Vayudoot Aviation

1.
The pictures in the diagram are showing an aircraft's position with respect to some thunderstorm cells and the image the pilot is getting from the radar. To detect this "blind alley" the pilot should?

Increase the range setting of the radar.

Switch over from normal to X mode.

Select the cosecant square beam fro better alley detection.

Initiate a steep climb.

2. The use of AWR on the ground is?

Only permitted to assist movement in low visibility conditions.

Permitted provided reduced power is used.

Not permitted.

Permitted provided special precautions, to safeguard personnel and equipment.

3. In Airborne Weather Radar (AWR), the main factors which determine whether a cloud will be detected are

Wavelength/frequency used.

Rotational speed of radar scanner.

Range from cloud.

Diameter of radar scanner.

4. The tilt angle on the AWR at which an active cloud just disappears from the screen is 4 degrees up. If the beam width is 5 degrees and the range to the cloud is 40 nm use the 1 in 60 rule to calculate the approximate height of the cloud relative to the aircraft?

6000 ft above.

4000 ft below.

4000 ft above.

6000 ft below.

5. The ISO-ECHO circuit is incorporated in the AWR?

To allow simultaneous mapping and detection of clouds.

To alert pilots to the presence of cloud.

To display areas of turbulence.

To allow ground mapping.

6. In an Airborne Weather Radar that has a colour cathode ray tube (CRT) the areas of greatest turbulence are indicated on the screen by

Blank iso-echo areas where there is no colour.

Large areas of flashing red colour.

Colour zones being closest together.

Iso-echo areas, which are, coloured black.

7. In order to ascertain whether a cloud return on an Aircraft Weather Radar (AWR) is at or above the height of the aircraft, the tilt control should be set to (assume a beam width of 5 degrees)?

5 degrees up.

0 degrees.

2.5 degrees up.

2.5 degrees down.

8. Before commencing a flight the weather radar should?

Be switched to a range function after push-back to make sure it is functioning.

Be kept at stand-by until line-up with the runway.

Not be switched on until clear of buildings.

Be switched to stand-by, but not used until airborne.

9. Using the airborne weather radar, before take-off?

The antenna tilt control should be set to maximum negative tilt.

The gain control should be adjusted according to the light conditions expected after take-off.

The radar transmitter should not be operated when personnel are observed in the sector ahead of the aircraft.

The contract control should be adjusted to maximum contrast.

10. On an AWR the sequence of colours indicating increasing water droplet size is?

Blue, amber, red.

Green, Yellow, red.

Black, amber, red.

Blue, green, red.

11. When using airborne weather radar in the mapping mode in polar areas one runs the risk?

Of understmating distance because the cold seawater is causing super refraction.

Of aurora borealis (polar light) causing false returns.

Of mistaking the edge of coastal ice off shore for the real coastline.

Of getting a distorted because of the ice reflections.

12. An aircraft flying at 25 00 feet is equipped with AWR. The beam width is 5 degrees. With the radar tilted 3.5 degrees up, the radar is showing top of a cloud return at 105 nm. The approximate height of the cloud is

25 600 ft.

30 300 ft.

14 300 ft.

35 600 ft.

13. Which of the following is a complete list of airborne weather radar antenna stabilisation axes?

Pitch and yaw.

Roll and yaw.

Roll and pitch.

Roll, pitch and yaw.

14. When the airborne weather radar is operating in its primary mode, to detect precipitation?

The radar beam is a cosecant beam.

Maximum tilt on the aerial will often be used.

The range will be limited, compared to the range obtainable in the ground mapping mode.

The radar beam is pencil shaped.

15. The ISO-ECHO feature of an airborne weather radar can be used to detect?

CAT

Wake turbulence.

Areas of possible turbulence is cloud.

Turbulence in cloud.

16. Which of the following lists phenomena that CANNOT be detected by weather radar?

Clear air turbulence; turbulence in cloud with precipitation

Dry hail; clear air turbulence

Snow; clear air turbulence

Snow; turbulence in clouds with preciptation.

17. A weather radar, set to the 100 NM scale, shows a squall at 50 NM. By changing the scale to 50 NM, the return on the radar screen should

Increase in area and appear nearer to the bottom of the screen

Decrease in area and move to the top of the screen

Increase in area and move to the top of the screen

Decrease in area but not change in position on the screen.

18. The pencil shaped beam of an airborne weather radar is used in preference to the mapping mode for the determination of ground features

Beyond 150 NM because the wider beam gives better definition

Beyond 50 to 60 NM because more power can be concentrated in the narrower beam.

When approaching coast-lines in polar regions

Beyond 100 NM because insufficient antenna tilt angle is available with the Mapping mode.

19. In the MAPPING MODE the airborne weather radar utilises a?

Fan shaped beam effective up to a maximum range of 50 nm to 60 nm.

Fan shaped beam effective up to a range of 150 nm.

Pencil beam effective from zero to 150 nm.

Pencil beam effective to a maximum range of 60 nm,

20. In which mode of operation does the aircraft weather radar use a cosecant radiation pattern?

CONTOUR.

MANUAL

WEATHER

MAPPING

21. Which of the following cloud types is most readily detected by airborne weather radar when using the weather beam?

Cumulus.

Cirrocumulus.

Altostratus

Stratus.

22. Which of the following list of phenomena are least likely to be detect by airborne weather radar?

Turbulence in cloud that has precipitation.

Precipiation.

Wet snow and turbulence in cloud that has precipitation.

Clear air turbulence.

23. In Airborne Weather Radar (AWR), the main factors which determine whether a cloud will be detected are

Size of the water droplets and the diameter of the scanner.

Rotational speed of radar scanner and the range from cloud.

Size of the water drops and the wavelength/frequency used.

Range from cloud and the wavelength/frequency used.

24. An airborne weather radar is using a 3 degrees beam. A cloud is detected at a range of 40 nm, If the scanner is tilted up to 3 degrees the cloud disappears. The top of the cloud, in relation to the aeroplane's cruising level is approximately?

12000 ft above the level.

6000 ft above the level.

At the same level.

18000 ft above the level.

25. An airborne weather radar, with a beam width of 4 degrees in azimuth, is being used in the mapping mode. At what maximum range will it be able to detect a 1 nm wide opening in a sea cliff?

45 nm.

60 nm.

4 nm.

15 nm.

26. In weather radar the use of a cosecant beam in 'Mapping' mode enables

Higher definition echoes to be produced giving a clearer picture.

Scanning of a large ground zone producing echoes whose signals are practically independent of distance.

A greater radar range to be achieved.

Better reception of echoes on contrasting terrain such as ground to sea.

27. The airborne weather radar (AWR) cannot detect?

Wet hail.

Dry hail.

Snow.

Moderate rain.

28. What frequency is typical chosen for AWR systems?

93.375 GHz. (9 decimal 375 GHz).

9375 kHz.

93.75 MHz. (93 decimal 5 kHz).

93.75 GHz. (93 decimal 75 kHz).

29. A frequency of airborne weather radar is

9375 MHz.

9375 GHz.

93.75 MHz.

9375 kHz.

30. In an Airborne Weather Radar the areas of greatest turbulence are usually indicated on the screen by?

Blank areas where there is no colour.

Areas which are coloured black.

Colour zones of red or magenta.

Colour zones of green or yellow.

31. In an Airborne Weather Radar that has a colour cathode ray tube (CRT) increasing severity of rain and turbulence is generally shown by a change of colour from

Yellow to orange to red.

Yellow to amber to blue.

Green to red to black.

Green to yellow to red.

32. Airborne weather radar uses a particularly high frequency radar signal, at 9 to 12 GHz, in order to?

Make it possible to present a colour display of the weather situation.

Al of the answers in this question are correct.

Get the most accurate range and bearing inforation.

Get good returns from droplets of water and other sorts of precipitation.

33. A side lobe from an aerial of a weather radar may produce an echo on the screen known as a "height ring". The pilot can use this?

To determine the aeroplane's height above the surface.

As a zero point for range measurement.

To determine that the weather radar is functioning.

As a range marker.

34. The heaviest turbulence is likely t be encountered?

Where the area of heaviest precipitation is closest to the edge of the thunderstorm cell.

In the area of heaviest precipitation.

In the very core of a thunderstorm cell.

About half way between two thunderstorm cells.

35. When using the AWR to detect long range ground features the most suitable mode of operation or beam selected would be?

The fan shaped beam.

The contour mode.

The mapping mode.

The manual mode.

36. The main factors, which affect whether an AWR will detect a cloud, are?

The size of the water droplets and the diameter of the antenna reflector.

The size of the water droplets and the wavelength/frequency.

The scanner rotation rate and the wavelength/frequency.

The size of the water droplets and the range to the cloud.

37. A frequency of 10 GHz is considered to be the optimum for use in airborne weather radar system because

Greater detail can be obtained at the more distant ranges of the smaller water droplets.

Less power output is required in the mapping mode

Static interference is minimised

The larger water droplets will give good echoes and the antenna can be kept relatively small.

38. The antennae of modern airborne weather radars are stabilized by means of?

Mercury swiches.

Artificial gravity switches.

Inputs from the aircraft's atitude system.

Feedback from the antenna accelerometers.

39. In the MAPPING MODE the airborne weather radar utilises a

Pencil beam effective from zero to 150 NM.

Pencil beam to a maximum range of 60 NM.

Fan shaped beam effective up to a range of 15 NM.

Fan shaped beam effective up to a maximum of 50 NM to 60 NM range.

40. AWR contour mode is used for?

Shorts range mapping.

Identifying areas of maximum turbulence within a cloud.

Long range mapping.

Identifying rain bearing clouds.

41. The airborne weather radar uses the following wavelength?

Myriametic.

Hectometric.

Centimetric.

Metric.

42. The "gain" control knob of an AWR adjusts?

The automatic gain control of the AWR is activated.

The receiver sensitivity in order to achieve optimum target acquisition.

The power level of the transmitted energy is made dependent on the selected range.

The brightness of the display.

43. Is is possible for weather radar to be operated on the ground?

Only whilst taxling

No, never.

Yes, if operating within regulations and guidelines.

Yes, always.

44. On the AWR display the most severe turbulence will be shown?

Alternating red and white stripes.

By a black hole.

By steep colour gradients.

In flashing red.

45. The colours used on a conventional AWR to indicate increasing intensity of returns are?

Green, Amber, Red.

Blue, Amber, Red.

Green, Yellow, Orange.

Blue, Green, Red.

46. Airborne weather radars use a frequency of approximately 9 GHz because?

The short wavelength allows signals to be reflected from cloud water droplets of all sizes.

It has a short wavelength, so producing higher frequency returns.

The frequency penetrates cloud quite easily enabling good mapping of ground feature in the mapping mode.

The wavelength is such reflections are obtained only from larger water droplets.

47. In an AWR with a colour CRT areas of greater turbulence are indicated by?

Large areas of flashing red.

Iso-echo areas coloured black.

Most rapid change of colour.

Iso-echo areas with no colour.

48. In an AWR with a 5 degrees beam width how do you orient the scanner to receive returns from clouds that are at or below your level?

5 degrees down tilt.

0 degrees tilt.

2.5 degrees down tilt.

2.5 degrees up tilt.

49. On a weather radar, the greatest turbulence is likely in an area where targets are?

Coloured red.

Show a rapid gradient of change from magenta to yellow.

Coloured magenta.

Show a clearly defined hole.

50. Which statements relating to the stabilization system of airborne weather radar antennae is true?

The are stabilized with respect to the yaw axis, but not with respect to the pitch and roll axes.

They are stabilized with respect to the pitch, roll and yaw axes.

They are stabilized with respect to the pitch and roll axes but not with respect to the yaw axis.

The pilot can choose the axes of stabilization with the system's stabilization selector switch.

Question Bank

Questions for AWR