Vayudoot Aviation

1. 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.

2. The flight control unit in an FMS?

Control vertical flight paths

Controls lateral flight paths.

Control all flight paths.

Controls only heading.

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

Distance.

Departure.

Speed along the local parallel.

Speed along the local horizontal

4. The correct latitude must be put into INS?

Because it cannot detect latitude. changes.

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 initial latitude.

5. 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

6. 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 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 true north virtually impossible.

7. 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.

8. 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.

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.

9. 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, 2, 3, 4.

2, 3, 4, 5.

1, 3, 4, 5.

10. In an INS a TAS input is ?

Required for great circle navigation.

Required for polar navigation.

Required in order to provide a wind velocity read out.

Not required.

11. The Schuler period is?

1 oscillation in azimuth.

66 minutes.

22 minutes.

84 minutes.

12. 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 .

2 degrees of freedom and a vertical spin axis .

1 degree of freedom and a horizontal spin axis .

13. A rate Integrating gyro is used in ?

Artificial horizon.

Flight Director.

Turn and slip Indicator.

Inertial navigation system.

14. 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.

1 degrees of freedom in the horizontal axis.

3 degrees of freedom in the vertical axis.

15. 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 compensate for earth rotation errors.

To establish the trihedron with reference to the earth.

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

To determine the computed trihedron

To determine magnetic north.

To compensate for aircraft movement.

To check the function of the laser gyros.

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?

Without 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 seconds.

With damping and a period of about 84 minutes.

18.
The diagram below shows a gyro-stabilised platform . 1 is a........ gyro gimbal and 2 is a ...... gimbal?

Roll yaw.

Roll Pitch.

Pitch Roll.

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

never always.

always never.

never never

always always.

20. 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, 2, 3, 4.

1, 4, 5, 6.

1, 3, 4, 5.

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

Warm up the gyroscopes.

Establish true and magnetic north.

Calculate the computed triehedron.

Establish latitude.

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

One degree of freedom and a vertical spin axis.

Two degrees of freedom and a horizontal spin axis.

Two degrees of freedom and a vertical spin axis.

One degree of freedom and a horizontal spin axis.

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

2 degree of freedom and a vertical axis.

1 degrees of freedom and a vertical axis.

1 degree of freedom and a horizontal axis.

2 degree of freedom and a horizontal axis.

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

More rapid alignment.

Longer life.

Lower electrical power requirements.

More rapid run up.

25. The position accuracy of an RLG INS is ?

2 nm/hr.

1 nm/hr.

10 nm/hr.

5 nm/hr.

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

It accepts both longitude and latitude errors.

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.

27. Setting zero cost index on an FMS gives?

Best range.

Best time.

Best endurance.

Lowest total costs.

28. 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.

3, 4, 5, 6.

2, 3, 4, 5.

1, 2, 3, 4.

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

Coriolis, unbounded and inherent.

Bounded, unbounded and inherent.

Bounded, unbounded and velocity.

Bounded, unbounded and accelerometer.

30. An FMS database is valid for?

28 days

It depends upon operational area.

7 days

56 days

31. 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.

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

Test the accuracy and serviceability of the laser ring gyros.

Establish true magnetic north.

Input initial heading information.

Establish the trihedron with reference to the earth.

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

TAKE-OFF.

IDENT

PRE-START.

INDEX.

34. Ring laser gyros use dither motors to?

Prevent unbounded errors.

Reduce random wander.

Level and align the gyros.

Prevent lock in of the laser beams.

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

48 seconds.

84 minutes.

84 seconds.

48 minutes.

36. 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 Km/hr.

1.37 Nm/hr.

11.42 Nm/hr.

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

Due to the output of the first stage integrators.

Track errors due to initial platform misalignment.

Due to the real wander of the platform gyroscopes.

Due to accelerometer errors.

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

Bounded, unbounded and velocity.

Bounded, unbounded and accelerometer.

Coriolis, unbounded and inherent.

Bounded, unbounded and inherent.

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

Hydrogen and argon.

Helium and argon.

Hydrogen and neon

Helium and neon.

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

Establish magnetic and true north.

Align the trihedron with True North.

Establish magnetic north.

Establish its position relative to magnetic and true north.

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° 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.

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

OFF ALIGN STBY NAV ATT.

OFF STBY ALIGN ATT NAV.

OFF ALIGN STBY ATT NAV.

OFF STBY ALIGN NAV ATT.

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

Magents

Red

White.

Cyan

44. IRS is different from INS in that it?

It suffers laser lock but spins up faster.

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.

It requires no corrections for central accelerations or Coriolis effects.

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

Re-erect laser gyros.

determine magnetic or true heading.

Check operation of the laser gyros.

Position the computing trihedron with reference to the earth.

46. 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 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.

47. The sequences for switching on INS is?

Off, Align, Standby, Nav.

Off, Standby, Align, Nav.

Off, Align, On, Standby.

Off, On, Align, Standby.

48. Integration of a yaw rate signal?

Gives heading.

Gives track.

Gives yaw acceleration rate.

Gives yaw displacement.

49. 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.

50. A cost index is?

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

An FMS output code.

A fixed code giving best fuel efficiency for each route.

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

Question Bank

Questions for KW INSTRUMENTS INS/IRS/FMS