Answer B is Incorrect, Try Again
Answer B is Incorrect, Try Again
Answer C is Incorrect, Try Again
| The pull of gravity provides the forward motion necessary to move the wings through the air in the same way a car coasting downhill receives its forward momentum through the pull of gravity on its own weight. |
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| If during flight, rough air or severe turbulence is encountered, the airspeed should be reduced to maneuvering speed or less to minimize the stress on the glider structure. |
| Weight X Arm = Moment. Total Moment / Total Weight = CG (inches aft of datum). |
| Removable trim ballast weights...are designed to compensate for a front seat pilot who weighs less than the minimum permissible front seat pilot weight. |
| Removable trim ballast weights...are designed to compensate for a front seat pilot who weighs less than the minimum permissible front seat pilot weight. |
| Angle of Attack - the angle between the chord line of the wing and the direction of the relative wind. |
| Angle of Attack - the angle between the chord line of the wing and the direction of the relative wind. |
| Extending flaps...increases wing lift and also increases induced drag. Increased lift enables a pilot to make steeper approaches to a landing without an increase in airspeed. |
| An airplane must be stalled in order to enter a spin. |
| As the airplane rotates around a vertical axis, the rising wing is less stalled than the descending wing creating a rolling, yawing, and pitching motion. |
 3600 SPH / V-MPH = SPMSPM x VS FPS = Ft-Alt-Loss/Mile SPH=sec/hr SPM=sec/mile |
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 3600 SPH / V-MPH = SPMSPM x VS FPS = Ft-Alt-Loss/Mile SPH=sec/hr SPM=sec/mile |
| Spoilers extend from the upper surface of the wing interrupting or spoiling the airflow over the wings |
| If airspeed increases and the angle of bank remains the same, the rate of turn will decrease. Conversely, a constant airspeed coupled with an angle of bank increase will result in a faster rate of turn. The radius of turn at any given bank angle varies directly with the square of the airspeed... if the angle of bank increases and the airspeed remains the same, the radius of turn is decreased. |
| MANEUVERING SPEED is the maximum speed at which the limit load can be imposed (either by gusts or full deflection of the control surfaces) without causing structural damage. |
| The glider will lose the least amount of altitude per unit of time at minimum sink airspeed. |
| 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. |
| With ballast... the best glide ratio is the same but it occurs at a faster speed. Ballast should be used under stronger thermal conditions for better speed between thermals. |
| With ballast... the best glide ratio is the same but it occurs at a faster speed. Ballast should be used under stronger thermal conditions for better speed between thermals. |
| When the datum is ahead of the aircraft, all the arms are positive and computational errors are minimized. |
| Determine the CG by dividing the total moment by the total weight. |
| Determine the CG by dividing the total moment by the total weight. |
| Determine the CG by dividing the total moment by the total weight. |
| Determine the CG by dividing the total moment by the total weight. |
| The weight and balance revision sheet should clearly show the revised empty weight, empty weight arm and/or moment index, and the new useful load. |
| Lift opposes the downward force of weight, is produced by the dynamic effect of the air acting on the wing, and acts perpendicular to the flightpath through the wing's center of lift. |
| A load factor is the ratio of the total airload acting on the airplane to the gross weight of the airplane...The airplane's stalling speed increases in proportion to the square root of the load factor. |
| In any airplane at any speed, if a constant altitude is maintained during the turn, the load factor for a given degree of bank is the same. For any given angle of bank, the rate of turn varies with the airspeed.. The load factor remains the same. |
| Negative flap is used at high speeds where wing lift reduction is desired to reduce drag. |
| Minimum total drag occurs at the airspeed where the induced and parasite drag curves intersect. This is the speed where the sailplane is operating with the best lift-to-drag ratio, or L/D. |
| The elliptical wing is more efficient in terms of L/D, but the stall characteristics are not as good as the rectangular wing. |
| Aspect ratio is determined by dividing the wingspan, by the average wing chord. High-aspect ratio wings produce a comparably high amount of lift at low angles of attack with less induced drag. |
| Aspect ratio is determined by dividing the wingspan, by the average wing chord. High-aspect ratio wings produce a comparably high amount of lift at low angles of attack with less induced drag. |
| Aspect ratio is determined by dividing the wingspan, by the average wing chord. High-aspect ratio wings produce a comparably high amount of lift at low angles of attack with less induced drag. |
| Performance ballast is loaded into the glider to improve high-speed cruise performance. |
| With ballast... the best glide ratio is the same but it occurs at a faster speed. Ballast should be used under stronger thermal conditions for better speed between thermals. |
| A spin can be defined as an aggravated stall that results in the glider descending in a helical, or corkscrew, path. |
| Determine the CG by dividing the total moment by the total weight. |
| Angle of Attack - the angle between the chord line of the wing and the direction of the relative wind. |
| As the angle of attack is increased, the airstream is forced to travel faster because of the greater distance over the upper surface of the wing, creating a greater pressure differential between upper and lower surfaces. At the same time, the airstream is deflected downward at a greater angle, causing an increased opposite reaction. Both the increased pressure differential and the increased opposite reaction increase lift and also drag. |
| Therefore, an airplane can be stalled in any attitude of flight with respect to the horizon, if the angle of attack is increased up to and beyond the critical angle of attack. |
| Parasite drag can be further classified into form drag, skin friction, and interference drag. |
| This single point is the center of lift, sometimes referred to as the center of pressure. The location of the center of pressure relative to the center of gravity is very important from the standpoint of stability. |
| ... the airspeed at which minimum drag occurs is the same airspeed at which the maximum lift-drag ratio (L/D) takes place. |
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| An increase in ...(airspeed) increases lift and drag. Lift is increased because: the increased impact of the relative wind on the wing's lower surface creates a greater amount of air being deflected downward. |
| Lift acts upward and perpendicular to the relative wind and to the wingspan. |
| Bernoulli's Principle states in part that "the internal pressure of a fluid decreases at points where the speed of the fluid increases." In other words, high speed flow is associated with low pressure, and low speed flow with high pressure. |
| Thus both the development of low pressure above the wing and reaction to the force and direction of air as it is deflected from the wing's lower surface contribute to the total lift generated. |
| Negative stability is in fact instability and can be illustrated by a ball on top of an inverted bowl. Even the slightest displacement of the ball will activate greater forces which will cause the ball to continue to move in the direction of the applied force. |
| Static stability means that if the airplane's equilibrium is disturbed, forces will be activated which will initially tend to return the airplane to its original position. |
| Controllability. The capability of an airplane to respond to the pilot's control, especially with regard to flightpath and attitude. |
| The three axes intersect at the center of gravity and each one is perpendicular to the other two. |
| Neutral stability can be illustrated by a ball on a flat plane. If the ball is displaced, it will come to rest at some new, neutral position and show no tendency to return to its original position. |
| Stability is the inherent ability of a body, after its equilibrium is disturbed, to develop forces or moments that tend to return the body to its original position. |
| Three factors that affect lateral stability are: Dihedral; Sweepback; Keel Effect. |
| A rule for determining the speed at which a wing will stall is that the stalling speed increases in proportion to the square root of the load factor. |
| The amount of excess load that can be imposed on the wing depends on how fast the airplane is flying. ...at speeds below design maneuvering speed, the airplane should stall before the load factor can become excessive. At speeds above maneuvering speed, the limit load factor for which the airplane is stressed can be exceeded by abrupt or excessive application of the controls or by strong turbulence. |
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| The plain flap is a portion of the trailing edge of the wing on a hinged pivot...The split flap is a hinged portion of the bottom surface of the wing...The Fowler flap also slides rearward on tracks...The slotted flap lets a portion of the high pressure air beneath the wing travel through a slot. |
| 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. |
| .. an airplane with forward loading is "heavier" and consequently slower than the same airplane with the center of gravity further aft. ..This requires a higher angle of attack of the wing, which results in more drag and, in turn, produces a higher stalling speed. |
| Loading in a tail-heavy condition has a most serious effect upon longitudinal stability, and can reduce the airplane's capability to recover from stalls and spins. Another undesirable characteristic produced from tail-heavy loading is that it produces very light control forces. |
| Loading in a tail-heavy condition has a most serious effect upon longitudinal stability, and can reduce the airplane's capability to recover from stalls and spins. Another undesirable characteristic produced from tail-heavy loading is that it produces very light control forces. |
| Ground effect is a condition of improved performance encountered when the aircraft is operating near the ground. A change occurs in the three-dimensional flow pattern around the airplane because the vertical component of airflow around the wing is restricted by the ground surface. |
| If the nose starts to move before the bank starts, rudder is being applied too soon. If the bank starts before the nose starts turning, or the nose moves in the opposite direction, the rudder is being applied too late. |
| In all ...constant airspeed turns, it is necessary to increase the angle of attack of the wing when rolling into the turn by applying up elevator. This is required because the total lift must be equal to the vertical component of lift plus the horizontal lift component. |
| When applying aileron to bank the airplane, the lowered aileron (on the rising wing) produces a greater drag than the raised aileron (on the lowering wing). This increased drag yaws the airplane toward the rising wing, or opposite the direction of turn. To counteract this adverse yawing moment, rudder pressure must be applied simultaneously with aileron in the desired direction of turn. |
| Because the outboard wing is developing more lift, it also has more induced drag. This causes a slight slip during steep turns that must be corrected by use of the rudder. |
| Flight instructors should have their students maneuver the airplane at airspeeds in configurations that will be encountered during takeoffs, climbs, descents, go-around and approaches to landing. Flight should also be practiced at the slowest airspeed at which the airplane is capable of maintaining controlled flight without stalling. |
| A stall occurs when the smooth airflow over the airplane's wing is disrupted, and the lift degenerates rapidly. This is caused when the wing exceeds its critical angle of attack. This can occur at any airspeed, in any attitude. |
| If the airplane is slipping toward the inside of the turn at the time the stall occurs, it tends to roll rapidly toward the outside of the turn as the nose pitches down because the outside wing stalls before the inside wing. If the airplane is skidding toward the outside of the turn, it will have a tendency to roll to the inside of the turn because the inside wing stalls first. If the coordination of the turn at the time of the stall is accurate, the airplane's nose will pitch away from the pilot just as it does in a straight flight stall, since both wings will stall simultaneously. |
| The objective of a cross-control stall demonstration maneuver is to show the effect of improper control technique and to emphasize the importance of using coordinated control pressures whenever making turns. |
| The rising wing has a decreasing angle of attack, where the relative lift increases and the drag decreases. In effect, this wing is less stalled. Meanwhile, the descending wing has an increasing angle of attack, past the wing's critical angle of attack (stall) where relative lift decreases and drag increases. |
| Since the downward deflected aileron produces more lift, it also produces more drag. This added drag attempts to yaw the airplane's nose in the direction of the raised wing. This is called adverse yaw. |
| To determine the loaded weight and CG: 1- List weight of airplane, occupants, etc. 2- Enter moment for each item (weight x arm = moment). 3- Total weights and moments. 4- To determine the CG, divide the total moment by the total weight. |
| If the weight of any object or component is multiplied by the distance from the datum (arm), the product is the moment. ...Any combination of weight and distance which, when multiplied, produces (the required moment) will balance the board. |
| If the weight of any object or component is multiplied by the distance from the datum (arm), the product is the moment. ...Any combination of weight and distance which, when multiplied, produces (the required moment) will balance the board. |
| If the weight of any object or component is multiplied by the distance from the datum (arm), the product is the moment. ...Any combination of weight and distance which, when multiplied, produces (the required moment) will balance the board. |
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