Vayudoot Aviation

1. 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 .

1 degree of freedom and a horizontal spin axis .

2 degrees of freedom and a vertical spin axis .

2 degrees of freedom and a horizontal spin axis .

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

Departure.

Speed along the local horizontal

Distance.

Speed along the local parallel.

3. In an IRS system?

Both the platform and accelerometers are gyro-stabilised.

Both the platform and accelerometers are strapped down

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

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

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

More rapid alignment.

Lower electrical power requirements.

Longer life.

More rapid run up.

5. 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 multiplied by the Cosine of latitude.

Be divided by the secant of latitude.

Be multiplied by the secant of latitude.

Be divided by the tangent of latitude.

6. 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.

All of the above.

2, 3, 4, 5.

3, 4, 5, 6.

1, 2, 3, 4.

7. What is the Schuler period?

48 seconds.

48 minutes.

84 minutes.

84 seconds.

8. Alignment of a RLG INS takes?

Less than 10 minutes.

10 to 15 minutes.

84.4 minutes.

15 to 20 minutes.

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

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

The platform is levelled.

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

The ramp position has been inserted and checked.

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

To establish the trihedron with reference to the earth.

To functionally test the ring laser gyroscopes.

To compensate for earth rotation errors.

To establish magnetic north and true north.

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

84 seconds.

48 seconds.

48 minutes.

84 minutes.

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

Establish magnetic north.

Align the trihedron with True North.

Establish magnetic and true north.

Establish its position relative to magnetic and true north.

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

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

The mean of the two inertial positions.

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

Identical to the primary inertial system position.

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

The FMC gives commands to the autopilot

The autopilot gives commands to the FMC.

The INS gives commands to the autopilot.

The term managed guidance is not related to FMS.

15. 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.

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

Establish latitude.

Calculate the computed triehedron.

Warm up the gyroscopes.

Establish true and magnetic north.

17. 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.

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 seconds.

18. The position accuracy of an RLG INS is ?

1 nm/hr.

10 nm/hr.

2 nm/hr.

5 nm/hr.

19. The schuler period is?

98 minutes.

84 minutes.

20 minutes.

12 minutes.

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

Two degrees of freedom and a horizontal spin axis.

One degree of freedom and a horizontal spin axis.

Two degrees of freedom and a vertical spin axis.

One degree of freedom and a vertical spin axis.

21. Integration of a yaw rate signal?

Gives track.

Gives heading.

Gives yaw acceleration rate.

Gives yaw displacement.

22. A cost index is?

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.

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

23. 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.

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

Flashes for 2 minutes before reaching the next waypoint.

Illuminates steadily for 2 minutes before reaching the next waypoint.

24. A longitude error in an INS will cause

A failure to align.

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

Poor alignment and degraded accuracy.

Will cause no problems at all.

25. 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?

11.42 Nm/hr.

1.37 Nm/hr.

1.37 Km/hr.

14.3 Nm/hr.

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

2 degree of freedom and a horizontal axis.

2 degree of freedom and a vertical axis.

1 degrees of freedom and a vertical axis.

1 degree of freedom and a horizontal axis.

27. The sequences for switching on INS is?

Off, Align, On, Standby.

Off, Standby, Align, Nav.

Off, On, Align, Standby.

Off, Align, Standby, Nav.

28. 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

1, 2, 3, 4.

2, 4, 5.

4, 5

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

2 degrees of freedom in the vertical axis.

3 degrees of freedom in the horizontal axis.

3 degrees of freedom in the vertical axis.

1 degrees of freedom in the horizontal axis.

30. 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.

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

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.

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

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

Input initial heading information.

Establish the trihedron with reference to the earth.

Establish true magnetic north.

Test the accuracy and serviceability of the laser ring gyros.

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

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

It rejects initial latitude or longitude errors.

It accepts both longitude and latitude errors.

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

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

Bounded, unbounded and velocity.

Bounded, unbounded and accelerometer.

Bounded, unbounded and inherent.

Coriolis, unbounded and inherent.

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

Bounded, unbounded and accelerometer.

Bounded, unbounded and velocity.

Bounded, unbounded and inherent.

Coriolis, unbounded and inherent.

35. When using an INS platform Coriolis affects?

The N/S accelerometer.

The E/W accelerometer.

Both a, and b.

Neither a, nor b.

36. 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 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.

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

37. 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 and 3 are correct.

Only statements 1,2 and 3, are correct

Only statements 2,3 and 4 are correct.

38. The flight control unit in an FMS?

Control all flight paths.

Controls lateral flight paths.

Controls only heading.

Control vertical flight paths

39.
The diagram below shows a gyro-stabilised platform . 1 is a........ gyro gimbal and 2 is a ...... gimbal?

Pitch Roll.

Roll yaw.

Pitch Roll.

Roll Pitch.

40. 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.

41. An INS in the ALIGN mode will?

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

Not accept an error on 10° latitude and 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.

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

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

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

The beacon frequency will be displayed Instead of its identifier

Alternative DME's are selected and employed.

The MCDU will display a warning message.

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

Hydrogen and argon.

Helium and argon.

Helium and neon.

Hydrogen and neon

44. 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 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.

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.

45. The Schuler period is?

84 minutes.

22 minutes.

1 oscillation in azimuth.

66 minutes.

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

The system reverts to heading mode.

The aircraft circles the waypoint until commanded to do otherwise.

The aircraft returns to the previous waypoint.

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

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

White.

Magents

Red

Cyan

48. IRS is different from INS in that it?

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.

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

It suffers laser lock but spins up faster.

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

IDENT

TAKE-OFF.

INDEX.

PRE-START.

50. The correct latitude must be put into INS?

Because it cannot detect initial latitude.

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.

Question Bank

Questions for KW INSTRUMENTS INS/IRS/FMS