Vayudoot Aviation

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

The FMS calculates MH and MT from the FMC positions.

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

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

And heading

Altitude, and heading

Heading and groundspeed

Only

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

IDENT, POS INIT, RTE

IDENT, POS INIT, DEPARTURES

POS INIT, IDENT, DEPARTURES

POS, INIT, RTE, IDENT

4. Some Inertial reference and navigation system are known as "strapdown". This means that?

The gyros are stabilised but the accelerometers are fixed to the aircraft structure.

The indicator units are strapped to the aircraft structure.

The accelerometers are fixed to the aircraft structure but the gyros are stabiised.

The gyroscopes and accelerometers become part of the unit's fixture to the aircraft structure.

5. 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?

Index numbers

Airport names

Grid references

Geographic coordinates

6. 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

Without damping and a period of 84.4 SEC

Without damping and period of 84.4 MIN

With damping and a period of 84.4 MIN

7. How does an FMS obtain magnetic variation information?

The FMS calculates MH and MT from the FMC positions

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

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

8. 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 must be re-aligned whilst in flight

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

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

The system will operate normally

9. Where and when are the IRS positions updated?

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

During flight IRS positions are automatically updated by the FMC

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

Only on the ground during the alignment procedure

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

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

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

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

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

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

Vertical

Horizontal

Horizontal and Vertical

Neither, because its definition is not related to these axes

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

DME/ADF

VOR/VOR

DME/DME

VOR/DME

13. The functions of the Boeing 737-400 FMS include?

Manual navigation & manual performance management

Manual navigation & automatic performance management

Automatic navigation & automatic performance management

Automatic navigation & manual performance management

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

Immediately prior to push back or taxi from the gate

At the holding point

After passengers and freight are aboard.

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

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

Will not differ as the information is averaged

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

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

Are likely to differ as the information comes from different sources

16. How does the FMS calculate groundspeed?

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

Input from IRS

Input from ADC of TAS and wind velocity

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

17. What do the sensors of an INS measure?

Velocity

The horizontal component of the earth's rotation

Precession

Acceleration

18. In a laser reference system (IRS), are compared to a gyro reference system (INS)

The platform is strapped down but the accelerometers are gryo-stabilised.

Accelerometers and platform are both gyro-stabilised.

Accelerometers and platform are both strapped down.

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

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

MAP, PLAN, EXP VOR/ILS

MAP, FULLVOR/ILS, FULL NAV

MAP,PLAN, FULL VOR/ILS

MAP, EXPVOR/ILS, EXP NAV

20. What does INS need for wind calculation?

EAS

mach Number

Heading

TAS

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

Movement in the yawing plane, secondary procession and pendulous oscillation

Gyroscopic Inertia, earth rotation and real drift

Aircraft manoeuvres, earth rotation, transport wander and coriollis

Vertical velocities, earth procession, centrifugal forces and transport drift

22. If t is the time since selecting the MSU from ALIGN to NAV the azimuth gyro heading error caused by drift rate of an INS/IRS azimuth gyro is?

Proportional to t

Proportional to t/2

Sinusoidal

Proportional to the square root of t

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

Be turned OFF

Have a new position inserted

Be selected to ALIGN and then to NAV

Not be used in NAV mode

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

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

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

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

Does not experience Schuler errors as accelerometers are strapped down

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

Does not need to correct for coriolis and central acceleration

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

Altitude and heading

And heading

Only

Heading and groundspeed

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

Never, because the FMS database is read-only

Every 28 days

When there is a fruit

When it is deemed to be necessary

28. In the B737-400 Flight Management System the CDUs 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

Automatically initialise the IRSs and FMC with dispatch information

Manually initialise the IRS, FMC and Authorities with dispatch information

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

ALING and ATT

ALING only

ATT and ALIGN

NAV and ALIGN

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

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

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

Fixed

Stabilised

Laser

Strapdown

32. 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

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

IDENT, POS INIT, DEPARTURES

POS INIT, IDENT, DEPARTURES

INIT, POS, RTE, IDENT

IDENT, POS INIT, RTE

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

The accelerometers are strapped down but the platform is gyro stabilised

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

Accelerometers and platform are both gyro-stabilsed

Accelerometers and platform are both strapped down

35. 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 SEC

With damping and a period of 48.4 MIN

With damping and a period of 84.4 SEC.

36. What is the highest priority and lowest priority, message produced by the CDU of the B737-400 EFIS?

Warning and Caution

Warning and Advisory

Urgent and Routine

Caution and Advisory

37. From what information is the FMC position calculated?

The average of the IRS positions

Computer generated from the IRS and radio navigation positions

Half way between the IRS and radio navigation positions

Computer generated from the radio navigation positions

38. In what way does IRS differ from INS?

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

Does not need to correct for coriolis and central acceleration

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.

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

Stabilised

Fixed

Laser

Strapdown

40.
Which Cyan symbol below represents an off-route waypoint?

A

C

D

B

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

VOR/DME

VOR/VOR

DME/ADF

DME/DME

42. 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 ALIGN NAV ATT

OFF STBY ALIGN NAV

OFF STBY NAV ATT

43. The IRS position is updated?

During flight IRS position are automatically updated

Only on the ground during the alignment proceudre.

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

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

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

Immediately prior to push back or taxi from the gate

After passengers and freight are aboard

At the holding point

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

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?

The INS2 is drifting

Both systems are serviceable as this error is within limits

Both systems are drifting

At least one of the inertial navigation systems is drifting

46. What format is used to enter positions into INS systems?

Hexadecimais

Ranges and bearings

Geographic coordinates

Waypoint names

47. 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

48. A pilot accidentally turning OFF the INS in flight, and then turns it back ON a few moments later. Following this incident?

It must be switched off or its gyros will apple

It cannot be used for the remainder of the flight

It can only be used for attitude reference

It can be used as normal

49. In an Inertial Navigation System (INS), what is the output of the first stage North/South integrator?

Velocity along the local meridian

Groundspeed

Longitude

Change of latitude

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

The system is mounted and fixed to the aircraft structure

The accelerometers are fixed but the gyros are stabilised

The system is mounted on a stabilised platform

The gyros are fixed but the accelerometers are stabilised

Question Bank

Questions for INS/IRS/FMS