Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/161

Click to flip

161 Cards in this Set

  • Front
  • Back
Scalar quantity
represents only magnitude, e.g. time, temperature, or volume
• Vector
represents magnitude and direction. Used to represent displacement, velocity, acceleration, or force
• Force
push or pull exerted on a body. Force = mass x acceleration.

F=ma
• Mass
quantity of molecular material that comprises an object
• Volume
amount of space occupied by an object
• Density
mass per unit volume. ρ=(mass/volume)
• Weight
force with which a mass is attracted toward the center of earth by gravity. g = 32.174 ft/s2
• Moment
vector quantity equal to a force (F) times the distance (d) from the point of rotation that is perpendicular to the force. M=F∙d
• Work
scalar quantity equal to the force (F) times the distance of displacement(s). W=F∙s
• Power (P)
rate of doing work or work done per unit of time
• Energy
scalar measure of a body’s capacity to do work. 2 types. Energy cannot be created or destroyed, but transformed from one form to another. Principle is called Conservation of Energy. Total energy equation is:
TE = KE + PE
• Potential Energy
ability of a body to do work because of its position or state of being. PE=weight∙height=mgh
• Kinetic Energy
ability of a body to do work because of its motion.
KE=½mV2
• 1st law of equilibrium
body at rest tends to remain at rest and a body in motion tends to remain in motion in a straight line at a constant velocity unless acted upon by some unbalanced force.
• 2nd law of acceleration
an unbalanced force acting on a body produces an acceleration (a) in the direction of the force that is directly proportional to the force and inversely proportional to the mass (m) of the body.
a = F/m or a = (Vout – Vin)/time
• 3rd law of interaction-
for every action, there is an equal and opposite reaction.
ex. thrust produced in a jet engine.
• Equilibrium
is the absence of acceleration, either linear or angular. Equilibrium exists when the sum of all the forces and the sum of all moments around the center of gravity equal zero.
• Trimmed flight
exists when the sum of the moments around the center of gravity is zero.
Contrast Equilibrium and Trimmed Flight
• In trimmed flight, the sum of the forces may not be equal to zero since you can trim an airplane into a turn. If you are in equilibrium flight, then you are in trimmed flight, but the reverse is not necessarily true.
• Static pressure- (Ps)
pressure each air particle exerts on another. Force acts perpendicular t any surface that the air particles collide with. Static pressure decreases with an increase in altitude at a rate of 1.0 in-Hg per 1000 ft.
• Air Density- (ρ)
total mass of air particles per unit volume. Air density decreases with an increase in altitude
• Temperature- (T)
measure of the average kinetic energy of the air particles
• Average Lapse Rate
temp decrease linearly with an increase in altitude at a rate of 2°C (3.57°F) per 1000 ft until 36,000 ft.
• Humidity
amount of water vapor in the air. As humidity increases, air density decreases.
• Viscosity (μ)
measure of the air’s resistance to flow and shearing. Air viscosity can be demonstrated by its tendency to stick to a surface. Air viscosity increases with an increase in temperature.
• Local Speed of Sound-
rate at which sound waves travel through a particular air mass. Dependant only on temperature. As the temperature of the air increases, the speed of sound increases.
State the relationship between humidity and air density.
Air viscosity increases with an increase in temperature.
State the relationship between temperature and local speed of sound
As temperature increases, the speed of sound increases.
State the pressure, temperature, lapse rate, and air density at sea level in the standard atmosphere using both Metric and English units of measurement.
English Metric
Static Pressure Pso |29.92 in-Hg | 1013.2 mb
Temperature To | 59°F | 15°C
Average Lapse Rate | 3.57°F / 1000 ft |2°C / 1000 ft
Air Density ρo | 0.002378 slugs / ft3 | 1.2255 gram / liter
Local Speed of Sound LSOSo | 661.7 kts | 340.4 m/s
State the relationships between altitude and temperature, pressure, air density, and local speed of sound within the standard atmosphere.
Temperature, pressure, air density, and local speed of sound all decrease with an increase in altitude within the standard atmosphere.
State the relationships between pressure, temperature, and air density using the General Gas Law.
Pressure (P), Density (ρ), Temperature (T), Universal Gas Constant (R)
P = ρRT
• Aircraft
any device used or intended to be used for flight in the air. (Balloon, dirigible, airplane, glider, helicopter)
• Airplane
is a heavier than air fixed wing aircraft that is driven by an engine and is supported by the dynamic reaction of airflow over its wings. (T-34 or T-37)
compare, and contrast an aircraft and an airplane.
Aircraft is used to describe a broad range of flying machines and Airplane describes more specific flying machines.
List and describe the 3 major control surfaces of an airplane.
•Ailerons- (and spoilers) are control surfaces that control roll.
•Rudder- upright control surface attached to vertical stabilizer to control yaw.
•Elevators- horizontal control surface attached to the horizontal stabilizer to control pitch
List and define the 5 major components of an airplane.
•Fuselage- basic structure of airplane.
•Wing- produce lift.
•Empennage- provides greatest stabilizing influence of all components of an airplane. Consists of aft part of fuselage, Vertical and Horizontal stabilizer.
•Landing Gear- ground taxi, absorb shock of takeoff and landings.
•Engine- provides thrust necessary for flight.
List and define the components of the airplane reference system.
•Center of Gravity (CG)- point at which all weight is considered t be concentrated, and about which all forces and moments (yaw, pitch ,and roll) are measured.
•Longitudinal Axis- passes from nose to tail of airplane.
•Lateral Axis- wingtip to wingtip.
•Vertical Axis- passes vertically through the center of gravity
Describe the orientation between the components of the airplane reference system.
An airplane reference system consists of 3 mutually perpendicular lines (axes) intersecting at the center of gravity.
List and define the motions that occur around the airplane center of gravity.
•Roll or Lateral Control- movement of lateral axis around the longitudinal axis.
•Pitch or Longitudinal Control- movement of the longitudinal axis around the lateral axis.
•Yaw or Directional Control- movement of longitudinal axis around the vertical axis.
• Wingspan (b)
length of wing from wing tip to wing tip.
• Chord line-
an infinitely long, straight line drawn through the leading and trailing edges of an airfoil
• Chord
Measure of the width of the wing or other control surface. Measured along the chordline from leading edge to trailing edge.
• Tip Chord (CT)-
measured at wing tip
• Root Chord (CR)-
chord at wing centerline.
• Average Chord (c)
average of every chord from the wing root to wing tip.
• Wing Area (S)
apparent surface area of a wing from wingtip to wingtip.
S = b∙c
• Taper
reduction in the chord of an airfoil from root to tip. The wings of the T-34 and T-37 are tapered to reduce weight, improve structural stiffness, and reduce wingtip vortices.
• Taper Ratio (λ)
ratio of the tip chord to the root chord.
λ = CT / CR
• Sweep Angle (Λ)
angle between a line drawn 25% aft of the leading edge and parallel to the lateral axis
• Aspect Ratio (AR)
ratio of wingspan to the average wing chord. High aspect ratio- glider. Low aspect ratio- fighter plane.
AR = b/c
• Wing loading (WL)
ratio of an airplane’s weight to the surface area of its wing. There tends to be an inverse relationship between aspect ratio and wing loading.
WL = (aircraft weight / wing area)
• Angle of Incidence
angle between the airplane’s longitudinal axis and the chordline of its wing.
• Dihedral angle
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.
Describe and state the advantages of the semi-monocoque fuselage construction.
Modified version of monocoque having skin, transverse frame members, and stringers, which all share in stress loads and may be readily repaired if damaged. T-37 and T-34 both use semi-monocoque fuselages.
Describe full cantilever wing construction.
All bracing is internal.
• Steady airflow-
exists if at every point in the airflow static pressure, density, temperature, and velocity remain constant over time. A particle of air follows the same path as the preceding particle.
• Streamline
is the path that air particles follow in steady airflow.
• Streamtube
a collection of streamlines forms a streamtube, which contains a flow just as effectively as a tube with solid walls. A streamtube is a closed system, therefore total mass and total energy must remain constant.
Describe the relationship between airflow velocity and cross sectional area within a streamtube using the continuity equation.
•Continuity Equation (A1V1 = A2V2)
•If the cross sectional area decreases on one side of the equation, the velocity must increase on the same side so both sides remain equal. Velocity and area in a streamtube are inversely related.
Describe the relationship between total pressure, static pressure, and dynamic pressure within a streamtube using Bernoulli’s equation.
•Bernoulli’s Equation PT = PS + q
•PT = Total pressure, also called Head Pressure (HT) equals the sum of Static Pressure (PS) + dynamic pressure (q = ½ρV2)
•As with total energy, total pressure also remains constant within a closed system. As area in a streamtube decreases, velocity increases, therefore, “q” must increase(q contains V2). Since q increases, PS must decrease.
List the components of the pitot static system.
Pitot Tube, Static Pressure Source, and the Black Box
State the type of pressure sensed by each component of the pitot static system.
•Pitot Tube- collects total pressure (PT)
•Static Pressure Port- collects ambient static pressure (PS)
•Black Box- Takes static pressure and subtracts it from the total pressure with a diaphragm. Through a series of springs and levers, the remaining static pressure, which is equal to dynamic pressure, is displayed on a pressure gauge inside the cockpit…the IAS gauge.
q = PT - PS
Define indicated airspeed, calibrated airspeed, equivalent airspeed, true airspeed, and ground speed.
•Indicated Airspeed (IAS)
instrument indication for the dynamic pressure the airplane is creating during flight.
Define indicated airspeed, calibrated airspeed, equivalent airspeed, true airspeed, and ground speed.
•Calibrated Airspeed (CAS)
IAS corrected for instrument error-installation and position error. (Often ignored in calculations)
Define indicated airspeed, calibrated airspeed, equivalent airspeed, true airspeed, and ground speed.
•Equivalent Airspeed (EAS)
Calibrated Airspeed corrected for Compressibility Error. EAS = TAS at sea level on a standard day that produces the same dynamic pressure as the actual flight condition (often ignored)
Define indicated airspeed, calibrated airspeed, equivalent airspeed, true airspeed, and ground speed.
•True Airspeed (TAS)
Actual velocity at which an airplane moves through an air mass. It is EAS corrected for Density. TAS is IAS (CAS and EAS are very minor and ignored) corrected for the difference between the local air density (ρ) and the density of the air at sea level on a standard day (ρo)
•TAS will equal IAS only under standard day, sea level conditions.
•Since air density decreases when you increase temperature or altitude, if IAS remains constant while climbing from sea level to some higher altitude, TAS must increase.
TAS = √(ρo/ρ) ∙ IAS
Define indicated airspeed, calibrated airspeed, equivalent airspeed, true airspeed, and ground speed.
•Ground Speed (GS)
measure of airplanes speed over ground. TAS corrected for wind.
GS = TAS – headwind or GS = TAS + tailwind
Mach number (M)
ratio of airplane’s true airspeed to the local speed of sound

M = (TAS/LSOS)
Critical Mach Number (Mcrit)
Supersonic airflow exist somewhere on the airplane, usually the upper surface of wing.
Describe the effects of altitude on Mach number and critical Mach number.
• An increase in altitude would increase Mach number and Critical Mach number because the local speed of sound would decrease. The speed of sound is temperature dependant and an increase in altitude results in a decrease in temperature which also reduces the speed of sound.
Pitch Attitude (θ)
angle between an airplane’s longitudinal axis and the horizon
Flight Path
is the path described by an airplane’s center of gravity as it moves through an air mass.
Relative Wind
airflow the airplane experiences as it moves through the air. Equal in magnitude and opposite in direction to flight path.
Angle of Attack (α)
angle between the relative wind and the chordline of an airfoil. Flight path, relative wind, and angle of attack should never be inferred from pitch attitude.
Mean Camber Line
line drawn halfway between the upper and lower surfaces.
Positive Camber
if mean camber line is above the chordline
Negative Camber
if the mean camber line is below the chordline.
Symmetric Airfoil
If the mean camber line is coincident with the chordline.
Aerodynamic Center
or quarter chord point, is the point along the chordline where all changes in the aerodynamic force takes place. On subsonic airfoils, the AC is located approximately one quarter (between 23% and 27%) of the length of the chord from the leading edge.
Airfoil Thickness
height of the airfoil profile. The point of max thickness corresponds to the aerodynamic center.
Spanwise Flow
airflow that travels along the span of the wing parallel to the leading edge. Does not produce lift.
Chordwise Flow
air flowing at right angles to the leading edge of an airfoil. It is the only airflow that produces lift.
Aerodynamic Force (AF)
force that is the result of pressure and friction distribution over an airfoil, and can be resolved into two components, lift and drag.
Lift (L)
component of the aerodynamic force acting perpendicular to the relative wind.
Drag (D)
component of the aerodynamic force acting parallel to and in the same direction as the relative wind.
Describe the effects on dynamic pressure, static pressure, and the aerodynamic force as air flows around a cambered airfoil and a symmetric airfoil.
•Symmetric Airfoil
At zero angle of attack produces identical velocity increases and static pressure decreases on both the upper and lower surfaces. Since there is no pressure differential perpendicular to the relative wind, the airfoil produces zero net lift.
Describe the effects on dynamic pressure, static pressure, and the aerodynamic force as air flows around a cambered airfoil and a symmetric airfoil.
•Cambered Airfoil
Is able to produce an uneven pressure distribution even at zero AOA. Because of the positive camber, the airflow above the wing will be greater than the velocity below the wing. The static pressure on the upper surface will be less than the static pressure on the lower surface, creating a pressure differential thus creating a lifting force.
Describe the effects of changes in angle of attack on the pressure distribution and aerodynamic force of cambered and symmetric airfoils.
• Increasing the angle of attack on any airfoil causes the area of the streamtube above the wing to decrease. This produces a greater velocity increase above the wing than below the wing. The greater velocity above the wing will create a pressure differential on a symmetric airfoil and will increase the pressure differential o a cambered airfoil. The greater pressure differential on the airfoil will increase the magnitude of the aerodynamic force.
Describe the effects of changes in density, velocity, surface area, camber, and angle of attack on lift.
•An increase in density or velocity will produce greater lift.
•An increase in wing surface area produces greater lift.
•Increase Camber will produce greater lift.
•Increase AOA will produce greater lift.
List the factors affecting lift that the pilot can directly control.
AOA, Velocity, Density, Surface Area, Camber
Compare and contrast the coefficients of lift generated by cambered and symmetric airfoils.
•Positive Camber
At zero AOA, the positive camber airfoil has a positive CL
•Negative Camber
At zero AOA, the negative camber airfoil has a negative CL
•Symmetric Airfoil
At zero AOA, the symmetric airfoil has a CL = 0
Describe the relationships between weight, lift, velocity, and angle of attack in order to maintain straight and level flight, using the lift equation.
In order to maintain level flight while increasing angle of attack, velocity must decrease. Otherwise, lift will be greater than weight, and the airplane will climb. Velocity and AOA are inversely related in level flight.

L = qSCL = 1/2ρV2SCL
Define boundary layer.
that layer of airflow over a surface that demonstrates local airflow retardation due to viscosity. No more than 1mm thick at the leading edge of an airfoil, and grows in thickness as it moves aft over the surface.
List and describe the types of boundary layer airflow.
•Laminar Flow
o Air molecules move smoothly along in streamlines. Produces very little friction, but is easily separated from the surface.

•Turbulent Flow
o Streamlines break up and the flow is disorganized and irregular. Turbulent layers produce higher friction drag, but adheres to the upper surface of the airfoil, delaying boundary layer separation.
State the advantages and disadvantages of each type of boundary layer airflow.
•Laminar Flow
oAdvantages- little friction
oDisadvantages- easily separated from the surface

•Turbulent Flow
oAdvantages- adheres to upper surface of airfoil, delaying boundary layer separation.
oDisadvantages- high friction drag
State the cause and effect of boundary layer separation.
•The adverse pressure gradient impedes the flow of the boundary layer
•If the boundary layer does not have sufficient kinetic energy to overcome the adverse pressure gradient, the lower levels of the boundary layer will stagnate
•The boundary layer will separate from the surface and cause the airfoil to lose the suction pressure that creates lift.
Define stall and state the cause of the stall.
•Stall
ois a condition of flight where an increase in AOA has resulted in a decrease in CL.

oThe only cause of a stall is excessive AOA beyond CLmax
Define and state the importance of CLmax and CLmax AOA.
•CLmax
is the peak Coefficient of Lift and any increase in AOA beyond CLmax AOA produces a decrease in CL

•CLmax AOA
is known as stalling AOA or critical AOA and the region beyond CLmax AOA is the stall region. Regardless of the flight conditions or airspeed, the wing will always stall beyond the same AOA.
State the procedure for stall recovery.
•The only action necessary for stall recovery is to decrease the AOA below CLmax AOA.
List common methods of stall warning, and identify those used for the T-34 and T-37.
•Common methods of stall warning are: AOA indicators, rudder pedal shakers, stick shakers, horns, buzzers, warning lights, and electronic voices.
•T-34- AOA indicator, AOA indexer and rudder pedal shakers that receive their input from an AOA probe on left wing.
•T-37- Aerodynamic stick shaker.
State the stalling AOA of the T-34C
•The T-34C AOA indicator is calibrated so that the airplane stalls between 29.0 and 29.5 units AOA regardless of airspeed, nose attitude, weight, or altitude.
Define stall speed.
is the minimum true airspeed required to maintain level flight at CLmax AOA.
State the purpose of high lift devices.
•Primary purpose of high lift devices is to reduce takeoff and landing speeds by reducing stall speed.
State the effect of boundary layer devices on the coefficient of lift, stalling AOA, and stall speed. (See graph pg 1.4-15)
•Coefficient of lift is increased
•Stalling AOA is increased
•Stall Speed is decreased
Describe different types of boundary layer control devices.
•Fixed Slots
gaps located at the leading edge of a wing that allow air to flow from below the wing to the upper surface.

•Slats
are moveable leading edge sections used to form automatic slots.
Describe the operation of boundary layer control devices.
•Fixed Slots
High pressure air from the leading edge stagnation point is directed through the slot, which acts as a nozzle converting the static pressure into dynamic pressure. The high kinetic energy air leaving the nozzle increases the energy of the boundary layer and delays separation.

•Slats
when slats are deployed it opens a slot.
State the effect of flaps on the coefficient of lift, stalling AOA, and stall speed. (See graph pg 1.4-16)
•Coefficient of lift is increased
•Stalling AOA (CLmax AOA) decreases
•Stall speed is decreased
Describe different types of flaps.
State the methods used by each type of flap to increase the coefficient of lift.
• Plain Flap
o simple hinged portion of the trailing edge that is forced down into the air stream to increase the camber of the airfoil.
Describe different types of flaps.
State the methods used by each type of flap to increase the coefficient of lift.
• Split Flap
o is a plate deflected from the lower surface of the airfoil. It creates a lot of drag because of the turbulent air between the wing and defected surface.
Describe different types of flaps.
State the methods used by each type of flap to increase the coefficient of lift.
• Slotted Flap
o similar to the plain flap, but moves away from the wing to open a narrow slot between the flap and wing for boundary layer control.
Describe different types of flaps.
State the methods used by each type of flap to increase the coefficient of lift.
• Fowler Flap
o used extensively on larger airplanes. When extended, it moves down increasing the camber, and aft causing a significant increase in wing area as well as opening a slot for boundary layer control.
Describe different types of flaps.
State the methods used by each type of flap to increase the coefficient of lift.
• Leading Edge Flaps
o Devices that change the wing camber at the leading edge of the airfoil. Similar to a trailing edge plain flap.
State the stall pattern exhibited by rectangular, elliptical, moderate taper, high taper, and swept wing platforms.
• Rectangular (λ = 1.0)
o lift distribution is due to low lift coefficients at the tip and high lift coefficients at the root. Since the area of the highest lift coefficient will stall first, the rectangular wing has a strong root stall tendency. Provides adequate stall warning and aileron effectiveness.
State the stall pattern exhibited by rectangular, elliptical, moderate taper, high taper, and swept wing platforms.
• Elliptical Wing
o Has even distribution of lift from the root to the tip and produces minimum induced drag. All sections stall at the same angle of attack. Little advanced warning and aileron effectiveness may be lost near stall.
State the stall pattern exhibited by rectangular, elliptical, moderate taper, high taper, and swept wing platforms.
• Moderate Taper (λ = 0.5)
o have a lift distribution and stall pattern that is similar to the elliptical wing.
State the stall pattern exhibited by rectangular, elliptical, moderate taper, high taper, and swept wing platforms.
• High Taper (λ = 0.25)
o Desirable form the standpoint of structural weight, stiffness, and wingtip vortices. Tapered wings produce most of the lift toward the tip, and have a strong tip stall tendency.
State the stall pattern exhibited by rectangular, elliptical, moderate taper, high taper, and swept wing platforms.
• Swept Wing
o Used on high speed aircraft because they reduce drag and allow the airplane to fly at higher Mach numbers. Have similar lift distribution to a tapered wing, stall easily and have a strong tip stall tendency. When wingtip stalls, it rapidly progresses over the remainder of the wing.
State the advantages and disadvantages of tapering the wings of the T-34 and T-37.
• Advantages
o The T-37 and T-34 use tapered wings because they reduce weight, improve stiffness, and reduce wingtip vortices.

• Disadvantages
o Even stall progression of tapered wings is undesirable because the ailerons are located near the tip. As stall progresses, the pilot will lose lateral control.
State the purpose of wing tailoring.
• Purpose of wing tailoring is to create a root to tip stall progression and give the pilot some stall warning while ensuring that the ailerons remain effective up to a complete stall.
Describe different methods of wing tailoring.
• Geometric Twist
• Geometric Twist
o Is a decrease in angle of incidence from wing root to wing tip. The root section is mounted at some angle of attack to the longitudinal axis and the leading edge of the remainder of wing is gradually twisted downward. This results in a decreased angle of attack at the wingtip due to its lower angle of incidence. The root stalls first because of its higher AOA.
Describe different methods of wing tailoring.
• Aerodynamic Twist
• Aerodynamic Twist
o Is a decrease in camber from wing root to wingtip. This causes a gradual change in cross section shape from positive camber at the wing root to a symmetric shape at the wingtip. Since positive camber airfoils stall at lower angles of attack, the wing root stalls before the wingtip.
State the types of wing tailoring used on the T-34.
oT-34 wing is geometrically twisted 3.1°
oT-34 wings are aerodynamically twisted to create a reduced camber at the tip.
State the types of wing tailoring used on the T-37.
•T-37
oWing is geometrically twisted 2.5°
oWings are aerodynamically twisted to create a reduced camber at the tip.
• Drag
Is the component of the aerodynamic force that is parallel to the relative wind and acts in the same direction.

D = 1/2ρV2SCD
• Total Drag
DT = DP + Di
• Parasite Drag (DP)
All drag that is not associated with the production of lift.
• Induced Drag (Di)
Is that portion of total drag associated with the production of lift
List the three major types of parasite drag.
Form Drag, Friction Drag, and Interference Drag
State the cause of each major type of parasite drag.
•Form Drag
oAlso known as pressure or profile drag, is caused by the airflow separation from a surface and the wake that is created by that separation.
•Friction Drag
oDue to viscosity, a retarding force called friction drag is created in the boundary layer.
•Interference Drag
oGenerated by mixing of streamlines between one or more components
State the aircraft design feature that reduce each major type of parasite drag.
•To reduce form drag, the fuselage, bombs, and other surfaces exposed to the airstream are streamlined.
•Friction Drag can be reduced by smoothing the exposed surfaces of the airplane through painting, cleaning, waxing, or polishing.
•Interference Drag can be minimized by proper fairing and filleting, which allows streamlines to meet gradually rather than abruptly.
Describe the effects in changes in density, velocity, and equivalent parasite area (f) on parasite drag, using the parasite drag equation.
DP = 1/2ρV2f = qf
•Parasite Drag varies directly with velocity squared. If you double you speed, you will create four times a much parasite drag.
•An increase in altitude will decrease density.
•Equivalent parasite area is a mathematically computed value 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. It is not cross sectional area of the airplane.
Describe the effects of upwash and downwash on the lift generated by an infinite wing.
For an infinite wing, the upwash exactly balances the downwash resulting in no net change in lift. Upwash and downwash exist any time an airfoil produces lift.
Describe the effects of upwash and downwash on the lift generated by a finite wing.
• The wind flows around the wingtips, combines with the chordwise flow that has already produced lift and adds to the downwash.
• Downwash approximately doubles by this process due to the spanwise airflow moving around the formation of wingtip vortices.
State the cause on induced drag.
•Caused by parallel component of lift and acts in the same direction as drag and tends to retard the forward motion of the airplane.
•Induced drag varies inversely with velocity and directly with angle of attack
State the aircraft design features that reduce induced drag.
•Install devices that impede spanwise airflow going around wingtips: winglets, wingtip tanks, and missile rails.
Describe the effects of changes in lift, weight, density, and velocity on induced drag, using the induced drag equation.
•Increase in weight will increase induced drag.
•Induced drag is reduced by increasing density (ρ), velocity (V), or wingspan (b).
•In level flight where lift is constant, induced drag varies inversely with velocity, and directly with angle of attack.
Describe the effects of changes in velocity on total drag. (See pg 1.5-8)
•An increase in velocity will increase parasite drag and decrease induced drag.
•A decrease in velocity will decrease parasite drag and will increase induced drag.
Define and state the purpose of the lift to drag ratio.
•Lift to Drag ratio
oDetermines efficiency of an airfoil.
oHigh lift to drag ratio indicates a more efficient airfoil.
State the importance of L/DMAX
•Produces the minimum total drag.
•Parasite drag and induced drag are equal.
•Produces the greatest lift to drag ratio.
•Most efficient AOA.
Describe the relationship between thrust and power.
PR = (TR∙V)/325

• Power required is Thrust required times velocity divided by 325.

• Thrust horsepower only depends on thrust and velocity. The term power (P) is used rather than thrust horsepower (THP) or shaft horsepower (SHP).
Define thrust required and power required.
• Thrust Required (TR)
o Amount of thrust required to overcome drag and is expressed in pounds.

• Power Required (PR)
o Amount of power that is required to produce thrust required
Describe how thrust required and power required varies with velocity.
• Power required is dependant on Thrust required and Velocity.
State the location of L/DMAX on the thrust required and power required curves. (pg 1.6-4)
• Thrust Required Curve, L/DMAX is at bottom of curve.

• Power Required Curve, L/DMAX is to the right of the bottom of the curve.
Define thrust available and power available.
• Thrust Available (TA)
o Amount of thrust that the airplane’s engines are actually producing at a given throttle setting, velocity, and density.

• Power Available (PA)
o Amount of power that the airplane’s engine is actually producing at a given throttle setting, velocity, and density.
Describe the effects of throttle setting , velocity, and density on thrust available and power available for a turbojet engine.
•Thrust Available
-Max engine output occurs at full throttle
-Turbojets do not suffer a decrease in thrust available with velocity because ram effect overcomes the decreased acceleration.
-As density decreases, thrust available also decreases.
•Power Available
-Max power available occurs at full throttle
-As velocity increases, power available will increase linearly
-Power available decreases with a decrease in density.
Describe the effects of PCL setting, velocity, and density on thrust available and power available for a turboprop engine.
• Thrust Available
-Max engine output occurs at full throttle
-Since propeller can only accelerate the air to a max velocity, as the velocity of the incoming air increases, the air is accelerated less through the propeller, and thrust available decreases
-As density decreases, thrust available also decreases

•Power Available
-Max power available occurs at full throttle
-Will initially increases, but will then decrease due to a decrease in thrust available.
-Power available decreases with a decrease in density.
Define thrust horsepower, shaft horsepower, and propeller efficiency.
•Thrust Horsepower (THP)
Is propeller output

•Shaft Horsepower (SHP)
Engine output

•Propeller Efficiency (p.e.)
Ability of the propeller to turn engine output into thrust.
State the relationship between thrust horsepower, shaft horsepower, and propeller efficiency.
•Under ideal conditions, SHP would equal THP, but due to friction in the gearbox and propeller drag, THP is always less than SHP. Propeller efficiency is always less than 100%.

THP = SHP ∙ p.e.
State the flat rated shaft horsepower and the Navy limited shaft horsepower of the T-34C PT6A-25 engine.
•Flat rated horsepower of T-34C
550 SHP (1315 ft-lbs of torque)

•Navy limit
425 SHP (1015 ft-lbs of torque) to extend service life of engine.
State the instrument indications for the flat rated shaft horsepower and the Navy limited shaft horsepower of the T-34C PT6A-25 engine.
• Flat rated horsepower of T-34C
o 550 SHP (1315 ft-lbs of torque)

• Navy limit
o 425 SHP (1015 ft-lbs of torque) to extend service life of engine.
State the sea level rated thrust of each T-37B J69-T-25A engine.
•Flat rated at 1025 pounds of thrust at 100% RPM, but is limited to 95% RPM for continuous operation.
State the instrument indications for the sea level rated thrust of the T-37B J69-T-25A
•Flat rated at 1025 pounds of thrust at 100% RPM, but is limited to 95% RPM for continuous operation.
Define thrust excess (TE) and power excess (PE).
•TE occurs if thrust available is greater than thrust required at a particular velocity.
TE = TA - TR

•PE is calculated in a similar manner as TE and will also produce an acceleration, a climb, or both.
PE = PA -PR
State the effects of a thrust excess or a power excess.
•Thrust Excess
-Positive TE causes an acceleration, a climb, or both depending on AOA
-Negative TE is called thrust deficit and has the opposite effect.

•Power Excess
-Will cause an acceleration, climb, or both
-Power deficit will cause a descent, a deceleration, or both
State the conditions necessary to achieve the maximum thrust excess and maximum power excess for a turbojet and a turboprop airplane.
•Max Thrust Excess
-Max TE occurs at full throttle setting.
-For a turbojet, max thrust excess occurs at L/DMAX.
-For a turboprop, max thrust excess occurs at a velocity less than L/DMAX.

•Max Power Excess
-Turbojet- max power excess occurs at a velocity greater than L/DMAX.
-Turboprop- max power excess occurs at L/DMAX.
Describe the effects of changes in weight on thrust required, power required, thrust available, and power available. (See pg 1.6-8)
An increase in weight will shift the TR and TA curve UP and RIGHT.
Describe the effects of changes in weight on maximum thrust excess and maximum power excess, and on the airspeeds necessary to achieve max thrust excess and max power excess.
• Thrust excess and power excess decrease at every AOA and velocity.
Describe the effects of changes in altitude on thrust required, power required, thrust available, and power available.
•Thrust Required
Increase in altitude, the thrust required curve shifts to the RIGHT, NOT UP.
•Power Required
Increase in altitude, the power required curve shifts UP AND TO THE RIGHT.
•Thrust Available
Decreases at higher altitudes due to reduction in air density.
•Power Available
Decreases at higher altitudes due to reduction in air density.
Describe the effect of changes in altitude on max thrust excess and max power excess and on the airspeeds necessary to achieve max thrust and max power excess.
•Max Thrust Excess
TE will decrease with an increase in altitude due to the decrease in thrust available.
•Max Power Excess
PE will decrease as altitude increases because power available decreases and power required increases.
•The airspeed necessary to achieve max thrust and max power excess will INCREASE.
Describe the effects of changes in configuration on thrust required, power required, thrust available, and power available.
•Lowering Landing Gear
-TR and PR increase. Curve moves UP
-TA and PA are not affected by the landing gear.

•Lowering Flaps
-TR and PR increase. Curve moves UP AND LEFT.
-TA and PA are not affected by the flaps.
Describe the effects of changes in configuration on maximum thrust excess and max power excess, and on the airspeeds necessary to achieve max thrust and max power excess.
•Lowering Landing Gear
-Thrust and power excess will decrease with deployment of landing gear because thrust and power required increase.

•Lowering Flaps
-Thrust ad power excess will decrease with deployment of the flaps because thrust and power required increase.
•The airspeed necessary to achieve max thrust and max power excess will DECREASE.