Airspeed Indicator

Question 1

What pressure does an ASI need to work?

Answer 1

Pt - Ps = Q (dynamic pressure)

Question 2

When is an ASI accurate?

Answer 2

Only at incompressible speeds (below mach 0.3)

above this we must apply compressibility correction = EAS (equivalent air speed)

Question 3

Vne

Answer 3

Never Exceed Speed

Question 4

Vno

Answer 4

Max Normal operating speed

Question 5

Vfe

Answer 5

Max speed with full flaps extended

Question 6

Vso

Answer 6

Stalling speed in landing config.

Question 7

Vs1

Answer 7

Stalling speed at specified config.

Question 8

Vyse

Answer 8

Best rate of climb - single engine out

Question 9

Vmc

Answer 9

minimum control speed - single engine, take off config..

Question 10

what is IAS?

Answer 10

Indicated Air Speed - the raw read out from the instrument. No corrections. Assumes ISA conditions

Question 11

What is CAS? What does it do?

Answer 11

Calibrated Air Speed - applies instrument/static/position error to IAS.

EAS correction often bunched in with CAS

Question 12

What is EAS? What does it do?

Answer 12

Equivalent Air Speed - compressibilitiy factor applied for speeds over M 0.3.

EAS = IAS at MSL due to incompressiblity.

Question 13

What is TAS? What does it do?

Answer 13

True Air Speed = true aircraft speed in relation to outsie air mass.

culmination of instrument, compressibility and finally DENSITY correction to reflect the true outside conditions.

IAS will only be accurate when density = ISA MSL value of 1225kg/m3

Therefore we must correct for ISA variations in real world conditions.

density drop as we gain altitude = higher TAS

Question 14

What is Mach speed?

Answer 14

Our aircraft speed (TAS) as a proportion of the local speed of sound (flucutates with temp).

for subsonic flight this is below 1, eg: 0.82.

Question 15

Ground speed?

Answer 15

Takes TAS and applies wind component.