Vayudoot Aviation

1. An aircraft equipped with an Inertial Navigation System (INS) flies with INS 1 coupled with autopilot 1. Both inertial navigation systems are navigating from waypoint A to B. The inertial systems' Central Display units (CDU) shows. XTK on INS 1 = 0, XTK on INS 2 = 10L (XTK = cross track). What can be deduced from this information?

Both systems are serviceable as this error is within limits

At least one of the inertial navigation systems is drifting

Both systems are drifting

The INS2 is drifting

2. What is the source of magnetic variation information in a Flight Management System (FMS)?

Magnetic variation is calculated by each IRS based on the respective IRS position and the aircraft magnetic heading

The main directional gyro, which is coupled to the magnetic sensor (flux valve) positioned in the wingtip

Magnetic variation information is stored in each IRS memory; it is applied to the true heading calculated by the respective IRS

The FMS calculates MH and MT from the FMC position

3. Gyro - compassing in an INS?

It is not possible in flight because the gyros cannot differentiate between acceleration due to aircraft movement and initial alignment errors.

d. Is possible in flight as he gyros cannot differentiate between acceleration due to aircraft movement and Initial alignment error.

Is not possible in flight as the gyros can differentiate between acceleration due to aircraft movement and Initial alignment errors.

Is possible in flight as the gyros can differentiate between acceleration due to aircraft movement and initial alignment errors.

4. How does the FMS calculate groundspeed?

Input from DME with change of range integrated with respect to time

Input of heading from either the IRS or gyro compass, TAS from ADC and wind velocity from selected metrological data

Input from ADC of TAS and wind velocity

Input from IRS

5. What are the positions(in the order left to right) on the Boeing 737-400 IRS Mode Selector Unit (MSU)?

OFF ALIGN NAV ATT

OFF STBY ATT NAV

OFF STBY NAV ATT

OFF STBY ALIGN NAV

6. How long does it take to align an IRS (Laser Ring Gyros)?

1 minute

5 minutes

10 minutes

15 minutes

7. Gyro drift occurs when the spin axis moves in the?

Horizontal and vertical

Neither, because its definition is not related to these axes

Vertical

Horizontal

8. When initial position is put into a B737-400 FMS, the system?

Rejects initial longitude error, but it will accept latitude error

Cannot detect input errors, and accepts whatever is put in

Rejects initial latitude error, but it will accept longitude error

Rejects initial latitude or longitude error

9.
Which Cyan symbol below represents an off-route waypoint?

B

D

C

A

10. The platform of an inertial navigation system (INS) is maintained at right angles to the local vertical by applying corrections to counter the effects of?

Movement in the yawing plane, secondary precession and pendulous oscillation

Vertical velocities, earth precession, centrifugal forces and transport drift

Gyroscopic Inertia, earth rotation and real drift

Aircraft manoeuvres, earth rotation, transport wander and coriolis

11. The IRS position is updated?

Updating is normally carried out by the crew when position (VOR station or NDB)

During flight IRS position are automatically updated

IRS positions are updated by pressing the 'Take-off at the start of the take-off roll

Only on the ground during the alignment proceudre.

12. An aircraft equipped with an Inertial Navigation System (INS) files with INS 1 coupled with autopilot. Both Inertial navigation systems are navigating from waypoint A to B. The Inertial systems 'Central Display Units (CDU) show? XTK on INS 1 = 0 XTK on INS 2 = 15L (XTK = cross track) What can be deduced from this information?

Only Inertial navigation system No. 2 is drifting

At least one of the Inertial navigation systems is drifting

The autopilot is unserviceable in NAV mode

Only Inertial navigation system No. 1 is drifting

13. The sensors of an INS measure?

Velocity

Position

Acceleration

TAS

14. What are the positions (In the order left to right) on the Boeing 737 - 400 IRS Mode Selector Unit (MSU)?

OFF STBY ATT NAV

OFF STBY NAV ATT

OFF ALIGN NAV ATT

OFF STBY ALIGN NAV

15. As the INS position of the departure aerodrome, coordinates 35°32,7'N 139°46.3'Ware input instead of 35°32.7'N 139°46.3'E. When the aircraft subsequently passes point 52°N 180°W, the longitude value shown on the INS will be?

099° 32.6'W

099° 32.6'E

199° 32.6'W

299° 32.6'W

16. On an aircraft equipped with a triple-fit IRS system, present positions on the CDU?

Wlli only differ if one IRS has been decoupled due to a detected malfunction

Are likely to differ as the information comes from different sources

Will only differ if an initial input error of aircraft position has been made

Will not differ as the information is averaged

17. The INS CDU mode selection required to display Initial Great Circle track is?

DSRTK/STS

TK/GS

HDG/DA

XTK/TKE

18. In what modes is the Weather Radar Display available on EFIS EHSI?

MAP, EXPVOR/ILS, EXP NAV

MAP, PLAN, EXP VOR/ILS

MAP,PLAN, FULL VOR/ILS

MAP, FULLVOR/ILS, FULL NAV

19. What is produced by double Integration of the output from the east/west accelerometer of an inertial navigation system (INS) when it is in the NAV MODE?

Distance east/west

Velocity east/west

Distance north/south

Vehicle longitude

20. In an INS/IRS, an azimuth gyro is found to have a drift rate. If t is the time since selecting the MSU from ALIGN to NAV the szimuth gyro heading error is?

Sinusoidal

Proportional to t

Proportional to the square root of t

Proportional to t/2

21. Some Inertial reference systems are known as 'strapdown'. This means

The system is mounted on a stabilised platform

The system is mounted and fixed to the aircraft structure

The accelerometers are fixed but the gyros are stabilised

The gyros are fixed but the accelerometers are stabilised

22. What is the purpose of the plezo-electric motor in an IRS system?

Shake

Dither

Vibrate

Shudder

23. When can a pilot change the data in the FMS database?

Never, because the FMS database is read-only

Every 28 days

When it is deemed to be necessary

When there is a fruit

24. For how long does the data in the FMS database remain valid?

Variable

One week

56 days

28 days

25. Some Inertial reference systems are known as 'strapdown'

The accelerometers are fixed but the gyros are stable

The gyros are fixed but the accelerometers are stable

The system is mounted and fixed to the aircraft strap

The system is mounted on a stabilised platform

26. In order to maintain an accurate vertical using a pendulous system, an aircraft Inertial platform incorporates a device?

With damping and a period of 84.4 MIN

With damping and a period of 48.4 MIN

With damping and a period of 84.4 SEC.

With damping and a period of 48.4 SEC

27. In the Boeing 737-400 aircraft the FMC aircraft position determined by radio navigation is derived from?

DME/DME

VOR/VOR

DME/ADF

VOR/DME

28. In which IRS mode does gyro-compassing take place?

ATT

ON

NAV

ALIGN

29. In order to maintain an accurate vertical using a pendulous system, an Aircraft inertial platform incorporates a device?

Without damping and a period of 84.4 SEC

With damping and a period of 84.4 MIN

Without damping and a period of 84.4 MIN

With draping and a period of 84.4 SEC

30. Double Integration of the output from the east/west accelerator navigation system(INS) in the NAV MODE given

Vehicle longitude

Distance east/west

Distance north/south

Velocity east/west

31. In a laser reference system(IRS), as compared to a gyro reference system (INS)

Accelerometers and platform are both gyro-stabilised

The platform is strapped down but the accelerometers are gyro-stabilised

Accelerometers and platform are both strapped down

The accelerometers are strapped down but the platform is gyro stabilised

32. Which of the following statements is true of a Ring Laser Gyro?

If doesn't suffer from 'lock in' and is unaffected by the earth's gravitational force

It is not necessarily fixed to true north and is quick to erect

It is fixed to true north and is quick to erect

It is not necessarily fixed to true north but takes along time to erect

33. How much time is required to align an Inertial Reference System?

10 minute

5 minute

15 minutes

1 minute

34. A gyro is said to drift when its spin axis moves in the ?

Horizontal

Horizontal and vertical

Neither, because its definition is not related to these

Vertical

35. An Inertial Navigation System (INS), calculates Ground Speed (GS)?

From TAS and WN from Air Data Computer (ADC)

By integrating measured acceleration

By integrating gyro precession in N/S and E/W directions respectively

From TAS and WN from RNAV data

36. When is the last point at which an INS or IRS may be selected to NAV mode?

On operation of TOGA switch when opening the throttles for the take-off

Immediately prior to push back or taxi from the gate

At the holding point

After passengers and freight are aboard.

37. In what formats can created waypoints be entered into the scratch pad of the B737-400 FMS?

Place Bearing/Distance, Place Bearing/Place Bearing, Along-Track Displacement, Latitude and Longitude

Place, Place Bearing/Distance, Along-Track Displacement, Latitude and Longitude

Place Bearing/Distance, Place Bearing/Place Bearing, Across-Track Displacement, Latitude and Longitude

Place Bearing/Distance, Place Distance/Place Distance, Along-Track Displacement, Latitude and Longitude

38. By what means in an accurate vertical maintained using a pendulous system, an aircraft Inertial platform Incorporates a device?

With damping and a period of 84.4 SEC

With damping and a period of 84.4 MIN

Without damping and a period of 84.4 SEC

Without damping and period of 84.4 MIN

39. List the sequence of pages on start-up of the Boeing 737-400 FMS?

POS, INIT, RTE, IDENT

IDENT, POS INIT, RTE

POS INIT, IDENT, DEPARTURES

IDENT, POS INIT, DEPARTURES

40. What principle is utilized by employing a plezo-electric motor to overcome laser lock in an IRS system?

Shudder

Vibrate

Dither

Shake

41. In what form are positions entered in all INS systems?

Ranges and bearings

Geographic coordinates

Hexadecimals

Waypoint names

42. How does the FMS calculate groundspeed?

Input from ADC of TAS and wind velocity

Input from DME with change of range integrated with respect to time

Input of heading from either the IRS or gyro compass, TAS from ADC and wind velocity from selected metrological data

Input from IRS

43. In which plane must the spin axis move to cause a gyro to drift?

Horizontal

Neither, because its definition is not related to these axes

Vertical

Horizontal and Vertical

44. What is the latest time at which the INS/IRS may be selected to NAV mode?

After passengers and freight are aboard

Immediately prior to push back or taxi from the gate

On operation of the TOGA switch when opening the throttles for the take-off

At the holding point

45.
Which EFIS symbol below represents the selected course?

C

B

A

D

46. Where and when are the IRS positions updated?

During flight IRS positions are automatically updated by the FMC

IRS positions are updated by pressing the 'Take-off/Go-around' button at the start of the take-off roll

Only on the ground during the alignment procedure

Updating is normally carried out by the crew when over-flying a known position (VOR station or NDB)

47. Gyro-compassing in an INS?

Is possible in flight as the gyros can differentiate between acceleration due to aircraft movement and initial alignment errors.

Is not possible in flight as the gyros can differentiate between acceleration due to aircraft movement and initial alignment errors.

It is not possible in flight because the gyros cannot differentiate between acceleration due to aircraft movement and initial alignment errors

It is possible in flight as the gyros cannot differentiate between acceleration due to aircraft movement and initial alignment errors

48. Which of the following lists the first three pages of the FMC/CDU normally used to enter data on initial start-up of the B737-400 Electronic Flight Instrument System?

IDENT - POS INIT - RTE

POS INIT - IDENT - RTE

RTE - POS INT - IDENT

PERF INIT - POD IDENT - INIT

49. What are, in order of highest priority followed by lowest, the two levels of message produced by the CDU of the B737-400 EFIS?

Caution and Advisory

Warning and Advisory

Urgent and Routine

Warning and Caution

50. If an IRS loses its position mid-flight it must?

Have a new position inserted

Be turned OFF

Not be used in NAV mode

Be selected to ALIGN and then to NAV

Question Bank

Questions for INS/IRS/FMS