Extra Powerplant Questions Flashcards
What is the purpose of a turbine deaerator in an oil tank?
Separating aerated oil from the scavenge pick up.
When an electric primer is used, fuel pressure is built up by the…?
Fuel forced through the engine driven bypass.
When installing a magneto on an engine, the piston in #1 cylinder must be?
Before TDC on compression stroke.
What is not a function of bleed air?
Actuator.
Fuel flow transmitter indicates?
Pounds per hour
What destroys vortices that would otherwise suck debris from the ground into engines mounted in pods low to the ground?
Vortex dissipater.
Carburetor icing is most sever at…?
Air temp below 32 degrees.
What is the purpose of a vortex dissipater?
Destroys vortices that would otherwise suck debris from the ground into engines mounted in pods low to the ground.
A type of propeller vibration in which the ends of the propeller blade twist back and forth at high frequency around an axis perpendicular to the engine crankshaft is known as what?
Fluttering.
How does hydromatic propeller operate?
By use of a double-acting governor that uses oil on both sides of the propeller piston.
Which part of an Aircraft in flight will accumulate ice first?
Fuel discharge nozzle.
Turbine EPR indicator compares which two pressures?
Compressor and turbine wheel.
What is the benefit of using a Hydraulic power pack?
It makes the Hydraulic system lightweight
Part of the ADF (auto direction finder) system used on aircraft includes?
Sense and loop antennas
When a CSD and an alternator are contained within one unit, the assembly is know as…?
An IDG
Which of the following has a direct input on generator output?
Strength of the magnetic field.
Centrifugal twisting forces causes the propeller to?
Move into a low pitch.
When is a hot section performed?
Perodically
How does CO2 extinguish a fire?
By diluting the atmosphere with an inert agent that does not support combustion
What is the probable cause when the starter switch to the turbine starter generator is energised and fails to rotate the engine?
Sheared starter drive coupling.
A safety feature usually employed in direct cranking electric starting systems that is used to disengage the starter from the engine drive is the?
Auto release clutch assembly (drive shaft shear point)
The primary source for oil contamination in a normally operating reciprocating engine is?
Carbon deposits from combustion blow by
Which of the following are used to prevent carburetor icing?
Heat induction air
A low tension circuit is preferred because of?
High amps and Low volts
The purpose of an after cooler used with turbo chargers is to cool?
Air entering the induction system from the turbo
A common cause of waste gate malfunction is?
Coke deposits or carbon build up
Which should be accomplished when installing an aircraft wing?
Prevent chaffing damage by attaching the bundle to a structure
When using a turbing engine analysis program, which is true?
Identify and measure particals in parts per million PPM by weight
Spark plug “heat range” refers to the classification and is determined by?
It’s ability to transfer heat to the cylinder head
Which of the following conditions occur when an excessively RICH fuel mixture enters the combustion of a turbine engine?
Hard start
When performing a run-up on a turbo jet or turbo fan engine, the exhaust hazard area extends aft of the engine approximately?
200ft
Which of the following could an A&P rated mech overhaul?
Float type carburetor.
Exhaust system components repairs…?
Cannot be performed in the field
Axial flow compressor blades are made from?
Stainless steel
An aluminium propeller blade has damage in a repairable area, that is not the leading or trailing edge, uses which method of repair?
Flat and round file
An out of balance, single wood propeller may be out of balance due to?
Spinner assembly
What is the typical expansion space of an oil tank for the APU
10%
What is a data speed plate used for?
Comparison of current performance thrust to original performance thrust at sea level.
What is the primary purpose of valve overlap?
Volumetric efficiency
An unbalanced wooden compressor would cause ?
Vibration in the Airframe
One function of the nozzle diaphragm in a turbine engine is to?
Direct the flow of gasses to strike the turbine blades at a high angle
Which of the following is true regarding a 4 stroke engine ?
exhaust valve opens on the power stroke. intake valve closes on the compression stroke.
On an aircraft that utilises an exhaust heat exchanger as a source of heat, how should the exhaust system be inspected?
remove the complete exhaust and or the exhaust heat shroud
Service the oil tank of the APU when?
it is shut down
If an engine and prepellor are completely submerbed in water, what should be done?
Dissassemble and spray on a corrosion inhibitor
In a reciprocating engine, how is the ignition switch different from other types of switches?
the off position completes the circuit through the switch to ground
Gear type and gerotor oil engine pumps are both what?
postitive displacement pumps
What is the fuel/mixture of 11:1?
11 parts air / 1 part fuel
How is a piston measured?
At zero (if talking about stroke)
the beta range of a propellor is considered to be a what blade angle?
Below flight idle
what condition indicated a hung start?
engine lights off, but the engine wont accelerate to idle
which of the following is a function of the carburetor venturi?
Measures the air (restricts the air)
an advantage of an axial compressor is?
small frontal area for given airflow
When should combustion be complete?
slightly past TDC
A pure turbo jet engine achieves thrust by?
imparting greater acceleration to a similar quantity
a cool off period prior to shut down is to prevent?
Seizure of the rotors
a cool off period of shut down of a turbine engine is accomplished in order to?
allow the turbine wheel to cool down before the case contracts around it
prolonged idling of an engine will usually result in?
fouling of spark plugs
vibrations of the prop are greatest?
only at a particular RPM
in some reciprocating engines, the hopper in the tank is used for?
speeding up dilution
Thrust reversers are operated…?
Mechanically
Prop auto feathering system, when armed, will feather?
only ONE prop
During a maintenance run, the fuel mix at rated power in an air cooled reciprocating engine is?
richer than the mixture used for cruise
the majority of reciprocating engines are cooled by?
forced ambient air
which type of air entrance is used on high bypass turbo fan engines?
Divided entrance
What type of ignition system is used on a turbine engine?
Capacitor
Turbine engine fuel controls schedule fuel delivery to match power settings using many different inputs, including?
Compressor discharge pressure
What do you do to an engine that was submerged in a flash flood?
use corrosion inhibitor
aircraft certified under PART 91, operating as a flight for hire, required what type of inspection?
100 HOUR INSPECTION
EPR is calculated at ?
Atmospheric temp (sea level)
what is the purpose of the propellor governor adjustable stop?
Limit maximum engine speed
carburetor heat is not generally used on takeoff unless it is absoutely necessary because of the?
loss of power due to decreased volumetric efficiency
shrouds on turbine blades with axial flow?
reduces fricition, reduces vibration
comapre a pure turbo jet to a turbo fan, the turbo fan generates relatively slower acceleration to?
a larger quanitiy of air
Free turbines normally started with propeller control lever in what position?
feather
Turbojet and turbofan thrust reverser systems can be actuated by hydraulic or?
pneumatic pressure
Preignition may be caused by?
worn valves
What’s the maximum numbers of bonding wires that can be attached to one stud?
4
The procedure for removing the accumulation of dirt deposits from the compressor blades is called?
Grit blasting
The circuit breaker or fuse should open the circuit before the conductor emits smoke. How
is this accomplished? The time/current characteristic at the protection device must?
must fall below that of associated conductor.
Aluminum propeller blade failure at the site of an unrepaired nick or scratch is usually the result of?
stress concentrator
Which of the following actions should be taken when a reciprocating engine and propeller have been recovered from a partial or total immersion in standing water or flash floods?
Engine parts and accessories should be removed and allowed to air dry
What should be used to clean ceramic coated exhaust stacks?
Degreaser or MEK
High tooth pressures and high rubbing velocities, such as occur with spur type gears, require the use of?
an extreme pressure lubricant
the purpose of a deareator tray in a turbine engine oil tank is to provide?
seperated air scavenged oil
Proper operation of electric deicing boots on individual propeller blades may best be determined by?
ensuring the timer operates continually for 2 minutes
to un feather a propeller?
start the engine and allow the prop governer to pump the oil out
where are the main oil filters located on a reciprocating engine?
after the pressurised pump
fuel is discharged for idlng speeds in a float type carburetor from?
from the idle feed passage (idle ports)
on a carburetor with an AMC, as you climb to altitude?
the needle will move back, allowing more fuel
what are 3 regulating components of a ground (sea level) boosted turbo system?
Exhaust bypass assy, density controller, differential pressure controller
fixed pitch propeller is removed because of sudden stoppage. The propellor, cone and hub should be examined for?
proper torque
which statement is correct regarding engine crankshafts?
dynamic dampers are incorporated on the crankshaft to reduce vibration
what do cascade vanes in thrust reversers have to do with the combustion section?
prevents air from entering the combustion section (cold stream type reversal)
Which of the following is an input parameter for a turbine engine control unit?
compressor inlet pressure
Designated areas, including engine power section, engine accessory section, APU compartments, and any fuel burning heater installations, are known as?
Fire Zones
Replacing multi-conductor cables with OTHER than original manufacturer’s cables could result in?
complications with servicing the aircraft
The gap setting on a spark plug should be checked with a?
round wire thickness gauge
How should the exhaust system be inspected on an aircraft that uses an exhaust heat exchanger as source of cabin heat?
remove the muffler heater air shroud (or complete exhaust system)
What stage in a turbine engine is gas pressure greatest?
compressor outlet
In a reciprocating engine, if airflow becomes clogged, what is the ALTERNATE way of supplying air?
ALTERNATE air door
Which is correct relating to a fuel level check of a float type carburetor?
the fuel level must be below the discharge nozzle outlet holes
Which of the following is an advantage of fuel injection on a reciprocating aircraft engine?
less danger of fuel system icing
Engine vibrations, that are the result of an unbalanced propellor, will usually occur?
Throughout the entire RPM range
under which of the following conditions will trimming the turbine engine be most accurate?
TEMP is corrected to a standard day and aircraft pointed NOSE INTO WIND
What is the purpose of cones on the propellor?
aline the prop splines with the drive shaft
a TURBINE engine fuel flow transmitter is an electrical device that uses a?
TURBINE
an electrically operated explosive device that fired a slug through a breakable disk to release fire exhingushing agent is a?
squib
what is a result when moisture has allowed current to burn its way across the surface of a magneto distributor?
Flashover leading to carbon tracking
which of the following may exist on an out of track fixed pitch wooden prop?
out of balance spinner
ally and sleel prop blades are usually cleaned by?
washing off with a suitable solvent
if there is too much valve clearance?
the valves wont open at idle
Air/fuel mixture ratio of 11:1 is?
11 pounds air to 1 pound fuel
when removing a shielded spark plug, which of the following is most likely to be damaged?
Barrel Insulator
Minor surface damaged located in a repairable area, but not on the leading or trailing edges of ally blades, may be repaired first by?
using a fine file
Powerplant instrument range markings show whether the current state of operation is normal, acceptable or?
in an unauthorized operation range.
When a ground incident results in a sudden reduction in engine speed, what maintenance action needs to be performed?
A thorough external inspection of the engine mount, crankcase, and nose section to determine whether any parts have been damaged. If damage is found that can not be corrected by line maintenance, remove the engine.
Refer to figure 5. When testing this, it will show good but fail when you start the engine? (you would be testing the ignitors and this wire would be broken)?
10
Trimming an aircraft engine, always face into the wind, never?
If icing conditions exist
Which of the following are used to distribute fire extinguishing agents into the engine section?
discharge nozzles
What are the two main sections of a turbine engine for inspection purposes?
Hot and cold
What is considered acceptable for return to service after one or more prop blades strike an object at low engine RPMs?
Refer to manafacture information
After disconnecting an AN or or MS electrical connector to prevent unintentional grounding, you should?
Mate it to an adjacent connector OR apply caps (boots) for protection
In a starter-generator system, which could be the result of insufficient airflow through the engine that would require the start to be aborted?
Hung start
Capacitance after firing of a spark plug is caused by?
Return of electric energy stored in capacitor of shielded ignition wires
What is one quality of fine wire electrode sparkplugs?
Easier to accurately adjust the electrode gap due to the wire being easier to bend. Fine wire spark plugs are more effective at igniting a fuel air mixture. They induce less strain on the magnetos and simply prove to last longer.
Turbine engine trimming should never be accomplished when?
icing conditions are present
A COMPRESSION test is done when the piston is?
on the COMPRESSION stroke
While inspecting flow engine compressor blades, minor damage is noticed. Can the minor damage be repaired?
Yes, if the damage can be removed without exceeding the allowable limits established by the manufacturer.
How many tachometers does a helicopter have?
2
When the air intake of a reciprocating engine becomes clogged, unfiltered air flows into the induction system by means of?
Alternate air door
The purpose of a density controller in a turbo system?
is to limit pressure produced by turbo at wide open throttle.
When the propellor blade angle is decreased, the propellor speed will?
increase
Which of the following could occur if a reciprocating engine muffer had an internal failure?
Internal failures (baffles, diffusers, etc.) can cause partial or or complete engine power loss by restricting the flow of the exhaust gases. If pieces of the internal bafling breaks loose and partially or totally blocks the flow of exhaust gases, engine failure can occur. In addition, local hot-spot areas caused by uneven exhaust gas flow can result in buming, bulging, or or rupture of the outer muffler wall.
What is the purpose of a data plate speed check on a turbine engine?
Comparison of future thrust requirements at the next test cell check
Reciprocating engine exhaust systems are?
normally replaced with new or reconditioned parts
What operates the beta control lever?
Linkage operation by the power lever
Turbine APU’s lubrication systems are required to incorporate an?
Oil filter or strainer
When replacing multi-conductor cables, a standard practice is to use cables with the same wire colour sequence to?
prevent complications in subsequent trouble shooting.
If the oil pressure gauge fluctuates over a wide range from zero to normal operating pressure, the most likely cause is?
a broken or weak pressure relief valve spring OR (low oil supply)
too much valve clearance, the valves dont open a wide and…?
dont remain open as long
spark plug gap errosion has been overcome by?
a hermetically sealed resistor in the center electrode
Which of the following keeps the propellor in low pitch position during shut down of a turbo prop engine?
Start lock latch
when necessary, during operation, CSD disconnect is usually accomplished by?
a switch in the cockpit
(Refer to Figure 4.) In a 1 15-volt system what is the maximum continuous current that can be carried by a single No. 8 copper wire 120 feet routed in free air?
50 amperes. (If not an option, choose 70)
A direct cranking electric starter consists of an electrical motor, reduction gears, and an automatic engaging and disengaging mechanism that is?
a sun gear operated by disengaging the spline shaft using centrifugal force.
What retains the nitrogen cage in a HDR container?
Frangible disk.
Which of the following is not used to detect fires in reciprocating engine nacelles?
Carbon monoxide detectors.
In a variable displacement pump, internal leakage keeps pump housing filled with fluid. How is the leakage returned?
It DOES NOT return to the system.
What is a rotary Vane turbine engine?
Combines positive displacement with continuous combustion to achieve the best of the efficiency and performance advantages of piston engines and gas turbines.
Transfer heat from the cylinder on an air-cooled reciprocating engine is by?
use of cooling fins on the cylinder head.
the purpose of cascade vanes in a thrust reverser system is to?
direct the fan airflow forward to slow the aircraft
what is the purpose of the accumulator in a constant speed prop system?
unfeathering
what happens to the compression of air as it accelerates rearwards in an axial flow turbine engine?
it decreases
what causes ignition in a diesel engine?
compression
during replacement of wiring you should?
refer to current regulations or approved SBs
pneumatic starters incorperate a safety feature should the clutch not release. its called?
drive shaft shear coupling
which of the following does a fuel totaliser provide?
Fuel flow rate, measured in pounds
volumetric efficency in a reciprocating engine will decrease?
incomplete scavenging
Calculations for EPR include turbine discharge pressure, compressor inlet temp and…?
ambient air temp and correct barometric pressure (correct sea level)
when performing a magneto check, the RPM and pitch should be at what setting?
minimum pitch angle and the engine for 50-65% power
valve assemblies of horizontal opposed reciprocating engines that use a dry sump are lubricated by?
pressure
fine wire spark plug electrodes….?
bend easier to produce a more accurate gap during gap setting
which engine instrument discrepancies require replacment?
indicator will not stabilize
ingestion of dust causes …?
cylinder wall wear
approx half of reciprocating engine exhaust system failures result in the areas of stress concentration. this is usually caused by?
thermal and vibration fatigue.
synethic oil (turbine engine) has 2 principle advantages over petroleum oil (reciprocating engine). it has less tendancy to deposit lacquer, coke and …?
decrease it ability to retain lacquer preventing corrosion
the purpose of the back suction mixture control in a float type carb is to adjust the mixture by?
regulating the air
which system most accurately indicates fuel usage of a large turbine engine?
Fuel Flow Meter
what is used to provide pressure to the variable inlet guide vane actuator or turbine engine compressors?
Oil
what will occur if the vapor vent float in a pressure carb loses its buoyancy?
the fuel consumption will decrease, causing the engine to run lean
the gas turbine engine hot section includes the combustion section, exhaust section, and the…?
turbine section
what advantage to mineral based lubricants have over vegetable oil based lubricants when used in reciprocating engines?
Chemical stability
what can be damaged most when removing spark plugs?
barrel
what type of nuts are be used to hold an exhaust system to the cylinders?
High temp self locking nuts. Low torque.
thermal efficiency of a turbine engine is affected by?
inlet temp
how does a starter solenoid work?
current flows from the battery to the solenoid and creates a magnetic field inside the solenoid. the magnetic field closes a high current circuit to engage the motor
engine crankshaft runout is usually checked
after engine sudden stoppage
a fire detection system operated on the principle of a build up of gas pressure within a tube proportional to temp. which of the following systems does this statement define?
continuous-element system (lindberg)
during overhaul of a reciprocating engine exhaust, valves are checked for stretch using?
micrometer or valve raduis gauge
a 100-hour inspection of a generator (starter) would include?
internal oil leaks
the most common type of thrust reverser on a turbo fan is?
aerodynamic
what section of the turbine can be used for anti icing?
compressor
which of the following is the cause of magneto breaker point erosion?
an open circuit condenser
wing (prop) leading edge anti ice is tested by?
testing the amps
a fire detection system that uses a single nickel wire surrounded by eutectic salt in a tube is the?
fenwall system
to control the detonation and preignition while increasing power, operate the engine….?
within the correct limits of manifold absolute pressure and cylinder head temp
where is the wet sump engine oil bulb heat indicator located?
it is located so that it measures the temp of the oil before it enters the engines hot section.
where is the fuel shut off valve usually located?
upstream of the engine fuel system
the exhaust section of a turbo prop is to?
provide small amounts of thrust
what is used to create low pressure at the low/rear at the rear of the cowling to promote cooling?
an augmenter
how should ceramtic coated exhaust components be cleaned?
MEK
what would an APU require?
oil filter
when replacing a complete ingition harness, where would you find the current firing order ?
engine manual
if the starter turns, but the turbine does not reach the RMP to start, that would be a?
hung start
reciprocating and turbine oil differ in?
viscosity and load carrying ability
while inspecting axial flow compressor blades, minor damage is noticed. can it be repaired?
YES, it can be removed without exceeding repair limits
one means of controlling the fuel temp on a turbine powered aircraft is?
engine bleed air to the heat exchanger
how is the reciprocating engine on a helicopter cooled?
by an elecrtic fan
manafactures normally require a dry sump engine oil to be services within a short time after engine shut down to prevent?
prevent overservicing
how can high tension ignition sheilding reduce radio interference?
by reducing leakage of high frequency voltage
chome plated cylinders have what have what kind of rings?
cast iron
in a reciprocatin engine, the injection nozzle is located?
in the cylinder intake cavity
during which phase of flight will the blade pitch angle of a constant speed propeller be greatest?
cruise
the thermostatic valve used on some reciprocating engine installs helps to regulate oil temp by?
by controlling the air flow through the oil cooler
dirt particals in the air being introduced into the compressor of the turbine engine will form a coating on the ?
inlet guide vanes and casing
whay operates the beta control valve?
linkage operated by the beta control lever
which of the following turbine engine compnents removes oil from the breather air?
deoiler
if an engine operates with low pressure and high temp, the problem may be caused by?
insuffient oil supply
a typical thermocouple system used to indicate engine temp uses?
a galvanometer
what is recomended for marking reciprocating engines?
grease
during engine timing, the magneto switch is placed in what position?
Both
AC alternators with CSD regulate the alternator to a constant?
hertz output
if an un-supercharged reciprocating engine equipped with a constant speed propeller is operated at part throttle and at cruise RPM, a reduction in RPM with no throttle change will result in?
an increase in manifold pressure
with a fixed pitch propeller, which of the following will indicate a weak engine?
Lower than normal static RPM at full throttle position
an engine has high EGT ant target EPRfor takeoff. What is the probable cause ?
the engine is out of trim
