Chapter 5.8 - In-Flight Performance

Question 1

What does CL stand for?

Answer 1

Climb.

Question 2

What does CZ stand for?

Answer 2

Cruise.

Question 3

What does DES stand for?

Answer 3

Descent.

Question 4

What’s the main purpose of In-flight Performance?

Answer 4

Finding the optimum Height, Speed and Power Setting to obtain the fastest cruise using the least amount of Fuel.

Question 5

Define Range in In-flight Performance?

Answer 5

Distance without refuelling with Fuel Reserves intact.

Question 6

What does SR stand for?

Answer 6

Specific Range.

Question 7

Define SR?

Answer 7

Distance per Fuel Unit/Fuel Unit per Distance.

Question 8

What does SGR stand for?

Answer 8

Specific Ground Range.

Question 9

Define SGR?

Answer 9

Distance is measured relative to the ground.

Question 10

What does SAR stand for?

Answer 10

Specific Air Range.

Question 11

Define SAR?

Answer 11

Distance is measured relative to the air.

Question 12

Name two distance units used for In-flight Performance and their abbreviations (2)?

Answer 12

• Air Nautical Miles (ANM).

- Ground Nautical Miles (GNM).

Question 13

Name four fuel units used in In-flight Performance and their abbreviations?

Answer 13

• US Gallons (Gal).
• Litres (L).
• Pounds (lb).
• Kilograms (kg).

Question 14

Specific Air Range is found from using which speed?

Answer 14

True Airspeed (TAS).

Question 15

What is the calculation for SAR and SGR?

Answer 15

Groundspeed/True Airspeed divided by Fuel Flow.

Question 16

Name four main factors which affect In-flight Performance?

Answer 16

• Airspeed.
• Fuel Consumption.
• Wind.
• Weight.

Question 17

True or False. Increase in Density Height will increase True Airspeed?

Answer 17

True.

Question 18

What Engine Control Settings are selected to optimise Fuel Consumption, with regards to Carburettor Heat and Mixture Control?

Answer 18

• Carburettor Heat OFF.

- Mixture Control LEAN.

Question 19

How does Headwind affect Specific Range?

Answer 19

Decreases.

Question 20

How does Tailwind affect Specific Range?

Answer 20

Increases.

Question 21

How can Weight affect Specific Range?

Answer 21

Decreasing Weight increases Specific Range.

Question 22

Name four factors which affect the Specific Fuel Consumption?

Answer 22

• Engine Speed (RPM).
• Manifold Pressure.
• Fuel/Air Mixture.
• Density Height.

Question 23

The best Specific Range is achieved when the Aircraft is flown at an Airspeed corresponding to what?

Answer 23

Minimum Ratio of Specific Fuel Consumption.

Question 24

True or False. The most important factor in obtaining Minimum Specific Fuel Consumption is achieved by having the leanest possible mixture with regards to engine smoothness and density height considerations?

Answer 24

True.

Question 25

When fuel unit per NM is found, what is the calculation for FBO?

Answer 25

FBO = Distance multiplied by SR.

Question 26

When NM per unit of fuel is found, what is the calculation for FBO?

Answer 26

FBO = Distance divided by SR.

Question 27

When Gross Weight is increased, the speed for Maximum Lift/Drag Ratio must be (increased/decreased)?

Answer 27

Increased.

Question 28

If the Wind Component is greater than 25% of the True Airspeed, what percentage of increase and decrease should the Airspeed be applied to Headwind and Tailwind conditions to obtain best Specific Ground Range (2)?

Answer 28

- Increase of 15% in Headwind conditions. | - Decrease of 5% in Tailwind conditions.

Question 29

For Light Training Aircraft, In-flight Performance is optimum at which settings for Cruise Power, Configuration, Mixture and Carburettor (4)?

Answer 29

- Cruise Power = Standard. - Configuration = Clean. - Mixture = Lean. - Carburettor = Off.

Question 30

Which is more important in determining Specific Ground Range (Groundspeed and Pressure Height/Temperature and Weight)?

Answer 30

Groundspeed and Pressure Height.

Question 31

What does Maximum Endurance mean?

Answer 31

Flying for as long as possible for a given amount of fuel.

Question 32

How does a Pilot achieve Minimum Fuel Flow?

Answer 32

By flying low as possible at an Airspeed for Best Glide.

Question 33

Name four calculations which can be found when using Climb Charts?

Answer 33

- Rate of Climb. - Time of Climb. - Fuel Consumption on Climb. - Climb Distance.

Question 34

True or False. The Cessna doesn’t have a Descent Chart?

Answer 34

False. It is assumed the cruise will always be to overhead of destination.