Performance

Question 0

What is the angle of incidence?

Answer 0

The angle formed by the longitudinal axis of the airplane and the chord of the wing. The AOI is fixed and cannot be changed by the pilot

Question 1

What are the four dynamic forces that act on an airplae?

Answer 1

Lift - Upward acting force
Gravity - (Weight), the downward acting force
Thrust - The forward acting force
Drag - The backward acting force

Question 2

What is Relative Wind?

Answer 2

The direction of airflow with respect to the wing. The flightpath and relative wind are always parallel but travel in opposite direction.

Question 3

What is the Angle of Attack?

Answer 3

The angle between the wing chord line and the direction of the relative wind. This can be changed by the pilot.

Question 4

What is “torque effect”?

Answer 4

“Newton’s 3rd law, every action has an equal and opposite reaction”. This means that as the internal engine parts and propeller are revolving in one direction, an equal force is trying to rotate the airplane in the opposite direction. It is greatest at low air speeds with high power settings and a high angle of attack.

Question 5

What effect does torque have on an airplane?

Answer 5

In Flight: Torque reaction is acting around the longitudinal axis, tending to make the plane roll.

On Ground: During takeoff roll, an additional turning moment around the vertical axis is induced. As you takeoff, the left side of the airplane is being forced down and more weight is placed on the left landing gear. This results in more friction/drag on the left tire rather than the right, causing the airplane to turn more to the left.

Question 6

What are the four factors that contribute to torque effect?

Answer 6

1) Torque Reaction of the engine and propeller - “For every

Question 7

What is Centrifugal Force?

Answer 7

Centrifugal force is the “equal and opposite reaction” of the airplane to the change in direction, and it acts “equal and opposite” to the horizontal component of lift

Question 8

What is load factor?

Answer 8

The ratio of the total load supported by the aircraft’s wing to the actual weight of the airplane and it’s contents.

Question 9

Give 2 reasons why load factor is important to pilots?

Answer 9

1) a dangerous overload could cause damage on the aircraft’s structure
2) An increased load factor increases the stalling speed and makes stalls possible at seemingly safe flight speeds

Question 10

What is Maneuvering Speed?

Answer 10

The maximum speed at which abrupt control movement can be applied or at which the airplane could be flown in turbulence without exceeding design load factor limits. The aircraft will stall before the load becomes excessive

Question 11

How does Maneuvering speed change with weight?

Answer 11

Va increases with an increase in weight, and Va decreases with a decrease in weight. Light aircraft are more vulnerable to rapid accelerations, where as a heavier aircraft is less likely to exceed design limit load factors and may be operated at the published Va speed for gross weight.

Question 12

What causes an aircraft to stall?

Answer 12

Excessive angle of attack. Each aircraft has one specific angle of attack where the stall occurs, regardless of airspeed, weight, load factor, or density altitude. This angle is usually between 16 and 20 degrees.

Question 13

What is a spin?

Answer 13

Aggravated stall in either a slip or skid (yaw in a stall). If a stall does not occur, and spin cannot occur.

Question 14

When are spins most likely to occur?

Answer 14

Most likely to occur during…

1) Engine Failure during climb out/takeoff - pilot tries to stretch glide or pilot tries to make a 180 turn to return to the runway
2) Cross-control turn from base to final - pilot overshoots final and makes an uncoordinated turn at a low airspeed
3) Engine Failure on approach to landing - pilot tries to stretch glide to the runway
4) Go-Around with full nose up trim - Pilot applies power with full flaps and nose up trim, with uncoordinated use of rudder
5) Go-Around w/ improper flap retraction - Go around with rapid flap retraction resulting in sink rate and pilot pulls back

Question 15

What causes “Adverse Yaw”?

Answer 15

When turning to the left for example, the right aileron produces lift, which also produces more drag. This drag attempts to pull the aircraft’s nose in the direction of the raised wing

Question 16

What is the “Empty Weight” of an aircraft?

Answer 16

The airframe, engines, and all operating equipment that have fixed locations and are permanently installed in the aircraft. Includes hydraulic fluid, unusable fuel, and un-drainable oil.

Question 17

What is “Gross Weight”?

Answer 17

The maximum allowable weight of both the aircraft and it’s contents

Question 18

What is “Useful Load”?

Answer 18

The weight of the pilot, copilot, passengers, baggage, usable fuel and drainable oil

Question 19

What is the “Center of Gravity”?

Answer 19

The CG is the point about which an aircraft would balance if it were possible to suspend it at that point. CG is expressed in inches from datum

Question 20

What is the “Datum”?

Answer 20

It is an imaginary vertical plane from which all measurements are taken. This is established by the manufacturer

Question 21

What are the “Arm” and “Moment”?

Answer 21

The arm is the distance in inches from the datum to the cg of the item
The moment is the product of the weight of an item multiplied by its’ arm

Question 22

What basic equation can you use to find the CG location?

Answer 22

Weight x Arm = Moment
You can re-arrange this.. ex:
Arm (CG) = Total (moment) / Total (weight)

Question 23

What performance characteristics can you expect from an overloaded aircraft?

Answer 23

Higher takeoff Speed
Longer Takeoff Run
Reduced rate and angle of climb
Lower maximum altitude
Shorter range
Reduced cruising speed
Reduced maneuverability
Higher stalling speed
Higher Landing Speed
Longer Landing Roll
Excessive weight on the nosewheel

Question 24

What effect does a forward CG have on an aircraft?

Answer 24

1) HIgher Stall Speed - Stalling angle of attack is reached at a higher airspeed due to increased wing loading
2) Slower Cruise Speed - Increased drag, greater angle of attack required to maintain altitude
3) More Stable - The CG is farther forward from the center of pressure which increases longitudinal stability
4) Greater Back Elevator Pressure - Longer T/O roll, higher app speed, difficult landing flare

Question 25

What effect does an AFT CG have on an aircraft’s flight characteristics?

Answer 25

Lower Stall Speed - Less Wing Loading
Higher Cruise Speed - Reduced drag, small AOA req. to maintain altitude
Less Stable - Stall and spin recovery are more difficult

Question 26

How does weight affect Takeoff and Landing performance?

Answer 26

1) Higher liftoff Speed
2) Greater mass to accelerate (slower than usual acceleration)
3) Increased retarding force (drag and ground friction)
4) Longer T/O Distance
5) For landing, the aircraft will need to approach at a faster airspeed resulting in a longer landing roll

Question 27

How does an increase in density altitude effect takeoff and landing performance?

Answer 27

1) Increased T/O distance
2) Reduced rate of climb
3) Increased true airspeed on approach and landing, same IAS
4) Increased landing roll distance

Question 28

What is density altitude?

Answer 28

Pressure altitude corrected for nonstandard temperature

Question 29

What factors affect air density?

Answer 29

Altitude - the higher the altitude, the less dense the air
Temperature - the warmer the air, the less dense it is
Humidity - more humid air is less dense

Question 30

What is “pressure altitude” and why is it important?

Answer 30

The altitude above the standard datum plane. It is the altitude indicated on the altimeter with the scale set to 29.92. Pressure altitude is used to calculate density altitude, true altitude, true airspeed, and other performance data.