AS 356, basically the whole class
For a 4 cycle, 4 cylinder horizontally opposed non-geared aircraft engine, how many 'power strokes' will each cylinder have if the engine crank shaft turns 2 full revolutions?
1 each
Name two types of electrical current
AC DC
What is critical altitude?
ALT at which a compressor can no longer hold sea level
What is the battery capacity?
AMP hours
A turbocharger compresses
Air
What is the principal fluid use for propulsion by most heat engines?
Air
Why are float carburetors more susceptible to icing (at least two reasons)?
Air Pressure/temp decrease due to the venturi
What principle differences exist between an ammeter and a loadmeter?
Ammeter measures current Loadmeter measures the load
Define 'propeller blade angle'.
Angle between blade cord line and plane of rotation
What are the advantages of the pressure carburetor over the float carburetor?
Better metering, Allows for auto mixture, fuel distributed by mass
Viewing the cross-section diagram of a propeller, identify the blade face and blade back.
Blade face- flat side of blade, facing the pilot. Blade back- Cambered side, facing away from pilot
What is BHP? How is it measured?
Brake Horse Power- Available power from an engine
List the 5 basic requirements needed to have a cabin pressurization system
Cabin structure compressed air source means of regulating temp of air going into the cabin way to regulate the pressure and rate of change in the cabin way to control the flow of air out of the cabin
List and describe 4 forces which act on an operating propeller.
Centrifugal- outwards force from the hub Thrust bending- blade bending forward with rotation Aerodynamic twisting- rotational force around the pressure center, lowers blade angle Torque bending- opposite rotations
What three energy forms does the reciprocating engine utilize or convert?
Chemical- Heat- Mechanical
What are the advantages of a fuel injection system, as a fuel metering system?
Less susceptible to icing, more even distribution to cylinders, reduces individual cylinder overheating, better fuel economy
What is 'electrolyte'?
Liquid that stores electricity
Define 'propeller slip'.
Loss of prop efficiency, difference between effective and geometric
What is the most effective propeller angle of attack for takeoff?
Lower Prop AOA
List 5 functions of aircraft engine oil (reciprocating engine).
Lubricate Clean Regulate Temp Seal O rings Prop governor systems ( he wanted something else I think)
What does the number printed on the face of a circuit breaker represent?
Max amps
List 3 types of aircraft engine oils and a brief description of each, including intended use
Mineral-New engines, thin Ashless Dispersant- thicker oil for broken in engines Synthetic- High compression engines, lasts longer
Which direction do electrons flow in an electrical circuit?
Negative to Positive
What are the advantages and disadvantages of lead-acid and nickel-cadmium batteries, for use in aircraft?
NiCAD gives constant voltage and has a wider temp range but is subject to thermal runaway and requires a deep cycle LeadAcid has electrolyte liquid that can be refilled and permits positive and negative flow but doesn't have constant voltage
Does the cabin pressure controller provide electrical control inputs to the outflow valve AND the positive and negative pressure safety relief valves?
No
What are the advantages of a wet sump system, compared to a dry sump?
No external parts No 2nd pump required, less chance of pump failure Operate in cooler temps
What is the relationship between aviation grade numbers an SAE numbers for lubricating oil?
Nothing
What will happen to the aircraft engine if there is a total failure of the electrical system?
Nothing
What is meant by 'demand' when discussing an oxygen 'pressure-demand' regulator?
O2 only flows when the user inhales
What is 'thermal runaway'?
Overheated battery causing a chemical chain reaction
List three types of bearings used in aircraft engines.
Plain, ball, and roller.
What is the difference between detonation and pre-ignition?
Pre-Ignition is where the fuel in the cylinder ignites before the spark plug fires where detonation is where the remaining fuel/air mix combusts after normal combustion
Which cockpit control will change the RPM on an engine?
Prop control
What are the advantages of the hydraulic lifters? Not on final
Reduce the amount of adjustments of valve operating linkages
Does application of carburetor heat richen or lean the mixture? How and why?
Richens the mixture by adding less dense air
What causes the engine's intake and exhaust valves to open? To close?
Rotation of the camshaft lobes pushing the push rod upwards which pushes on the rocker arm opening the valves.
On light aircraft, where does the force to operate the propeller pitch changing mechanism come from?
SE- Oil in front of the spring ME Oil behind the spring
Is the lowest blade angle near the shank or the tip? Why? Was it built that way?
Shank because the difference in speeds across the blade
What is the difference between a relay and a solenoid?
Solenoid had moving parts where relay doesn'
What is the only circuit in the aircraft electrical system that is not protected by a fuse or a circuit breaker?
Starter
What is the difference between static and dynamic balancing?
Static- CG is along the axis of rotation Dynamic- Balancing while in motion
What is the 'cloud point' of a liquid?
Temperature at which liquid becomes opaque (condenses)
What is the 'flash point' of a liquid?
Temperature at which liquid gives off flammable vapors
Why is it important for the pilot to know an engine's exhaust gas temperature?
There is correlation between Exhaust temp and the mixture ratio being burned
Which cockpit control will change the MAP on an engine?
Throttle
What is THP (name and define, or describe it)?
Thrust Horse Power- (Net thrust X aircraft speed)/ 375 HP equivalent of turbojet thrust produced
Describe the purpose and operation of a dynamic damper.
To reduce vibration
Under what conditions would the use of carburetor heat be detrimental?
Unfinished surfaces because carb heat is no filtered so it can pick up dirt and gravel putting it directly into the engine
In what form does fuel exit the fuel nozzles on a fuel-injected engine?
Vapor
What provides the low pressure at the discharge nozzle of a float carburetor?
Venturi
What is viscosity?
a liquid's resistance to flow
Define 'thermal shock'.
a rapid change in engine temperature that can be stressful to an engine
Why does MAP increase when RPM is decreased when there is no change in throttle position?
a reduction in RPM brings MAP closer to ambient pressure
What is a 'bus bar'?
a terminal in the aircraft electrical system to connect the main electrical system to the equipment using electricity as a source of power.This simplifies the wiring system and provides a common point from which voltage can be distributed throughout the system. Single plug thingy like a power bar that distributes power while decreasing weight and wires needed
Define 'propeller angle of attack'.
angle between the face of the prop blade and the plane of rotation
What forces are used to feather a propeller?
centrifugal
With a fixed RPM, does propeller blade angle of attack increase or decrease as airspeed increases?
decrease
HW 9 What is the principal difference between pneumatics and hydraulics?
difference is where power comes from. Hydraulics is from oil/liquid where pneumatics is compressed gas
What are the functions of the spider?
evenly distribute the fuel/air mixture into cylinders, provide positive shut off when at idle
What makes the crankshaft turn?
firing pistons
What component(s) in the governor opposes the force of the speeder spring?
flyweight and pilot valve
Where are the fuel injection nozzles located on a typical light aircraft engine?
in the cylinder head near the intake valves
HW 4 Define 'stoichiometric mixture'?
mixture Ratio 15:1
What component physically meters the flow of air from the cabin of a pressurized aircraft?
outflow valve
What are the purposes of positive and negative cabin pressure relief valves?
regulate cabin pressure by releasing or increasing pressure automatically
Briefly outline the difference in operation for a light single engine and multi-engine aircraft propeller system.
single engine is constant speed with no feathering where multi is constant speed with feathering.
HW 6 Define 'over boost' for turbocharge engines.
supercharger is operating at too high of speed
In an automatic turbocharger, what provides the force to activate the waste gate?
the exhaust gas
Define compression ratio.
the ratio for maximum to minimum volume in the cylinder
Which has the higher operating speed and temperature, a turbocharger or a supercharger?
turbo
Define 'Hertz'
Frequency of something
A supercharger compresses __________________ and ____________________ (carbureted engine).
Fuel and Air
What makes the camshaft turn?
Gears driven by the crankshaft
Define effective and geometric pitch of a propeller.
Geometric- Distance the propeller should move with one rotation Effective- Distance it actually moves
What is the color code for oxygen cylinders and other components?
Green
Define and describe the function of the following: Ground boosted engine Normally aspirated engine Supercharger Turbocharger Waste gate
Ground boosted engine: Compressed air directly into the engine to increase overall power output Normally Aspirated Engine: air intake is ambient, no compression is used Super charger: Compresses Air to increase density of air put into the engine Turbocharger: Exhaust powered, increases airflow into engine Waste gate: regulates exhaust gas flowing into the turbine to control the speed
Why is viscosity important when selecting a lubricant
High viscosity at high temps results in lower consumption and less engine wear.
Regarding oxygen safety precautions, what material must not come into contact with oxygen?
Hydrocarbons
What does a carburetor air temperature gauge permit a pilot to do?
Indicates potential icing and if carb heat is needed
What are the 4 'strokes' of operation for a 4 cycle reciprocating engine?
Intake, compression, combustion, exhaust
Describe the operating cycle of the typical aircraft reciprocating engine.
Intake- intake of fuel/air mixture Compression- compressing of the fuel/air mixture Combustion- ignition of compressed mixture Exhaust- expulsion of remaining exhaust
What are the differences between a two-position and a ground adjustable propeller?
2 position has only 2 options that you can adjust in flight while ground adjustable can be adjusted to what you want on the ground.
HW 5 Altimeter setting at Flagstaff airport, field elevation 7000 ft is 30.12" Hg. What should MAP be, before engine start and during takeoff with fully opened throttle?
29.12 adjusted for SL
For a 4 cylinder horizontally opposed aircraft engine (such as a Lycoming IO-360) how many types of rings are found on a piston? What are their purposes?
3 Rings. Oil control- regulates the amount of oil entering the piston. Compressor ring-prevents escape of gas from the piston. Oil Scraper- retains extra oil from the piston.
At what speed does the camshaft turn?
50% of the crankshaft speed
A feathered propeller will have a blade angle of approximately ______ degrees?
90
What is the main function of a piston?
Compress the fuel/air mixture
Briefly describe the two kinds of 'electron flow'.
Conventional and electron flow
What is the purpose of an intercooler and how does it work?
Cools the air that has been compressed before it goes to the engine
Describe the function of: Density controller Differential pressure controller
Density controller: takes into account the density inside the MAP to help regulate the waste gate Differential pressure controller: Maintains constant differential pressure
Define thrust
Directed Power or force
What is the purpose of a bonding strap?
Discharge static electricity
What is the formula for 'Ohm's Law'?
E=IxR
List 2 types of engine lubrication (oil) pumps; which one is on all aircraft reciprocating engines?
Electric Driven Engine Driven- Recip
When should carburetor heat be used on the ground (several answers)?
Engine start in cold temps, high humidity with low temps
HW8 Define 'electricity'
Flow of electrons
The amount of CURRENT produced in a generator is dependent upon which 3 things?
Flux lines speed at which it turns number of conductors