Vayudoot Aviation

1. When switching on the weather radar, after start-up, a single very bright line appears on the screen. This means that the?

Transmitter is faulty.

Scanning of the cathode ray tube is faulty.

Scanner is not rotating.

Receiver is faulty.

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

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

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

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

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

3. 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?

0 degrees tilt.

2.5 degrees up tilt.

2.5 degrees down tilt.

5 degrees down tilt.

4. The heaviest turbulence is likely t be encountered?

In the very core of a thunderstorm cell.

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

About half way between two thunderstorm cells.

In the area of heaviest precipitation.

5. 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.

6. Ground checks of AWR are?

Prohibited at all times.

Allowed under specific health and safety regulations.

Unrestricted.

Allowed only when the aircraft has undergone major servicing.

7. Weather radar is used by the pilot to assist in the?

Detection of other aircraft through clouds.

Detection and determination of a route through active cloud formations.

Detection and avoidance of potentially turbulent cloud cells.

Detection and avoidance of turbulence.

8. Before commencing a flight the weather radar should?

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

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

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

Not be switched on until clear of buildings.

9. 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.

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

Cirrocumulus.

Cumulus.

Altostratus

Stratus.

11. The use of AWR on the ground is?

Permitted provided special precautions, to safeguard personnel and equipment.

Permitted provided reduced power is used.

Not permitted.

Only permitted to assist movement in low visibility conditions.

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

By a black hole.

Alternating red and white stripes.

In flashing red.

By steep colour gradients.

13. 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 above.

6000 ft below.

4000 ft below.

14. The stabilisation of the weather radar aerial is effective?

For up to +/- 20 degrees of combined pitch and roll.

For up to +/- 30 degrees of combined pitch and roll.

For up to +/- 5 degrees in pitch and roll.

For up to +/- 40 degrees of combined pitch and roll.

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

The mapping mode.

The manual mode.

The fan shaped beam.

The contour mode.

16. 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.

Range from cloud and the wavelength/frequency used.

Rotational speed of radar scanner and the range from cloud.

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

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

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

Increase in area and move to the top of the screen

18. 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)?

2.5 degrees down.

2.5 degrees up.

5 degrees up.

0 degrees.

19. The ISO-ECHO facility of an airborne weather radar is provided in order to

Extend the mapping range.

Give an indication of cloud tops.

Inhibit unwanted ground returns.

Detect areas of possible severe turbulence in cloud.

20. Airborne weather radar system use a wavelength of approximately 3 cm in order to

Detect the smaller cloud formations as well as large.

Transmit at a higher pulse repetition frequency for extended range.

Obtain optimum use of the Cosecant squared beam.

Detect the larger water droplets.

21. AWR in the __________ Mode progressively _________ As distances ___________ To equalise screen brightness?

Weather, decreases gain, increases.

Mapping, increases gain, decreases.

Mapping, decreases power, decreases.

Weather, increases power, decreases.

22. AWR contour mode is used for?

Identifying areas of maximum turbulence within a cloud.

Identifying rain bearing clouds.

Shorts range mapping.

Long range mapping.

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

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

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

When approaching coast-lines in polar regions

Beyond 150 NM because the wider beam gives better definition

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

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

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

The contract control should be adjusted to maximum contrast.

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

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

Of aurora borealis (polar light) causing false returns.

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

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

Of getting a distorted because of the ice reflections.

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

Green, Yellow, Orange.

Blue, Green, Red.

Blue, Amber, Red.

Green, Amber, Red.

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

Coloured magenta.

Show a clearly defined hole.

Coloured red.

Show a rapid gradient of change from magenta to yellow.

28. If the AWR transmitter is to be switched on before take-off the scanner should be tilted up with?

none of the above.

The weather mode selected.

The mapping mode selected.

Either of the modes selected.

29. What frequency is typical chosen for AWR systems?

93.75 MHz. (93 decimal 5 kHz).

93.375 GHz. (9 decimal 375 GHz).

93.75 GHz. (93 decimal 75 kHz).

9375 kHz.

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

Dry hail.

Snow.

Wet hail.

Moderate rain.

31. In general the operation of airborne weather radar equipment on the ground is

Permitted anywhere

Unrestrictedly permitted in aerodrome maintenance areas

Only permitted with certain precautions, to safeguard health of personnel and to protect equipment.

Totally prohibited

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

Higher definition echoes to be produced giving a clearer picture.

A greater radar range to be achieved.

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

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

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

Maximum tilt on the aerial will often be used.

The radar beam is pencil shaped.

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

The radar beam is a cosecant beam.

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

CONTOUR.

WEATHER

MAPPING

MANUAL

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

Get the most accurate range and bearing inforation.

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

Al of the answers in this question are correct.

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

36.
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?

Switch over from normal to X mode.

Initiate a steep climb.

Select the cosecant square beam fro better alley detection.

Increase the range setting of the radar.

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

Wavelength/frequency used.

Range from cloud.

Diameter of radar scanner.

Rotational speed of radar scanner.

38. An airborne weather radar unit transmits a 5 degrees beam from a parabolic dish aerial reflector assembly. If the wavelength is 4 cm, the diameter of the dish is?

87.5 in.

87.5 cm

56 cm.

20 cm.

39. Airborne Weather Radar has been primarily developed to detect?

The kinds of precipitation, which are usually accompanied by turbulence.

All kinds of frozen precipitation such as hail, snow and graupel.

Areas of severe clear air turbulence.

Areas of wind sheer and severe aircraft icing.

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

No, never.

Only whilst taxling

Yes, always.

Yes, if operating within regulations and guidelines.

41. On the airborne weather radar display in WX mode, different colours use used?

To display ground height differences.

To display different intensity of precipitation.

To display clouds, indicating different levels of visibility.

To display echoes from other aircraft.

42. The AWR can be used on the ground provided: 1. The aircraft is clear of personnel, buildings and vehicles. 2. The conical beam is selected. 3. Maximum up tilt is selected. 4. The AWR must never be operated on the ground

1, 2, 3.

2, 3.

1, 2.

4

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

Snow; turbulence in clouds with preciptation.

Clear air turbulence; turbulence in cloud with precipitation

Dry hail; clear air turbulence

Snow; clear air turbulence

44. 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.

15 nm.

4 nm.

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

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.

The automatic gain control of the AWR is activated.

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

Blank areas where there is no colour.

Colour zones of green or yellow.

Areas which are coloured black.

Colour zones of red or magenta.

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

Roll and yaw.

Roll, pitch and yaw.

Pitch and yaw.

Roll and pitch.

48. 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?

At the same level.

12000 ft above the level.

6000 ft above the level.

18000 ft above the level.

49. 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

14 300 ft.

35 600 ft.

30 300 ft.

25 600 ft.

50. The theoretical maximum range for an airborne weather radar is determined by the?

Pulse length.

Pulse repetition frequency.

Carrier wave frequency.

Beam width.

Question Bank

Questions for AWR