INSTRUMENTS INS/IRS/FMS – Air – DGCA Question Bank For Politics

#1. What is the Schuler period?

48 minutes.

84 seconds.

48 seconds.

84 minutes.

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

1 degree of freedom and a horizontal axis.

1 degrees of freedom and a vertical axis.

2 degree of freedom and a horizontal axis.

2 degree of freedom and a vertical axis.

#3. 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 minutes.

With damping and a period of about 84 seconds.

Without damping and a period of about 84 minutes.

Without damping and a period of about 84 seconds.

#4. Heading information given by a gyro platform is given by a gyro with?

3 degrees of freedom in the vertical axis.

3 degrees of freedom in the horizontal axis.

2 degrees of freedom in the vertical axis.

1 degrees of freedom in the horizontal axis.

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

Illuminates steadily for 2 minutes before reaching the next waypoint.

Flashes for 2 minutes before reaching the next waypoint.

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

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

#6. 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 secant of latitude.

Be divided by the tangent of latitude.

Be multiplied by the Cosine of latitude.

#7. An INS with the accelerometers aligned N/S and E/W is limited to use at latitudes below about 82°. This is because?

It loses horizontal reference as dip becomes large.

At high speed on East or West tracks the rate of convergency is faster than the azimuth motor can correct.

The functions of secant latitude and tangent latitude used in certain corrections in the computer start to approach infinity and the computer cannot handle the rapid changes involved.

The correction for the Coriolis effect of the earth rotation approaches infinity above 82° latitude.

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

Roll Pitch.

Pitch Roll.

Roll yaw.

Pitch Roll.

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

1 degree of freedom and a horizontal spin axis .

1 degree of freedom and a vertical spin axis .

2 degrees of freedom and a horizontal spin axis .

2 degrees of freedom and a vertical spin axis .

#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).

All of the above statements are correct.

Only statements 2,3 and 4 are correct.

Only statements 1,2 and 3, are correct

Only statements 2 and 3 are correct.

#11. Ring laser gyros use dither motors to?

Reduce random wander.

Prevent unbounded errors.

Level and align the gyros.

Prevent lock in of the laser beams.

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

Departure.

Speed along the local parallel.

Speed along the local horizontal

Distance.

#13. 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 north 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 magnetic 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.

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.

#14. 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.

#15. When using an INS platform Coriolis affects?

The N/S accelerometer.

The E/W accelerometer.

Both a, and b.

Neither a, nor b.

#16. 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.

#17. The fundamental difference between INS and IRS is that?

The INS is a strap down system with 2 accelerometers mounted at 90° to each other.

The IRS is a strap down system with 2 accelerometers mounted at 90° to each other.

The INS is a strap down system with 3 accelerometers mounted at 90° to each other.

The IRS is a strap down system with 3 accelerometers mounted at 90° to each other.

#18. The position accuracy of an RLG INS is ?

1 nm/hr.

2 nm/hr.

5 nm/hr.

10 nm/hr.

#19. 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?

1.37 Km/hr.

1.37 Nm/hr.

11.42 Nm/hr.

14.3 Nm/hr.

#20. In an INS a TAS input is ?

Not required.

Required for polar navigation.

Required for great circle navigation.

Required in order to provide a wind velocity read out.

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

Due to the output of the first stage integrators.

Due to the real wander of the platform gyroscopes.

Due to accelerometer errors.

Track errors due to initial platform misalignment.

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

The ramp position has been inserted and checked.

The platform is levelled.

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

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

#23. An INS in the ALIGN mode will?

Not accept an error on 10° latitude and 10° longitude of the inserted initial position.

Accept an error of 10° latitude and 10°of longitude of the inserted position.

Accept an error of 10° latitude but not an error of 10° longitude of the inserted initial position.

Accept an error of 10° longitude but not one of 10°of latitude in the inserted initial position.

#24. An IRS with laser gyros should (i) ....... be Schuler tuned , and (ii) ...... be strapped down?

(i) always (ii) always.

(i) always (ii) never.

(i) never (ii) always.

(i) never (ii) never.

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

To determine magnetic north.

To check the function of the laser gyros.

To determine the computed trihedron

To compensate for aircraft movement.

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

Helium and argon.

Hydrogen and neon

Helium and neon.

Hydrogen and argon.

#27. Alignment of a RLG INS takes?

Less than 10 minutes.

10 to 15 minutes.

15 to 20 minutes.

84.4 minutes.

#28. In an INS the gyros should ..... be strap down. In an IRS the gyros should ..... be strapped down?

always never.

always always.

never always.

never never

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

Position the computing trihedron with reference to the earth.

Check operation of the laser gyros.

determine magnetic or true heading.

Re-erect laser gyros.

#30. when Initial position is put into an INS system?

It rejects initial latitude or longitude errors.

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

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

It accepts both longitude and latitude errors.

#31. 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 suffers laser lock but spins up faster.

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

#32. An FMS database is valid for?

7 days

28 days

56 days

It depends upon operational area.

#33. In an IRS system?

Both the platform and accelerometers are strapped down

Both the platform and accelerometers are gyro-stabilised.

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

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

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

Cyan.

Magents

Red

White.

#35. The sequences for switching on INS is?

Off, Standby, Align, Nav.

Off, Align, Standby, Nav.

Off, On, Align, Standby.

Off, Align, On, Standby.

#36. The correct latitude must be put into INS?

Because it cannot detect initial latitude.

Because it cannot detect latitude. changes.

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.

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

Establish true magnetic north.

Test the accuracy and serviceability of the laser ring gyros.

Establish the trihedron with reference to the earth.

Input initial heading information.

#38. The schuler period is?

12 minutes.

20 minutes.

84 minutes.

98 minutes.

#39. 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, 2, 3, 4, 5.

1, 3, 4, 5.

2, 3, 4, 5.

1, 2, 3, 4.

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

OFF STBY ALIGN ATT NAV.

OFF ALIGN STBY NAV ATT.

OFF ALIGN STBY ATT NAV.

OFF STBY ALIGN NAV ATT.

#41. What is the first page on an FMS CDU?

INDEX.

IDENT

TAKE-OFF.

PRE-START.

#42. Setting zero cost index on an FMS gives?

Best range.

Best time.

Best endurance.

Lowest total costs.

#43. 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, 3, 4, 5.

1, 4, 5, 6.

2, 3, 4, 6.

#44. 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.

1, 2, 3, 4.

2, 4, 5.

3, 4, 5

4, 5

#45. Integration of a yaw rate signal?

Gives heading.

Gives yaw displacement.

Gives yaw acceleration rate.

Gives track.

#46. The Schuler period is?

1 oscillation in azimuth.

22 minutes.

66 minutes.

84 minutes.

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

To compensate for earth rotation errors.

To establish the trihedron with reference to the earth.

To functionally test the ring laser gyroscopes.

To establish magnetic north and true north.

#48. Obtaining heading information from a gyro stabilised platform requires a gyro with?

Two degrees of freedom and a vertical spin axis.

Two degrees of freedom and a horizontal spin axis.

One degree of freedom and a vertical spin axis.

One degree of freedom and a horizontal spin axis.

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

Establish true and magnetic north.

Establish latitude.

Calculate the computed triehedron.

Warm up the gyroscopes.

#50. 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.

1, 2, 3, 4.

2, 3, 4, 5.

3, 4, 5, 6.

All of the above.

#51. Which of the following is closest to the Schuler period?

48 seconds.

84 seconds.

48 minutes.

84 minutes.

#52. Modern systems employ ring laser gyros because they offer?

More rapid run up.

More rapid alignment.

Longer life.

Lower electrical power requirements.

#53. A rate Integrating gyro is used in ?

Artificial horizon.

Flight Director.

Inertial navigation system.

Turn and slip Indicator.

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

The INS gives commands to the autopilot.

The FMC gives commands to the autopilot

The autopilot gives commands to the FMC.

The term managed guidance is not related to FMS.

#55. What would be the FMC displayed position in an aircraft equipped with a twin inertial system and DME?

Identical to the primary inertial system position.

The mean of the radio fix position and the primary inertial position.

The mean between the radio fix and the mean of the two inertial positions.

The mean of the two inertial positions.

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

The beacon frequency will be displayed Instead of its identifier

The MCDU will display a warning message.

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

Alternative DME's are selected and employed.

#57. A cost index is?

An FMS output code.

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

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

A fixed code giving best fuel efficiency for each route.

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

The aircraft circles the waypoint until commanded to do otherwise.

The aircraft returns to the previous waypoint.

The system reverts to heading mode.

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

#59. The flight control unit in an FMS?

Control vertical flight paths

Controls lateral flight paths.

Control all flight paths.

Controls only heading.

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

Establish magnetic north.

Establish magnetic and true north.

Establish its position relative to magnetic and true north.

Align the trihedron with True North.

Dgca Question Bank For Pilots

Results

#1. What is the Schuler period?

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

#3. 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?

#4. Heading information given by a gyro platform is given by a gyro with?

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

#6. 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?

#7. An INS with the accelerometers aligned N/S and E/W is limited to use at latitudes below about 82°. This is because?

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

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

#11. Ring laser gyros use dither motors to?

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

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

#14. A longitude error in an INS will cause:

#15. When using an INS platform Coriolis affects?

#16. The errors of an INS fall into three categories?

#17. The fundamental difference between INS and IRS is that?

#18. The position accuracy of an RLG INS is ?

#19. 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?

#20. In an INS a TAS input is ?

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

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

#23. An INS in the ALIGN mode will?

#24. An IRS with laser gyros should (i) ....... be Schuler tuned , and (ii) ...... be strapped down?

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

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

#27. Alignment of a RLG INS takes?

#28. In an INS the gyros should ..... be strap down. In an IRS the gyros should ..... be strapped down?

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

#30. when Initial position is put into an INS system?

#31. IRS is different from INS in that it?

#32. An FMS database is valid for?

#33. In an IRS system?

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

#35. The sequences for switching on INS is?

#36. The correct latitude must be put into INS?

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

#38. The schuler period is?

#39. 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.

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

#41. What is the first page on an FMS CDU?

#42. Setting zero cost index on an FMS gives?

#43. 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

#44. 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.

#45. Integration of a yaw rate signal?

#46. The Schuler period is?

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

#48. Obtaining heading information from a gyro stabilised platform requires a gyro with?

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

#50. 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.

#51. Which of the following is closest to the Schuler period?

#52. Modern systems employ ring laser gyros because they offer?

#53. A rate Integrating gyro is used in ?

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

#55. What would be the FMC displayed position in an aircraft equipped with a twin inertial system and DME?

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

#57. A cost index is?

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

#59. The flight control unit in an FMS?

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