Chapter1 Air,Atmosphere,Airspeed

Question 1

What is a fluid

Answer 1

A fluid is a liquid or gas that has an ability to flow

Question 2

What is Air

Answer 2

Air is the name for the particular mix of gases in our atmosphere.

Air is a fluid and has all the properties of a fluid.

Question 3

What is Density

Answer 3

The mass of gas per unit volume.

Question 4

Density of air at MSL

Answer 4

1.225kg per m*3

Question 5

Define Mass Flow

Answer 5

Mass flow is the amount of mass of air which flows through a given volume of space.

Question 6

What are the Aerodynamic forces and how are they produced

Answer 6

Forces produced by doing work on the air. Lift,Thrust,Drag,Weight.
Only produced by an aircraft in motion.

Question 7

What affects Air density

Answer 7

Air density will decrease if the air pressure reduces, temperature increase, humidity increases.

Question 8

What is Mass flow dependent on

Answer 8

Depends on density of air. Greater air density faster the flow.
Provided by location/altitude.
Depends also on Speed which is provided by aircraft. Greater the speed greater the mass flow.
Provided by plane.

Question 9

What is static pressure

Answer 9

The Pressure exerted by a fluid(air) on a body when it is at rest. When air comes into a stationary object its puts pressure on it. Pressure is felt equally in all directions.

Question 10

What happens to static pressure with altitude

Answer 10

Decreases as you increase in altitude. less air molecules so less air weighing down.

Question 11

What is Viscosity

Answer 11

Viscosity is the stickiness of a fluid. A fluids resistance to flow. Air is Viscous.

Question 12

What is Humidity

Answer 12

Concentration of water vapour in the air. Increasing Humidity reduces air density as vapour particles mix with air particles.

Question 13

What is Dynamic Air pressure

Answer 13

The pressure exerted onto a body due to it being in motion. Used to measure speed of aircraft in air.

Question 14

Equation for Kinetic Energy

Answer 14

0.5x p(rho) x v*2
P(rho) is the density of the air
V is velocity of air flow

Question 15

Effect of air density on dynamic pressure

Answer 15

If the density of air halves dynamic pressure will halve. If density doubles dynamic pressure doubles.

Question 16

Total Air pressure

Answer 16

Dynamic pressure+ Static pressure

Question 17

Effect of TAS on dynamic pressure

Answer 17

Doubling the TAS produces 4 times the dynamic pressure.

Due to the v*2

Question 18

Four Types of Airspeed

Answer 18

IAS-indicated air speed
CAS-calibrated air speed
EAS-Equivalent air speed
TAS-True air speed

Question 19

What is IAS

Answer 19

Indicated air speed. Shown by an air speed indicator. Calculated by the amount of dynamic pressure exerted into a pitot tube.Increase in IAS results in Increased dynamic pressure.

Question 20

What is CAS

Answer 20

CAS is IAS corrected for instrument error(limitations of the manufacturing process) and positional error(no perfect place to put pitot tube to align perfectly with airflow.)

Question 21

What is EAS

Answer 21

EAS is CAS corrected for compressibility. At high speeds air entering pitot tube becomes compressed which raises its density giving incorrect measurements of pressure

Question 22

What is TAS

Answer 22

True Air Speed.

Actual speed of aircraft relative to the air. Also TAS is EAS corrected for density.

Question 23

What is the relationship between density pressure and temperature

Answer 23

Air density is proportional to pressure but inversely proportional to temperature.