The Airspeed Indicator

Question 1

The ASI is calibrated to what standard?

Answer 1

The international standard atmosphere

Question 2

At what conditions does CAS = TAS?

Answer 2

When the atmosphere is at the ISA conditions

Question 3

When flying faster than TAS 300, compressibility starts to affect the IAS. Does this effect cause the ASI to over-read or under-read?

Answer 3

Over-read

Question 4

CAS corrected for compressibility error = ?

Answer 4

EAS (equivalent airspeed)

Question 5

IAS +/- position and instrument error = ?

Answer 5

CAS

Question 6

CAS +/- density error = ?

Answer 6

TAS (may have compressibility error)

Question 7

CAS - compressibility error = ?

Answer 7

EAS

Question 8

EAS +/- density error = ?

Answer 8

TAS

Question 9

The ASI indicates the last recorded airspeed, the problem is?

Answer 9

The pitot head is blocked, maintaining the last recorded pressure. If there is a leak in the pressure line the airspeed will drop to zero.

Question 10

What will occur of the static source becomes blocked in level flight?

Answer 10

The ASI will indicate normally, assuming no change in static pressure.

Question 11

The mnemonic to remember blockages effects while climbing and descending?

Answer 11

CPO = Climbing - Pitot(blocked) - Over-read

CSU = Climbing - Static(blocked) - Under-read

DPU - Descending - Pitot(blocked) - under-read

DSO - Descending - Static - Over-read

Question 12

What does the lowest point of the white arc represent?

Answer 12

Vso, the stalling speed with full flaps extended.

Question 13

What does the highest point of the white arc represent?

Answer 13

Vfe, maximum speed with flap extended.

Question 14

What does the lowest point of the green arc represent?

Answer 14

Vs1, the stalling speed with flaps up.

Question 15

What does the highest point of the green arc represent?

Answer 15

The maximum normal operating range (Vno)

Question 16

What does the blue line on a multi-engined ASI represent?

Answer 16

Vyse, the best rate of climb with one engine inoperative

Question 17

To compensate for the contraction and expansion of the linkage system due temperature changes, the ASI linkage system includes?

Answer 17

A Bi-metallic strip

Question 18

Manoeuvre induced error is caused by?

Answer 18

Changes of aircraft attitude or when the pitot head is not aligned with the airflow(climb or descent). It is also due to changes of aircraft configuration, flap operation or landing gear being lowered etc. The error is random and no compensation can be made

Question 19

The type of error that is random and also cannot allow for compensation is?

Answer 19

Manoeuvre induced error

Question 20

At TAS 300+ compressibility causes the ASI to?

Answer 20

Overread

Question 21

What If the pitot head becomes blocked in level flight?

Answer 21

The Pitot pressure line and capsule will hold the pressure and the ASI reading will be maintained at the last recorded airspeed regardless of any power and airspeed change.

Question 22

What If the static line becomes blocked in level flight?

Answer 22

The ASI will read correctly assuming no change in static pressure.

Question 23

what if the pitot line from the pitot head to the ASI leaks?

Answer 23

The ASI will underread since the dynamic pressure is too low

Question 24

VS1 is?

Answer 24

The stalling speed with flaps up

Question 25

VSO is?

Answer 25

Stalling speed in the landing configuration

Question 26

Remembering TAS, CAS and IAS:

Answer 26

ICETPCD

(Ice tea preferred cold drink)

=

ICET = IAS, CAS, EAS and TAS:

PCD = Position/instrument error, Compressibility, Density:

IAS + P = CAS

CAS + C = EAS

EAS + D = TAS

Question 27

The indicated Mach number is independent of:

Answer 27

temperature

Question 28

TAS increases:

Answer 28

With altitude and temperature

Question 29

CAS =

Answer 29

rho squared x TAS

Question 30

CAS = TAS at -

Answer 30

ISA temperature, any temperature above ISA the ASI will underread. This is called density error, and is rectified by using TAS.