block 14 final test study guide
What are the positions of the carburetor heat control?
'cold' position used normally and 'hot' position used if icing has occurred
Generally, starter brushes should be replaced when when worn down to approximately ______ the original lengh
1/2
Boosted systems will increase the pressure in the induction system to above ______ in. Hg.
30
Bootstrapping can be defined as:
A drift in manifold pressure caused by power change where by the system is trying to reach a state of equilibrium
What instrument is used to test a ignition lead for electrical leakage?
A high-tension lead tester
which spark plug will have the longer insulator nose
A hot plug
Why is an exhaust system leak in a turbocharge system more dangerous than a leak in a normally aspirated engine?
A turbocharge engine exhaust system leak will blow out of high intensity and is very hot
Any dirt, oil or carbon tracking found on a magneto component should be cleaned with a lint-free cloth moistened with:
Acetone
The "Shower of Sparks" ignition has 2 sets of points, these are referred to as:
Advance and retard points
Radio-frequency energy that radiates from the ignition lead wire each time the spark jumps the gap in the spark plug is intercepted by shielding and carried to ground. by directing this energy to ground, the shielding prevents that stray energy from interfering with ?
Aircraft radios and other electrically sensitive equipment
A heavy black soot (not wet) in a spark plug indicates:
An overly rich mixture
(1) When replacing the breaker points in a magneto, the internal timing must be reset and checked before installing the magneto in the engine. (2) when conducting a magneto check (on a running engine) you should see a RPM drop when switching to either magneto.
Both statements are true...
Exhaust system use a special type of nut to secure the exhaust pipes on the engine cylinder. what type of nut is used?
Brass or special high temp locknuts
What are three main units of induction system?
Carb, air scoop and intake manifold
Flashover can lead to?
Carbon tracking
Normal inspection items for the air turbine starter include:
Checking the magnetic drain plug for metal particles and checking the oil level
the typical starter motor is a 12 or 24 volt,_______ motor
DC series wound
Most reciprocating engines are of this type:
Direct cranking type
Cascade vanes are used for;
Directing the air, coming out of the fan, forward to slow the aircraft
Because a turbine engine ignition system is dangerous to maintenance personnel; there are certain procedures that need to be followed. Generally these are:
Disconnecting the main exciter box input, wait the prescribed amount of time before removing the ignition lead from the igniter and ground the center electrode on the ignition lead
What differentiates between overshoot and over boost?
Duration, or length of time that manifold pressure exceeds their max rate
The turbocharger can supply the intake with?
Greater than atmospheric air
Air turbine starters are designed to provide high starting torque from a small, lightweight source. This gives the air turbine starter a:
High power-to-weight ratio
What are the components of the magnetic circuit?
Magnet, coil core, pole shoes and pole shoe extensions
In Piper aircraft; what function does the density controller provide?
Modulates the waste gate valve movement at full throttle position
(1) Turbine engine ignition system must be able to ignite the fuel under the extreme conditions of low temperatures and high altitudes. (2) Turbine engine ignition systems must be able to ignite the fuel under the extreme conditions of high temperatures and high altitudes.
Only statement one is true
___________ is defined as manifold pressure exceeding the engine's prescribed limits
Over-boost
What powers the thrust reverser to deploy and stow?
Pneumatic pressure, hydraulic pressure and sometimes electrical power
A high-tension magneto has the following circuits
Primary circuit, secondary circuit and the magnet circuit
The differential pressure controller senses differences between upper deck and manifold pressure. This controller will help:
Reduce the effects of "Bootstrapping" at full throttle operation
During the performance of an ignition check (magneto check), excessive RPM drop was indicated on a certain magneto. This drop of RPM happened rapidly. What would be the reason for this rapid and excessive drop in RPM>
Spark plugs fouled, ignition leads defective or problem in the magneto
Air density inside the intake manifold is a function of:
Temperature and pressure
If the engine does not cease firing in the off position, the;
The P-lead is open and should be corrected
When using a ground unit to supply the air for the air turbine starter; once the cut-out-speed is reached:
The start valve is closed by the activation of a flyweight cutout switch
One feature of the direct cranking air turbine starter that is used to prevent it from reaching burst peed is:
The stators are designed to choke off the supply air and stabilize the speed of the turbine
Minimum maintenance is required with turbine engine igniters because:
They are not in continuous operation
In an air turbine starter that uses clutch system, a clicking sound is heard as the engine coasts to a halt:
This a normal condition, the noise is coming from pawls and ratchet gear
By regulating the speed of the turbocharger, the upper deck pressure is regulated. What component regulates the sapped of the turbocharger?
Waste gate actuator
Which of the following type of ignitor operates at a colder temperature because the spark occurs beyond the face of the combustion chamber?
a constrained gap type
If an engine is equipped with a constant-speed propeller, how can carb ice be detected?
a decrease in manifold with no change in RPM will be noticed
If the clutch in an air turbine starter does not release from the engine drive when it should, this safety feature will keep the engine gear box from being damage.
a drive shaft that will shear on the air turbine starter
The ignition system on a turbine engine must be a certain type. Which type would spark the ignitors with high voltage and and intense enough heat that will ignite the turbine fuel?
a high-energy capacitor-type
The aerodynamic blockage type of thrust reverser is a cold stream type. The mechanical blockage type of thrust reverser is a hot stream reverser type. What engine would possible use both?
a low bypass ducted turbofan
if an engine is not classified as supercharged or turbocharged, it is classified as?
a normally aspirated engine
What atmospheric conditions will icing be the most severe?
air temperatures of 30 degrees F. and 40 degrees F. with the relative humidity above 60%
What is the basic definition of turbocharger?
an air pump
at which position the magnet in a magneto when the greatest density of flux lines exists in the magnet circuit?
at full register position
The density controller controls the density:
at full throttle only
In normally aspirated engine during full power output operation, in which of the following areas will be the highest pressure?
at the entrance of the air scoop for the carb
It is a general recommendation that the exhaust system components be sent out to a certified station for any repair. why is the case?
because is difficult to repair in the field
Where is the PRVs usually located?
between the compressor outlet and the fuel metering device
(1) Ceramic-coated components may be clean by using a degreasing solution (2) Ceramic-coated components should never be sandblasted or cleaned with an alkali product
both statements are true
(1) The ignition system on a turbine engine in the normal mode sparks the igniters during the start sequence and shuts off once the engines starts. (2) The ignition system of a turbine engine may have continuous ignition mode to help with engine relight during critical phases of flight.
both statements are true
How does turboprop aircraft provide clean air to the engine?
by using deflector doors which give the particles a change in direction to take advantage of inertia energy
If an exhaust leak is nit found during an inspection and not What happens to the to the engine airflow to the engine is repaired as a result; what is one major problem that may happen ?
carbon monoxide may enter the cabin and poison the crew and passengers
One end of the secondary coil is connected to the high-tension terminal that feeds the distributor. Where is the other end of the secondary coil connected?
connects to the coil core or the primary's coil ground
Lycoming engines route the induction tubes through the oil sump. This is to:
cool the oil and warm the fuel/air mixture
what provides the driving force of an externally driven turbocharger?
engine exhaust gases
What happens to the engine when the airflow to the engine is restricted?
engine will lose power
what drives the turbine portion of the turbocharger?
exhaust gases
An alternate air system is used on engines equipped with fuel injection. Where is the alternate air coming from?
from inside the cowling and is not filtered before it enters the induction system
Induction system icing is generally classified into three types:
impact ice, throttle ice and fuel evaporation ice
What component delivers the air/fuel mixture to the cylinder?
intake manifold
Which of the following materials are not recommended for the use on exhaust system?
lead pencils and galvanized/zinc-plated tools
The air coming out of the throttle (going downstream of the throttle) is referred as;
manifold pressure
define "overshoot" as per this article.
manifold pressure increase above the max and then return to the max level
The position of the waste gate valve, which determines engine power output, is controlled by:
oil pressure
What is used to cool and lubricate the turbocharger and where does it come from?
oil, comes from engines onboard tank
(1) the retard breaker points in a "Shower of sparks" ignition system is designed to open when the piston is close to TDC to prevent engine to "kickback" (2) the retard beaker points in a "Shower of sparks" ignition system is designed to be back-up for the advance breaker points.
only statement no. 1 is true
(1) to turn a magneto off, the secondary circuit must be grounded. (2) in a low-tension magneto system, the ignition switch must be in the "on" position for current to flow in the ignition coil
only statement number 2 is TRUE
The condenser/capacitor is wired in
parallel with the breaker points
The triggering transformer in the DC capacitor discharge system is responsible for:
producing the high-voltage pulses necessary to bridge the gap in the ignitor
A bellmouht compressor inlet is used in engines that are run on a test stand. What is the purpose of this inlet?
provide an efficient way for the air to enter the engine
In a naturally aspirated engines induction system, the alternate air door is used to:
provide the alternate source if the filter becomes blocked or clogged
What is an other benefit of using turbocharger?
provides air for the cabin pressurization
Induction system ice can be prevented or eliminated by:
raising the temperature of the air that passes through the carb
the Impulse coupling performs 2 functions:
retards e timing of the firing of the spark plug and rotates the magnet in the magneto fast during engine start
What is used to start a spark plug into the cylinder?
start by hand
When the magnet in the magneto rotates past the neutral position a few degrees neutral, this position is called?
the E-gap angle, this is where the points began to open
the heat range of a spark plug is:
the ability to transfer the heat generated by the combustion prosses into the cylinder head
What happens to the density of the air in the intake manifold if the temperature of the air increases?
the air expands and the density will decrease
the waste gate on a turbocharged engine controls?
the amount of exhaust gases flowing into the turbo charger
Lead fouling of a spark plug occurs when:
the cylinder head temperatures are low
When performing an ignition switch check, the lowest RPM (usually idle RPM) is used. Performing this test will check?
the ground integrity of the magnetos
An intense heat spark across the gap of the igniters is necessary because?
the high heat/energy spark will blast off carbon deposits, thus cleaning the gap on the igniter
Spark plug reach is defined as?
the length of threated portion of the spark plug
When replacing a magneto in an engine, two considerations are to be made. The first consideration is whether the internal timing of the magneto is correct and the second is:
the position of the crankshaft relative to No 1 cylinder on the compression stroke a few degrees before TDC
The rate-of-change controller controls:
the rate at which the temperature in the upper deck increases
A spark plug is considered fouled when:
the spark does not bridge the gap between the ground electrode and the center electrode
Part throttle operation can lead to icing in the area of the carb;
the throttle area
What are the effects on the engine as air density decreases?
the weight of the fuel/air charge will decrease, volumetric efficiency will decrease and engine power will decrease
During the operation check of a turbine engine ignition system, loud snapping noise was heard;
this is an indication that the ignition system is working normally
Dropping a spark plug will way usually cause the insulator to developed small cracks. This condition will result in the following maintenance action.
throw away the spark plug and replaced with a new one
In a low-tension system, low voltage is generated in the magneto and then sent:
to a transformer coil located near the spark plug
A faulty capacitor/condenser will cause the breaker points:
to have a course-grained appearance to the mating surfaces
Which of the following components are in a typical turbine engine ignition system?
two igniter plugs, two high-tension leads and one exciter box (which houses dual units)
localized hot spots and exhaust flow restriction may may be caused by which of the following?
welds that protrude inside the exhaust tubes
Which of the following statements best describes the operation of any starter motor?
when the starter motor is first energized, the current draw is the greatest and will decreased as the starter motor increases in speed
When does "over-boosting" occur?
whenever the throttle is fully open and the maximum allowable pressure is exceeded
