Vayudoot Aviation

1. With reference to an FMS, what does the term managed guidance mean?

The FMC gives commands to the autopilot

The INS gives commands to the autopilot.

The autopilot gives commands to the FMC.

The term managed guidance is not related to FMS.

2. What is the first page on an FMS CDU?

PRE-START.

TAKE-OFF.

IDENT

INDEX.

3. The JAR 25 standard colour for an FMS active planned route is?

Red

White.

Cyan

Magents

4. In an IRS system?

Both the platform and accelerometers are gyro-stabilised.

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

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

Both the platform and accelerometers are strapped down

5. The correct latitude must be put into INS?

Because small latitude errors will not be detected but will cause unbounded errors during the subsequent flight.

Large latitude errors will be undetected but cause large errors during the subsequent flight.

Because it cannot detect latitude. changes.

Because it cannot detect initial latitude.

6. The errors of an INS fall into three categories?

Bounded, unbounded and velocity.

Coriolis, unbounded and inherent.

Bounded, unbounded and inherent.

Bounded, unbounded and accelerometer.

7. In an INS a TAS input is ?

Not required.

Required in order to provide a wind velocity read out.

Required for great circle navigation.

Required for polar navigation.

8.
The diagram below shows a gyro-stabilised platform . 1 is a........ gyro gimbal and 2 is a ...... gimbal?

Pitch Roll.

Roll Pitch.

Pitch Roll.

Roll yaw.

9. IRS is different from INS in that it?

Its strapped down accelerometers are not rotated with the aircraft and hence do not suffer schuler errors.

It requires no corrections for central accelerations or Coriolis effects.

It is not affected by vertical accelerations due to gravity, but it requires a longer spin-up time.

It suffers laser lock but spins up faster.

10. with reference to Inertial Navigation Systems, the functions of the integrator are? 1. At the second stage integration to suppress unbounded errors (when in nav mode). 2. At the first stage of integration to convert accelerations with respect to time, into speed, (when in nav mode.) 3. At the second stage of integration to convert speed with respect to time, into distance gone, (when in nav mode). 4. To align the platform (when in level and align modes)

Only statements 1,2 and 3, are correct

Only statements 2,3 and 4 are correct.

All of the above statements are correct.

Only statements 2 and 3 are correct.

11. The position accuracy of an RLG INS is ?

10 nm/hr.

2 nm/hr.

1 nm/hr.

5 nm/hr.

12. A rate Integrating gyro is used in ?

Inertial navigation system.

Artificial horizon.

Turn and slip Indicator.

Flight Director.

13. During Initialisation of an INS the aircraft must not be moved until?

The platform is levelled.

The green READY NAV light is illuminated and the mode selector switch has been set to the NAV position.

The gyros and the accelerometers are all in the Null position.

The ramp position has been inserted and checked.

14. The fundamental difference between INS and IRS is that?

Bounded, unbounded and inherent.

Bounded, unbounded and velocity.

Coriolis, unbounded and inherent.

Bounded, unbounded and accelerometer.

15. The flight control unit in an FMS?

Control vertical flight paths

Controls only heading.

Controls lateral flight paths.

Control all flight paths.

16. A longitude error in an INS will cause

A failure to align.

Poor alignment and degraded accuracy.

Will be corrected for once the E/W accelerometer has aligned to true north

Will cause no problems at all.

17. The selection on an IRS mode panel are used in the following order?

OFF ALIGN STBY ATT NAV.

OFF STBY ALIGN NAV ATT.

OFF STBY ALIGN ATT NAV.

OFF ALIGN STBY NAV ATT.

18. While inertial platform system is operating on board an aircraft , it is necessary to use a device with the following characteristics, in order to keep the vertical line with the pendulous system?

With damping and a period of about 84 seconds.

Without damping and a period of about 84 seconds.

Without damping and a period of about 84 minutes.

With damping and a period of about 84 minutes.

19. An FMS database is valid for?

7 days

56 days

28 days

It depends upon operational area.

20. The sequences for switching on INS is?

Off, Standby, Align, Nav.

Off, On, Align, Standby.

Off, Align, Standby, Nav.

Off, Align, On, Standby.

21. Heading information given by a gyro platform is given by a gyro with?

3 degrees of freedom in the horizontal axis.

2 degrees of freedom in the vertical axis.

3 degrees of freedom in the vertical axis.

1 degrees of freedom in the horizontal axis.

22. Setting zero cost index on an FMS gives?

Best time.

Best range.

Best endurance.

Lowest total costs.

23. A cost index is?

A fixed code giving the best fuel efficiency for each aircraft type.

A fixed code giving best fuel efficiency for each route.

An FMS output code.

An FMS input code telling the FMS the required balance between optimising fuel costs and sector time.

24. Integration of a yaw rate signal?

Gives yaw acceleration rate.

Gives yaw displacement.

Gives track.

Gives heading.

25. What happens if an FMC that autotunes to DME stations for fixing purposes , does not receive a satisfactory decode?

The MCDU will display a warning message.

Alternative DME's are selected and employed.

The identifier codes are retrieved from memory and displayed in red.

The beacon frequency will be displayed Instead of its identifier

26. Laser gyros are used in an IRS. Why must accurate latitude and longitude be inserted?

To compensate for aircraft movement.

To determine the computed trihedron

To determine magnetic north.

To check the function of the laser gyros.

27. The amber ALERT light on an INS control and display unit?

Illuminates if power from the aircraft bus bar has been lost and the system is operating on standby battery.

Flashes for 2 minutes before reaching the next waypoint.

Illuminates steadily for 2 minutes before reaching the next waypoint.

Illuminates steadily after passing a waypoint in manual mode, until the next leg is programmed in.

28. Valid FMS CDU waypoint entries include? 1. Runway number 2. Navaid limitations. 3. Airport ICAO identifier. 4.Navaid identifier 5. Waypoint name 6. Country code

1, 2, 3, 4.

1, 4, 5, 6.

1, 3, 4, 5.

2, 3, 4, 6.

29. The product of the first integration of the E/W acceleration sensed by an INS system is?

Speed along the local horizontal

Distance.

Speed along the local parallel.

Departure.

30. To obtain heading information from a gyro-stabilised platform, the gyros should be?

1 degree of freedom and a horizontal axis.

2 degree of freedom and a vertical axis.

2 degree of freedom and a horizontal axis.

1 degrees of freedom and a vertical axis.

31. Alignment of a RLG INS takes?

84.4 minutes.

15 to 20 minutes.

10 to 15 minutes.

Less than 10 minutes.

32. Modern systems employ ring laser gyros because they offer?

Longer life.

More rapid run up.

More rapid alignment.

Lower electrical power requirements.

33. Why is the Inertial strapdown unit in an IRS programmed with coordinates during alignment?

To establish the trihedron with reference to the earth.

To establish magnetic north and true north.

To compensate for earth rotation errors.

To functionally test the ring laser gyroscopes.

34. In an INS which is Schuler tuned , the largest unbounded errors are?

Track errors due to initial platform misalignment.

Due to accelerometer errors.

Due to the output of the first stage integrators.

Due to the real wander of the platform gyroscopes.

35. During initial alignment the IRS must be given coordinates to?

Establish true magnetic north.

Establish the trihedron with reference to the earth.

Input initial heading information.

Test the accuracy and serviceability of the laser ring gyros.

36. The inputs to the FMS include? 1. Air data computer information 2. Route data. 3.Radio aids information. 4.Power pland data. 5.Operating data

1, 3, 4, 5.

1, 2, 3, 4, 5.

2, 3, 4, 5.

1, 2, 3, 4.

37. When an INS is turned on it is aligned in order to?

Align the trihedron with True North.

Establish magnetic north.

Establish its position relative to magnetic and true north.

Establish magnetic and true north.

38. Why is an INS platform virtually unusable at very high latitudes?

The value of the earth rate affecting the E/W accelerometer is a component dependent on the sine lat. At high latitudes this component is nearly zero and makes alignment to true magnetic virtually impossible.

The value of the earth rate affecting the E/W accelerometer is a component dependent on the sine lat. At high latitudes this component is nearly zero and makes alignment to true north virtually impossible.

The value of the earth rate affecting the E/W accelerometer is a component dependent on the cosine lat. At high latitudes this component is nearly zero and makes alignment to true north virtually impossible.

The value of the earth rate affecting the E/W accelerometer is a component dependent on the cosine lat. At high latitudes this component is nearly zero and makes alignment to magnetic north virtually impossible.

39. When using an INS platform Coriolis affects?

The E/W accelerometer.

Neither a, nor b.

Both a, and b.

The N/S accelerometer.

40. The vertical reference unit of a three axis data generator is equipped with a gyro with?

1 degree of freedom and a vertical spin axis .

2 degrees of freedom and a horizontal spin axis .

1 degree of freedom and a horizontal spin axis .

2 degrees of freedom and a vertical spin axis .

41. Which of the following is closest to the Schuler period?

84 seconds.

48 seconds.

48 minutes.

84 minutes.

42. What happens If an FMC operating in VNAV and LNAV modes reaches a waypoint beyond which no route has been input?

The autopilot will disconnect and a warning will be sounded and illuminated on EICAS/ECAM.

The system reverts to heading mode.

The aircraft circles the waypoint until commanded to do otherwise.

The aircraft returns to the previous waypoint.

43. At the second state of integration E/W speed is converted into E/W distance gone. To convert this departure into change of longitude it has to?

Be divided by the secant of latitude.

Be multiplied by the Cosine of latitude.

Be divided by the tangent of latitude.

Be multiplied by the secant of latitude.

44. The triangular cavity in a RLG is filled with which combination of gasses?

Hydrogen and argon.

Hydrogen and neon

Helium and argon.

Helium and neon.

45. The control and display unit of an inertial navigation system indicates a position of 4810.9° N 00012.2° W on a ramp position 4807.5°N 00005.1°E. What is the radial error rate of the system if it has been in NAV mode for 8 hours 20 minutes?

14.3 Nm/hr.

1.37 Nm/hr.

1.37 Km/hr.

11.42 Nm/hr.

46. The Inputs to an FMS Include? 1. Operating data. 2. Terminal data. 3. Air data 4. Route data 5.Engine data 6. Radio aids data.

2, 3, 4, 5.

1, 2, 3, 4.

3, 4, 5, 6.

All of the above.

47. When an IRS is first switched on It must be aligned in order to ?

Warm up the gyroscopes.

Establish latitude.

Establish true and magnetic north.

Calculate the computed triehedron.

48. In order to align a strap-down inertial unit, it is required to insert the local geographical coordinates. This is necessary to?

Check operation of the laser gyros.

Re-erect laser gyros.

determine magnetic or true heading.

Position the computing trihedron with reference to the earth.

49. Where would a rate integrating gyro be used? 1. Turn and slip indicators. 2.Servo stabiliser mechanisms. 3. Autopilots. 4. Inertial attitude units 5. Inertial navigation units.

3, 4, 5

2, 4, 5.

4, 5

1, 2, 3, 4.

50. when Initial position is put into an INS system?

It accepts both longitude and latitude errors.

It rejects initial longitude errors, but will accept latitude errors.

It rejects initial latitude errors, but accepts initial longitude errors.

It rejects initial latitude or longitude errors.

Question Bank

Questions for KW INSTRUMENTS INS/IRS/FMS