PRELIMS Flashcards
1
Q
What are the four forces of flight present on an aircraft?
A
- thrust
- lift
- drag
- weight
2
Q
What is the upward acting force?
A
lift
3
Q
What is the downward acting force due to gravity?
A
weight
4
Q
What is the forward acting force?
A
thrust
5
Q
What is the backward acting force?
A
drag
6
Q
Drag is also called ___________.
A
wind resistance
7
Q
________ is generated by the motion of the airplane through the air and considered as an aerodynamic
force.
A
lift
8
Q
___________ is a force that is always directed toward the center of the earth.
A
weight
9
Q
The magnitude of the
weight depends on what?
A
- mass of all the airplane parts
- amount of fuel
- any payload on board like people, baggage, freight, etc.
10
Q
_______ is directed along and opposed to the flight direction.
A
drag
11
Q
To overcome drag, airplanes use a ______________ to generate a force called __________.
A
propulsion system, thrust
12
Q
The direction of the thrust force depends on ____________________________.
A
how the engines are attached to the aircraft
13
Q
What produces thrust to propel an aircraft?
A
aircraft engine or powerplant
14
Q
Two main types of powerplant used in aircrafts.
A
- reciprocating engines
- gas turbine engines
15
Q
Reciprocating engines or _____________ work in combination with a ___________ to produce thrust.
A
piston engines, propeller
16
Q
Gas turbine engines produce thrust by ___________________ flowing through the engine.
A
increasing the velocity of air
17
Q
Where does the reciprocating engine derive its name from?
A
the back-and-forth or reciprocating movement of its pistons
18
Q
What are powered hops?
A
partially controlled glides
19
Q
____________ designed and built steam engines that were practical in their use to propel wheeled land vehicles.
A
James Watt
20
Q
Who is considered as the “Father of Aerial Navigation”?
A
Sir George Cayley
21
Q
Who designed and experimented with a calorific engine which burned gunpowder as the
fuel?
A
Sir George Cayley
22
Q
__________________________ successfully flew a clockwork (wound spring) powered model having the very modern characteristics of monowing construction, rear empennage, tricycle gear, and with the propeller located in the nose.
A
Felix du Temple of France
23
Q
_______________ search for the ideal powerplant caused him to reject the available steam engines (too heavy) and gasoline engines (unreliable).
A
Felix du Temple’s
24
Q
He used a “hot air engine” which was reported to operate in a manner similar to that of a steam engine; unfortunately, the underpowered engine was not able to propel the aircraft beyond a “powered hop”.
A
Felix du Temple
25
____________________________ model experiments employed a miniature steam engine that includes two propellers and gearing.
William Samuel Henson and John Stringfellow’s
26
____________________ attached a steam engine to a bicycle, creating their first powered motorcycle.
French Michaux brothers
27
____________________ journeyed to America and then to England where he eventually found two suitable steam engines of 10 and 20 horsepower (HP) for his flight experiments.
Alexander F. Mozhaiski
28
___________________ conducted flight experiments in his steam powered “Eole” aircraft, and even claimed to be the first man to have successfully flown a heavier-than-aircraft.
French inventor Clement Ader
29
Clement Ader's later efforts that resulted in the October 1897 flight of the Avion ill, a bat-winged aircraft powered by two 20-HP steam engines was funded by?
French War Ministry
30
________________________ model Aerodrome experiments used small steam engines. His highly successful flights of the model Aerodrome No.5 utilized a 1 HP steam engine.
Samuel Pierpoint Langley's
31
A crude version of the two stroke engine was initially designed by _______________ and patented in 1804. In his design, fuel and air was to be ignited in the cylinder at atmospheric pressure, a design which most likely would have resulted in relatively low power output; unfortunately, he was assassinated before he could build his engine.
Frenchman Phillipe Lebon d'Humberstein
32
_________________________ patented a somewhat more useful two stroke engine. In their design, the ignited fuel-air mixture pushed against a free piston within a cylinder which transferred motion to another piston, rotating a shaft.
Eugenio Barsanti and Felice Matteucci
33
________________, fascinated by inventing useful devices, began work in 1850 on a new type of engine that electrically ignited lighting gas (typically used for street lamps) with atmospheric-pressure air, thereby producing the expanding gases that could be harnessed for the generation of power.
Etienne Lenoir
34
_________________ designed variations of the two cycle Lenoir non-compressed (atmospheric pressure) gas engine.
Nicolaus August Otto and his brother Wilhelm
35
_______________________, then made the critical technical advance of compressing the fuel-air charge before it entered the cylinder.
The Otto brothers, with Eugren Langren
36
The engine used by Langley in the attempted flights of his full sized Aerodrome aircraft was developed by _______________, based on a substantial redesign of a _________ automobile engine.
Charles M. Manly, Balzer
37
The early experiments of Orville and Wilbur Wright employed ___________________ designed by Wright employee and mechanic __________________.
a horizontally arranged inline 4-cylinder, four cycle engine; Charles Taylor
38
Types of a reciprocating engine
- radial engine
- in-line engine
- v-type engine
- horizontally-opposed engine
39
______________ consists of one or more rows of odd-numbered cylinders arranged in a circle around a central crankshaft.
radial piston engine
40
Due to the small size of the crankcase, this engine type had a better power-to-weight ratio than most other designs of their day.
radial piston engine
41
It provides the greatest drag of all the types of engines. It is also considered as the most widely used engines ever built.
radial piston engine
42
It is also considered
as straight type engine because of its cylinder arrangement.
in-line engine
43
If the in-line engine is designed to operate with the cylinders below the crankshaft, it is called an __________________.
inverted engine
44
If the in-line engine is designed to operate with the cylinders above the crankshaft, it
is called an ____________.
upright engine
45
The cylinders of a _______________ are arranged around a single crankshaft in two in-line banks that are 45, 60, or 90 degrees apart.
V-type engine
46
The cylinders on a V-type engine could be above the crankshaft or below it, in which case the engine is referred to as an _________________________.
inverted V-type engine
47
____________________ are the most popular reciprocating engines
used on light aircrafts.
Horizontally-opposed or opposed type engines
48
It is also considered as boxer type or flat type engine. It always have an
even number of cylinders, and a cylinder on one side of a crankcase "opposes" a cylinder on the
other side.
Horizontally-opposed or opposed type engines
49
The temperature of the burning gases in the engine cylinder reaches up to _________________, which is above the melting point of the material of the cylinder body and head of the engine.
1500 to 2000°C
50
Cooling system serves two purposes in the working of an engine:
- It takes away the excessive heat generated in the engine and saves it from overheating.
- It keeps the engine at working temperature for efficient and economical working.
51
Several effects of excessive heat within the engine:
- Adversely affects the combustion of fuel and air charge.
- Weakens and shortens life of engine parts.
- Impairs lubrication.
52
two main requirements of an efficient engine cooling system:
- must be capable of removing only about 30% of the heat generated in the combustion chamber. Too much removal of heat lowers the thermal efficiency of the engine.
- should remove heat at a fast rate when the engine is hot. During the starting of the engine, the cooling should be very slow so that the different working parts reach their operating temperatures in a short time.
53
types of engine cooling system
- air cooling system
- liquid cooling system
54
Four stroke order
-intake stroke
-compressio stroke
- power stroke
-exhaust stroke
55
The __________begins as the piston starts
its downward travel from top dead center up to bottom dead center. When this happens,
the intake valve opens and the fuel-air
mixture is drawn into the cylinder.
intake stroke
56
The ____________ begins when the
intake valve closes, and the piston starts
moving back to the top dead center of the
cylinder. This phase of the cycle is used to
obtain a much greater power output from the
fuel-air mixture once it is ignited.
compression stroke
57
The _______________ begins when the
fuel-air mixture is ignited. This causes a
tremendous pressure increase in the
cylinder and forces the piston downward
away from the cylinder head, creating the
power that turns the crankshaft.
power stroke
58
The ___________ is used to purge the
cylinder of burned gases. It begins when
the exhaust valve opens, and the piston
starts to move toward the cylinder head
once again.
exhaust stroke
59
PROCESS OF FOUR STROKE ORDER
Fuel is vaporized and mixed with
air,
forced or drawn into a cylinder,
compressed by a piston, and then,
ignited by an electric spark.
60
Each cycle has four strokes
which are:
intake, compression,
power, and exhaust.
61
Each cycle has five events
which are:
intake, compression,
ignition, power, and exhaust.
62
The two primary reciprocating engine designs are:
the spark ignition (gasoline) and the
compression ignition (diesel).
63
The main difference between spark ignition and
compression ignition is ____________.
the process of igniting the fuel
64
engines use a spark plug to ignite a
pre-mixed fuel-air mixture.
Spark ignition
65
A _________ first compresses
the air in the cylinder, raising its temperature to a
degree necessary for automatic ignition when fuel
is injected into the cylinder.
compression ignition engine
66
(__________ is the
ratio of the “weight” of fuel to the “weight” of air in the mixture to be burned.)
Fuel-air mixture
67
In a __________, the conversion of chemical energy into
mechanical energy
two-stroke engine
68
Because a __________ has a power stroke upon each
revolution of the crankshaft, it typically has higher
power-to-weight ratio than a comparable four-stroke engine.
two-stroke engine
69
Due to the inherent inefficiency and disproportionate emissions
of the earliest designs, use of the __________ has been
limited in aviation.
two-stroke engine
70
Due to very high temperatures, the film of the lubricating oil will get oxidized, thus
producing carbon deposits on the surface. This will result in ______________-.
piston seizure
71
Due to very high temperatures, the film of the lubricating oil will get __________, thus producing __________ on the surface.
oxidized, carbon deposits
72
Due to overheating, large temperature differences may lead to a _____________ due to the thermal stresses set up.
distortion of
the engine components
73
In this type of cooling system, the heat, which is conducted to the outer parts of the
engine, is radiated and conducted away by the stream of air, which is obtained from
the atmosphere.
Air Cooling System
74
Problems also occur at over cooling:
It increases the internal friction of lubricants due to the
increase in viscosity of oil. This will lead to the increase
of frictional horsepower (power loss due to friction) in
the engine, thus, reducing the total power output.
Reducing the ability of liquid fuel to change its state from liquid to vapor.
75
are
metallic ridges, which are formed during the
casting of the cylinder and cylinder head.
fins
76
In order to have efficient cooling by means of air,
providing ________ around the cylinder and cylinder
head increases the contact area.
fins
77
_________ are designed to force air over the cylinder cooling fins.
Cowling and baffles
78
The ________ direct the air close around the cylinders and prevent it from forming hot pools
of stagnant air while the main streams rush by unused.
baffles
79
are built into the baffles to direct jets of cooling air onto the rear spark
plug elbows of each cylinder to prevent overheating of ignition leads.
Blast tubes
80
The amount of heat carried off by the air-cooling depends upon the following factors:
a. The total area of the fin surfaces,
b. The velocity and amount of the cooling air and
c. The temperature of the fins and of the cooling air.
81
Advantages of Air Cooled Engines
1. Its design of air-cooled engine is simple.
2. It is lighter in weight than water-cooled engines due to the absence of water jackets, radiator, circulating pump and the weight of the
cooling water.
3. It is cheaper to manufacture.
4. It needs less care and maintenance.
5. This system of cooling is particularly advantageous where there are extreme climatic conditions in the arctic or where there is scarcity of
water as in deserts.
6. No risk of damage from frost, such as cracking of cylinder jackets or radiator water tubes.
82
A _________ block and cylinder head have interconnected coolant
channels running through them. At the top of the cylinder head all the channels
converge to a single outlet.
liquid cooled engine
83
A pump, driven by a pulley and belt from the crankshaft, drives hot coolant out of the
engine to the radiator, which is a form of __________.
heat exchanger
84
_________ is passed from the radiator into the air stream, and the ___________
then returns to an inlet at the bottom of the block and flows back into the channels
again.
Unwanted heat, cooled liquid
85
Usually the pump sends coolant up through the ______and down through the
__________
engine , radiator
86
The radiator is linked to the engine by __________ and has a top and bottom tank
connected by a core a bank of many fine tubes.
rubber hoses
87
The tubes pass through holes in a
_____________, so that the core has a very large surface area and can lose heat rapidly to the cooler air passing through it.
stack of thin sheet-metal fins
88
In an engine at its ordinary working temperature, the coolant is only just _______ normal boiling point.
below
89
The risk of boiling is avoided by increasing the pressure in the
system, which raises the ___________.
boiling point
90
The __________ is limited by the radiator
cap, which has a pressure valve in it. _________opens the valve, and
coolant flows out through an overflow pipe.
extra/excessive pressure
91
In a cooling system of this type there is a ___________ if the engine
runs very hot. The system needs topping up from time to time
continual slight loss of coolant
92
The main parts in the water-cooling system are the following:
water/liquid pump, fan, radiator
and pressure cap, fan belt, water jacket, thermostat valve, temperature gauge and hose pipes.
93
This is a centrifugal type pump. It is centrally mounted at the front of the cylinder block and
is usually driven by means of a belt.
Water/Liquid Pump
94
Water/Liquid Pump consists of the following parts:
body
or casing, impeller or rotor, shaft, bearings or bush, liquid pump seal and pulley.
95
The bottom of the radiator is connected to the suction side of the pump. The power is transmitted to the ___________ at the end of the crankshaft.
pump spindle from a pulley mounted
96
Seals
of various designs are incorporated in the pump to prevent _______ from the system.
loss of coolant
97
The ______ is generally mounted on the water pump pulley, although on some engines it is
attached directly to the crankshaft.
fan
98
the fan serves two purposes in the cooling system of an
engine:
a) It draws atmospheric air through the radiator and thus increases the efficiency of
the radiator in cooling hot water.
b) It throws fresh air over the outer surface of the engine, which takes away the heat
conducted by the engine parts and thus increases the efficiency of the entire
cooling system.
99
The purpose of the ________ is to cool down the water received from the engine.
The radiator consists of three main parts: upper tank, lower tank and tubes.
radiator
100
Hot water from the upper tank, which comes from the engine, flows ________ through the tubes.
downward
101
Hot water from the upper tank, which comes from the engine, flows downwards through the tubes. The heat contained in the hot water is conducted to the __________ provided around
the tubes.
copper fins
102
An __________, connected to the upper tank, permits excess water or steam to escape.
overflow pipe
103
Three types of radiators:
gilled tube radiator, tubular radiator and honey comb or
cellular radiator.
104
It is a kind of check valve which opens and closes with the effect of temperature. It is fitted in the liquid outlet of the engine.
Thermostat Valve
105
During the____________, the thermostat is closed and the water pump circulates the water only throughout the cylinder block and cylinder head.
warm-up period
106
When the _________ is reached, the thermostat valve opens and
allows hot water to flow towards the radiator.
normal operating temperature
107
Standard thermostats are designed to start opening at _______ and they fully open at
______.
70 to 75°C, 82°C
108
High temperature thermostats, with permanent anti-freeze solutions start opening at
____________ and fully open at
80 to 90°C, 92°C.
109
three types of thermostats:
bellow type, bimetallic type and pellet type.
110
In the case of the ordinary water-cooling system where the cooling water is subjected to
atmospheric pressure, the water boils at _______.
212°F
111
when water is boiled in a closed radiator
under high pressure, the boiling temperature of water ___________.
increases
112
The ____________ gives more efficient engine performance and affords additional protection under high altitude and tropical conditions for long hard driving periods.
Higher water
temperature
113
a ________ is used with the forced circulation cooling system.
pressure-
type radiator cap
114
The cap is fitted on the radiator neck with an____________.
air tight seal
115
The pressure-release valve is set
to open at a pressure between ________ and _______ . With this increase in pressure, the boiling
temperature of water increases to _______________.
4 and 13 psi, 243°F
116
On cooling, the vapors will condense and a partial vacuum will be created which will result in the collapse of the___________ .
hoses and tubes
117
In order to prevent the water in the cooling system from freezing, some chemical solutions
which are known as _________ are mixed with water.
anti-freeze solutions
118
In cold areas, if the engine is kept without AF Solutions solution for some time, the water may freeze and expand leading to
fractures in the _________ , ___________, _______________
cylinder block, cylinder head, pipes and/or radiators.
119
The _______ of the anti-freeze solution should be as high as that of water.
boiling point
120
commonly used anti-
freeze solutions:
Alcohol, denatured alcohol, glycerine, ethylene, glycol, propylene glycol, mixtures of alcohol and glycerine and various mixtures of other chemicals
121
ENGINE IDENTIFICATION & NUMBERING SYSTEM
O – Opposed, as in horizontally opposed cylinders
R - Radial engine
V - V-type engine
T – Turbocharged
TS – Twin turbocharged / turbo-supercharged
I – Injected or fuel injected, instead of carbureted
S - Supercharged
G - Geared nose section (propeller reduction gearing)
F – FADEC (Full Authority Digital Engine Control) equipped
L - Left-hand rotation or counter-rotating (for multi-engine installations)
H - Horizontal mounting (usually for helicopters)
V - Vertical mounting (for helicopters)
A – Inverted mount
AE – Aerobatic, presumably inverted fuel and oil systems
122
The numbers in an engine identification code indicate an .
engine's piston displacement in cubic
inches
