# Shared Flashcard Set

## Details

Ground Instructor
Flight & Ground Instructor and Pilot Examiner
58
Aviation
Professional
12/02/2008

## Additional Aviation Flashcards

Term
 Which statement relates to Bernoulli's principle?
Definition
 Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface.  Bernoulli's principle states in part that the internal pressure of a fluid (liquid or gas) decreases at points where the speed of the fluid increases.
Term
 Lift produced by an airfoil is the net force developed perpendicular to the
Definition
 Relative wind Lift produced by an airfoil is the net force developed perpendicular to the relative wind.
Term
 An airplane leaving ground effect will
Definition
 Experience a decrease in stability and a nose up change in moments. An Airplane will: require an increase in angle of attack to maintain the same lift coefficient, an increase in induced drug & thrust required, decrease in stability & nose up change in moment, reduction in static source & increase in indicated airspeed.
Term
 Which characteristics of a spin is not a characteristic of a steep spiral?
Definition
 Stalled wing During a spin, both wings are stalled although 1 wing in less stalled than the other. In a steep spiral (steep, descending turn), the wings are flying at a relatively low angle of attack and at a high airspeed.
Term
 As the angle of bank is increased, the vertical component of lift
Definition
 Decreases and the sink increases In a streight-and-level flight the vertical component of lift acts dirctly opposite to the component of gravity or weight. The vertical component of lift decreases. As a result, gravity is not offset by as much vertical lift, and the sink rate increses.
Term
 When rolling out of a steep-banked turn, what causes the lowered aileron to create more drag than when rolling into the turn?
Definition
 The wing's angle of attack is greater as the rollout is started. When rolling out of a turn, the adverse yaw effect caused by the loweered aileron is more apparent than rolling into a turn, due to the higher angle of attack, wing loading, and the slower airspeed of the lowered wing wher rollout is started.
Term
 If the aircraft's nose initially tends to move farther from its original position after the elevator control is pressed forward and released, the aircraft displays
Definition
 Negative Static Stability When the airplane's nose moves farther from its original position, it has the undesirable characteristics of negative static stability.
Term
 Which type of flap creates the least change in pitching moment?
Definition
 Split The split flap creates the least change in pitching moment because, although it provides lift, it also results in considerably more drag than other types of flaps. Accordingly, it requires more power during approaches.
Term
 Which statement is true relating to the factors which produce stalls?
Definition
 The stalling angle of attack is independent of the speed of airflow over the wings. While the stalling speed of a particula airplane varies, the airplane will always stall at the same angle of attack regardless of airspeed, weight, load factor, or density altitude.
Term
 Which type of flap is characterized by large increases in lift coefficient with minimum changes in drag?
Definition
 Fowler When extended, he fowler flap increases the angle of attack, wing camber, and wing area,which provides added lift without significatly increasing drag. Thus, the fowler flap produces large increases in lift coefficient with minimum changes in drag.
Term
 During flight with zero angle of attack, the pressure along the upper surface of a wing would be
Definition
 Less than atmospheric pressure Zero angle of attack means that the chord line of the wing coincides with the relative wind. Air flows a greater distance oe the upper wing surfae than the lower wing surface of an asymmetrical airfoil, the upper surface has a lower pressure (less than atmospheric pressure) than the lower surface.
Term
 Why does increasing speed also increase lift?
Definition
 The increased impact of the relative wind on an airfoil's lower surface creates a greater amount of air being deflected downward.  Increasing speed increases the air flowing over and under an airflow. The increased impact of teh relative wind on an airfoil's surface creates a greater amount of air being deflected downward, producing greater lift.
Term
 During a steady climb, the angle of climb depends on
Definition
 Excess thrust For a given weight of the airplane, the angle of climb depends on the difference between thrust and drag, or the excess thrust. The maximum angle of cloimb wold occur where there exists the greatest difference between thrust available and thrust required.
Term
 If an increase in power tends to make the nose of an airplane rise, this is the result of the
Definition
 Line of thrust being below the center of gravity If an increase in power tends to make the nose of an airplane rise, it is an indication that the line of thrust is below the center of gravity. This combines with the changing load on the tail surface to create a pitch-up attitude.
Term
 The force which imparts a change in the velocity of a mass is called
Definition
 Thrust Thrust is the force which imparts a change in the velocity of the mass. It may be measured in pounds but has no element of time or rate.
Term
 That portion of the aircraft's total drag created by the producion of lift is called
Definition
 Induced drag, and is greatly affected by changes in airspeed Induced drag is the undesirable but unavoidable by-product of lift and is greatly affected by changes in airspeed. The slower the airplane flies, the greater the coefficient of lift and thus the greater the induced drag.
Term
 The point on an airfoil through which lift acts is the
Definition
 Center of pressure Although lift is generated over the entire wing, an imaginary point is established which represents the resultant of all lift forces. This single point is the center of lift, also known as the center of pressure.
Term
 An aircraft wing is designed to produce lift resulting from
Definition
 Positive air pressure below the wing's surface and negative air pressure above the wing's surface. In the same period of time the air flowing over the curved top of the wing must travel farther than the air flowing along the flat bottom. This means the air on top must go faster. Bernoulli's principle.
Term
 When the angle of attack of a symmetrical airfoil is increased, the center of pressure will
Definition
 Remain unaffected Unlike that of an asymetrical airfoil, the center of pressure of a symmetrical airfoil remains unaffected, regardless of angle of attack.
Term
 Maximum gliding distance of an aircraft is obained when
Definition
 Induced drag and parasite drag are equal The maximum gliding distance of an aircraft is obtained when the total drag is the minimum, and L/D ratio is at the maximum. Minimum drag occurs when induced drag and parasite drag are equal.
Term
 As airspeed increases in level flight, total drag of and aircraft becomes greater than the total drag produced at the maximum lift/drag speed because of the
Definition
 Increase in parasite drag As airspeed increases, the total drag of an aircraft becomes greater than the total produced at L/DMAX because of the increase in parasite drag.
Term
 During a steady climb, the rate of climb depends on
Definition
 Excess power For a given weight of the airplane, the rate of climb depends on the difference between the power available and the power required, or the excess power. The maximum rate would occur where there exists the greatest difference between power required and power available.
Term
 Lift produced by an airfoild is the net force developed perpendicular to the
Definition
 Relative wind Lift produced by an airfoil is the net force developed perpendicular to the relative wind.
Term
 Which statement is true regarding the forces acting on an airplane in a steady-state climb?
Definition
 The sum of all upward forces is equal to the sum of all downward forces In a steady flight condition, the opposing forces are equal. Thus, in steady climb, descent, or straight-and-level flight, total upward forces equal total downward forces.
Term
 Changes in the center of pressure of a wing affect the aircraft's
Definition
 Aerodynamic balance and controllability Center of pressure (CP) is the imaginary but determinable point at which all of the upward lift forces on the wing are concetrated. At high angles of attack the CP moves forwar while at low angles of attack the CP moves aft. The relationship of the CP & CG affects aerodynamic balance and controllability.
Term
 An airplane would have a tendeny to nose up and have an inherent tendency to enter a stalled condition when the center of pressure is
Definition
 Forward of the center of gravity As the angle of attact increases, the center of pressure moves forward. If it moves forward of the center of graity, it will ted to raise the nose of the airplane, thus increasing the angle of attack een more. This will lead to a stalled condition.
Term
 The resistance, or skin friction, due to the viscosity of the air as is passes along the surface of a wing is called
Definition
 Profile drag Profile drag is the resistance, or skin friction, due to the viscosity (stickiness) of the airas it passes alog the surface of the wing.
Term
 Which statement describes the relationship of the forces acting on an aircraft in a constant-power and constat-airspeed descent?
Definition
 Thrust is equal to drag; lift is equal to weight In a steady flight condition, no change in speed or flight path occus. The forces that oppose each other are also equal to each other. Lift equals weight, and thrust equals drag in a steady climb, descent, or straight-and-level flight.
Term
 Which relationship is correct when comparing drag and airspeed?
Definition
 Induced drag varies inversely as the square of the airspeed Parasite drag increases as the square of the airspeed, and induced drag varies inversely as the square of the airspeed.
Term
 When considering the forces acting upon an airplane i straight-an-level flight at constant airspeed, which statement is correct?
Definition
 Weight always acts verticaly toward the center of the Earth Weight is the force which is caused by gravity accelerating the mass of the airplane and alaways acts verticaly toward the center of the Earth.
Term
 As airspeed decreases in level flight, total drag of an aircraft becomes greater than the total drag produced at the maximum lift/drag speed because of the
Definition
 Increase in induced drag As airspeed decreases the total drag of an aircraft becomes greater than the total drag produced at L/DMAX because of the increase in induced drag. The lower the airspeed the greater the angle of attack required to produce lift to equal the sum of the downward forces & consequently the induced drag will be greater.
Term
 If an airplane's gross weight is 3250 pounds, what is the load acting on this airplane during a level 60° banked turn?
Definition
 6500 pounds Load factor is the ratio of the total load supported by the airplane's wing to the actual weight of the airplane and its contents. A level 60° bank imposes a load factor of appreximately 2.0. Thus, imposing a load factor of 2.0 on an airplane that weights an actual 3250 lb would impose a wingload of 6500 lb.
Term
 An airplane as a normal stalling speed of 60 MPH but is forced into an accelerated stall at twice that speed. What maximum load factor will result from this maneuver?
Definition
 4 G's A rule for determining the speed at which an airplane will stall is that the stalling speed increases in proportion to the square root of the load factor. Thus, in order to force an accelerated stall at twice the normal stalling speed, the load factor would have to be 4 since square root of 4 is 2.
Term
 A sweptwing airplane with weak static directional stability and increased dihedral causes an increase in
Definition
 Dutch roll tenency A sweptwing airplane has an increase in dihedral effect. When an airplane's dihedral effect is large in comparison with its static directional stability, its Dutch roll tendencies will increase.
Term
 A rectangular wing, as compared to he other wing platforms, has a tendency to stall first at the
Definition
 Wing root providing adequate stall warning A rectangular wing as compared to other wing platforms, has a tendency to stall first at the wing root, with the stall progression toward the wingtip, which provies adequate stall warning. Because the wingtips and the ailerons stall later, you are provided aileron control in avoiding and recovering from the stall.
Term
 At a constant veocity in airflow, a high aspect ratio wing will have (in comparison with a low aspect ratio wing)
Definition
 Decreased drag, especially at a high angle of attack An increase in aspect ratio with constant velocity will decrease the drag, especially at high angles of attack, improving climb performance and decreasing stall speed.
Term
 If severe turbulance is encountered, the aircraft's airspeed should be reduced to
Definition
 Maneuvering speed In severe turbulance, the airplane should be slowed to its maneuvering speed (VA), i.e. the airspeed ta which the airplane will stall before excessive loads can be imposed on the wings sufficient to cause structural damage.
Term
 The angle between the chord line of the wing and the longitudinal axis of the aircraft is known as
Definition
 The angle of incidence The angle of incidence is the acute angle formed by the chord line of the wing and the longitudinal axis of the aircraft.
Term
 A line drawn from the leading edge to the trailing edge of an airfoil and equidistant at all points from the upper and the lower contours is called the
Definition
 Camber line a reference line drawn from the leading edge to the trailing edge whch is equidistant at all points from the upper and  lower surface of the wing is the mean camber line.
Term
 Which is the est technique for minimizing the wing-load factor when flying in severe turbulance?
Definition
 Set power and trim to obtain an airspeed at or below maneuvering speed, maintain wing level, and accept variations of airspeed and altitude. When in severe turbulance you should be at or below VA so that the airplane will stall prior to incurring structural loads of a magnitude sufficient to cause stractural damage. You should attempt to keep the wings level and accept changes in airspeed and altitude.
Term
 The use of a slot in the leading edge of the wing enables an airplane to land at a slower speed because it
Definition
 Delays the stall to a higher angle of attack The use of a slot and/or slat in the leading edge of the wing provides for the passage of air, which accelerates the boundary layer on the upper surface. The stall is delayed to a higher angle of attack, thus enabling the airpane to land at a slower speed.
Term
 A wing with a very high aspect ratio (in comparison with a low aspect ratio wing) will have
Definition
 A low stall speed An increase in aspect ratio with costant velocity will decrease the drag, especialy at a high angle of attack, improving climb prformance and decreasing stall speeds.
Term
 Which subsonic planform provides the best lift coefficient?
Definition
 Elliptical wing The best subsonic wing planform from a lift coefficient standpoint is the elliptical wing.
Term
 On which planform does the stall begin at the wing root and progress outward toward the wingtip?
Definition
 Rectangular wing Rectangular wings have a tendency to stall first at the wing root, progressing toward the wingtp. This tendency gives adequate stall warning, adequate aileron effectiveness, and leads to a wing which is usually quite stable. Rectangular wings are therefore favored in the design of low-cost, low-speed airplanes.
Term
 Aspect ration of a wing is defined as the ratio of the
Definition
 Wingspan to the mean chord The aspect ratio is the ratio of the wingspan to the mean chord.
Term
 The purpose of aircraft wing dihedral angle is to
Definition
 Increase lateral stability Dihedral is the angle at which the wings are slanted upward from the root to the tip. When the airplane sideslips slightly, one wing is forced down. The greater angle of attack on the lower wing produces increased lift, with a tedency to return the airplane to wings-level flights, i.e. lateral stability is enhanced
Term
 The three axes of an aircraft intersect at the
Definition
 Center of gravity
Term
 Action of the ailerons moves the airplane on its
Definition
 Longitudinal axis An airplane is moved about its longitudinal axis (rolling motion) by action of the ailerons.
Term
 Action of the elevators moves the airplane on its
Definition
 Lateral axis An airplane is moved about its lateral axis (pitching motion) by action of the elevators.
Term
 If the pilot applies right rudder to a stable airplane, the
Definition
 Tail deflects right and the nose moves right The rudder pedals and the rudder itself move in the same direction. By pressing the right rudder pedal in the cockpit, the pilot is causing the rudder to move to the right as well. This causes the airplane to yaw to the right.
Term
 The angle of attack of a wing directly controls the
Definition
 Distriution of positive and negative pressure acting on the wing The angle of attact of a wing directly controls the distribution of positive and negative pressure acting on the wing by altering the speed of the airflow over the wing surfaces.
Term
 The angle between the chord line of an airfoil and the relative wind is known as the angle of
Definition
 Attack The angle of attack is the acute angle between the chord line of the wing and the direction of the relative wind.
Term
 The critical angle of attack at which a given aircraft stalls is dependent on the
Definition
 Design of the wing The angle of attack at which an airplane atalls is dependent upon the wing design. It is a fixed number, usually an angle of attack between 15° and 20°.
Term
 What action is necessary to make an aircraft turn?
Definition
 Change the direction if lift In straight-and-level flight, lift acts directly opposite to gravity or weight. As the aircraft is banked, the lift is divided into horizontal and vertical components. This horizontal component of lift pulls the aircraft around the turn.
Term
 How can a pilot increase the rate of turn and decrease the radius at the same time?
Definition
 Steepen the bank and decrease airspeed The rate of turn is dependent upon the horizontal component of lift. As the horizontal component is increased (steepen bank) the rate of turn increases. The radius of a turn is dependent upon airspeed. As airspeed is decreased, the turn radius decreases.
Term
 Adverse yaw during a turn entry is aused by
Definition
 Decreased induced drag on the lowered wing and increased induced drag on the raised wing When the pilot applies pressure to the control stick or turns the control yoke to the left, the right aileron surface deflects downward and the left aileron surface deflects upward. The downward-deflection aileron produces more lift and more drag which attempts to pull or veer the airplane's nose in the direction of the raised wing.
Term
 As the angle of bank is increased, the vertical component of lift
Definition
 Decreases and the sink rate increases In straight-and-level flight, the vertical component of lift acts directly opposite to the component of gravity or weight. Therefore, the vertical component of lift decreases. As a result, gravity is not offset by as much vertical lift, and the sink rate increases.
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