Pre-Flight Planning: Airspeed

Question 1

The airspeed indicator receives indication from what aircraft system?

Answer 1

Pitot-static system

Question 2

What is dynamic pressure?

Answer 2

Pressure experienced by a body moving through the air or a stationary body experiencing a moving air mass

Question 3

What is the pressure experienced by a body moving through the air or a stationary body experiencing a moving air mass

Answer 3

Dynamic pressure

Question 4

What pressure is experienced constantly and is a result of the weight of the atmosphere?

Answer 4

Static pressure

Question 5

Static pressure is the result of the…

Answer 5

Weight of the atmosphere

Question 6

Total Pressure formula

Answer 6

Total Pressure = Static Pressure + Dynamic Pressure

Question 7

Static pressure is independent of..

Answer 7

Speed

Question 8

Why is the dynamic pressure less at a higher altitude?

Answer 8

Air is less dense at higher altitudes
Reduced dynamic pressure

Question 9

Dynamic Pressure formula

Answer 9

1/2 x Air Density x True Airspeed ^2

Question 10

How does an airspeed diaphragm respond to changes in dynamic pressure alone?

Answer 10

Static pressure is both inside and outside the diaphragm
Diaphragm contracts and expands in changes to dynamic pressure

Question 11

Air density is often represented by what symbol?

Answer 11

Rho (p)

Question 12

What happens to the TAS of an aircraft climbing at a constant IAS?

Answer 12

It must increase

Question 13

What happens to dynamic pressure for an aicraft climbing at a constant IAS?

Answer 13

Dynamic pressure remains constant

Question 14

Constant TAS for a climbing aircraft means its IAS is what?

Answer 14

Decreasing

Question 15

Two reasons for differences in reading between CAS/RAS and IAS?

Answer 15

Instrument error (inherent defects)
Position error (pitot tube usually not aligned with incident airflow)

Question 16

What factors affect density of air?

Answer 16

Pressure altitude and air temperature variations

Question 17

Calculation of a true airspeed on flight computer (process)

Answer 17

Calculate pressure altitude using QNH and planned/desired altitude
Use the pressure altitude, OAT and IAS to calculate the TAS

Question 18

How is pressure altitude usually calculated

Answer 18

Find difference between QNH and 1013
If QNH < 1013, pressure altitude is higher
If QNH > 1013, pressure altitude is lower