Instruments

Question 1

What is Brass?

Answer 1

an alloy of copper and zinc

Question 2

What is steel?

Answer 2

an alloy of iron and carbon

Question 3

What is a Wheatstone bridge?

Answer 3

The measuring of electrical resistance to measure temperature, as electrical resistance changes with temperature of a resistor exposed to the outside air.

Question 4

What is a TAT probe made of?

Answer 4

Nickel-plated beryllium copper with a platinum wire resistance sensor inside

Question 5

What 3 air temp errors exist?

Answer 5

Instrument error

Environmental error (solar heating (use shading), icing)

Heating error - friction

Question 6

What total air temp prob does the 737 have?

Answer 6

Aspirated - generates airflow from bleed air to pull in outside air when stationary.

Question 7

What are the 2 basic types of air temp thermometer?

Answer 7

Direct reading

Remote reading

Question 8

What is static air temperature?

Answer 8

Temp of undisturbed air

Question 9

TAT =

and

RAT =

Answer 9

TAT = SAT + RAM RISE

RAT = SAT + MEASURED RAM RISE

Question 10

What is TAT?

Answer 10

Max temp of air when brought to a stop, inc heating

Question 11

What is ram rise?

Answer 11

Difference between air temp and temp due to heating

Or put another way: difference between SAT and TAT

Question 12

What is measured ram rise?

Answer 12

Unable to measure exact due to inefficiencies - less that total ram rise

Question 13

What does RAT stand for?

Answer 13

Ram Air Temperature - similar to TAT but less due to inefficiencies

Question 14

What is the recovery factor Kr?

Answer 14

Ratio of measured ram rise to total ram rise.

Question 15

Measured ram rise formula =

Answer 15

Ram rise x Kr

Question 16

SAT formula =

Answer 16

RAT/ 1+(0.2 x Kr x M^2)

In Kelvin

Question 17

TAT read out on 737 is really what?

Answer 17

RAT - because cannot get entirely accurate

Question 18

What can SAT sometimes be called?

Answer 18

OAT or COAT (Corrected Outside Air Temp)

Question 19

What is RAT sometimes called?

Answer 19

IOAT (Indicated Outside Air Temp)

Question 20

RAT can be converted to SAT by which 4 methods?

Answer 20

Navigation computer
Accurate formula
Tables
Air Data Computer

Question 21

What is the rapid formula to work out ram rise in the air?

Answer 21

(TAS/100)^2

Question 22

What is absolute zero in deg C?

Answer 22

-273

Question 23

What is 0 deg C in Fahrenheit?

Answer 23

32 deg F

Question 24

PITOT PRESSURE =

Answer 24

DYNAMIC + STATIC

Question 25

What instruments use only static pressure?

Answer 25

Altimeter | VSI

Question 26

Which instruments use static and pitot pressure?

Answer 26

ASI | Machmeter

Question 27

What is position error?

Answer 27

Location on aircraft will affect air. Suction will reduce static pressure. Pitot affected too. How much depends on location, speed, turb, aoa etc

Question 28

Position error is greatest when?

Answer 28

High aoa and low speed

Question 29

What is manoeuvre Induced Error?

Answer 29

Temporary fluctuations of air pressure at the static vents mostly due to change in aoa, flaps/slats activation.

Question 30

Pressure instruments can lag and may not be instant due to...?

Answer 30

Manoeuvre Induced Error | Higher Alt = the longer the Error will last

Question 31

What is CAS or RAS corrected for?

Answer 31

Position error and Instrument error

Question 32

What is VFE?

Answer 32

Max flap operating speed

Question 33

What is VS0?

Answer 33

Flaps down stall speed also with undercarriage down.

Question 34

What is VLO?

Answer 34

Max landing gear operation speed

Question 35

What is VLE?

Answer 35

Max speed with landing gear extended

Question 36

With a blocked static vent the ASI will: In a descent...? In a climb...?

Answer 36

Descent = over-read Climb = under-read

Question 37

With a blocked pitot tube, the ASI will: In descent...? In climb...?

Answer 37

Descent = under-read Climb = over-read

Question 38

If there is a leak in the pitot tube what will happen to the ASI?

Answer 38

Reduce pitot pressure so ASI will under-read

Question 39

What is ISA at MSL? Pressure = Temp = Density=

Answer 39

``` Pressure = 1013.25 hPa Temp = 15 deg C Density= 1225 g/m^3 ```

Question 40

From MSL up to 36,090 (11km) temp reduces by...?

Answer 40

1.98 deg C/1000ft

Question 41

From what Alt is temp a constant -56.5 deg C?

Answer 41

36,090 ft up to 65,617 ft (20km)

Question 42

How many feet per hPa at ISA MSL?

Answer 42

27 ft

Question 43

Density Alt formula =

Answer 43

Density Alt = Pressure Alt + (ISA Deviation x 120)