
Shrinks the compressor case to maintain optimum compressor blade tip clearance.
What system(s) can dissipate this vortex? A) Flat bottom nacelle or blow away jets B) No systems can dissipate the vortex. C) Bleed valve in the compressor D) Bypass valve for the compressor fan
Flat bottom nacelle or blow away jets
How can you visually determine whether an engine is a turbojet or a turbofan? A) The turbofan has a bypass duct B) The turbojet has a bypass duct C) The turbofan has more turbine stages D) The turbojet has more turbine stages
The turbofan has a bypass duct
An engine has a bypass ratio of 1:1. What type of engine is it? A) Turbojet B) Turbofan C) All turbine engines have a bypass ratio D) Turboprop or turboshaft
Turbofan
Which statement is true? A) Reciprocating engines create the most thrust at airspeeds below "A" B) Turbojet engines create more thrust at all airspeeds C) Turbofan engines create the most thrust between "A" and "E" D) Reciprocating engines create the least thrust at all airspeeds
Reciprocating engines create the most thrust at airspeeds below "A"
What type of turbine-powered engine is pictured and what feature distinguishes it as such? A) Turbofan due to the presence of a bypass duct B) Turbojet due to the multi-spool (shaft) design. C) Turboshaft due to the presence of a free-power turbine. D) Turbojet due to the presence of a compressor fan.
Turbofan due to the presence of a bypass duct
The Engine Alliance GP7200 is a dual-spool turbofan engine. What is the name and purpose of the component in the yellow circle? A) N2 compressor B) N1 compressor C) N2 turbine D) N1 turbine
N2 compressor
You are flying a turboprop airplane, cruising at FL 230 over KBRL, and are in the clouds (visible moisture). What, if any action should you take considering the following winds/temperatures aloft forecast and the included image? A) Open the inertial separator. B) Close the inertial separator. C) This airplane is not equipped for flight in icing conditions. D) No action is necessary.
Open the inertial separator.
Which statement is true regarding propulsive efficiency at 400 mph (approximately M 0.6)? A) The turboprop is the most efficient engine B) The turboprop creates the most thrust C) The high-bypass turbofan is the most efficient D) The turbojet creates the highest aircraft speed
The turboprop is the most efficient engine
How are many accessory gearboxes driven? A) By a radial drive shaft and a bevel gear. B) By a hydraulic pump and calibrated reduction valve. C) By an electric motor and a high-current diode. D) By a chain affixed to a flywheel.
By a radial drive shaft and a bevel gear.
What is the name and purpose of the component indicated by the yellow circle near the top of the image? A) Combustor diffuser. Increase static pressure. B) Inlet guide vane. Provide uniform airflow velocity. C) Combustor. Burn fuel and air mixture. D) High pressure compressor. Increase static pressure.
Combustor diffuser. Increase static pressure.
ATC instructs you to descend immediately so you abruptly decrease power. What might occur as a result of the rapid power reduction? A) Compressor stall or surge due to insufficient combustor pressure. B) Combustor over-pressure due to excessive compression ratio C) Turbine overspeed due to insufficient combustor pressure D) Combustor flameout due to insufficient mass airflow
Compressor stall or surge due to insufficient combustor pressure.
What type of combustor is shown in this picture? A) Annular B) Can C) Can-annular D) Cannular
Can
What turbine stage most likely spins the propeller in this Lancair Evolution turboprop? A) Nf. Free power turbine. B) N1. Low pressure turbine. C) N2. High pressure turbine. D) The propeller is not spun by the turbine.
Nf. Free power turbine.
The Boeing B-29 Superfortress had four Wright R-3350 supercharged radial engines. Who developed the first supercharger? A) Sanford Moss B) Frank Whittle C) Hans Von Ohain D) Giovanni Branca
Sanford Moss
Who developed the first turbojet engine and the engine that eventually flew in this airplane? A) Frank Whittle B) Hans Von Ohain C) Giovanni Branca D) Sanford Moss
Frank Whittle
What type of engine is used in this aircraft? A) Turboshaft B) Turboprop C) Turbojet D) Turbofan
Turboprop
Why is there a gap between the inlet and the fuselage on the F-4 Phantom? A) To regulate the boundary layer and prevent turbulent inlet airflow B) To add high-energy air to the boundary layer C) To create shockwaves that reduce intake air velocity D) To eliminate shockwaves that reduce intake air velocity
To regulate the boundary layer and prevent turbulent inlet airflow
Accessories in the gearbox (e.g. fuel pump, oil pump, alternator) turn at a RPM that is... A) Equal to, higher, or lower than the engine RPM. B) Always lower than the engine RPM C) Always higher than the engine RPM D) Always the same as the engine RPM
Equal to, higher, or lower than the engine RPM.
Why does the Pratt & Whitney J58 engine have a lower specific impulse than the GE CF6 engine? A) Low thrust to fuel consumption ratio B) High thrust to fuel consumption ratio C) Low fuel consumption to thrust ratio D) High thrust always leads to low specific impulse
Low thrust to fuel consumption ratio
What is the mass airflow (lbs/sec) of a HF120 turbofan engine with the following criteria: Compressor fan diameter: 25.8 inches Airplane velocity: 320 knots (nautical miles per hour)
What is the propulsive efficiency of a CFM-56 engine given the following conditions: **Write answers as a percent (e.g. 28) but do not include the % symbol** **Round all answers to the nearest whole number** Aircraft speed: 480 knots (nautical miles per hour) Exhaust gas velocity: 1071 ft/s
86
You are on the runway in a Dassault Falcon 8x and have added power to begin the takeoff roll. Assuming the airplane has not started moving, what is the acceleration (A) in feet per second of the air that passes through the engine in 1 second? Exhaust gas velocity: 375 knots (nautical miles per hour)
633
How much thrust (Fp)(lbs) does a Pratt & Whitney PT6 engine produce on a Piper Meridian given the following conditions: Shaft horsepower: 835 Hp Cruise speed: 290 mph Propeller efficiency: 80%
864
How much thrust-horsepower (Thp) does a turbojet engine produce given the following conditions: Thrust: 8,350 lbs Speed: 638 mph
14,206