Vayudoot Aviation

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

2 degrees of freedom and a vertical spin axis .

2 degrees of freedom and a horizontal spin axis .

1 degree of freedom and a vertical spin axis .

1 degree of freedom and a horizontal spin axis .

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

Warm up the gyroscopes.

Establish true and magnetic north.

Establish latitude.

Calculate the computed triehedron.

3. 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.

Position the computing trihedron with reference to the earth.

Re-erect laser gyros.

determine magnetic or true heading.

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

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

It accepts both longitude and latitude errors.

It rejects initial latitude or longitude errors.

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

5. 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 vertical spin axis.

Two degrees of freedom and a vertical spin axis.

One degree of freedom and a horizontal spin axis.

6. 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.

7. The schuler period is?

98 minutes.

84 minutes.

12 minutes.

20 minutes.

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

Speed along the local horizontal

Distance.

Departure.

Speed along the local parallel.

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

Bounded, unbounded and inherent.

Bounded, unbounded and velocity.

Bounded, unbounded and accelerometer.

Coriolis, unbounded and inherent.

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

Alternative DME's are selected and employed.

The MCDU will display a warning message.

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

The beacon frequency will be displayed Instead of its identifier

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

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

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

It loses horizontal reference as dip becomes large.

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.

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

The autopilot gives commands to the FMC.

The FMC gives commands to the autopilot

The term managed guidance is not related to FMS.

The INS gives commands to the autopilot.

13. The position accuracy of an RLG INS is ?

10 nm/hr.

1 nm/hr.

5 nm/hr.

2 nm/hr.

14. A cost index is?

An FMS output code.

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

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

A fixed code giving best fuel efficiency for each route.

15. The flight control unit in an FMS?

Control all flight paths.

Controls only heading.

Controls lateral flight paths.

Control vertical flight paths

16. 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?

Without damping and a period of about 84 seconds.

With 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.

17. 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.

18. Ring laser gyros use dither motors to?

Prevent lock in of the laser beams.

Prevent unbounded errors.

Level and align the gyros.

Reduce random wander.

19. Setting zero cost index on an FMS gives?

Best endurance.

Lowest total costs.

Best range.

Best time.

20. When using an INS platform Coriolis affects?

The E/W accelerometer.

The N/S accelerometer.

Both a, and b.

Neither a, nor b.

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

Coriolis, unbounded and inherent.

Bounded, unbounded and accelerometer.

Bounded, unbounded and inherent.

Bounded, unbounded and velocity.

22. The sequences for switching on INS is?

Off, Standby, Align, Nav.

Off, On, Align, Standby.

Off, Align, Standby, Nav.

Off, Align, On, Standby.

23. In an IRS system?

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

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.

24. 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.

25. Integration of a yaw rate signal?

Gives yaw displacement.

Gives heading.

Gives track.

Gives yaw acceleration rate.

26. 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 Nm/hr.

11.42 Nm/hr.

14.3 Nm/hr.

1.37 Km/hr.

27. 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.

28. IRS is different from INS in that it?

It suffers laser lock but spins up faster.

It requires no corrections for central accelerations or Coriolis effects.

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

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

29. 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.

1 degrees of freedom and a vertical axis.

2 degree of freedom and a horizontal axis.

30. 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

2, 3, 4, 6.

1, 4, 5, 6.

1, 3, 4, 5.

1, 2, 3, 4.

31. 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

4, 5

1, 2, 3, 4.

2, 4, 5.

32. 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 2 and 3 are correct.

All of the above statements are correct.

Only statements 2,3 and 4 are correct.

Only statements 1,2 and 3, are correct

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

Cyan

Red

Magents

White.

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

To functionally test the ring laser gyroscopes.

To establish magnetic north and true north.

To establish the trihedron with reference to the earth.

To compensate for earth rotation errors.

35. Alignment of a RLG INS takes?

Less than 10 minutes.

84.4 minutes.

10 to 15 minutes.

15 to 20 minutes.

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

OFF STBY ALIGN NAV ATT.

OFF STBY ALIGN ATT NAV.

OFF ALIGN STBY NAV ATT.

OFF ALIGN STBY ATT NAV.

37. An FMS database is valid for?

56 days

28 days

It depends upon operational area.

7 days

38. 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.

All of the above.

3, 4, 5, 6.

39. 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 secant of latitude.

Be divided by the secant of latitude.

Be divided by the tangent of latitude.

Be multiplied by the Cosine of latitude.

40. An INS in the ALIGN mode will?

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

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

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

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

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

Establish magnetic and true north.

Align the trihedron with True North.

Establish its position relative to magnetic and true north.

Establish magnetic north.

42. The Schuler period is?

66 minutes.

84 minutes.

22 minutes.

1 oscillation in azimuth.

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

Due to the real wander of the platform gyroscopes.

Track errors due to initial platform misalignment.

Due to the output of the first stage integrators.

Due to accelerometer errors.

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

INDEX.

IDENT

TAKE-OFF.

PRE-START.

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

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 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.

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

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

The mean of the two inertial positions.

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

Identical to the primary inertial system position.

47. A rate Integrating gyro is used in ?

Turn and slip Indicator.

Flight Director.

Inertial navigation system.

Artificial horizon.

48. What is the Schuler period?

84 seconds.

84 minutes.

48 minutes.

48 seconds.

49. The correct latitude must be put into INS?

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

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

Because it cannot detect latitude. changes.

Because it cannot detect initial latitude.

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

More rapid run up.

Lower electrical power requirements.

More rapid alignment.

Longer life.

Question Bank

Questions for KW INSTRUMENTS INS/IRS/FMS