Flight Instruments

Question 0

How does the altimeter work?

Answer 0

Android wafers expand & contract as atmospheric pressure changes.
Shaft & gear linkage rotate the pointers on the dial of altimeter.

Question 1

What instruments operate from Pitot/static system?

Answer 1

Altimeter

Vertical Speed Indicator

Airspeed Indicator

Question 2

What limitations does a pressure altimeter have?

Answer 2

Temperature variations: expand/contract atmosphere and raises/lowers pressure levels.

Changes in surface pressure also affect pressure levels at altitude

Question 3

Rule of thumb for limitations of a pressure altimeter:

Answer 3

Hi to low or hot to cold look out below!

Question 4

For IFR flight, what is the maximum allowable error for an altimeter?

Answer 4

75 feet off field elevation

anything more considered unreliable

Question 5

Define indicated altitude:

Answer 5

Read off the face of the altimeter

Question 6

Define pressure altitude:

Answer 6

Indicated altitude with 29.92” Hg set in Kollsman window.

Question 7

Define true altitude:

Answer 7

Height above sea level

Question 8

Define absolute altitude:

Answer 8

Height above ground.

Subtract the terrain elevation from true altitude.

Question 9

Define density altitude:

Answer 9

Pressure altitude corrected for nonstandard temperature

Question 10

How does airspeed indicator work?

Answer 10

It measures the difference between RAM pressure from the Pitot and atmospheric pressure from the static source

Question 11

What limitations does an airspeed indicator have?

Answer 11

It must have proper flow of air through the pitot/static system

Question 12

What errors does an airspeed indicator have?

Answer 12

Position error: slip stream flow
Density error: changes in altitude and temperature not compensated for by the instrument
Compressibility error: packing the air into pitot tube at high airspeed

Question 13

Define indicated airspeed:

Answer 13

Speed read off the airspeed indicator

Question 14

Defined calibrated airspeed:

Answer 14

Airspeed after corrected for position, installation and instrument errors

Question 15

Defined equivalent airspeed:

Answer 15

Airspeed corrected for position, instrument error and for adiabatic compressible flow

Question 16

Defined true airspeed:

Answer 16

Speed in relation to air mass in which it is flying

Question 17

Function airspeed indicator: white Arc

Answer 17

Flat operating range

Question 18

Function airspeed indicator: bottom of white arc

Answer 18

Flaps down stall speed

Question 19

Function airspeed indicator: top of white arc

Answer 19

Maximum airspeed for flaps down flight

Question 20

Function airspeed indicator: green arc

Answer 20

Normal operating range

Question 21

Function airspeed indicator: bottom of green arc

Answer 21

Flaps up stall speed

Question 22

Function airspeed indicator: top of green arc

Answer 22

Maximum airspeed for rough air

Question 23

Function airspeed indicator: yellow arc

Answer 23

Structural warning area

Question 24

Function airspeed indicator: bottom of yellow arc

Answer 24

Maximum airspeed for rough air

Question 25

Function airspeed indicator: top of yellow arc

Answer 25

Never exceed airspeed

Question 26

Function airspeed indicator: red radial line

Answer 26

Never exceed airspeed

Question 27

How does the vertical speed indicator work?

Answer 27

Change of pressure expands/contract a diaphragm.

It is connected to the indicating needle through gears and levers.

VSI is connected to a static pressure line through a calibrated leak.

Question 28

What are the limitations of the vertical speed indicator?

Answer 28

Not accurate until stabilized.

Sudden or abrupt changes will cause Arronia’s instrument readings.

Not reflected immediately due to calibrated leak.

Question 29

Is Pitot ram air inlet & drain hole freezes, what instruments are affected?

Answer 29

Only airspeed indicator.

Acts like the altimeter.

Question 30

What instruments are affected if static port freezes?

Answer 30

Airspeed indicator: descent will read high, climb will read low. (Very dangerous)
Altimeter: will indicate sustained altitude
Vertical speed: will indicate level flight

Question 31

What is the corrective action if the Pitot tube freezes?

Answer 31

Turn pitot heat on

Question 32

What is the corrective action if the static port freezes?

Answer 32

Use alternate air if available

or break the face of the static instrument

Question 33

When using alternate air, altimeter will indicate:

Answer 33

Higher than actual altitude

Question 34

When using alternate air, airspeed will indicate:

Answer 34

Greater than actual airspeed

Question 35

When using alternate air, vertical speed will indicate:

Answer 35

A climb while in level flight