Commercial Ground - Basic Aerodynamics

(Refer to Figure 4.) What is the stall speed of an airplane under a load factor of 2 Gs if the unaccelerated stall speed is 60 knots? a. 66 knots. b. 74 knots. c. 84 knots.

84 knots. From a load factor of 2, go horizontally to the curved line labeled 'Load Factor.' From that point of intersection, go up to the curve labeled 'Stall Speed Increase.' From there, go to the left and read the increase: 40%. The new accelerated stall speed will be 140%, or 1.4 times, the original value. 60 x 1.4 = 84 knots.

Which is true regarding the use of flaps during level turns? a. The lowering of flaps increases the stall speed. b. The raising of flaps increases the stall speed. c. Raising flaps will require added forward pressure on the yoke or stick.

The raising of flaps increases the stall speed. If flaps are raised, the stall speed increases. Answer (A) is incorrect because flaps decrease the stall speed. Answer (C) is incorrect because raising the flaps decreases the lift provided, therefore, back pressure is required to maintain altitude.

To hold an airplane in level flight at airspeeds from very slow to very fast, a pilot must coordinate thrust and a. angle of incidence. b. gross weight. c. angle of attack.

angle of attack. Straight-and-level flight may be sustained at a wide range of speeds. The pilot coordinates angle of attack and thrust in all speed regimes if the aircraft is to be held in level flight.

The stalling speed of an airplane is most affected by a. changes in air density. b. variations in flight altitude. c. variations in airplane loading.

variations in airplane loading. The indicated stalling speed is most affected by load factor. The airplane's stalling speed increases in proportion to the square root of the load factor, whereas a change in altitude (air density) has no effect on the indicated stalling speed.

The angle of attack at which a wing stalls remains constant regardless of a. weight, dynamic pressure, bank angle, or pitch attitude. b. dynamic pressure, but varies with weight, bank angle, and pitch attitude. c. weight and pitch attitude, but varies with dynamic pressure and bank angle.

weight, dynamic pressure, bank angle, or pitch attitude. When the angle of attack becomes so great that the air can no longer flow smoothly over the top wing surface, it becomes impossible for the air to follow the contour of the wing. This is the stalling or critical angle of attack. For any given airplane, the stalling or critical angle of attack remains constant regardless of weight, dynamic pressure, bank angle, or pitch attitude. These factors will affect the speed at which the stall occurs, but not the angle. Answer (B) is incorrect because the stall speed varies with weight and bank angle. Answer (C) is incorrect because the stall speed varies with weight and bank angle.

Stall speed is affected by a. weight, load factor, and power. b. load factor, angle of attack, and power. c. angle of attack, weight, and air density.

weight, load factor, and power. The indicated stalling speed is affected by: 1. Weight. As the weight is increased, the stall speed also increases. 2. Bank angle (load factor). As the bank angle increases, so does the stalling speed. 3. Power. An increase in power will decrease the stalling speed. A change in density altitude (air density) or angle of attack has no effect on the indicated stalling speed, since for a given airplane, the stalling or critical angle of attack remains constant.

A rectangular wing, as compared to other wing planforms, has a tendency to stall first at the a. wingtip, with the stall progression toward the wing root. b. wing root, with the stall progression toward the wing tip. c. center trailing edge, with the stall progression outward toward the wing root and tip.

wing root, with the stall progression toward the wing tip. The rectangular wing has a tendency to stall first at the wing root with the stall pattern progressing outward to the tip. This type of stall pattern decreases undesirable rolling tendencies and increases lateral control when approaching a stall.

(Refer to Figure 3.) How much altitude will this airplane lose in 3 statute miles of gliding at an angle of attack of 8°? a. 440 feet. b. 880 feet. c. 1,320 feet.

1,320 feet. To find the glide ratio (L/D) at an angle of attack of 8°, move upward from the angle of attack scale to the L/D curve. Then move horizontally to the right to find the value located on the L/D scale. This gives a 12:1 glide ratio. The question only deals with glide ratio, so that is the only scale needed. With this glide ratio, the airplane will descend 1 foot of altitude for every 12 feet covered horizontally. L ÷ D = 12 ÷ 1 = horizontal distance ÷ vertical distance 12 ÷ 1 = 5,280 feet (3 SM) ÷ X X = 1,320 feet.

(Refer to Figure 2.) Select the correct statement regarding stall speeds. The airplane will stall a. 10 knots higher in a power-on 60° bank with gear and flaps up than with gear and flaps down. b. 25 knots lower in a power-off, flaps-up, 60° bank, than in a power-off, flaps-down, wings-level configuration. c. 10 knots higher in a 45° bank, power-on stall than in a wings-level stall with flaps up.

10 knots higher in a power-on 60° bank with gear and flaps up than with gear and flaps down. The stalling speed (in knots) for a power-on, 60° bank, with gear and flaps up is 76 knots. For a power-on, 60° bank, and gear and flaps down, the stalling speed is 66 knots, which is 10 knots slower.Answer (B) is incorrect because the airplane will stall 35 knots higher (not 25) in this specified configuration. Answer (C) is incorrect because this configuration is not specified in the question.

(Refer to Figure 3.) The L/D ratio at a 2° angle of attack is approximately the same as the L/D ratio for a a. 9.75° angle of attack. b. 10.5° angle of attack. c. 16.5° angle of attack.

16.5° angle of attack. The glide ratio (L/D) at a 2° angle of attack is about 7.6:1, which is the same glide ratio (L/D) as at a 16.5° angle of attack.

(Refer to Figure 4.) What increase in load factor would take place if the angle of bank were increased from 60° to 80°? a. 3 Gs. b. 3.5 Gs. c. 4 Gs.

4 Gs. Proceed vertically along the line above 60° angle of bank to where it intersects the curve labeled 'Load Factor.' Next, proceed along this line to the left to the corresponding load factor or 'G' unit, which is 2 Gs in this case. Now, repeat the procedure using 80° of bank, which should yield a load factor of 6, which is a difference of 4 Gs.

(Refer to Figure 4.) If an aircraft with a gross weight of 2,000 pounds was subjected to a 60° constant-altitude bank, the total load would be a. 3,000 pounds. b. 4,000 pounds. c. 12,000 pounds.

4,000 pounds. The load factor in a 60° bank is 2 Gs. Load Factor = G Load x Aircraft Weight. Therefore, 2,000 x 2 = 4,000 pounds.

(Refer to Figure 3.) If an airplane glides at an angle of attack of 10°, how much altitude will it lose in 1 mile? a. 240 feet. b. 480 feet. c. 960 feet.

480 feet. To find the glide ratio (L/D) at an angle of attack of 10°, move upward from the angle of attack scale to the L/D curve. Then move horizontally to the right to find the value located on the L/D scale. This gives an 11:1 glide ratio. The question only deals with glide ratio, so that is the only scale needed. With this glide ratio, the airplane will descend 1 foot of altitude for every 11 feet covered horizontally. L ÷ D = 11 ÷ 1 = horizontal distance ÷ vertical distance 11 ÷ 1 = 5,280 feet (1 SM) ÷ X X = 480 feet

(Refer to Figure 4.) What is the stall speed of an airplane under a load factor of 2.5 G's if the unaccelerated stall speed is 60 knots? a. 62 knots. b. 84 knots. c. 96 knots.

96 knots. From a load factor of 2.5, go horizontally to the curved line labeled "Load Factor." From that point of intersection, go up to the curve labeled "Stall Speed Increase." From there, go to the left and read the increase: 60%. The new accelerated stall speed will be 160%, or 1.6 times the original value. 60 x 1.6 = 96 knots.

Which maximum range factor decreases as weight decreases? a. Altitude. b. Airspeed. c. Angle of attack.

Airspeed. The maximum range condition is obtained at maximum L/D ratio which occurs at a particular angle of attack and lift coefficient. As gross weight decreases, the airspeed for maximum L/D decreases. Answer (A) is incorrect because as weight decreases, the maximum range altitude may increase. Answer (C) is incorrect because angle of attack does not play a role in determining maximum range factor.

Which statement is true relative to changing angle of attack? a. A decrease in angle of attack will increase pressure below the wing, and decrease drag. b. An increase in angle of attack will increase drag. c. An increase in angle of attack will decrease pressure below the wing, and increase drag.

An increase in angle of attack will increase drag. Air striking the underside of the wing is deflected downward, producing an opposite reaction which pushes (lifts) the wing upward. To increase lift, the wing is tilted upward, increasing the angle of attack and deflecting more air downward. The larger the angle of attack, the more the lift force tilts toward the rear of the aircraft, increasing drag.

In small airplanes, normal recovery from spins may become difficult if the a. CG is too far rearward and rotation is around the longitudinal axis. b. CG is too far rearward and rotation is around the CG. c. spin is entered before the stall is fully developed.

CG is too far rearward and rotation is around the CG. The recovery from a stall in any airplane becomes progressively more difficult as its center of gravity moves aft. This is particularly important in spin recovery, as there is a point in rearward loading of any airplane at which a 'flat' spin will develop. Answer (A) is incorrect because rotation is around the CG in a spin. Answer (C) is incorrect because an airplane must first stall in order to spin.

A sweptwing airplane with weak static directional stability and increased dihedral causes an increase in a. Mach tuck tendency. b. Dutch roll tendency. c. longitudinal stability.

Dutch roll tendency. When the dihedral effect is large in comparison with static direction stability, the dutch roll motion has weak dampening and is increased. Answer (A) is incorrect because Mach tuck tendency occurs when going through the sound barrier. Answer (C) is incorrect because longitudinal stability is not affected by directional stability or dihedral.

Which is correct with respect to rate and radius of turn for an airplane flown in a coordinated turn at a constant altitude? a. For a specific angle of bank and airspeed, the rate and radius of turn will not vary. b. To maintain a steady rate of turn, the angle of bank must be increased as the airspeed is decreased. c. The faster the true airspeed, the faster the rate and larger the radius of turn regardless of the angle of bank.

For a specific angle of bank and airspeed, the rate and radius of turn will not vary. At a specific angle of bank and a specific airspeed, the radius of the turn and the rate of turn would remain constant if the altitude were maintained. Rate of turn varies with airspeed, or bank angle. If the angle of bank is held constant and the airspeed is increased, the rate of turn will decrease, and the radius of turn will increase. To maintain a constant rate of turn as the airspeed is increased, the angle of bank must be increased. Answer (B) is incorrect because you must decrease the angle of bank when the airspeed is decreased if you are to maintain a steady rate of turn. Answer (C) is incorrect because for a given bank angle a faster airspeed gives a slower rate of turn.

What is the best indicator to the pilot of the load factor on the airplane? a. How firmly the pilot is pressed into the seat during a maneuver. b. Amount of pressure required to operate the controls. c. Airspeed when pulling out of a descent.

How firmly the pilot is pressed into the seat during a maneuver. Load factor can be detected by noting how firmly the pilot is pressed into the seat during a maneuver. If an aircraft is pulled up from a dive, subjecting the pilot to 3 Gs, he or she would be pressed down into the seat with a force equal to three times his or her weight.

What changes in airplane longitudinal control must be made to maintain altitude while the airspeed is being decreased? a. Increase the angle of attack to produce more lift than drag. b. Increase the angle of attack to compensate for the decreasing lift. c. Decrease the angle of attack to compensate for the increasing drag.

Increase the angle of attack to compensate for the decreasing lift. As the airplane slows down, the decreasing airspeed or velocity requires increasing the angle of attack to produce the constant lift needed to maintain altitude. Answer (A) is incorrect because if you are generating more lift than drag, an increase in the angle of attack will cause the airplane to climb. Answer (C) is incorrect because the angle of attack must be increased in order to maintain altitude, if airspeed is being decreased.

If an airplane category is listed as utility, it would mean that this airplane could be operated in which of the following maneuvers? a. Limited acrobatics, excluding spins. b. Limited acrobatics, including spins (if approved). c. Any maneuver except acrobatics or spins.

Limited acrobatics, including spins (if approved). Utility category airplanes can do all normal category maneuvers plus limited acrobatics, including spins (if approved). Answer (A) is incorrect because the utility category includes spins. Answer (C) is incorrect because the normal category prohibits acrobatics and spins.

To avoid possible wake turbulence from a large jet aircraft that has just landed prior to your takeoff, at which point on the runway should you plan to become airborne? a. Past the point where the jet touched down. b. At the point where the jet touched down, or just prior to this point. c. Approximately 500 feet prior to the point where the jet touched down.

Past the point where the jet touched down. Vortices cease to be generated when the aircraft lands. Plan to become airborne beyond this point.

(Refer to Figure 2.) Select the correct statement regarding stall speeds. a. Power-off stalls occur at higher airspeeds with the gear and flaps down. b. In a 60° bank the airplane stalls at a lower airspeed with the gear up. c. Power-on stalls occur at lower airspeeds in shallower banks.

Power-on stalls occur at lower airspeeds in shallower banks. Power-on stalls occur at lower airspeeds than power-off stalls because of increased airflow over the wing and because some lift is produced by the vertical component of thrust, reducing the lift needed to be produced by velocity. Power-on or -off stalls occur at a lower airspeed in a shallower bank. Answer (A) is incorrect because stall speed is lower with power-off stalls, with gear and flaps down. Answer (B) is incorrect because the gear position alone will not affect stall speed in a 60° bank.

When landing behind a large aircraft, which procedure should be followed for vortex avoidance? a. Stay above its final approach flightpath all the way to touchdown. b. Stay below and to one side of its final approach flightpath. c. Stay well below its final approach flightpath and land at least 2,000 feet behind.

Stay above its final approach flightpath all the way to touchdown. Stay at or above the large aircraft's final approach flight path. Note the touchdown point and land beyond it.

Choose the correct statement regarding wake turbulence. a. Vortex generation begins with the initiation of the takeoff roll. b. The primary hazard is loss of control because of induced roll. c. The greatest vortex strength is produced when the generating airplane is heavy, clean, and fast.

The primary hazard is loss of control because of induced roll. Vortices sink at 400-500 fpm. Vortex generation begins when lift is being produced at takeoff. Greatest vortex strength is produced when the airplane is heavy, clean, and slow. The primary hazard is loss of control due to induced roll caused by the spinning vortices. Answer (A) is incorrect because vortex generation begins at the rotation point when the airplane takes off. Answer (C) is incorrect because the greatest vortex strength is when the generating aircraft is heavy, clean, and slow.

While executing a 60 degree level turn, your aircraft is at a load factor of 2.0. What does this mean? a. The total load on the aircraft's structure is two times its weight.. b. The load factor is over the load limit. c. The gust factor is two times the total load limit.

The total load on the aircraft's structure is two times its weight.. Load factor is the ratio between the total airload supported by the wing to the total weight of the airplane; i.e., the total airload supported by the wings divided by the total weight of the airplane.

Which is true with respect to vortex circulation in the wake turbulence generated by an aircraft? a. Helicopters generate downwash turbulence only, not vortex circulation. b. The vortex strength is greatest when the generating aircraft is heavy, clean, and slow. c. When vortex circulation sinks into ground effect, it tends to dissipate rapidly and offer little danger.

The vortex strength is greatest when the generating aircraft is heavy, clean, and slow. The strength of a vortex is governed by the weight, speed, and the shape of the wing of the generating aircraft. Maximum vortex strength occurs when the generating aircraft is heavy, clean, and slow.

Which is true regarding the force of lift in steady, unaccelerated flight? a. At lower airspeeds the angle of attack must be less to generate sufficient lift to maintain altitude. b. There is a corresponding indicated airspeed required for every angle of attack to generate sufficient lift to maintain altitude. c. An airfoil will always stall at the same indicated airspeed; therefore, an increase in weight will require an increase in speed to generate sufficient lift to maintain altitude.

There is a corresponding indicated airspeed required for every angle of attack to generate sufficient lift to maintain altitude. To maintain the lift and weight forces in balance, and to keep the airplane straight-and-level in a state of equilibrium, as velocity increases, angle of attack must be decreased. Conversely, as the airplane slows, the decreasing velocity requires the angle of attack be increased enough to create sufficient lift to maintain flight. Therefore, for every angle of attack, there is a corresponding indicated airspeed required to maintain altitude in steady, unaccelerated flight - all other factors being constant. Answer (A) is incorrect because to provide sufficient lift, the angle of attack must be increased as the airspeed is reduced. Answer (C) is incorrect because the angle of attack must be increased to compensate for the decreased lift.

Which statement is true, regarding the opposing forces acting on an airplane in steady-state level flight? a. These forces are equal. b. Thrust is greater than drag and weight and lift are equal. c. Thrust is greater than drag and lift is greater than weight.

These forces are equal. During straight-and-level flight at constant airspeed, thrust and drag are equal and lift and weight are equal.

The need to slow an aircraft below V(A) is brought about by the following weather phenomenon: a. High density altitude which increases the indicated stall speed. b. Turbulence which causes an increase in stall speed. c. Turbulence which causes a decrease in stall speed.

Turbulence which causes an increase in stall speed. When severe turbulence is encountered, the airplane should be flown at or below maneuvering speed. This is the speed least likely to result in structural damage to the airplane, even if full control travel is used, and yet allows a sufficient margin of safety above stalling speed in turbulent air. When an airplane is flying at a high speed with a low angle of attack, and suddenly encounters a vertical current of air moving upward, the relative wind changes to an upward direction as it meets the airfoil. This increases the angle of attack on the wings and has the same effect as applying a sharp back pressure on the elevator control. It increases the load factor which in turn increases the stall speed. Answer (A) is incorrect because indicated stall speed is not affected by changes in density altitude. Answer (C) is incorrect because the higher load factors imposed on the aircraft by turbulence increases stall speed.

(Refer to Figure 5.) What does the intersection of the dashed line at point C represent? a. Va. b. Negative limit load factor. c. Positive limit load factor.

Va. Point C represents the intersection of the positive limit load factor and the line of maximum positive lift capability. The airspeed at this point is the minimum airspeed at which the limit load can be developed aerodynamically. Any airspeed greater than this provides a positive lift capability sufficient to damage the aircraft. Conversely, any airspeed less than this does not provide positive lift capability sufficient to cause damage from excessive flight loads. This point is commonly referred to as "maneuvering speed" or VA.

o generate the same amount of lift as altitude is increased, an airplane must be flown at a. the same true airspeed regardless of angle of attack. b. a lower true airspeed and a greater angle of attack. c. a higher true airspeed for any given angle of attack.

a higher true airspeed for any given angle of attack. In order to maintain its lift at a higher altitude, an airplane must fly at a greater true airspeed for any given angle of attack. Answer (A) is incorrect because true airspeed must be increased as altitude increases to generate the same amount of lift. Answer (B) is incorrect because true airspeed must be increased as altitude increases to generate the same amount of lift.

To produce the same lift while in ground effect as when out of ground effect, the airplane requires a. a lower angle of attack. b. the same angle of attack. c. a greater angle of attack.

a lower angle of attack. If the airplane is brought into ground effect with a constant angle of attack, it will experience an increase in lift coefficient and a reduction in the thrust required. The reduction of the wing-tip vortices due to ground effect alters the spanwise lift distribution and reduces the induced flow. The reduction in induced flow causes a significant reduction in induced drag, but has no direct effect on parasite drag.

Your flight takes you in the path of a large aircraft. In order to avoid the vortices you should fly a. at the same altitude as the large aircraft. b. below the altitude of the large aircraft. c. above the flight path of the large aircraft.

above the flight path of the large aircraft. Fly above the jet's flight path whenever possible, because the vortices descend. Avoid flight below and behind a large aircraft's path.

An airplane will stall at the same a. angle of attack regardless of the attitude with relation to the horizon. b. airspeed regardless of the attitude with relation to the horizon. c. angle of attack and attitude with relation to the horizon.

angle of attack regardless of the attitude with relation to the horizon. The definition of a stall is when the airplane exceeds the critical angle of attack. This happens because the smooth airflow over the airplane's wing is disrupted and the lift degenerates rapidly. This can occur at any airspeed, in any attitude, with any power setting.

Airplane wing loading during a level coordinated turn in smooth air depends upon the a. rate of turn. b. angle of bank. c. true airspeed.

angle of bank. For any given angle of bank, the rate of turn varies with the airspeed. If the angle of bank is held constant and the airspeed is increased, the rate of turn will decrease. Because of this, there is no change in centrifugal force for any given bank angle. Therefore, the load factor remains the same. Load factor varies with changing bank angle and increases at a rapid rate after the angle of bank reaches 50°. Answer (A) is incorrect because rate of turn and true airspeed do not have an impact on wing loading in a coordinated turn. Answer (C) is incorrect because rate of turn and true airspeed do not have an impact on wing loading in a coordinated turn.

When transitioning from straight-and-level flight to a constant airspeed climb, the angle of attack and lift a. are increased and remain at a higher lift-to-weight ratio to maintain the climb. b. remain the same and maintain a steady state lift-to-weight ratio during the climb. c. are momentarily increased and lift returns to a steady state during the climb.

are momentarily increased and lift returns to a steady state during the climb. When transitioning from level flight to a climb, the forces acting on the airplane go through certain changes. The first change, an increase in lift, occurs when back pressure is applied to the elevator control. This initial change is a result of the increase in the angle of attack which occurs when the airplane's pitch attitude is raised. This results in a climbing attitude. When the inclined flight path and the climb speed are established, the angle of attack and the corresponding lift stabilize at approximately the original value.

During a takeoff made behind a departing large jet airplane, the pilot can minimize the hazard of wingtip vortices by a. being airborne prior to reaching the jet's flightpath until able to turn clear of its wake. b. maintaining extra speed on takeoff and climbout. c. extending the takeoff roll and not rotating until well beyond the jet's rotation point.

being airborne prior to reaching the jet's flightpath until able to turn clear of its wake. Vortices begin to form when the jet rotates. Plan to be off the runway prior to reaching the jet's point of rotation, then fly above or turn away from the jet's flight path.

Recovery from a stall in any airplane becomes more difficult when its a. center of gravity moves aft. b. center of gravity moves forward. c. elevator trim is adjusted nosedown.

center of gravity moves aft. The recovery from a stall in any airplane becomes progressively more difficult as its center of gravity moves aft.

While maintaining a constant angle of bank and altitude in a coordinated turn, an increase in airspeed will a. decrease the rate of turn resulting in a decreased load factor. b. decrease the rate of turn resulting in no change in load factor. c. increase the rate of turn resulting in no change in load factor.

decrease the rate of turn resulting in no change in load factor. For any given angle of bank the rate of turn varies with the airspeed. In other words, if the angle of bank is held constant and the airspeed is increased, the rate of turn will decrease, or if the airspeed is decreased, the rate of turn will increase. Because of this, there is no change in centrifugal force for any given bank. Therefore, the load factor remains the same. Answer (A) is incorrect because load factor remains the same at a constant angle of bank. Answer (C) is incorrect because the rate of turn in a constant angle of bank will decrease with an increase in airspeed, and the load factor will remain the same.

As the angle of bank is increased, the vertical component of lift a. decreases and the horizontal component of lift increases. b. increases and the horizontal component of lift decreases. c. decreases and the horizontal component of lift remains constant.

decreases and the horizontal component of lift increases. Lift during a bank is divided into two components, one vertical and the other horizontal. The vertical component of lift must be equal to the weight to maintain altitude. Since the vertical component of lift decreases as the bank angle increases, the angle of attack must be progressively increased to produce sufficient vertical lift to support the airplane's weight. The increased back elevator pressure provides the increased angle of attack.

The angle of attack of a wing directly controls the a. angle of incidence of the wing. b. amount of airflow above and below the wing. c. distribution of pressures acting on the wing.

distribution of pressures acting on the wing. The angle of attack of an airfoil directly controls the distribution of pressure below and above it. By changing the angle of attack, the pilot can control lift, airspeed, and drag. Answer (A) is incorrect because the angle of incidence is a fixed angle between the chordline of the aircraft and the aircraft's longitudinal axis. Answer (B) is incorrect because the amount of airflow above and below the wing stays constant.

Load factor is the lift generated by the wings of an aircraft at any given time a. divided by the total weight of the aircraft. b. multiplied by the total weight of the aircraft. c. divided by the basic empty weight of the aircraft.

divided by the total weight of the aircraft. Load factor is the ratio between the total airload supported by the wing to the total weight of the airplane; i.e., the total airload supported by the wings divided by the total weight of the airplane. Answer (B) is incorrect because load factor multiplied by airplane weight equals required lift. Answer (C) is incorrect because load factor is lift divided by the total weight of the airplane.

Longitudinal stability involves the motion of the airplane controlled by its a. rudder. b. elevator. c. ailerons.

elevator. Longitudinal stability or pitching is the motion around the lateral axis. Pitch is controlled by the elevator. Answer (A) is incorrect because the rudder affects directional stability. Answer (C) is incorrect because the ailerons affect lateral stability.

An airplane leaving ground effect will a. experience a reduction in ground friction and require a slight power reduction. b. experience an increase in induced drag and require more thrust. c. require a lower angle of attack to maintain the same lift coefficient.

experience an increase in induced drag and require more thrust. As the wing encounters ground effect and is maintained at a constant lift coefficient, there is a reduction in the upwash, downwash, and wing-tip vortices. This causes a reduction in induced drag. While in ground effect, the airplane requires less thrust to maintain lift. It will also require a lower angle of attack. When an airplane leaves ground effect, there is an increase in drag which will require a higher angle of attack. Additional thrust will be required to compensate for the loss. Answer (A) is incorrect because ground friction is reduced when breaking ground. Answer (C) is incorrect because a higher angle of attack is required to maintain the same lift coefficient when leaving the ground.

On a wing, the force of lift acts perpendicular to and the force of drag acts parallel to the a. chord line. b. flightpath. c. longitudinal axis.

flightpath. Lift acts upward and perpendicular to the relative wind. Drag acts parallel to, and in the same direction as the relative wind, which is parallel to the flightpath. Answer (A) is incorrect because there is not a fixed relationship between lift and drag with respect to the airplane's chord line or longitudinal axis. Answer (C) is incorrect because there is not a fixed relationship between lift and drag with respect to the airplane's chord line or longitudinal axis.

Lift on a wing is most properly defined as the a. force acting perpendicular to the relative wind. b. differential pressure acting perpendicular to the chord of the wing. c. reduced pressure resulting from a laminar flow over the upper camber of an airfoil, which acts perpendicular to the mean camber.

force acting perpendicular to the relative wind. Lift opposes the downward force of weight. It is produced by the dynamic effect of the air acting on the wing, and acts perpendicular to the flight path (relative wind) through the wing's center of lift.

Which is true regarding the forces acting on an aircraft in a steady-state descent? The sum of all a. upward forces is less than the sum of all downward forces. b. rearward forces is greater than the sum of all forward forces. c. forward forces is equal to the sum of all rearward forces.

forward forces is equal to the sum of all rearward forces. In steady-state flight, the sum of the opposing forces is equal to zero. The sum of all upward forces equals the sum of all downward forces. The sum of all forward forces equals the sum of all backward forces.

In theory, if the angle of attack and other factors remain constant and the airspeed is doubled, the lift produced at the higher speed will be a. the same as at the lower speed. b. two times greater than at the lower speed. c. four times greater than at the lower speed.

four times greater than at the lower speed. Lift is proportional to the square of the airplane's velocity. For example, an airplane traveling at 200 knots has four times the lift as the same airplane traveling at 100 knots, if the angle of attack and other factors remain constant. Answer (A) is incorrect because as airspeed doubles, lift will be four times greater than at the lower speed. Answer (B) is incorrect because as airspeed doubles, lift will be four times greater than at the lower speed.

In theory, if the airspeed of an airplane is doubled while in level flight, parasite drag will become a. twice as great. b. half as great. c. four times greater.

four times greater. Parasite drag has more influence at high speed, and induced drag has more influence at low speed. For example, if an airplane in a steady flight condition at 100 knots is then accelerated to 200 knots, the parasite drag becomes four times as great.

(Refer to Figure 1.) At an airspeed represented by point B, in steady flight, the pilot can expect to obtain the airplane's maximum a. endurance. b. glide range. c. coefficient of lift.

glide range. Point B represents the airspeed that results in the greatest L/D ratio. At this point the aircraft will have its maximum glide range. Answer (A) is incorrect since only jet aircraft will obtain maximum endurance at L/D(MAX). Answer (C) is incorrect because the critical angle of attack and the maximum coefficient of lift occur at the same point, where total drag is also high because of an increase in induced drag.

A load factor of 1.2 means the total load on an aircraft's structure is 1.2 times its a. gross weight. b. load limit. c. gust factor.

gross weight. In aerodynamics, load factor is the ratio of the maximum load an aircraft can sustain to the gross weight of the aircraft. For example, a load factor of 1.2 means the total load on an aircraft's structure is 1.2 times its gross weight.

(Refer to Figure 1.) At the airspeed represented by point A, in steady flight, the airplane will a. have its maximum L/D ratio. b. have its minimum L/D ratio. c. be developing its maximum coefficient of lift.

have its maximum L/D ratio. At point A, the total drag curve is at its lowest point. When an aircraft is flown at the airspeed and angle of attack that results in the lowest total drag possible, then the resulting L/D ratio is at its maximum. Answer (B) is incorrect because the minimum L/D ratio occurs when parasite drag is very high, a result of high airspeeds. Answer (C) is incorrect because the maximum coefficient of lift occurs at slower airspeeds, which results in higher induced drag and a lower L/D ratio.

An aircraft airfoil is designed to produce lift resulting from a difference in the a. negative air pressure below and a vacuum above the airfoil's surface. b. vacuum below the airfoil's surface and greater air pressure above the airfoil's surface. c. higher air pressure below the airfoil's surface and lower air pressure above the airfoil's surface.

higher air pressure below the airfoil's surface and lower air pressure above the airfoil's surface. The highest velocity is at the top of the airfoil with the lowest velocity at the bottom. Because there is a difference of velocity above and below the wing, the result is a higher pressure at the bottom of the wing and a lower pressure on the top of the wing. This low-pressure area produces an upward force known as the Magnus Effect, the physical phenomenon whereby an object's rotation affects its path through a fluid, including air.

An aircraft wing is designed to produce lift resulting from a difference in the a. negative air pressure below and a vacuum above the wing's surface. b. vacuum below the wing's surface and greater air pressure above the wing's surface. c. higher air pressure below the wing's surface and lower air pressure above the wing's surface.

higher air pressure below the wing's surface and lower air pressure above the wing's surface. The wing is designed to provide actions greater than its weight by shaping it to develop a relatively positive (high)-pressure lifting action from the air mass below the wing and a negative (low)-pressure lifting action from lowered pressure above the wing. The increased speed of the air over the top of the airfoil produces the drop in pressure. The pressure difference between the upper and lower surface does not account for all the lift produced. Air also strikes the lower surface of the wing, and the reaction of this downward-backward flow results in an upward-forward force on the wing.

To increase the rate of turn and at the same time decrease the radius, a pilot should a. maintain the bank and decrease airspeed. b. increase the bank and increase airspeed. c. increase the bank and decrease airspeed.

increase the bank and decrease airspeed. The horizontal component of lift will equal the centrifugal force of steady, turning flight. To increase the rate of turn, the angle of bank may be increased and the airspeed may be decreased. Answer (A) is incorrect because although at a given angle of bank a decrease in airspeed will increase the rate of turn and decrease the radius, it will not be as effective as steepening the bank and decreasing the airspeed. Answer (B) is incorrect because the pilot should decrease airspeed to decrease the turn radius.

If the same angle of attack is maintained in ground effect as when out of ground effect, lift will a. increase, and induced drag will decrease. b. decrease, and parasite drag will increase. c. increase, and induced drag will increase.

increase, and induced drag will decrease. If the airplane is brought into ground effect with a constant angle of attack, it will experience an increase in lift coefficient and a reduction in the thrust required. The reduction of the wing-tip vortices due to ground effect alters the spanwise lift distribution and reduces the induced flow. The reduction in induced flow causes a significant reduction in induced drag, but has no direct effect on parasite drag.

To maintain a standard rate turn as the airspeed increases, the bank angle of the aircraft will need to a. remain constant. b. increase. c. decrease.

increase. As airspeed is increased in a constant bank angle the rate of turn will decrease. For example, in a 30 degree bank at 100 knots your rate of turn will equal 6.5 degrees per second. If you maintain the 30 degree bank angle and increase speed to 150 knots your rate of turn will decrease to 4.4 degrees per second. Therefore, to maintain a standard rate turn of either 3 or 1.5 degrees per second (high-speed aircraft), as airspeed is increased bank angle will need to be increased.

In a rapid recovery from a dive, the effects of load factor would cause the stall speed to a. increase. b. decrease. c. not vary.

increase. There is a direct relationship between the load factor imposed upon the wing and its stalling characteristics. The stalling speed increases in proportion to the square root of the load factor.

As airspeed decreases in level flight below that speed for maximum lift/drag ratio, total drag of an airplane a. decreases because of lower parasite drag. b. increases because of increased induced drag. c. increases because of increased parasite drag.

increases because of increased induced drag. Parasite drag is greatest at higher airspeeds. Induced drag is the by-product of lift and becomes a greater influence at higher angles of attack and slower airspeeds. It increases in direct proportion to increases in the angle of attack. Any angle of attack lower or higher than that for L/D(MAX) reduces the lift-drag ratio and consequently increases the total drag. Answer (A) is incorrect because total drag increases when airspeed decreases below L/D(MAX) due to increased induced drag. Answer (C) is incorrect because parasite drag decreases with speeds below L/D(MAX).

For a given angle of bank, in any airplane, the load factor imposed in a coordinated constant-altitude turn a. is constant and the stall speed increases. b. varies with the rate of turn. c. is constant and the stall speed decreases.

is constant and the stall speed increases. In an airplane at any airspeed, if a constant altitude is maintained during the turn, the load factor for a given degree of bank is the same, which is the resultant of gravity and centrifugal force. Load supported by the wings increases as the angle of bank increases. Stall speeds increase in proportion to the square root of the load factor. Answer (B) is incorrect because rate of turn does not affect the load factor. Answer (C) is incorrect because stall speed will increase with an increase in bank.

If an airplane is loaded to the rear of its CG range, it will tend to be unstable about its a. vertical axis. b. lateral axis. c. longitudinal axis.

lateral axis. Lateral stability is controlled by the CG along the longitudinal axis. An airplane will become less laterally stable as the CG is moved further rearward along the longitudinal axis. Longitudinal stability (pitching) is stability about the lateral axis.Answer (A) is incorrect because the CG has little to do with the vertical axis. Answer (C) is incorrect because lateral stability is not greatly affected by the CG location.

A propeller rotating clockwise as seen from the rear, creates a spiraling slipstream. The spiraling slipstream, along with torque effect, tends to rotate the airplane to the a. right around the vertical axis, and to the left around the longitudinal axis. b. left around the vertical axis, and to the right around the longitudinal axis. c. left around the vertical axis, and to the left around the longitudinal axis.

left around the vertical axis, and to the right around the longitudinal axis. The slipstream strikes the vertical fin on the left causing a yaw to the left, at the same time it causes a rolling moment to the right.

By changing the angle of attack of a wing, the pilot can control the airplane's a. lift, airspeed, and drag. b. lift, airspeed, and CG. c. lift and airspeed, but not drag.

lift, airspeed, and drag. By changing the angle of attack, the pilot can control lift, airspeed, and drag. Answer (B) is incorrect because the angle of attack does not affect the CG. Answer (C) is incorrect because the angle of attack also determines drag.

The ratio between the total airload imposed on the wing and the gross weight of an aircraft in flight is known as a. load factor and directly affects stall speed. b. aspect load and directly affects stall speed. c. load factor and has no relation with stall speed.

load factor and directly affects stall speed. The load factor is the ratio between the total airload imposed on the wings of an airplane and the gross weight of the airplane. An increased load factor increases stalling speed and a decreased load factor decreases stalling speed.

Why is it necessary to increase back elevator pressure to maintain altitude during a turn? To compensate for the a. loss of the vertical component of lift. b. loss of the horizontal component of lift and the increase in centrifugal force. c. rudder deflection and slight opposite aileron throughout the turn.

loss of the vertical component of lift. Lift during a bank is divided into two components, one vertical and the other horizontal. The vertical component of lift must be equal to the weight to maintain altitude. Since the vertical component of lift decreases as the bank angle increases, the angle of attack must be progressively increased to produce sufficient vertical lift to support the airplane's weight. The increased back elevator pressure provides the increased angle of attack. Answer (B) is incorrect because this describes a skidding turn. Answer (C) is incorrect because slight opposite aileron pressure may be required to compensate for the overbanking tendency, not to maintain altitude.

If airspeed is increased during a level turn, what action would be necessary to maintain altitude? The angle of attack a. and angle of bank must be decreased. b. must be increased or angle of bank decreased. c. must be decreased or angle of bank increased.

must be decreased or angle of bank increased. To compensate for added lift which would result if the airspeed were increased during a turn, the angle of attack must be decreased, or the angle of bank increased, if a constant altitude is to be maintained. Answer (A) is incorrect because either the angle of attack can be decreased or the angle of bank increased to maintain altitude as airspeed is increased. Answer (B) is incorrect because to maintain constant altitude in a turn as the airspeed increases, the angle of bank must decrease.

If the airplane attitude remains in a new position after the elevator control is pressed forward and released, the airplane displays a. neutral longitudinal static stability. b. positive longitudinal static stability. c. neutral longitudinal dynamic stability.

neutral longitudinal static stability. Neutral static stability is the initial tendency of the airplane to remain in the new condition after its equilibrium has been disturbed. When an airplane's attitude is momentarily displaced and it remains at the new attitude, it is displaying neutral longitudinal static stability. Longitudinal stability makes an airplane stable about its lateral axis (pitch). Answer (B) is incorrect because positive longitudinal static stability is the initial tendency of the airplane to return to its original attitude after the elevator control is pressed forward and released. Answer (C) is incorrect because neutral longitudinal dynamic stability is the overall tendency for the airplane to remain in the new condition over a period of time.

In theory, if the airspeed of an aircraft in level flight is cut in half while in level flight, parasite drag will become a. one-third as much. b. one-half as much. c. one-fourth as much.

one-fourth as much. Parasite drag increases as the square of the airspeed.

Longitudinal dynamic instability in an airplane can be identified by a. bank oscillations becoming progressively steeper. b. pitch oscillations becoming progressively steeper. c. Trilatitudinal roll oscillations becoming progressively steeper.

pitch oscillations becoming progressively steeper. Longitudinal stability, or pitching about the lateral axis, is considered to be the most affected by certain variables in various flight conditions. A longitudinally unstable airplane has a tendency to dive or climb progressively into a steep dive or climb which may result in a stall. A longitudinally unstable airplane is difficult and sometimes dangerous to fly. Answer (A) is incorrect because roll oscillations refer to lateral stability. Answer (C) is incorrect because roll oscillations refer to lateral stability.

(Refer to Figure 5.) The horizontal dashed line from point C to point E represents the a. ultimate load factor. b. positive limit load factor. c. airspeed range for normal operations.

positive limit load factor. C to E is the maximum positive load limit. In this case it is 3.8 Gs, which is appropriate for normal category airplanes.

If the airplane attitude initially tends to return to its original position after the elevator control is pressed forward and released, the airplane displays a. positive dynamic stability. b. positive static stability. c. neutral dynamic stability.

positive static stability. Static stability deals with initial tendencies. Positive static stability is the initial tendency of the airplane to return to its original state after being disturbed.

One of the main functions of flaps during the approach and landing is to a. decrease the angle of descent without increasing the airspeed. b. provide the same amount of lift at a slower airspeed. c. decrease lift, thus enabling a steeper-than-normal approach to be made.

provide the same amount of lift at a slower airspeed. Extending the flaps increases wing lift and also increases induced drag. The increased drag enables the pilot to make steeper approaches without an increase in airspeed. Answer (A) is incorrect because the flaps will increase the angle of descent without increasing the airspeed. Answer (C) is incorrect because the flaps increase lift and induced drag.

What performance is characteristic of flight at maximum lift/drag ratio in a propeller-driven airplane? Maximum a. gain in altitude over a given distance. b. range and maximum distance glide. c. coefficient of lift and minimum coefficient of drag.

range and maximum distance glide. Maximum range condition would occur where the proportion between speed and power required is greatest. The maximum range condition (of propeller driven airplanes) is obtained at maximum lift-drag ratio (L/D(MAX)). The best angle of glide is one that allows the airplane to travel the greatest distance over the ground with the least loss of altitude. This is also the airplane's maximum L/D and is usually expressed as a ratio. This implies that the airplane should be flown at L/D(MAX) to obtain the greatest glide distance.

While holding the angle of bank constant in a level turn, if the rate of turn is varied the load factor would a. remain constant regardless of air density and the resultant lift vector. b. vary depending upon speed and air density provided the resultant lift vector varies proportionately. c. vary depending upon the resultant lift vector.

remain constant regardless of air density and the resultant lift vector. For any given angle of bank the rate of turn varies with the airspeed. In other words, if the angle of bank is held constant and the airspeed is increased, the rate of turn will decrease, or if the airspeed is decreased, the rate of turn will increase. Because of this, there is no change in centrifugal force for any given bank. Therefore, the load factor remains the same. Answer (B) is incorrect because rate of turn will vary based on airspeed with a constant angle of bank. Answer (C) is incorrect because load factor varies based on the resultant load vector.

If the airspeed is increased from 90 knots to 135 knots during a level 60° banked turn, the load factor will a. increase as well as the stall speed. b. decrease and the stall speed will increase. c. remain the same but the radius of turn will increase.

remain the same but the radius of turn will increase. At a given angle of bank, a higher airspeed will make the radius of the turn larger and the airplane will be turning at a slower rate. This compensates for added centrifugal force, allowing the load factor to remain the same.

If the airspeed is decreased from 98 knots to 85 knots during a coordinated level 45 degree banked turn, the load factor will a. remain the same, but the radius of turn will decrease. b. decrease, and the rate of turn will decrease. c. remain the same, but the radius of turn will increase.

remain the same, but the radius of turn will decrease. At a given angle of bank, a lower airspeed will make the radius of the turn smaller and the airplane will be turning at a faster rate. This compensates for the reduced centrifugal force, allowing the load factor to remain the same.

If the airspeed is increased from 89 knots to 98 knots during a coordinated level 45° banked turn, the load factor will a. decrease, and the radius of turn will decrease. b. remain the same, but the radius of turn will increase. c. increase, but the rate of turn will decrease.

remain the same, but the radius of turn will increase. When a turn is made at a higher true airspeed at a given bank angle, the inertia is greater and the horizontal lift component required for the turn is greater, causing the turning rate to become slower. Therefore, at a given angle of bank, a higher true airspeed will make the radius of turn larger because the airplane will be turning at a slower rate. This compensates for added centrifugal force, allowing the load factor to remain the same.

(Refer to Figure 5.) The vertical line from point E to point F is represented on the airspeed indicator by the a. upper limit of the yellow arc. b. upper limit of the green arc. c. blue radial line.

upper limit of the yellow arc. V(NE) (never exceed airspeed), the vertical line from point E to F, is marked on airspeed indicators with a red radial line, the upper limit of the yellow arc.

To maintain altitude during a turn, the angle of attack must be increased to compensate for the decrease in the a. forces opposing the resultant component of drag. b. vertical component of lift. c. horizontal component of lift.

vertical component of lift. Lift during a bank is divided into two components, one vertical and the other horizontal. The vertical component of lift must be equal to the weight to maintain altitude. Since the vertical component of lift decreases as the bank angle increases, the angle of attack must be progressively increased to produce sufficient vertical lift to support the airplane's weight. The increased back elevator pressure provides the increased angle of attack. Answer (A) is incorrect because the phrase 'the resultant component of drag' has no meaning. Answer (C) is incorrect because as the horizontal component of lift decreases, the vertical component of lift increases, therefore the angle of attack must be decreased.