Performance and Limitations

Question 1

What are the four dynamic forces that act on an airplane during all maneuvers

Answer 1

Lift - the upward acting force
Gravity - weight, the downward acting force
Thrust - the forward acting force
Drag - The backward acting force

Question 2

What flight conditions will result in the sum of the opposing forces being equal

Answer 2

IN steady-state, straight-and-level, unaccelerated flight, the sum of the opposing forces is equal to zero. There can be no unbalanced forces in steady, straight flight (newton’s 3rd law). This is true whether flying level or when climbing or descending. It does not mean the four forces are equal. It means the opposing forces are equal to, and thereby cancel the effects of each other.

Question 3

What is an airfoil? State some examples

Answer 3

An airfoil is a device which gets a useful reaction from air moving over its surface, namely LIFT. Wings, horizontal tail surface, vertical tail surfaces, and propellers are examples of airfoils

Question 4

What is the angle of incidence

Answer 4

The angle of incidence is the angle formed by the longitudinal axis of the airplane and the chord of the wing. It is measured by the angle at which the wing is attached to the fuselage. The angle of incidence is fixed and cannot be changed by the pilot

Question 5

What is relative wind

Answer 5

The relative wind is the direction of the airflow with respect to the wing. When a wing is moving forward and downward the relative wind moves backward and upward. The flight path and relative wind are always parallel but travel in opposite directions

Question 6

What is the angle of attack

Answer 6

The angle of attack is the angle between the wing chord line and the direction of the relative wind; it can be changed by the pilot

Question 7

What is Bernoulli’s Principle

Answer 7

The pressure of a fluid (liquid or gas) decreases at points where the speed of the fluid increases. In the case of airflow, high speed flow is associated with low pressure and low speed flow with high pressure. The airfoil of an aircraft is designed to increase the velocity of the airflow above its surface, thereby decreasing pressure above the airfoil. Simultaneously, the impact of the air on the lower surface of the airfoil increases the pressure below. This combination of pressure decrease above and increase below produces life

Question 8

What are several factors which will affect both lift and drag

Answer 8

Wing area - lift and drag action on a wing are roughly proportional to the wing area. A pilot can change wing area by using certain types of flaps

Shape of the airfoil - As the upper curvature of an airfoil is increased (up to a certain point) the lift produced increases. Lowering an aileron or flap device can accomplish this. Also, ice or frost on a wing can disturb normal airflow, changing its camber, and disrupting its lifting capability

Angle of attack - As angle of attack increases, both lift and drag are increased, up to a certain point

Velocity of the air - An increase in velocity of air passing over the wing increases lift and drag

Air density - Lift and drag vary directly with the density of the air. As air density increases, lift and drag increase. As air density decreases, lift and drag decrease. Air density is affected by these factors: pressure, temperature, and humidity

Question 9

What is torque effect

Answer 9

Torque effect involves Newton’s third law of physics - for every action, there is an equal and opposite reaction. Applied to the airplane, this means that as the internal engine parts and the propeller are revolving in one direction, an equal force is trying to rotate the airplane in the opposite direction. It is greatest when at low airspeeds with high power settings and a high angle of attack

Question 10

What effect does torque reaction have on an airplane on the ground and in flight

Answer 10

In flight - Torque reaction is acting around the longitudinal axis, tending to make the airplane roll. To compensate, some of the older airplanes are rigged in a manner to create more lift on the wing that is being forced downward. The more modern airplane are designed with the engine offset to counteract this effect of torque.

On the ground - during the takeoff roll, an additional turning moment around the vertical axis is induced by torque reaction. As the left side of the airplane is being forced down by torque reaction, more weight is being placed on the left main landing great. This results in more ground friction, or drag, on the left tire than on the right, causing a further turning moment

Question 11

What are the four factors that contribute to torque effect

Answer 11

Torque reaction of the engine and propeller. For every action there is an equal and opposite reaction. The rotation of the propeller to the right, tends to roll or bank the airplane to the left

Gyroscopic effect of the propeller. Gyroscopic precession applies here: the resultant action or deflection of a spinning object when a force is applied to the outer rim of its rotational mass. If the axis of a propeller is tilted, the resulting force will be exerted 90 degrees ahead in the direction of rotation and in the same direction as the applied force. It is most noticeable on takeoff in taildraggers when the tail is raised

Corkscrewing effect of the propeller slipstream. High-speed rotation of an airplane propeller results in a corkscrewing rotation to the slipstream as it moves rearward. At high propeller speed and low forward speed, as in a takeoff, the slipstream strikes the vertical tail surface on the left side pushing the tail to the right and yawing the airplane to the left

Asymmetrical loading of the propeller (P-factor). When an airplane is flying with a high angle of attack, the bite of the downward moving propeller blade is greater than the bite of the upward moving blade. This is due to the downward moving blade meeting the oncoming relative wind at a greater angle of attack than the upward moving blade. Consequently there is greater thrust on the downward moving blade on the right side, and this forces the airplane to yaw to the left

Question 12

What is centrifugal force

Answer 12

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 13

What is load factor

Answer 13

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. In other words, it is the actual load supported by the wings divided by the total weight of the airplane. It can also be expressed as the ratio of a given load to the pull of gravity. That is to refer to a load factor of three as 3Gs. In this case the weight of the airplane is equal to 1G and if a load of three times the actual weight of the airplane were imposed upon the wing due to curved flight, the load factor would be equal to 3Gs

Question 14

For what two reasons is load factor important to pilots

Answer 14

because of the obviously dangerous overload that it is possible for a pilot to impose on the aircraft structure

Because an increase load factor increases the stalling speed and makes stalls possible at seemingly safe flight speeds

Question 15

What situations may result in load factors reaching the maximum or being exceeded

Answer 15

Level Turns - The load factor increases at a terrific rate after a bank has reached 45 or 50 degrees. The load factor in a 60 degree bank turn is 2G. The load factor in an 80 degree bank turn is 5.7G. The wing must produce lift equal to these load factors if altitude is to be maintained

Turbulence - Severe vertical gusts cause a sudden increase in angle of attack, resulting in large load which are resisted by the inertial of the airplane

Speed - The amount of excess load that can be imposed upon the wing depends on how fast the airplane is flying. At speeds below maneuvering speed, the airplane will stall before the load factor can become excessive. At speeds above maneuvering speed, the limit load factor for which an airplane is stressed can be exceeded by abrupt or excessive application of the controls or by strong turbulence

Question 16

What are the different operational categories for aircraft and within which category does your aircraft fall

Answer 16

Normal - +3.8 to -1.52*
Utility - +4.4 to -1.76
Aerobatic - +6 to -3

Question 17

What effect does an increase in load factor have on stalling speed

Answer 17

As load factor increases, stalling speed increases. Any airplane can be stalled at any airspeed within the limits of its structure and the strength of the pilot. At a given airspeed the load factor increases as angle of attack increases, and the wing stalls because the angel of attack has been increased to a certain angle. Therefore, there is a direct relationship between the load factor imposed upon the wing and its stalling characteristics. 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

Question 18

Define the term maneuvering speed

Answer 18

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. It is the speed below which you can, in smooth air, move a single flight control one time to its full deflection for one axis of airplane rotation only (pitch, roll or yaw) without risking of damage to the airplane. Speeds up to, but not exceeding the maneuvering speed allow an aircraft to stall prior to experiencing an increase in load factor that would exceed the limit load of the aircraft.

Question 19

Discuss the effect on maneuvering speed of an increase or decrease in weight

Answer 19

Maneuvering speed increase with an increase in weight and decreases with a decrease in weight. An aircraft operating at a reduced weight is more vulnerable to rapid accelerations encountered during flight through turbulence or gusts. Design limit load factors could be exceeded if a reduction in maneuvering speed is not accomplished. An aircraft operating at or near gross weight in turbulent air is much less likely to exceed design limit load factors and may be operated at the published maneuvering speed for gross weight if necessary

Question 20

Define LOC-I and describe several situations that might increase the risk of an LOC-I accident occurring

Answer 20

LOC-I is defined as a significant deviation of an aircraft from the intended flight path and it often results from an airplane upset. Maneuvering is the most common phase of flight for LOC-I accident to occur; however, LOC-I accidents occur in all phases of flight. Situations that increase the risk of this include uncoordinated flight, equipment malfunctions, pilot complacency, distraction, turbulence, and poor risk management, such as attempting to fly in IMC when the pilot is not qualified or proficient in it

Question 21

What causes an airplane to stall

Answer 21

The direct cause of every stall is an excessive angle of attack. Each airplane has a particular angle of attack where the airflow separate from the upper surface of the wing and the stall occurs. This critical angle of attack varies from 16 to 20 degrees depending on the airplane’s design, but each airplane has only one specific angle of attack where the stall occurs, regardless of airspeed, weight, load factor, or density altitude

Question 22

What is a spin

Answer 22

A spin in a small airplane or glider is a controlled or uncontrolled maneuver in which the airplane or glider descends in a helical path while flying at an angle of attack greater than the critical angel of attack. Spins result from aggravated stalls in either a slip or skid. If a stall does not occur, a spin cannot occur

Question 23

What causes as spin

Answer 23

The primary cause of an inadvertent spin is exceeding the critical angel of attack while applying excessive or insufficient rudder and to a lesser extent aileron

Question 24

When are spins most likely to occur

Answer 24

A stall/spin situation can occur in any phase of flight but is most likely to occur in the following situations

Engine failure on takeoff during clime out - pilot tries to stretch glide to landing area by increasing back pressure or makes an uncoordinated turn back to departure runway at a relatively low airspeed

Crossed-control turn from base to final - pilot overshoots final and makes uncoordinated turn at a low airspeed

Engine failure on approach to landing - pilot tries to stretch glide to runway by increasing back pressure

Go-around with full nose up trim - pilot applies power with full flaps and nose-up trim combine with uncoordinated use of rudder

Go-around with improper flap retraction - pilot applies power and retracts flaps rapidly resulting in a rapid sink rate followed by an instinctive increase in back pressure

Question 25

What procedure should be used to recover from an inadvertent spin

Answer 25

Close the throttle Neutralize the ailerons Apply full opposite rudder Briskly move the elevator control forward to neutral position Neutralize the rudder when the spin stops Gradually apply enough aft elevator pressure to return to level flight

Question 26

What causes adverse yaw

Answer 26

When turning an airplane to the left for example, the downward deflected aileron on the right produces more lift on the right wing. Since the downward deflected right aileron produces more lift, it also produces more drag, while the opposite left aileron has less lift and less drag. This added drag attempt to pull or veer the airplane's nose in the direction of the raised wing; that is; it tries to turn the airplane in the direction opposite to that desired. This undesired veering is referred to as adverse yaw

Question 27

What is ground effect

Answer 27

Ground effect is a condition of improved performance the airplane experiences when it is operating near the ground. A change occurs in the 3D flow pattern around the airplane. because the airflow around the wing is restricted by the ground surface. This reduces the wing's upwash, downwash, and wingtip vortices. In order for ground effect to be of a significant magnitude, the wing must be quite close to the ground

Question 28

What major problems can be caused by ground effect

Answer 28

During landing at a height of approximately one-tenth of a wing span above the surface, drag may be 40 percent less than when the airplane is operating out of ground effect. Therefore, an excess speed during landing phase may result in a significant float distance. In such cases, if care is not exercised by the pilot, he/she may run out of runway and options at the same time During takeoff due to the reduces drag in ground effect, the aircraft may seem capable of takeoff well below the recommended speed. However, as the airplane rises out of ground effect with a deficiency of speed, the greater induces drag may result in very marginal climb performance, or the inability of the airplane to fly at all. In extreme conditions, such as high temperature, high gross weight, and high-density altitude, the airplane may become airborne initially with a deficiency of speed and then settle back to the runway

Question 29

Define the following: Empty weight, gross weight, useful load, arm, moment, center of gravity, datum

Answer 29

Empty weight - The weight of the airframe, engines, all permanently installed equipment, and unusable fuel. Depending on the FARs under which the aircraft was certificated, either the undrainable oil or full reservoir of oil is included Gross weight - The maximum allowable weight of both the airplane and its contents Useful load - the weight of the pilot, copilot, passengers, baggage, usable fuel and drainable oil Arm - The horizontal distance in inches from the reference datum line to the center of gravity of the item CG - The point about which an aircraft would balance if it were possible to suspend it at that point. Expressed in inches from datum Datum - An imaginary vertical plane or line from which all measurement of are are taken. Established by the manufacturer

Question 30

What basis equation is used in all weight and balance problems to find the CG location of an airplane and/or its components

Answer 30

Weight X Arm = Moment Weight = Moment / Arm Arm (CG) = (Total) Moment / (Total) Weight

Question 31

What performance characteristics will be adversely affected when an aircraft has been overloaded

Answer 31

``` Higher takeoff speed Longer take off roll 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 32

What effect does a forward center of gravity have on an aircraft's flight characteristics

Answer 32

higher stall speed - stalling angle of attack is reached at a higher speed due to increased win loading more stable - center CG is farther forward from the center of pressure which increases longitudinal stability Greater back elevator pressure required - longer takeoff roll; higher approach speeds and problems with landing flare

Question 33

What effect does a rearward center of gravity have on an aircraft's flight characteristics

Answer 33

Lower stall speed - less wing loading Higher cruise speed - reduced drag; smaller angle of attack is required to maintain altitude Less table - stall and spin recovery more difficult; the center of gravity is closer to the center of pressure, causing longitudinal instability

Question 34

What are standard weight assumed for the following when calculating weight and balance problems

Answer 34

Crew and passengers 190lb each Gasoline 6lb/gal Oil 7.5 lb /gal Water 8.35 lb/gal

Question 35

What are some of the main elements of aircraft performance

Answer 35

``` Takeoff and landing distance rate of climb ceiling payload range speed fuel economy maneuverability stability ```

Question 36

What factors affect the performance of an aircraft during takeoffs and landings

Answer 36

``` Air density Surface wind Runway surface Upslope or downslope of runway Weight ```

Question 37

What effect does wind have on aircraft performance

Answer 37

Landing - The effect of win on landing distance is identical to its effect on takeoff distance. A headwind will lower ground speed and increase airplane performance by steepening the approach angle and reducing the landing distance. A tailwind will increase ground speed and decrease performance, by decreasing the approach angle and increasing the landing speed Cruise flight - Winds aloft have somewhat an opposite effect on airplane performance. A headwind will decrease performance by reducing groundspeed, which in turn increase the fuel required for the flight. A tailwind will increase performance by increasing the ground speed, which in turn reduces the fuel requirement for the flight

Question 38

How does weight affect takeoff and landing performance

Answer 38

Increased gross weight can have a significant effect on takeoff performance Higher liftoff speed greater mass to accelerate / slow acceleration Increased retarding force (drag and ground friction) Longer takeoff distance The effect of gross weight on landing distance is that the airplane will require a greater speed to support the airplane at the landing angel of attack and lift coefficient resulting in an increased landing distance

Question 39

What effect does an increase in density altitude have on takeoff an landing performance

Answer 39

An increase in density altitude results in increased takeoff distance reduced rate of climb increased true airspeed on approach and landing increased landing roll distance

Question 40

Define the term density altitude

Answer 40

Density altitude is pressure altitude corrected for nonstandard temperature. Under standard atmospheric condition, air at each level of the atmosphere has a specific density, and under standard conditions, pressure altitude and density altitude identify the same level. Therefore, density altitude is the vertical distance above sea level in the standard atmosphere at which a given density is found

Question 41

How does air density affect aircraft performance

Answer 41

``` The density of the air has a direct effect on lift produced by the wings power output of the engine propeller efficiency drage force ```

Question 42

What factors affect air density

Answer 42

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 43

How does temperature, altitude, and humidity affect density altitude

Answer 43

Density altitude will increase (low air density) when on or more of the following occurs Higher air temp High altitude High humidity Density altitude will decrease (high air density) when one or more of the following occurs low air temp low altitude low humidity

Question 44

Vso

Answer 44

Stall speed in landing configuration

Question 45

Vs1

Answer 45

Stall speed clean configuration

Question 46

Vy

Answer 46

Best rate-of-climb max alt. per unit of time

Question 47

Vx

Answer 47

Best angle-of-climb highest alt. in given horizontal distance

Question 48

Vle

Answer 48

Max landing great extend speed

Question 49

Vlo

Answer 49

Max landing great operating speed

Question 50

Vfe

Answer 50

Max flap extend speed

Question 51

Va

Answer 51

Maneuvering speed

Question 52

Vno

Answer 52

Normal operating speed

Question 53

Vne

Answer 53

Never exceed speed

Question 54

What information can you obtain from the following charts

Answer 54

Takeoff charts - These allow you to compute the takeoff distance of the airplane with no flaps or with a specific flap configuration. You can also compute distance for a no flap takeoff over a 50" obstacle. The takeoff distance chart provides for various airplane weights, altitudes, temp. winds, and obstacle heights Fuel, time, and distance-to-climb chart - This chart will give the fuel amount used during the climb, the time it will take to accomplish the climb, and the ground distance that will be covered during the climb. To use this chart obtain the information for the departing airport and for the cruise altitude Cruise and range performance chart - This is designed to give true airspeed, fuel consumption, endurance in hours, and range in miles at specific cruise configurations Crosswind and headwind component chart - This allows for figuring the headwind and crosswind component for any given wind direction and velocity Landing charts - Provide normal landing distance as well as landing distance over 50" obstacle Stall speed performance charts - These are designed to give an understanding of the speed at which the airplane will stall in a given configuration. Will typically take into account the angle of bank, the position of the gear and flaps and the throttle position

Question 55

Define the term pressure altitude and state why it is important

Answer 55

Pressure altitude - the altitude indicated when the altimeter setting window is adjusted to 29.92. This is the altitude above the standard datum plane, a theoretical plane where air pressure at 15 degrees C equals 29.92' Hg. Pressure altitude is used to compute density altitude, true altitude, true airspeed, and other performance data

Question 56

What is the normal climb-out speed

Answer 56

76kts

Question 57

What is the best rate-of-climb Vy

Answer 57

76

Question 58

What is the best angel of climb Vx

Answer 58

64

Question 59

What is the maximum flap extension speed Vfe

Answer 59

102

Question 60

What is the stall speed in the normal configuration Vso

Answer 60

45

Question 61

What is the stall speed in the clean configuration

Answer 61

50

Question 62

What is the normal approach-to-land speed

Answer 62

66

Question 63

What is maneuvering speed

Answer 63

89-113

Question 64

What is red-line speed

Answer 64

154

Question 65

What engine-out glide speed will give you max rnage

Answer 65

76

Question 66

What is the make and horsepower of the engine

Answer 66

Lycoming 180 BHP

Question 67

How many usable gallons of fuel can you carry

Answer 67

48

Question 68

Where are the fuel tanks located, and what are their capacities

Answer 68

wings 24 US gal each of usable fuel

Question 69

Where are the fuel vents for your aircraft

Answer 69

Fuel vents are on top of the wing

Question 70

What is the octane rating of the fuel used by your aircraft

Answer 70

100LL

Question 71

Where are the fuel sumps located on your aircraft? When should you drain them?

Answer 71

One under each wing tank and 1 behind the firewall in the engine. They should be drained for the first flight of the day and after each refueling

Question 72

What are the minimum and max oil capacities

Answer 72

min 2 max 8 qt

Question 73

What wight of oil is being used

Answer 73

40

Question 74

What is the maximum oil temp and pressure

Answer 74

245F | 115 PSI

Question 75

What are the nose wheel turning limitations

Answer 75

30 degrees

Question 76

What is the x/w comp

Answer 76

17 kt

Question 77

How many people will this aircraft cary safely with a full fuel load

Answer 77

2

Question 78

What is the max weight the A/C can carry with baggage

Answer 78

2550 (2350 with 200lb of bags)

Question 79

Takeoff distance at sea-level

Answer 79

2,000 feet

Question 80

What is your max allowable useful load

Answer 80

860.63

Question 81

How much fuel can be carried

Answer 81

48 gal 300/lb