Review Chapter 12

Fundamental Flight Maneuvers• Straight and Level• Turns• Climbs • Descents

Turns• The horizontal component of lift.• Load Factor and Turns• The relationship between angle of

bank , load factor, and stall speed is the same for all airplanes

Turns• Banking - increases stall speed• To increase the rate of turn and at

the same time decrease the radius - increase bank and decrease speed

• To maintain altitude - increase angle of attack

Four Aerodynamic Forces• Lift• Thrust• Drag• Weight• When are they in equilibrium?

Lift• Perpendicular to the relative wind• Induced drag is a by-product of lift• In theory if the angle of attack and

other factors remain constant double the speed - four times the lift

Controlling Lift• Increase airspeed• Change the angle of attack• Change the shape of the airfoil• Change the total area of the

wings

Bernoulli’s Principle• As the velocity of a fluid

increase, its internal pressure decreases

• High pressure under the wing and lower pressure above the wing’s surface

Angle of Attack• Directly controls the distribution

of pressure acting on a wing. By changing the angle of attack, you can control the airplane’s lift, airspeed and drag.

Angle of Attack• Angle of attack at which a wing

stalls remains constant regardless of weight, dynamic pressure, bank angle or pitch attitude.

Stalls• Stall speed is not a fixed value• Stall speed is affected by weight,

load factor and power• Frost can cause a wing to stall at a

lower than normal angle of attack

Flaps• Plain• Split• Slotted• Fowler

Ground Effect• Within one wingspan of the

ground• An airplane leaving ground effect

will experience an increase in what kind of drag?

• Induced

Drag• What kind of drags rate of

increase is proportional to the square of the airspeed?

• Parasite Drag• What kinds of drag make up

parasite Drag

Drag• Form• Interference• Skin Friction

Load Factor• Ratio between the lift generated

by the wings at any given time divided by the total weight of the airplane.

Load Factor• A heavily loaded plane stalls at a

higher speed than a lightly loaded airplane.

• It needs a higher angle of attack to generate required lift at any given speed than when lightly loaded.

Aircraft Stability• Achieved by locating the center

of gravity slightly ahead of the center of lift

• Need a tail down force on the elevator

Aircraft Stability• In light planes, recovery from a

spin may be difficult with a rearward CG

• Longitudinal stability involves motion about the lateral axis and is controlled by the elevator

Density Altitude• High• Hot • Humid

Surface Winds• Headwind or tailwind component

–a 10 knot headwind might improve performance by 10%

–a 10 knot tailwind might degrade performance by 40%

Performance Charts• Experience Test Pilots• Factory new Airplanes• Repeated Tests using Best

Results• Format -Table -Graphic

Cruise Charts• Range is the distance an airplane

can travel with a given amount of fuel

• Endurance is the length of time the airplane can remain in the air

Cruise Charts• Maximum range is at L/Dmax or

best glide speed• Maximum endurance is about

76% or best glide speed• Generally close to stall speed

Excessive Weight• Higher takeoff speed• Longer takeoff run• Reduced rate and angle of climb• Lower maximum altitude

Excessive Weight• Shorter range and endurance• Reduced cruise speed and

maneuverability• Higher stall speed• Higher landing speed and longer

landing roll

Forward CG Effects• Higher takeoff speed and ground

roll• Reduced rate and angle of climb• Lower maximum altitude• Reduced maneuverability

Forward CG Effects• Higher stalling speed• Reduction in performance

caused by increased tail-down loading

• Reduced pitch authority

Beyond Aft CG Effects• Decreased stability and increased

susceptibility to over control• Increased risk of stalls and spins

of which recovery may be difficult or impossible

Weight Shift Computations

Weight of Cargo Moved Distance CG moves

Airplane weight = Distance Between Arm locations