Vayudoot Aviation

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

Shudder

Vibrate

Shake

Dither

2. How does the FMS calculate groundspeed?

Input from IRS

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

Input from ADC of TAS and wind velocity

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

3. What is the function of the MCDUs in the B737-400Flight Management System when carrying out preflight checks?

Manually initialise the IRSs and FMC with dispatch information

Manually initialise the Flight Director System and FMC with dispatch information

Automatically initialise the IRSs and FMC with dispatch information

Manually initialise the IRSs,FMC and Authorities with dispatch Information

4. The FMC position is?

Computer generated from the IRS and radio navigation positions

The average of the IRS positions

Computer generated from the radio navigation positions

Half way between the IRS and radio navigation positions

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

Be selected to ALIGN and then to NAV

Be turned OFF

Have a new position inserted

Not be used in NAV mode

6. When a triple-fit system is employed, the present positions on the CDU?

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

Will not differ as the information is averaged

Are likely to differ as the information comes from different sources

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

7. Gyro compassing of an Inertial system (IRS) is accomplished with the mode selector switched to?

NAV

STBY

ATT REF

ALIGN

8. From what source does an FMS obtain magnetic variation information?

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

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

The FMS calculates MH and MT from the FMC positions.

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

9. The CDUs in the B737-400 Flight Management System are used during preflight to?

Manually initialise the Flight Director System and FMC with dispatch information

Manually initialise the IRSs and FMC with dispatch information

Manually initialise the IRSs, FMC and Authorities with dispatch information

Automatically initialise the IRSs and FMC with dispatch information

10. In an Inertial Navigation System(INS), Ground Speed (GS) is calculated?

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

From TAS and WN from RNAV data

By integrating measured acceleration

From TAS and WN from Air Data Computer (ADC)

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

Neither, because its definition is not related to these axes

Vertical

Horizontal and Vertical

Horizontal

12. When aligning the B737-400 FMS, the system?

Cannot detect input errors, and accepts whatever is put in

Rejects initial latitude error, but it will accept longitude error

Rejects initial longitude error, but it will accept latitude error

Rejects initial latitude or longitude error

13. How does an FMS obtain magnetic variation information?

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

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

The FMS calculates MH and MT from the FMC positions

14. 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.

15. What can be used to enter positions on all INS systems?

Hexadecimals

Waypoint names

Geographic coordinates

Ranges and bearing

16. The dither motor in a ring laser gyro sis used to?

Enhance the accuracy of the gyro at all rotational rates

Overcome laser lock

Compensation for transport wander

Stabilise the laser frequencies

17. Gyro - compassing in an INS?

Is possible in flight as the gyros can 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.

It is not possible in flight because the gyros cannot 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.

18. Which of the following lists all of the methods that can be used to enter 'Created Waypoints' into the CDU of a B737 - 400 Electronic Flight Instrument System?

Identifier grid reference, location name, Height above MSL, latitude and Rhumb line position.

Identifier name and range; location name; Height above MSL; latitude nd longitude.

Identifier range, location name; Height above MSL; latitude and longitude.

Identifier bearing/distance; place bearing/place bearing; along-track displacement; latitude and longitude.

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

Shake

Vibrate

Shudder

Dither

20. 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 MIN

With damping and a period of 84.4 MIN

Without damping and a period of 84.4 SEC

With damping and a period of 84.4 SEC

21. An IRS differs from an INS in that it?

Does not experience Schuler errors as accelerometers are strapped down

Does not need to correct for coriolis and central acceleration

Has a shorter spin-up time and suffers from laser lock

Has a longer spin-up time and is not affected by vertical accelerations due to gravity

22. On the IRS, selection of ATT mode gives attitude?

Only

Altitude, and heading

And heading

Heading and groundspeed

23. Waypoints can be entered in an INS memory in different formats. In which of the following formats can waypoints be entered into all INS systems?

Grid references

Index numbers

Airport names

Geographic coordinates

24. On a triple-fit IRS system, present positions on the CDU?

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

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

Will not differ as the information is averaged

Are likely to differ as the information comes from different sources

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

ALIGN

ON

ATT

NAV

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

From TAS and WN from RNAV data

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

From TAS and WN from Air Data Computer (ADC)

By integrating measured acceleration

27. Alignment of INS and IRS equipments can take place in which of the following modes?

ATT and ALIGN

ALIGN only

NAV and ALIGN

ALIGN and ATT

28. 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?

PERF INIT - POD IDENT - INIT

POS INIT - IDENT - RTE

RTE - POS INT - IDENT

IDENT - POS INIT - RTE

29. In order to keep the platform of an inertial navigation system (INS) at right angles to the local vertical in flight, corrections must be applied to compensate for?

Movement in the yawing plane, secondary precession and pendulous oscillation

Aircraft manoeuvres, earth rotation, transport wander and coriolis

Gyroscopic inertia, earth rotation and real drift

Vertical velocities, earth precession, centrifugal forces and transport drift

30. The principle of 'Schuler Tuning' as applied to the operation of Inertial Navigation Systems/Inertial Reference Systems is applicable to

Both gyro-stabilised and laser gyro systems but only when operating in the non 'strapdown' mode.

Only to 'strapdown' laser gyro systems.

Both gyro-stabilised platform and strapdown systems.

Only gyro-stabilised systems

31. What does INS need for wind calculation?

Mach Number

Heading

EAS

TAS

32. In a Boeing 737-400 FMS the sequence of pages on start-up is?

INIT, POS, RTE, IDENT

IDENT, POS INIT, DEPARTURES

POS INIT, IDENT, DEPARTURES

IDENT, POS INIT, RTE

33. A pilot turns off the power to his IRS whilst in flight. He switches it on again after just a few seconds. What will be the effect?

There will be no effect

It cannot be used for navigation, but can be used provide attitude information

It can be repositioned whilst in flight

It cannot be used and must be shut down

34. In what way does IRS differ from INS?

Does not need to correct for coriolis and central acceleration

Has a shorter spin-up time and suffers from laser lock

Has a longer spin-up time and is not affected by vertical acceleration due to gravity.

Does not experience Schuler errors as accelerometers are strapped down.

35. What principle is utilized by the plezo-electric motor in an IRS system?

Shudder

Shake

Vibrate

Dither

36. What is the period of validity of an FMS databse?

Variable

28 days

56 days

One week

37. A Ring Laser Gyro?

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

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

It is fixed to true north and is quick to erect

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

38. FMC aircraft position determined by radio navigation is derived on the B737-400 FMS from?

VOR/DME

DME/ADF

DME/DME

VOR/VOR

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

5 minutes

1 minute

15 minutes

10 minutes

40. Which FMC/CDU page normally appears on initial power application to the B737-400 Electronic Flight Instrument System?

POS INIT

PERF INIT

RTE

IDENT

41. On the IRS, selection of ATT mode gives attitude?

And heading

Altitude and heading

Heading and groundspeed

Only

42. The FMS on a 737-400 provides?

Manual navigation & manual performance management

Automatic navigation & manual performance management

Automatic navigation & automatic performance management

Manual navigation & automatic performance management

43. How does the FMS calculate groundspeed?

Input from IRS

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

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

Input from ADC of TAS and wind velocity

44. What do you call a system of gyros and accelerometers that is fixed to the aircraft?

Strapdown

Stabilised

Laser

Fixed

45. 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

Both systems are drifting

The INS2 is drifting

At least one of the inertial navigation systems is drifting

46. Alignment of INS and IRS equipments can take place in which of the following modes?

ATT and ALIGN

ALING and ATT

NAV and ALIGN

ALING only

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

Gyroscopic Inertia, earth rotation and real drift

Movement in the yawing plane, secondary procession and pendulous oscillation

Aircraft manoeuvres, earth rotation, transport wander and coriollis

Vertical velocities, earth procession, centrifugal forces and transport drift

48. The principle of 'Schuler Tuning' as applied to the operation of Inertial Navigation Systems/Inertial Reference Systems is applicable to

Both gyro-stabilised and laser gyro systems but only when operating in the non 'strapdown' mode.

Both gyro-stabilised platform and strapdown systems

Only to 'strapdown' laser gyro systems

Only gyro-stabilised systems

49. What will be the effect if the crew of an aircraft switch off the power to his IRS whilst in flight, before switching it back on a few seconds later?

It cannot be used for navigation, but can be used to provide attitude information

It must be re-aligned whilst in flight

It cannot be used and must be shut down or the gyros will topple

The system will operate normally

50. From what source is the FMC aircraft position determined by radio navigation in the Boeing 737-400 aircraft derived?

DME/ADF

VOR/VOR

VOR/DME

DME/DME

Question Bank

Questions for INS/IRS/FMS