Sensors and Instruments 2

Question 1

The disadvantages of a single-phase A.C. generator tachometer are:
1- the presence of spurious signals due to a D.C. generator commutator
2- the importance of line resistance on the information value
3- the influence of temperature on the tachometer information
The combination regrouping all the correct statements is:

Answer 1

2.

Question 2

The altimeter is supplied with:

Answer 2

static pressure.

Question 3

Torque can be determined by measuring the:

Answer 3

change in phase between the torque shaft and the reference shaft.

Question 4

The engine instrument utilising an aneroid pressure diaphragm is the:

Answer 4

manifold pressure gauge.

Question 5

A thermocouple type temperature sensor is composed of:

Answer 5

two dissimilar metals joined together at one end (called hot junction or measure junction).

Question 6

During an acceleration phase at constant attitude, the control system of the artificial horizon results in the horizon bar indicating a:

Answer 6

nose-up attitude

Question 7

To permit turbine exit temperatures to be measured, gas turbines are equipped with thermometers which work on the following principle:

Answer 7

thermocouple

Question 8

Concerning the direct reading magnetic compass, the turning error:

Answer 8

increases with the magnetic latitude.

Question 9

During deceleration following a landing in a southerly direction, a magnetic compass made for the northern hemisphere indicates:

Answer 9

no apparent turn.

Question 10

Total Air Temperature (TAT) is:

Answer 10

higher or equal to Static Air Temperature (SAT) depending on Mach number and SAT

Question 11

An aircraft takes-off on a runway with an alignment of 045°; the compass is made for the northern hemisphere. During rolling take-off, the compass indicates:

Answer 11

a value below 045°.

Question 12

Below the tropopause in standard conditions, when climbing at a constant Mach number:

Answer 12

TAS decreases.

Question 13

Below the tropopause in standard conditions, when descending at a constant Mach number:

Answer 13

TAS increases.

Question 14

CAS is obtained from IAS by correcting for the:

Answer 14

position and instrument errors.

Question 15

During a deceleration phase at constant attitude, the control system of an air driven artificial horizon results in the horizon bar indicating a:

Answer 15

nose down attitude.

Question 16

During deceleration following a landing in a westerly direction, a magnetic compass made for the northern hemisphere indicates:

Answer 16

an apparent turn to the south.

Question 17

During deceleration following a landing in an easterly direction, a magnetic compass made for the northern hemisphere indicates:

Answer 17

an apparent turn to the south.

Question 18

The EAS is obtained from CAS by correcting for the following errors: 1 - position 2 - compressibility 3 - instrument 4 - density The combination regrouping all the correct statements is:

Answer 18

2.

Question 19

The EAS is obtained from CAS by correcting for:

Answer 19

compressibility error.

Question 20

The EAS is obtained from IAS by correcting for the following errors: 1 - instrument 2 - position 3 - density 4 - compressibility The combination regrouping all the correct statements is:

Answer 20

1, 2, 4.

Question 21

During a climb at a constant CAS below the tropopause in standard conditions:

Answer 21

TAS and Mach number increase.

Question 22

Maintaining CAS and flight level constant, a fall in ambient temperature results in:

Answer 22

lower TAS because air density increases.

Question 23

Parallax error is:

Answer 23

a reading error.

Question 24

The mode selector of an inertial unit comprises the OFF - STBY - ALIGN - NAV - ATT positions: 1 - on “STBY”, the unit aligns on the local geographic trihedron; 2 - the “ATT” position is used in automatic landing (mode LAND); 3 - on “NAV” the coordinates of the start position can be entered; 4 - the platform is levelled before azimuth alignment; 5 - in cruise, the unit can only be used in “NAV” mode. The combination regrouping all the correct statements is:

Answer 24

4.

Question 25

The range of a low altitude radio altimeter is:

Answer 25

2 500 ft.

Question 26

The TAS is equal to the EAS only if:

Answer 26

P = 1013,25 hPa and OAT = 15°C.

Question 27

True Air Speed (TAS) is obtained from Calibrated Air Speed (CAS) by correcting for the following errors: 1 - instrument 2 - compressibility 3 - position 4 - density The combination regrouping all the correct statements is:

Answer 27

2, 4.

Question 28

When climbing at a constant CAS in a standard atmosphere:

Answer 28

TAS increases.

Question 29

When descending at a constant CAS in a standard atmosphere: 1 - TAS increases 2 - TAS decreases 3 - Mach number increases 4 - Mach number decreases The combination regrouping all the correct statements is:

Answer 29

2, 4.

Question 30

When descending at a constant CAS:

Answer 30

Mach number decreases.

Question 31

Which of the following statements are correct for an aeroplane cruising at FL 60 with a true airspeed (TAS) of 100 kt in standard atmospheric conditions? 1 - The TAS is approximately 10% higher than the IAS. 2 - The difference between the equivalent airspeed (EAS) and the calibrated airspeed (CAS) is negligible. 3 - The speed displayed on the airspeed indicator is a calibrated airspeed (CAS) if the position error and instrument error are zero.

Answer 31

1, 2 and 3 are all correct.

Question 32

During a descent at a constant CAS below the tropopause in standard conditions:

Answer 32

Mach number and TAS decrease.

Question 33

Magnetic compass errors are:

Answer 33

about north change, depending on the bank angle and magnetic heading.

Question 34

The basic principle of a capacitance fuel gauge system is that the:

Answer 34

capacity of a capacitor depends on the nature of the dielectric in which it is immersed.

Question 35

The most common system used to monitor turbine gas exhaust temperature is the:

Answer 35

hot and cold junction, alumel/chromel system.

Question 36

The Mach Number is proportional to the ratio: NB: “a” indicates the local speed of sound.

Answer 36

TAS/a

Question 37

For an aircraft flying a true track of 360° between the 5°S and 5°N parallels, the precession error of the directional gyro due to apparent drift is equal to:

Answer 37

approximately 0°/hour

Question 38

Equivalent Air Speed (EAS) is:

Answer 38

Calibrated Air Speed (CAS) corrected for compressibility error.

Question 39

Electrical requirements for an alumel/chromel indicating system are

Answer 39

power for gauge lighting only.

Question 40

During a descent at a constant calibrated airspeed (CAS) below the tropopause in ISA conditions:

Answer 40

Mach number and TAS decrease.