Airspeed Indicator

Question 1

Airspeed Indicator

Answer 1

Displays airspeed information

• Connected to both pitot tube and static port
• Measures the difference between total pressure and static pressure

Total Pressure - Static Pressure = Dynamic Pressure

Question 2

Parts of an Airspeed indicator

Answer 2

Needle
Numbering
-Knots or MPH
Color Coding

Question 3

Airspeed Indicator Color Coding

Answer 3

WHITE ARC: Normal Flaps Operating Range

GREEN ARC: Normal Operating Range:

YELLOW ARC: Caution operating Range

RED LINE: Never Exceed Speed

Question 4

Types of Airspeed

Answer 4

Airspeed Indicator Reading (ASIR) – airspeed READ by the INSTRUMENT

Indicated Airspeed (IAS) – ASIR corrected for INSTRUMENT ERRORS

Calibrated Airspeed (CAS) – IAS corrected for POSITION ERROR

Equivalent Airspeed (EAS) – CAS corrected for COMPRESSIBILITY ERROR

True Airspeed (TAS) – EAS corrected for NON-STANDARD TEMPERATURE

Ground Speed (GS) – TAS corrected for WIND

Question 5

Airspeed Indicator Errors

Answer 5

Instrument Error – manufacturing imperfections and wear due to usage

Pressure/Position Error – inherent airflow disturbances on the probes

Maneuver-induced Error – momentary airflow fluctuations on the probes due to maneuvers

Density Error – variations of air density in the atmosphere

Pitot Static System Blockages & Leak

Question 6

Pitot-Head Blockage

Answer 6

Airspeed will decrease to zero

Question 7

Pitot Head and Drain hole blockage

Answer 7

TOFU

Pitot tube
Overread - Climbing
Freeze - Cruise
Underread - Descending

Question 8

Static Port blockage

Answer 8

PUNO

Static Port
Underread - Climbing
Normal - Cruise
Overread - Descending

Question 9

Static Port, Pitot Head, and Drain hole Blockage

Answer 9

All phases freeze

Question 10

Pitot tube and static port leakage

Answer 10

Pitot tube - underread
Static port -
Low pressure - overread
high pressure- underread