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