NIFE Aerodynamics 2-3-1 Performance Characteristics

Question 1

Define takeoff and landing air speeds in terms of stall speed

Answer 1

Takeoff: 20% above the power-off stall speed
Landing: 30% higher than stall speed

Question 2

Describe the effects on takeoff performance given variations in weight, altitude, temp, and humidity

Answer 2

(Indicated will always stay the same)

• Weight increase > V increases
• Altitude increase > Density decrease > V increases
• Temp increase > Density decrease > V increases
• Humidity increase> density decrease > V increases

Question 3

4-H club

Answer 3

High, hot, heavy, humid AND tailwind

Question 4

Describe the effects on landing performance given variations in weight, altitude, temp, and humidity

Answer 4

• W increase > V increases
• Alt increase > dense decrease > V increase
• Temp increase > dense decrease > V increase

Question 5

Define maximum angle of climb profile (AOC, gamma sign)

Answer 5

Maximum vertical velocity for a minimum horizontal velocity. Getting over an obstacle.

Question 6

Define maximum rate of climb profile (ROC)

Answer 6

Flying at max ROC yields a maximum vertical velocity. Used to expedite a climb to an assigned altitude. Max altitude in min amount of time

Question 7

Define maximum range profile

Answer 7

Max distance traveled over the ground for a given amount of fuel.

Question 8

Define maximum endurance profile

Answer 8

The max amount of time that an airplane can remain airborne on a given amount of fuel.

Question 9

Explain the requirements yielding max range in relation to the power curve

Answer 9

Must minimize fuel flow per unit of velocity. Any straight line drawn from the origin represents a constant ratio of fuel flow to velocity. Max range is found at L/Dmax AOA and velocity. Max range is faster than max endurance.

Question 10

Explain the requirements yielding max endurance in relation to the power curve

Answer 10

Min fuel flow occurs at the bottom of the power curve. Therefore, max endurance is found at a velocity less than L/Dmax, and an AOA greater than L/Dmax AOA for a turboprop

Question 11

Describe the effect of altitude on max range and max endurance performance

Answer 11

An increase in altitude requires a higher throttle setting due to the lower density. Eventually the temp decrease will make the turbines more efficient > less fuel req’d > max endurance performance increases.

Question 12

Define maximum glide range profile

Answer 12

Max distance traveled in a glide (fly at L/Dmax AOA)

Question 13

Define maximum glide endurance profile

Answer 13

Max time airborne in a glide (velocity is less that L/Dmax velocity, and AOA is greater than L/Dmax AOA)

Question 14

Describe the locations of the region of normal command on the power curve

Answer 14

Velocities above maximum endurance. Velocity and throttle settings for level flight are directly related.

Question 15

Describe the locations of the region of reverse command on the power curve

Answer 15

Velocities below maximum endurance. Velocity and throttle setting for level flight are inversely related

Question 16

Explain the relationship between power required and airspeed in the region of normal command

Answer 16

Velocity and throttle settings for level flight are directly related. To fly in equilibrium at a faster speed, more throttle is needed than at a lower airspeed. To fly slower, less throttle is needed.

Question 17

Explain the relationship between power required and airspeed in the region of reverse command

Answer 17

Velocity and throttle setting for level flight are inversely related. The slower a plane flies, the more throttle will be needed to overcome the extra induced drag due to the higher AOA.

Question 18

Aerodynamic braking

Answer 18

Accomplished by increasing the parasite drag on the airplane by holding a constant pitch attitude after touchdown and exposing more of the airplane’s surface to the relative wind. Reduces wear on brakes

Question 19

Mechanical braking

Answer 19

(AKA Frictional/wheel braking) effective only after enough weight is transferred to the wheels and the airplane has slowed sufficiently. Used toward the end of the landing roll.

Question 20

Crosswinds

Answer 20

Rudder is the primary means of maintaining directional control during t/o and landing. Ailerons must also be placed into the wind to prevent it from rolling.

Question 21

Define CG range

Answer 21

The safe zone in which the balance point must fall. The extremities of the range are called the forward and aft CG limits. Expressed in inches, along the longitudinal axis from the plane’s datum

Question 22

m

Answer 22

m

Question 23

m

Answer 23

m