Ch. 11 Aircraft Performance

Question 1

Standard Atmosphere

Answer 1

15 degrees Celsius (59 degrees Fahrenheit)

29.92 in Hg (1013.2 mb)

Question 2

Standard lapse rate

Answer 2

Temperature decreases at the rate of approximately 3.5 degrees Fahrenheit or 2 degrees Celsius per thousand feet up to 36,000 ft MSL.

Question 3

Above what altitude is temperature considered constant up to 80,000 feet MSL?

Answer 3

36,000 feet MSL.

Question 4

Standard pressure lapse rate

Answer 4

Pressure decreases at a rate of 1”Hg per thousand feet of altitude gain to 10,000 feet.

Question 5

Any temperature or pressure that differs from the standard lapse rate is considered:

Answer 5

Nonstandard temperature and/or pressure.

Question 6

Height above the standard datum plane.

Answer 6

Pressure altitude

Question 7

What is the standard datum plane?

Answer 7

A theoretical level at which the pressure of the atmosphere is 29.92”Hg.

Question 8

What are two reasons pressure altitude is important?

Answer 8

1. Basis for determining aircraft performance

2. Assigning flight levels to aircraft operating at or above 18,000 feet MSL.

Question 9

What are the three ways of calculating the pressure altitude?

Answer 9

1. Setting altimeter to 29.92”Hg and reading output.
2. By applying a correction factor to the indicated altitude according to the reported altimeter setting.
3. Using a flight computer.

Question 10

The altitude in the standard atmosphere corresponding to a particular value of air density.

Answer 10

Density altitude

Question 11

Pressure altitude corrected for nonstandard temperature.

Answer 11

Density altitude

Question 12

As the density of the air increases (lower density altitude), aircraft performance:

Answer 12

Increases.

Question 13

As air density decreases (higher density altitude), aircraft performance:

Answer 13

Decreases.

Question 14

Under standard conditions, pressure altitude and density altitude identify:

Answer 14

The same level.

Question 15

Air density is affected by changes in:

Answer 15

Altitude, temperature, and humidity.

Question 16

How does density of air vary with temperature?

Answer 16

Inversely. As temperature goes up, density goes down and vice versa.

Question 17

How does density of air vary with pressure?

Answer 17

Directly. As pressure increases so does density and vice versa.

Question 18

In the atmosphere, both temperature and pressure decrease with altitude and have conflicting effects upon density. So for us pilots should we expect the density of air to increase or decrease with altitude? Why?

Answer 18

Expect the density to decrease with altitude. The fairly rapid drop in pressure as altitude is increased usually has the dominant effect on density.

Question 19

Refers to the amount of water vapor contained in the atmosphere and is expressed as a percentage of the maximum amount of water vapor the air can hold.

Answer 19

Humidity or relative humidity.

Question 20

The amount of water vapor that air can hold is based upon:

Answer 20

Temperature of the air.

Question 21

The density of air increases or decreases with more humidity?

Answer 21

Decreases.

Question 22

The ability of an aircraft to accomplish certain things that make it useful for certain purposes.

Answer 22

Performance

Question 23

The various items of aircraft performance result from the combo of:

Answer 23

Aircraft and power plant characteristics.

Question 24

The unaccelerated condition of flight is achieved with the aircraft trimmed and powerplant set for:

Answer 24

Lift equal to weight and thrust equal to drag.

Question 25

Thrust is a:

Answer 25

Force

Question 26

Power is a:

Answer 26

Measurement of the rate of performing work or transferring energy. (How much work, how fast)

Question 27

Maximum angle of climb (AOC)

Answer 27

Maximum amount of altitude gain per horizontal distance traveled.

Question 28

Max angle of climb occurs at the airspeed and AOA combination which allows the maximum excess:

Answer 28

Thrust.

Question 29

Maximum rate of climb (ROC)

Answer 29

Maximum gain in altitude over a given period of time.

Question 30

Maximum rate of climb occurs at an airspeed and AOA combination that produces the maximum excess:

Answer 30

Power.

Question 31

As altitude is increased the max ROC, max AOC, maximum and minimum level flight airspeeds converge at what point?

Answer 31

The absolute ceiling of the aircraft.

Question 32

Absolute ceiling

Answer 32

Altitude which produces zero ROC.

Question 33

Service ceiling

Answer 33

Altitude which aircraft is unable to climb at rate greater than 100 fpm.

Question 34

Total weight of aircraft divided by rated horsepower of engine. Expressed in pounds per horsepower.

Answer 34

Power loading

Question 35

Total weight divided by wing area. Expressed as pounds per square foot.

Answer 35

Wing loading.

Question 36

Why is power loading significant?

Answer 36

It is a significant factor in aircraft’s takeoff and climb capabilities.

Question 37

Why is wing loading significant?

Answer 37

Determines landing speed.

Question 38

Nautical miles of flying distance versus the amount of fuel consumed.

Answer 38

Specific range.

Question 39

1/fuel flow

Answer 39

Specific endurance

Question 40

If maximum endurance is required, the flight condition must provide a:

Answer 40

Minimum fuel flow.

Question 41

Best endurance speed happens at what power setting?

Answer 41

Minimum power required.

Question 42

If maximum specific range is desired, the flight condition must provide a:

Answer 42

Maximum of speed per fuel flow.

Question 43

Where does the maximum speed per fuel flow occur in a propeller driven airplane?

Answer 43

At the L/Dmax. Best glide speed.

Question 44

The values of specific range versus speed are affected by three principal variables. What are they?

Answer 44

1. Aircraft gross weight 2. Altitude 3. The external aerodynamic configuration of the aircraft.

Question 45

The control of the optimum airspeed, altitude, and power setting to maintain the 99% max specific range condition.

Answer 45

Cruise control.

Question 46

Total range is dependent on both:

Answer 46

Fuel available and specific range.

Question 47

In a propeller-driven aircraft the fuel flow is determined mainly by:

Answer 47

Shaft power put to the propeller rather than thrust.

Question 48

Region of power curve that while holding a constant altitude, a higher airspeed requires a higher power setting and vice versa.

Answer 48

Region of normal command

Question 49

Region of power curve while holding a constant altitude which a higher airspeed requires a lower power setting and vice versa.

Answer 49

Region of reversed command

Question 50

Where does the airplane get into the region of reversed command?

Answer 50

Below the best endurance speed.

Question 51

The speed at which the lowest brake horsepower sustains level flight.

Answer 51

Best endurance speed.

Question 52

What formula relates our landing distance to the amount of energy our plane has when touching down?

Answer 52

Work energy formula. F*d=0.5*m*V^2

Question 53

The amount of power that is applied to the brakes without skidding the tires is referred to as:

Answer 53

Braking effectiveness

Question 54

A positive runway gradient means the runway is sloping

Answer 54

Upwards

Question 55

A negative runway gradient means the runway is sloping:

Answer 55

Downwards

Question 56

A condition in which the aircraft tires ride on a thin sheet of water rather than on the runway’s surface.

Answer 56

Dynamic hydroplaning.

Question 57

Minimum speed at which hydroplaning begins formula.

Answer 57

9*SQRT(Main gear tire pressure)

Question 58

Increased gross weight can be considered to produce a threefold effect on takeoff performance:

Answer 58

1. Higher lift-off speed 2. Greater mass to accelerate 3. Increased retarding force (drag and ground friction)

Question 59

The effect of a headwind is to allow the aircraft to reach the lift-off speed at a lower:

Answer 59

Groundspeed

Question 60

The effect of a tailwind is to require the aircraft to achieve a greater:

Answer 60

Groundspeed to attain lift-off speed.

Question 61

Does wind effect landing distance in the same way that it affects takeoff distance?

Answer 61

Yes.

Question 62

An increase in density altitude can produce a twofold effect on takeoff performance:

Answer 62

1. Greater takeoff speed | 2. Decreased thrust and reduced net acceleration force

Question 63

Regardless of density altitude the aircraft requires what two conditions to always be the same for takeoff?

Answer 63

1. Dynamic pressure | 2. Lift Coefficient

Question 64

Does the indicated airspeed for takeoff change with altitude?

Answer 64

No. Indicated airspeed remains the same.

Question 65

The minimum landing distance is obtained by landing at:

Answer 65

Some minimum safe speed

Question 66

Landing is accomplished at some particular value of:

Answer 66

Lift coefficient and AOA.

Question 67

The particular lift coefficient and AOA for landing are independent of:

Answer 67

Weight, altitude, and wind.

Question 68

By creating a continuous peak deceleration of the aircraft; that is, extensive use of the brakes for maximum deceleration you can achieve:

Answer 68

Minimum landing distance

Question 69

Considerable excess runway may allow extensive use of aerodynamic drag to minimize wear and tear on the tires and brakes. This results in what kind of landing roll?

Answer 69

Ordinary landing roll

Question 70

The use of aerodynamic drag is applicable only for deceleration to:

Answer 70

60-70% of touchdown speed.

Question 71

At speeds less than 60-70% of touchdown speed, aerodynamic drag is so slight as to be of little use. Therefore, how is deceleration continued?

Answer 71

Brakes.

Question 72

One of the principal items determining the landing distance is:

Answer 72

Gross weight

Question 73

One effect of an increased gross weight is that a greater speed is required to support the aircraft at the landing:

Answer 73

AOA and lift coefficient

Question 74

Landing distance increases approximately by how much for every 1000’ altitude gain?

Answer 74

4% per 1000’ gain

Question 75

Landing distance is proportional to velocity how?

Answer 75

Proportional to the square of velocity. A 10% increase in landing speed increases landing distance by 21%.

Question 76

The most critical conditions of landing performance are combinations of what three things?

Answer 76

1. High gross weight 2. High density altitude 3. Unfavorable wind

Question 77

The speed of the aircraft in relation to the air mass in which it is flying.

Answer 77

True airspeed (TAS)

Question 78

The speed of the aircraft as observed on the ASI. It is the airspeed without correction for indicator, position (or installation) and instrument errors. (Equal to TAS at sea level in standard atmosphere)

Answer 78

Calibrated airspeed

Question 79

The ASI reading corrected for position (or installation), for instrument error, and for a diabetic compressible flow for the particular altitude. Equal to CAS at sea level in standard atmosphere.

Answer 79

Equivalent airspeed (EAS)

Question 80

The calibrated power-off stalling speed or the minimum steady flight speed at which the aircraft is controllable in the landing configuration.

Answer 80

Vso

Question 81

The calibrated power-off stalling speed or the minimum steady flight speed at which the aircraft is controllable in a specified configuration.

Answer 81

Vs1

Question 82

The speed at which the aircraft obtains the maximum increase in altitude per unit time.

Answer 82

Vy

Question 83

The speed at which the aircraft obtains the highest altitude in a given horizontal distance.

Answer 83

Vx

Question 84

The maximum speed at which the aircraft can be safely flown with the landing gear extended. This is a problem involving stability and controllability.

Answer 84

Vle

Question 85

The maximum speed at which the landing gear can be safely extended or retracted. This is a problem involving the air loads imposed on the operation mechanism during extension or retraction of the gear.

Answer 85

Vlo

Question 86

The highest speed permissible with the wing flaps in a prescribed extended position. This is because of the air loads imposed on the structure of the flaps.

Answer 86

Vfe

Question 87

The airspeed below which you can move a single flight control, one time, to its full deflection for one axis of airplane rotation (pitch, roll, yaw) in smooth air without risk of damage to the airplane.

Answer 87

Va

Question 88

The maximum speed for normal operation or the maximum structural cruising speed. This is the speed at which exceeding the limit load factor may cause permanent deformation of the aircraft structure.

Answer 88

Vno

Question 89

The speed that should never be exceeded. If flight is attempted above this speed, structural damage or structural failure may result.

Answer 89

Vne

Question 90

Information the manufacturer provides on their performance charts has been gathered from:

Answer 90

Flight tests conducted in a new aircraft, under normal operating conditions while using average piloting skills, and with the aircraft and engine in good working order.

Question 91

Should you compensate performance numbers if the aircraft or engine isn’t in good working order, or if the pilot flying doesn’t have average skill?

Answer 91

Yes.

Question 92

Taking known information from performance charts and computing intermediate information.

Answer 92

Interpolating

Question 93

When interpolating performance numbers that reflect slightly more adverse conditions provides what two things?

Answer 93

1. A reasonable estimate of performance information. | 2. Slight margin of safety.

Question 94

Charts whose information is based on actual flight tests conducted in an aircraft of the same type.

Answer 94

Climb and cruise charts