Exam 1 Flashcards
Ch. 1-5
The fulcrum is at one end of the lever and the weight or resistance to be overcome is at the other end, with effort applied at some point between.
Third-Class Levers
Meaning to occupy space
Volume
What are the advantages of a wet sump system, compared to a dry sump?
A wet sump is attached to the bottom of the case, it is integral and complete, requiring no external parts and fittings to complicate installation and maintenance
No second (scavenge) pump is required
Chance of oil pump failure us reduced
This system can be operated in much colder ambient temperatures w/o concern that the oil congeal in the external lines
quantity which is useful when describing matter, especially when in the liquid or gaseous state
Density
Newton 3rd law
for every action there is an equal and opposite reaction
has neither a definite volume nor a definite shape.
gas
What is the relationship between aviation grade number and SAE numbers for lubricating oil?
Society of Automotive engineers divides all oils into groups according to viscosity at either 130F or 210F
Whagt forces are used to feather a propeller?
Centrifugal force
Resistance to motion is greatly reduced if an object is mounted on wheels or rollers
Rolling Friction
Prevents the escape of gas past the piston during engine operation
Compression Ring
Has a definite volume, but they take the shape of the containing vessel.
liquids
measure of the inertia of a body, and therefore is a measure of the quantity of matter associated with the body
Mass
Liquid cooled and air cooled with even number of cylinders. two in-line banks generally 30-60 degrees apart
V-type Engine
Work/Time
Power
What distinguishes a liquid from a gas?
Liquid has a definite volume, but they take the shape of the containing vessel. Gases not only take the shape of the containing vessel, but they expand and fill the vessel, no matter what it’s volume
The useful output of all aircraft powerplants is the
Force thrust
A feathered propeller will have a blade angle of approximately how many degrees?
90%
four-stroke cycle is?
Intake, compression, power, exhaust
The indicated horspower minus the brake horsepower
Friction Horsepower
What is the function of an augmenter tube?
Provide additional cooling airflow, especially for low speed, high power conditions (Climb)
How does opening cowl flaps affect engine cooling? Cabin cooling?
Open cowl flaps increase cooling over the engine and through the oil cooler
Hot and cold airflow into the cabin is reduced in most single engine installations due to reduced aur pressure inside and in front of the cowling when the cowl flaps are open
a force that results from the characteristic of particles of matter that causes attraction or pull on other particles of matter
Gravitation
Prevent leakage of gas pressure from the combustion chamber and reduce to a minimum the seepage of oil into the combustion chamber
Piston Ring
What is Force X Distance
Work
How are the cylinder walls lubricated in a typical opposed engine?
Oil sprayed from the crankshaft and crankpin bearings
How does the cowling contribute to the engine cowling?
Designed to force air over the cylinder cooling fins
The foundation of an engine.
Crankcase
The rate of doing work or the terms of work accomplished per unit of time
Power
Value of pressure of the standard day atmosphere at sea level
29.92 In of mercury
76 cm of mercury
- 7 psi
- 25 mb
34 ft of water
Basic components of a aircraft propeller
Blade Tip. The maximum reach of the blade from the center of the propeller hub.
Leading Edge. That part of the blade nearest the boat, which first cuts through the water.
Trailing Edge. That part of the blade farthest from the boat
Cup
Blade Face
Blade Back
Blade Root
Inner Hub
List three types of aircraft engine oils
Straight mineral oils-often used in reciprocating engines after overhaul
Ashless dispersant oil-usually replaces mineral oil after the piston rings have seated, as evidenced by decreased oil consumption
Synthetic oil
a substance which changes its shape easily and takes the shape of its container
Fluid
With a fixed RPM, does the propeller blade angle of attack increase or decrease as airspeed increases?
Decreases
What is the ‘flash point’ of a liquid?
Determined by laboratory tests that show the temperature at which a liquid will begin to give off ignitable vapors (flash) and the temperature at which there are sufficient vapors to support a flame
Used for timing of the valves. For a reciprocating to operate properly, each valve must open at the proper time, stay open for the required length of time, and close at the proper time
Valve-Operating Mechanism
Basic parts of a reciprocating engine
Crankshaft
Cylinders
Pistons
Connecting Rods
Valves
Valve-operating mechanism
Crankcase
List and describe 4 forces which act on an operating propeller.
Centrifugal: Outwards from the hub
Torque Bending: Twist, opposite rotations
Thrust Bending: Blades Bend Forward
Aerodynamic Twisting: Rotational Force about the center of pressure that tends to lower the blade angle
Define ‘propeller blade angle.’
The angle between the chordline of the blade and the plane of rotation