AERONAUTICAL ENGINEERING QUIZ Flashcards
Which of the following could cause a compressor stall?
Engine rpm is too low.
Low pressure in subsequent compressor stages.
A bleed air valve stuck in the open position.
Insufficient intake air.
Insufficient intake air.
You are starting engines at an airport with an altitude of 5700 ft msl and 32 degrees Celsius. You notice that the EGT is rising rapidly as N2 increases. What start anomaly are you experiencing and what is the approach action?
No start, disengage the starter.
Hot start, disengage the starter.
Hung start, re-engage the starter and motor the engine.
Hot start, cutoff the fuel.
Hot start, cutoff the fuel.
The ability of an airplane to efficiently convert fuel energy into flying distance is one of the most important items of airplane performance. The formula used to calculate a specified distance with fuel expenditure is the formula for:
Specific range.
Specific endurance.
Specific fuel consumption.
Specific drag.
Specific range.
Since turbine ignition systems are operated mostly for a brief period during the engine-starting cycle, they are:
As a rule, more trouble-free than the typical reciprocating engine ignition system.
As a rule, less trouble-free than the typical reciprocating engine ignition system.
As a rule, more typical of a reciprocating engine ignition system design.
As a rule, more typical of a diesel engine ignition system design.
As a rule, more trouble-free than the typical reciprocating engine ignition system.
Which of the following might contribute to an engine hot start?
A headwind in excess of 15 knots.
A tailwind.
Ice blocking the P2T2 sensor.
Insufficient fuel flow.
A tailwind.
WHEN CONSIDERING FACTORS RELATING TO TAKEOFF AND CRUISE FLIGHT PLANNING, WHICH OF THE FOLLOWING STATEMENTS ARE TRUE
USE OF THE BEST ANGLE SPEED WILL RESULT IN LESS TRIP FUEL BURNED AND FASTEST TIME TO CLIMB TO CRUISE ALTITUDE
USE OF BEST RATE SPEED WILL RESULT IN MORE TRIP FUEL BURNED AND SLOWEST TIME TO CLIMB TO CRUISE ALTITUDE
USE OF BEST RATE SPEED WILL RESULT IN LESS TRIP FUEL BURNED AND FASTEST TIME TO CLIMB TO CRUISE ALTITUDE
USE OF BEST ANGLE SPEED WILL RESULT IN MORE TRIP FUEL BURNED AND FASTEST TIME TO CLIMB TO CRUISE ALTITUDE
USE OF BEST RATE SPEED WILL RESULT IN LESS TRIP FUEL BURNED AND FASTEST TIME TO CLIMB TO CRUISE ALTITUDE
When the aircraft is shut down after flight, what is typically used to maintain pressure for the parking brake?
The in-line variable restrictor orifice.
The hydraulic fuse.
The hydraulic reservoir.
The hydraulic accumulator.
The hydraulic accumulator.
A principle advantage of an axial flow compressor on a turbine engine compared to a centrifugal flow compressor is:
It requires relatively low inlet velocities
Simplicity
High compressor ratio per stage
Ability to handle large volumes of airflow.
Ability to handle large volumes of airflow.
During engine starts, what initial indication might signify an impending hot start?
Low N1 rotation.
Higher than normal fuel flow.
Higher than normal N1 rotation
Lower than normal fuel flow.
Higher than normal fuel flow.
The primary reason for using a crossfeed fuel system is to:
Be able to purge any fuel tank.
Allow fuel to be used for ballast when needed.
Jettison fuel during emergencies.
Help maintain aircraft center of gravity.
Help maintain aircraft center of gravity.
PLANNING TAKEOFFS AT HIGH ALTITUDE AIRPORTS WITH HIGH TEMPERATURES REQUIRE SOME SPECIAL CONSIDERATIONS. WHICH OF THE FOLLOWING IS ONE OF THOSE CONSIDERATIONS?
POTENTIAL TO EXCEED BRAKE ENERGY LIMITS
ENGINE EGT MARGINS BEING EXCEEDED
DECREASED EFFECTIVENESS OF REVERSE THRUST
INCREASING PAYLOAD TO ENHANCE BRAKING EFFECTIVENESS DURING A REJECTED TAKEOFF
POTENTIAL TO EXCEED BRAKE ENERGY LIMITS
WHICH STATEMENT COULD BEST DESCRIBE GROUND EFFECT
A CUSHION OF AIR THAT AN AIRPLANE FLOATS ON NEAR THE GROUND
A REDUCTION OF DOWNWASH
AN INCREASE OF UPWASH WITHIN ONE WINGSPAN LENGTH OF THE GROUND
AN INCREASE OF STABILITY DUE TO ANHEDRAL WING DESIGN
A REDUCTION OF DOWNWASH
REDUCED DOWNWASH BUT UPWASH STAYS THE SAME.
Under normal operating conditions during flight, what is typically powering the electrical system of a large turbine aircraft?
A generator providing 115 volts, 400-Hz alternating current, powered through a ram air turbine.
A generator providing 115 volts, 400-Hz alternating current, powered through an engine’s constant speed drive unit.
A generator providing 115 KVA, 400-Hz alternating current, powered through an engine’s generator control unit.
A generator providing 115 volts, 400-Hz alternating current, powered through an engine’s constant speed drive unit.
THROUGH THE CONSTANT SPEED DRIVE.
Why are hydraulic reservoirs pressurized?
To provide an alternate source of pressure in case of a hydraulic pump failure.
To assure a positive feed of foam-free fluid to the hydraulic pump at high altitudes.
To insure an adequate supply of fluid to the hydraulic pump inlet during negative-G flight.
To provide an alternate source of hydraulic fluid in the event a hydraulic filter becomes clogged.
To assure a positive feed of foam-free fluid to the hydraulic pump at high altitudes.
A major advantage of ni-cad batteries over lead-acid batteries is that ni-cad batteries:
Put out sustained voltage over a longer period of time. 2. Are less expensive.
Are less expensive.
Are not subject to thermal runaway.
Do not need to be deep-cycled for optimal performance.
Put out sustained voltage over a longer period of time. 2. Are less expensive.
WHICH OF THE FOLLOWING MIGHT CONTRIBUTE TO AN ENGINE HOT START
A HEADWIND IN EXCESS OF 15 KNOTS
A TAILWIND
ICE BLOCKING THE P2T2 SENSOR
INSUFFICIENT FUEL FLOW
A TAILWIND
What increases or decreases the voltage of a generator so it carries its share of the load?
Current limiter
Rectifier.
Paralleling circuit.
Reverse current cut-out relay.
Paralleling circuit.
During an engine start after the fuel is introduced, the engine fails to reach a self-sustaining speed. This might be an example of which start anomaly?
Hot start.
No start anomaly exists in this scenario.
Hung start.
No start.
Hung start.
The basic elements of the accessory section of a turbofan engine are:
The accessory case, which has machined mounting pads for the engine-driven accessories, and the gear train, which is housed within the accessory case.
The accessory gearbox, which has machined mounting pads for the engine-driven accessories, and the gear train, which is housed on the accessory case.
The engine starter, auxillary power unit, oil pump and filter, and the gear train, which is housed within the accessory case.
The engine starter, auxillary power unit, oil pump and filter, and the gear train, which is housed on the accessory case.
The accessory case, which has machined mounting pads for the engine-driven accessories, and the gear train, which is housed within the accessory case.
The primary purpose of an aircraft’s electrical ground is to:
Act as an electrical shock absorber in the event of a lightning strike.
Complete the electrical circuit.
Dissipate electrical build-ups caused by the airframe’s interaction with clouds that would otherwise interfere with radio transmissions.
Electrically connect the aircraft to the fuel truck in order to prevent sparks from occurring when the truck’s fuel hose first comes in contact with the aircraft’s refueling port.
Complete the electrical circuit.
High fuel flow during engine start can be an indication of what?
A tailwind.
Introducing fuel into the engine before the compressor is up to proper speed.
Engine fuel pump malfunction.
Fuel control malfunction.
Fuel control malfunction.
DURING AN ENGINE START AFTER THE FUEL IS INTRODUCED, THE ENGINE FAILS TO REACH A SELF-SUSTAINING SPEED. THIS MIGHT BE AN EXAMPLE OF WHICH TYPE OF START ANOMALY
HOT START
NO START ANOMALY EXISTS IN THIS SCENARIO
HUNG START
NO START
HUNG START
WHEN CONSIDERING OBSTACLE CLEARANCE FOR ONE ENGINE INOPERATIVE TAKEOFF PERFORMANCE, WHICH OF THE FOLLOWING IS TRUE
PERFORMANCE IS PREDICATED ON CLEARING A 15 FOOT OBSTACLE WITH WET RUNWAY CONDITIONS
PERFORMANCE IS PREDICATED ON CLEARING A 35 FOOT OBSTACLE WITH WET RUNWAY CONDITIONS
PERFORMANCE IS PREDICATED ON CLEARING A 15 FOOT OBSTACLE WITH DRY RUNWAY CONDITIONS
PERFORMANCE IS PREDICATED ON CLEARING A 50 FOOT OBSTACLE WITH DRY RUNWAY CONDITIONS
PERFORMANCE IS PREDICATED ON CLEARING A 15 FOOT OBSTACLE WITH WET RUNWAY CONDITIONS
WHICH OF THE FOLLOWING ARE TRUE STATEMENTS WITH REGARDS TO BEST RATE OF CLIMB SPEED (Vy)
PROVIDES THE GREATEST ACHIEVEMENT OF ALTITUDE OVER A SPECIFIED DISTANCE
USES MORE TRIP FUEL
WILL TAKE A LONGER AMOUNT OF TIME REACH CRUISE ALTITUDE
USES LESS TRIP FUEL
USES LESS TRIP FUEL
Which are protective functions of an AC generator control unit?
Undervoltage, differential fault, and manual paralleling.
Generator underspeed and bus-tie circuit-breaker automatic closing.
Overvoltage, current limiting, and generator underspeed.
Overvoltage, current limiting, and generator overspeed.
Overvoltage, current limiting, and generator overspeed.
A turbine engine usually has an accessory section gear train driven by:
The engine low-pressure fan turbine through an accessory drive shaft gear coupling.
The engine high-pressure fan turbine through an accessory drive shaft gear coupling.
The engine low-pressure compressor through an accessory drive shaft gear coupling.
The engine high-pressure compressor through an accessory drive shaft gear coupling.
The engine high-pressure compressor through an accessory drive shaft gear coupling.
Which start anomaly, if any, is caused by the engine reaching a self-sustaining speed but the combustion is unstable?
Hot start
Start is normal
No ignition
Hung start
Hot start
In relation to the cooling function of the oil, the engine is most prone to critical overheating:
During climb-out.
During cruise flight.
During an idle descent.
After the engine has been shut down.
During climb-out.
WHAT IS A CHARACTERISTIC OF FOWLER FLAPS
LESS DRAG IN THE LANDING RANGE THAN A NORMAL FLAP
INCREASES THE SURFACE AREA OF THE WING AND ARE GENERALLY SLOTTED
SIGNIFICANTLY INCREASES DRAG IN LOW FLAP SETTING RANGES
DO NOT ALLOW FOR DECREASED APPROACH SPEEDS COMPARED TO OTHER FLAP DESIGNS
INCREASES THE SURFACE AREA OF THE WING AND ARE GENERALLY SLOTTED
A principle disadvantage of a centrifugal flow compressor on a turbine engine compared to an axial flow compressor is:
It is more expensive to manufacture.
The provision of more than one or two stages is rarely feasible.
It is more susceptible to foreign-object damage.
Its total compression section is heavier.
The provision of more than one or two stages is rarely feasible.
During an engine start you notice that the N2 is lower than normal and the EGT is higher than usually seen, but not excessive or approaching the start limits. What problem, if any, is the engine experiencing?
A hot start.
Start is normal.
A possible hung start.
Weak igniters in the combustor section.
A possible hung start.
Fill in the blanks: Fowler flaps not only _____ the trailing edge of the wing when deployed but also slide _____, effectively _____ the area of the wing.
Raise; forward; decreasing.
Lower; laterally; increasing.
Lower; aft; increasing.
Lower; forward; decreasing.
Lower; aft; increasing.
When wing fuel tanks on certain heavy aircraft, such as the MD-11, get below a certain fuel quantity, VMO/MMO is reduced. The primary reason for this is because:
The weight of the fuel in the wing fuel tanks that has been burned off is no longer available to provide added structural stability required at higher true airspeeds.
The weight of the fuel in the wing fuel tanks that has been burned off is no longer available to provide added structural stability required at higher indicated airspeeds.
Without the added weight of the fuel on the wing, the angle of attack increases, making the aircraft more susceptible to Mach tuck at higher airspeeds.
Without the added weight of the fuel on the wing, the angle of attack increases, making the aircraft more susceptible to wing twist at higher airspeeds
The weight of the fuel in the wing fuel tanks that has been burned off is no longer available to provide added structural stability required at higher indicated airspeeds.
The primary function of the turbine section in a gas turbine engine is to:
Progressively “squeeze” air in preparation for combustion.
Accelerate air from the combustion section and subsequently provide thrust through the exhaust nozzles.
Help to direct and compress the flow of air between each set of rotor blades.
Drive the compressors through common shafts.
Drive the compressors through common shafts.
WHY IS IT IMPORTANT TO DE-ROTATE AS QUICKLY AS POSSIBLE ON LANDING.
ALLOWS AERODYNAMIC BRAKING TO BE MORE EFFECTIVE
HYDROPLANING IS LESS LIKELY TO OCCUR IF THE NOSE WHEEL IS ON THE GROUND.
TO INCREASE BRAKING EFFECTIVENESS
IT NOT REALLY IMPORTANT SINCE AERODYNAMIC BRAKING IS 2 TIMES MORE EFFECTIVE AT LANDING SPEEDS CERTIFIED ON TRANSPORT CATEGORY AIRCRAFT
TO INCREASE BRAKING EFFECTIVENESS
During climb out on departure your EGT and engine rpm indications are fluctuating significantly on your number 2 engine. You suspect a compressor stall. The pilot with whom you are flying references the airplane’s Quick Reference Handbook for the appropriate procedure. In the meantime, as you are flying, the best course of action would be to:
Reduce the throttle, increase the aircraft’s angle of attack, and increase airspeed.
Reduce the throttle, decrease the aircraft’s angle of attack, and increase airspeed.
Increase the throttle, decrease the aircraft’s angle of attack, and increase airspeed.
Increase the throttle, increase the aircraft’s angle of attack, and increase airspeed.
Reduce the throttle, decrease the aircraft’s angle of attack, and increase airspeed.
One of the most important characteristics of hydraulic fluid is that it cannot be:
Capable of breaking down insulation on electrical wires.
Susceptible to vaporization.
Harmful while coming into contact with human skin.
Corrosive.
Susceptible to vaporization.
The primary function of the oil system in the modern gas turbine engine is to:
Cool and lubricate the main bearings and accessory drive gears.
Move the variable geometry diffusers and inlet guide vanes
Heat the fuel just prior to entering the fuel filters.
Operate the thrust reversers.
Cool and lubricate the main bearings and accessory drive gears.
