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Aero 1 Review
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164
Aviation
Graduate
06/07/2011

Additional Aviation Flashcards

 


 

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Term
Define Scalar
Definition
Represents only magnitude
Term
Define Vector
Definition
Represents magnitude and direction.  Used to represent displacement, velocity, acceleration, or force.
Term
Define Force
Definition
A push or pull exerted on a body.  Force = Mass x Acceleration
Term
Define Mass
Definition
Quantity of molecular material that comprises an object.
Term
Define Volume
Definition
Amout of space occupied by an object.
Term
Define Density
Definition
Mass per unit volume.
Term
Define weight
Definition
Force with which a mass is attracted toward the center of earth by gravity.
Term
Define Moment
Definition
wector quantity equal to a force (F) times the distance (d) from the point of rotation that is perpendicular to the force.  M=F*d
Term
Define Work
Definition

scalar quantity equal to the force times distance of displacement.

W=F*s

Term
Define Power
Definition
(P) Rate of doing work per unit of time
Term
Define Energy
Definition
Measure of a bodys capacity to do work.
Term
TE =
Definition
TE = PE + KE
Term
Potential Energy
Definition

Ability of a body to do work because of position or state.

PE = Hieght x weight = mgh

Term
Kinetic Energy
Definition

Ability of a body to do work because of its motion

KE = 1/2mV2

Term
What are Newtons 3 Laws
Definition

Law 1 - Equillibruim

Law 2 - Acceleration

Law 3 - Interaction

(EAI)

Term
Newtons 1st Law
Definition
A body at rest tends to stay at rest, a body in motion tends to stay in motion in a straight line at a constant velocity unless acted on by some unbalanced force.
Term
Newtons 2nd Law
Definition
an unbalanced force acting on a body produces an acceleration in the direction of the force that is directly proportional to the force and inversely proportional to the mass of the body.
Term
Newtons 3rd Law
Definition
For every action there is an equal and opposite reaction.
Term
Give a flight example of Newtons 1st Law
Definition
An aircraft in equillibrium flight
Term
Give an example of Newtons 2nd Law
Definition
Airplanes thrust causing it to move forward.
Term
Give a flight example of Newtons 3rd Law
Definition
Thrust produced by a jet engine.
Term
Define Equillibrium flight.
Definition
absence of acceleration, either linear or angular.  Equilibrium exists when the sum of all forces and the sum of all moments aroudn the center of gravity equal zero
Term
Defined trimmed flight
Definition
Trimmed flight exists when the sum of the moments around the CG is zero.
Term
Tell me about being in trimmed and equillibrium flight.
Definition

Equillibrium = Trimmed

Trimmed does not always = equillibrium because you can be trimmed into a turn.

Term
Define Static Pressure
Definition
pressure each air particle exerts on another.  Fore acts perpendicualar to any surface the air particles collide with.
Term
Air density
Definition
Total mass of air particles per unit volume.
Term
Define Temperature
Definition
Measure of the average kinetic energy of the air particles. (T)
Term

Average Lapse Rate

 

Definition

Temperature decrease with an increase in altitude.

2 degrees C

3.57 degrees F

Term
Humidity
Definition
Amount of water vapor in the air. 
Term
As humidity increases, air density _______
Definition
Decreases
Term
Viscosity
Definition
Measure of the air's resistance to flow and shearing.
Term
Air Viscosity increases with an increase in _______
Definition
Temperature.
Term
Local Speed of Sound
Definition
Rate at which sound waves travel through a particular air mass.  
Term
LSOS is dependant only on ___________
Definition
Temperature
Term
As the Temperature of Air increases, the LSOS ___________
Definition
Increases
Term
State the relationship between humidity and air density
Definition
As humidity increases, air density decreases.
Term
State the relationship between temperature and LSOS
Definition
As Temprature increases, LSOS increases.
Term
State the relationship between altitude and Temperature, Pressure, density, and LSOS
Definition
Temp, pressure, density, and LSOS all decrease with an increase in altitude.
Term
The 5 Major Aircraft Compenents are:
Definition
Fuselage, Empenage, Landing Gear, Wings, Engine
Term
What is the largest factor that increases stall speed.
Definition
Weight
Term
State the relationship between pressure, temprature, and density using the General Gas Law
Definition

P=pRT

While density is constant - Increasing Pressure will increase temprature.

While pressure is constant - there is an inverse relationship between density and temperature. 

Increasing temp will decrease density

Increasing density will decrease temp

Term
All changes in aircraft pitch occur about the?
Definition
CG
Term
If doubled ________ causes the greatest increase in lift.
Definition
Velocity.
Term
What is the equivalent to ƒ
Definition
A combo of an aircrafts cross sectional area presented to the relative wind and other aircraft surfaces which air flows.
Term

True or False

Vortices can cause one or both wings to stall on a trailing aircraft.

Definition
True
Term
p.e. is
Definition
The ability of the prop to turn engine output into thrust.
Term
Define, Compare, Contrast an aircraft and an airplane.
Definition

Aircraft-any device intended for use in air. balloon, glider, etc.

Airplane - Heavier than air fixed wing aircraft driven by an engine and supported by the dynamic reaction of airflow over its wings.

Aircraft describes a broad range - airplane is a more specific flying machine.

Term
List and describe 3 major control surfaces.
Definition

Ailerons - (and spoilers) control roll

Rudder - attached to the vert stab and controls yaw

Elevator - horizontal part of empenage that controls pitch

Term
List and Describe the 5 major components of an airplane
Definition

Fuselage - Basic Structure

Wing - Produces Lift

Empennage - Provides greatest stabilizing influence

Landing gear - ground taxi, shock absorbing

Engine - provides thrust for flight

Term
List and define the components of the airplane reference system.
Definition

CG - point at which all weight is considered to be concentrated. All forces and moments take place around it

Longitudinal Axis - Passes from nose to tail of airplane

Lateral Axis - Wingtip to wingtip

Vertical Axis - Passes vertically through the CG

Term
Describe the orientation between the components of the airplane reference system.
Definition
The reference system consists of 3 mutually perpendicular axes intersecting at the CG
Term
List and describe the motions that occur around the CG
Definition

Roll or Lateral control - movement of lateral axis around the longitudinal

Pitch - movement of the longitudinal around the lateral

Yaw or directional - Movement of longitudinal around the vertical.

Term
Define Wingspan
Definition
(b) length from wingtip to wingtip
Term
Define Chord Line
Definition
infinately long straight line drawn through the leading edge and trailing edge of an airfoil
Term
Chord
Definition
measure of the width of the wing or other control surface measured along the chordline from leading edge to trailing edge.
Term
Tip Chord
Definition
CT - Chord Measured at the wingtip
Term
Root Chord
Definition
CR - Chord at wing centerline
Term
Average Chord
Definition
(c) average of every chord from root to tip
Term
Wing Area
Definition

(S) apparent surface area of a wing from tip to tip

S=b*c

Term
Taper
Definition
Reduction in the chord of an airfoil from root to tip.  The T34 and T-37 are tapered to reduce weight, improve structural stiffness, and reduce wingtip vortices.
Term
Taper Ratio
Definition

λ = CT/CR

Ratio of tip chord to root chord

Term
Sweep Angle
Definition

Angle between a line drawn 25% aft of the leading edge and the lateral axis

Λ

Term
Aspect ratio
Definition

AR = b/c

Ratio that shows lift

Term
Wing Loading
Definition

WL = w/S

Ratio of weight to surface area.  Tends to be an inverse relationship between AR and WL

Term
Angle of Incidence
Definition
Angle between the airplane's longitudinal axis and the chordline of it's wing
Term
Dihedral Angle
Definition
Angle between the spanwise inclination of the wing and the lateral axis. The T-34 and T-37 both have dihedral wings to improve lateral stability.
Term
Describe the advantages of a semi-monocoque fuselage
Definition
Semi monocoque aircraft have skin transverse frame members, and stringers which share stress loads and may be rapidly repaired.  T-34 and T-37 have semi monocoque
Term
Describe full cantilever wing construction.
Definition
All bracing is internal
Term
Define steady airflow
Definition
Exists if at every point in the airflow static pressure, density, temprature, and velocity remain constant over time.  A particle of air follows the same path as the one in front of it.
Term
Define Streamline
Definition
The path that air particles follow in a steady airflow.
Term
Streamtube
Definition
A collection of streamlines forms a streamtube, which contains a flow just as effectively as a tube with solid walls.  Streamtube is a closed system.  Therefore total mass and energy remain constant
Term
Continuity Equation
Definition
A1V1=A2V2
Term
Describe the relationship between airflow velocity and cross sectional area within a streamtube using the continuity equation.
Definition
If the cross sectional area decreases on one side of the equation, velocity must increase on the same side so both sides remain equal. Velocity and area in a streamtube are inversely related.
Term
Give Bernouli's equation
Definition

PT = PS + q

Total Pressure AKA Head Pressure is = static pressure + dynamic pressure.

Term
List the components of the pitot-static system
Definition
Pitot tube, static pressure source, black box.
Term
The Pitot Tube Collects?
Definition
Total Pressure
Term
Static Pressure Port Collects?
Definition
Ambient static pressure
Term
The Black Box Does What
Definition
Takes static pressure and subtracts it from total pressure.  The remaining static pressure is = to dynamic pressure and displayed in the cockpit.
Term
IAS
Definition
Indicated Airspeed - Indication for dynamic pressure the airplane is creating during flight.
Term
CAS
Definition
IAS corrected for instrument error.
Term
EAS
Definition
Equivalent airspeed - CAS corrected for compressibility error. EAS = TAS at sea level on a standard day.
Term
TAS
Definition
True Airspeed - actual velocity at which the airplane is moving through an air mass.
Term
M
Definition
Mach - Ratio of airplanes true airspeed to LSOS
Term
Mcrit
Definition
Critical mach number - the mach number where sonic flows will start to be experienced somewhere on the airplane.
Term
Describe the effect of altitude on Mach and critical Mach number
Definition
As altitude increases mach# would increase because LSOS is decreasing.
Term
Define Pitch Attitude
Definition
Angle between an airplane's longitudinal axis and the horizon.
Term
Flight Path
Definition
The path described by an airplanes CG as it moves through an air mass
Term
Relative Wind
Definition
Airflow the airplane experiences as it moves through the air. Equal in magnitude and opposite direction of FP
Term
AOA
Definition
Angle between the relative wind and the chordline of an airfoil. FP, RW, AOA should never be inferred from pitch attitude.
Term
Mean Camber Line
Definition
line drawn halfway between the upper and lower surfaces
Term
Positive Camber
Definition
If mean camber is above the chordline
Term
Negative camber
Definition
If the mean camber is below the chordline.
Term
Symmetric Airfoil
Definition
If the mean camber line is coincident with the chordline.
Term
Aerodynamic center
Definition
Point along the chordline where all changes in aerodynamic force take place.
Term
Airfoil Thickness
Definition
Height of the airfoil profile.  Point of max thickness corresponds to the AC
Term
Spanwise flow
Definition
Airflow that travels along the span of the wing parallel to the leading edge.  Does not produce lift.
Term
Chordwise flow
Definition
air flowing at right angles to the leading edge of an airfoil.  It produces lift.
Term
AF
Definition
aerodynamic force - force that is a result of pressure and friction distribution over an airfoil.  LIFT AND DRAG
Term
Lift
Definition
Component of airodynamic force (AF) acting perpendicular to the relative wind.
Term
Drag
Definition
D - component of aerodynamic force acting parallel and in the same direction as the relative wind.
Term
Describe the effects on q, static pressure, and AF as air flows around a symmetric airfoil.
Definition
At zero AOA velocity increases and static pressure decreases the same on the upper and lower surfaces.  Since there is no pressure differential perpendicular to the relative wind, no lift is created.
Term

Describe the effects on q, static pressure, and AF as air flows around a cambered airfoil.

Definition
Produces uneven pressure distribution at zero AOA.  Because of positive camber velocity above is greater than above and pressure below is greater than above and creates lift.
Term
Describe the effects of changes in AOA on the pressure distribution and AF on cambered and symetric airfoils.
Definition
AOA on any airfoil causes area of the streamtube above the wing to decrease.  This creates greater velocity above which in turn creates a greater pressure differential and increases AF
Term
Describe changes in density
Definition
Increase in density or velocity will create more lift.
Term
Describe the effect of surface area
Definition
More surface area will create more lift
Term
Describe the effects of camber
Definition
an increase in camber will produce more lift
Term
Describe the effects of AOA
Definition
Increase in AOA will produce greater lift.
Term
List the factors affecting lift the pilot can directly control
Definition
AOA, Velocity, Density, Surface area, Camber
Term
Compare and contrast CL generated by cambered and symmetric airfoils.
Definition

Positive Camber - @ Zero AOA  positive camber airfoil makes positive CL

Negative Camber - @ Zero AOA negative camber airfoil makes negative CL

Symmetric Airfoil - @ Zero AOA symmetric airfoil makes no positive or negative lift.

Term
Lift equation
Definition
L = qSCL
Term
Describe the relationship between weight, lift, velocity, and AOA IOT maintain level flight.
Definition
IOT maintain level flight while increasing AOA velocity must be decreased.  Otherwise the aircraft would climb. Velocity and AOA are inversely related in level flight.
Term
Define boundry layer
Definition
Layer of airflow over a surface that demonstrates local airflow retardation due to viscosity.
Term
List the two types of boundary layer airflow
Definition

Laminar

Turbulent

Term
Laminar flow
Definition
monecules move smoothly along in streamlines. Produces little friction but is easily separated from surface.
Term
Turbulent Flow
Definition
Streamlines break up and flow is disorganized and irregular.  Higher friction drag, adheres to upper surface better, delays boundary layer seperation.
Term
State the advantage/disadvantage of laminar flow
Definition

Adv - little friction

DisAdv - Easily seperated from surface

Term
State the advantages and disadvantages of turbulent flow.
Definition

Adv - adheres to airfoil and delays boundary layer seperation.

DisAdv - High friction drag.

Term
State cause and effect of boundary layer seperation.
Definition

-Adverse pressure gradient impedes flow of boundary layer

-If boundary layer does not have sufficient kinetic energy to overcome adverse pressure gradient the lower levels of the boundary layer will stagnate.

-The boundary layer will seperate from the surface and cause the airfoil to lose the suction pressure that causes lift.

Term
Define stall and its cause and effect.
Definition

Stall - A condition in flight where an increase in AOA has resulted in a decrease CL

The only cause of a stall is the exsessive AOA beyond CLMAX

Term
Define and state the importance of CLmax
Definition
is the peak coefficient of lift and any increase of AOA beyond CLmax will decrease CL
Term
Define and state the importance of CLmax AOA
Definition
is known as the stalling AOA or critical AOA and the region beyond CLmaxAOA  is the stall region.  
Term
List the methods of stall warning in the T-34 and T-37
Definition

AOA indicators

Rudder pedal shakers

stick shakers, horns, buzzers, warning lights, electronic voices.

Term
T-34C stalling AOA
Definition
29 - 29.5 units.
Term
Define stall speed.
Definition
The minimum TAS required to maintain level flight at CLmaxAOA
Term
Describe the effect of weight on stall speed
Definition
A reduction in weight will decrease stall speed.
Term
Describe the effect of altitude on stall speed.
Definition
An increase in altitude will increase stall speed.
Term
Describe the effect of thrust on stall speed.
Definition
Power on stalls will be less than power off stalls because at high pitch attitudes part of the weight of the airplane is being supported by the vertical component of thrust.
Term
State the purpose of high lift devices
Definition
Reduce takeoff and landing speeds by reducing stall speed.
Term
State the effect of boundary layer devices on the coefficient of lift, stall speed, stalling AOA.
Definition

Coefficient of lift is increased

Stalling AOA is increased

Stall Speed is decreased.

Term
What are the two types of boundary layer control devices.
Definition

Fixed Slots

Slats

Term
Describe fixed slots
Definition
Gaps located at the leading edge of a wing that allow air to flow from below the wing to the upper surface.
Term
Describe slats
Definition
movable leading edge sections that form slots
Term
Describe the operation of fixed slots
Definition
Leading edge air is directed through the slot, which acts like a nozzle converting static pressure into dynamic pressure.  The high kinetic energy air leaving the nozzle increases the energy of the boundary layer and delays seperation.
Term
When slats are deployed it opens a
Definition
slot
Term
State the effect of flaps on coefficient of lift, AOA, and stall speed.
Definition

Coefficient of lift is increased

Stalling AOA decreases

Stall speed is decreased

Term
Describe plain flaps
Definition
Plain flaps are simple hinged flaps that increase camber
Term
Describe split flaps
Definition
it is a plate deflected from the lower surface of the wing. It creates alot of drag.
Term
Describe slotted flaps
Definition
similar to a plain, but moves away fromt he wing to open a narrow slot for boundary layer control.
Term
Describe the fowler flap
Definition
Used extensively on larger aircraft.  moves down and increases camber, and aft increasing wing area and opens a slot for boundary layer control.
Term
Describe a leading edge flap
Definition
Changes camber at the leading edge of the airfoil.  Similar to a trailing edge plain flap.
Term
State the stall pattern of a rectangular wing
Definition
Strong Root stall tendancy - provides adequate stall warning and aileron effectiveness.
Term
State the stall pattern of an elliptical wing.
Definition
Has even lift distribution and all sections will stall at the same AOA, little warning and loss of aileron control.
Term
State the stall pattern of a moderate taper wing.
Definition
All sections stall at same AOA, little warning and loss of aileron effectiveness.
Term
State the stall pattern of a high taper wing.
Definition
Good structural stiffness but strong tip stall tendancy.
Term
State the stall characteristics of a swept wing.
Definition
Strong tip stall tendancy and rapidly progresses over remainder of the wing.
Term
State the advantage and disadvantage of tapering the wings of a T-43C and T-37
Definition

Adv - reduce weight, improve stiffness, and reduce wingtip vortices.

DisAdv - Wing stalls evenly and ailerons lose lateral control.

Term
State the purpose of wing tailoring.
Definition
Create root to tip stall progression and give the pilot warning and ensure ailerons remain effective up to complete stall.
Term
Geometric twist
Definition
Reduction in the angle of incidence.
Term
Aerodynamic twist
Definition
Reduction in camber and or thickness from root to tip.
Term
State the wing tailoring on the T-34C
Definition

Geometrically twisted 3.1 degrees

Aerodynamically twisted to create a reduced camber at the tip.

Term
State the wing tailoring on the T-37
Definition

Geometrically twisted 2.5 degrees

Aerodynamically twisted to reduce camber at the tip.

Term
Define Drag
Definition

Is the component of the Aerodynamic Force that is parrelell to the relative wind and acts in the same direction 

 

Term
Define Parasite Drag
Definition
All Drag that is not associated with the production of lift.
Term
Define Induced drag
Definition
Is that portion of total drag associated with the production of lift.
Term
List the three major types of parasite drag
Definition
Induced, Friction, Interference
Term
State the cause of form drag
Definition
Also known as pressure or profile drag, is caused by the airflow seperation from a surface and the wake that is created by that seperation
Term
State the cause of friction drag
Definition
Due to viscosity, a retarding force called friction drag is created in the boundary layer.
Term
State the cause of interference drag
Definition
Generated by mixing of streamlines between one or more components.
Term
State a design feature to reduce form drag
Definition
Streamlining
Term
State a design feature that reduces friction drag
Definition
Waxing or polishing
Term
State a design feature that reduces interference drag
Definition
Proper fairing and filleting.
Term
Equivalent parasite area is
Definition
equal to the area of a flat plate perpendicular to the relative wind that would produce the same amount of drag as form drag, friction drag, and interference drag combined.
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