C02 - Air, Atmosphere and Airspeed

Question 1

Define Fluid?

Answer 1

Is a liquid or gas that has an ability to flow.

Question 2

What happens to Air Pressure, Temperature and Humidity if Air Density decreases (3)?

Answer 2

• Air Pressure decreases.
• Temperature increases.
• Humidity increases.

Question 3

Define Static Pressure?

Answer 3

A force acting over an area.

Question 4

What is Static Pressure measured in?

Answer 4

Newtons per Square Metre (N/m²).

Question 5

Static Pressure reduces as Altitude ‘____’?

Answer 5

Increases.

Question 6

What is the definition of Temperature?

Answer 6

The measure of heat energy associated with the movement and collision of molecules in a gas, liquid or solid.

Question 7

How does Temperature affect Air Density (2)?

Answer 7

• Higher the Temperature the Density decreases.

- Lower the Temperature the Density increases.

Question 8

Air Density is ‘___’ proportional to the absolute Temperature?

Answer 8

Inversely.

Question 9

What is +20°C in K?

Answer 9

293K (273K + 20K).

Question 10

What is -50°C in K?

Answer 10

223K (273K - 50K).

Question 11

Define Viscosity?

Answer 11

The stickiness of the fluid.

Question 12

True of False. Viscosity over a wing can cause turbulence and disruption in air flow?

Answer 12

True.

Question 13

Define Humidity?

Answer 13

The amount of water vapour in the atmosphere.

Question 14

True or False. Air Density reduces with decreasing Humidity?

Answer 14

False. Increasing with Humidity.

Question 15

What is the MSL Temperature?

Answer 15

+15°C.

Question 16

What is the MSL Pressure (3)?

Answer 16

• 1013.25 hPa.
• 29.92 inHg.
• 760 mmHg.

Question 17

What is the MSL Density?

Answer 17

1.225 kg/m³.

Question 18

What is the Temperature Lapse Rate from the surface to the Tropopause (2)?

Answer 18

• 1.98°C per 1,000ft.

- 0.65°C per 100m.

Question 19

What is the height of the Tropopause?

Answer 19

• 36,000ft.

- 11km.

Question 20

What is the Temperature above the Tropopause?

Answer 20

-56.5°C.

Question 21

Define Temperature Lapse Rate?

Answer 21

The term used to describe the reduction in Temperature with Altitude.

Question 22

An Aircraft can only become airborne, and stay airborne, if it does ‘____’ on the air to produce a force to oppose ‘____’ (2)?

Answer 22

• Work.

- Gravity.

Question 23

What is the formula for Kinetic Energy?

Answer 23

½ mV².

Question 24

Define Dynamic Pressure?

Answer 24

The additional air pressure in a volume of air which relates to its Kinetic Energy.

Question 25

What is the formula of Dynamic Pressure?

Answer 25

½ pV².

Question 26

Dynamic Pressure ‘____’ if the Air Density increases?

Answer 26

Increases.

Question 27

Dynamic Pressure increases rapidly if the True Airspeed ‘____’?

Answer 27

Increases.

Question 28

Define IAS (2)?

Answer 28

• Indicated Airspeed.

- Airspeed found on the Airspeed Indicator.

Question 29

What is Total Air Pressure?

Answer 29

Static Pressure + Dynamic Pressure.

Question 30

How can you calculate Dynamic Pressure?

Answer 30

Total Pressure - Static Pressure.

Question 31

What instrument is used to measure Total Pressure?

Answer 31

Pitot Tube.

Question 32

Name three types of errors found in basic Airspeed Indicators?

Answer 32

• Instrument Error.
• Pressure Error.
• Compressibility Error.

Question 33

Define Instrument Error on Airspeed Indicators?

Answer 33

Limitations of the manufacturing process.

Question 34

Define Pressure Error on Airspeed Indicators?

Answer 34

The error in the measurement of both Total and Static Pressure due to the position of the Pitot and Static ports.

Question 35

Define Compressibility Error on Airspeed Indicators?

Answer 35

High speed air entering the Pitot Tube which can falsely increase the Density.

Question 36

Define CAS (2)?

Answer 36

• Calibrated Airspeed.

- IAS corrected from its instrument and pressure errors.

Question 37

Define EAS (2)?

Answer 37

• Equivalent Airspeed.

- CAS correct from compressibility error.

Question 38

What is the equation for working out EAS when given a TAS?

Answer 38

EAS = TAS √(Air Density of Aircraft ÷ Air Density at MSL).

Question 39

The EAS provides the most accurate indication of what?

Answer 39

Dynamic Pressure.

Question 40

Define TAS (2)?

Answer 40

• True Airspeed.

- The actual speed of the Aircraft through the air.

Question 41

The TAS can be used to determine the Aircraft’s speed over the ground once it the ‘____’ is taken into account?

Answer 41

Wind Velocity.