Vayudoot Aviation

1. Freezing rain occurs when

water vapour first turns into water droplets

rain falls into a layer of air with temperatures below 0°C

snow falls into an above-freezing layer of air

ice pellets melt

2. A vertical temperature profile indicates the possibility of severe icing when the temperature profile

indicates temperatures below -40°C

coincides with a dry adiabatic lapse rate

intersects the 0°C isotherm twice

indicates temperatures above 3°C

3. Under which conditions would you expect the heaviest clear ice accretion to occur in a CB?

Between -2°C and -15°C

Close to the freezing level

Between -20°C and -30°C

Between -30°C and -40°C

4. Hoar frost is most likely to form when

flying inside convective clouds.

flying in supercooled drizzle.

flying inside stratiform clouds.

taking off from an airfield with a significant ground inversion.

5. Glaze or clear ice is formed when supercooled droplets are

small and freeze rapidly

small and at a temperature just below freezing

large and at a temperature just below freezing

of any size at temperatures below -35°C

6. Clear ice is dangerous because it

spreads out and contains many air particles

is heavy and is difficult to remove from the aircraft surfaces

is not translucent and forms at the leading edges

is translucent and only forms at the leading edges

7. A small supercooled cloud droplet that collides with an airfoil will most likely

travel back over the wing, creating clear ice

freeze immediately and create clear ice

travel back over the wing, creating rime ice

freeze immediately and create rime ice

8. In which of these cloud types can icing be virtually ruled out?

AS

NS

SC

CS

9. In which environment is aircraft structural ice most likely to have the highest rate of accretion?

Cirrus clouds

Stratus clouds

Snow

Freezing rain

10. Which of the following statements is true regarding moderate-to-severe airframe icing?

It always occurs in altostratus cloud

It will occur in clear-sky conditions

It is likely to occur in nimbostratus cloud

It may occur in the uppermost levels of a cumulonimbus capillatus formation

11. In which of these cloud types can icing be virtually ruled out?

CU

NS

CI

SC

12. You have been flying for some time in dense layered cloud. The outside air temperature is - 25°C. Which of the following statements is true?

If you do not have weather radar on board there is no need to worry as CB is unlikely to form in such cloud

Severe airframe icing is unlikely under these conditions

In a dense layered cloud icing is unlikely

Severe airframe icing is quite likely under these conditions

13. The most dangerous form of airframe icing is

hoar frost

rime ice

clear ice.

dry ice

14. Two aircraft, one with a sharp wing profile (S), and the other with a thick profile (T), are flying through the same cloud with same true airspeed. The cloud consists of small supercooled droplets. Which of the following statements is most correct concerning ice accretion?

Aircraft S and T experience the same amount of icing

Neither of the aircraft accumulate ice due to the small size of droplets

Aircraft T experiences more icing than S

Aircraft S experiences more icing than T

15. How does freezing rain develop?

Rain falls through a layer where temperatures are below 0°C

Rain falls on cold ground and then freezes

Through melting of ice crystals

Through melting of sleet grains

16. Large supercooled water drops, which freeze on impact on an aircraft, form

rime ice

cloudy ice

hoar frost

clear ice

17. How does a pilot react to heavy freezing rain at 2000 FT/AGL, when he is unable to deice, nor land?

He descends to the warm air layer below

He ascends to the cold air layer above

He turns back before the aircraft loses maneuverability

He continues to fly at the same altitude

18. In which of the following situations can freezing rain be encountered?

Ahead of a cold front in the winter

Ahead of a warm front in the winter

Ahead of a cold front in the summer

Behind a warm front in the summer

19. Freezing fog exists if fog droplets

are frozen

freeze when temperature falls below zero

are freezing very rapidly

are supercooled

20. While descending through a cloud cover at high level, a small amount of a white and rough powder-like contamination is detected along the leading edge of the wing. This contamination is called

Frost

Clear ice.

Mixed ice.

Rime ice.

21. Supercooled droplets can be encountered

at any time of the year

only in winter above 10000 FT

only in winter at high altitude

in winter only in high clouds

22. During the formation of rime ice in flight, water droplets freeze

slowly and spread out

rapidly and do not spread out

slowly and do not spread out

rapidly and spread out

23. Which of the following conditions is most likely to cause airframe icing?

GR

+FZRA

PE

SHSN

24. Supercooled droplets are always

at a temperature below -60°C

at a temperature below freezing

large and at a temperature below freezing

small and at a temperature below freezing

25. Freezing precipitation occurs

mainly in the form of freezing hail or freezing snow

only in the precipitation of a warm front

mainly in the form of freezing rain or freezing drizzle

only in the precipitation of a cold front

26. At what degree of icing should ICAO’s “Change of course and/or altitude desirable” recommendation be followed?

Light

Moderate

Extreme

Severe

27. Hoar frost forms on an aircraft as a result of

droplets forming on the aircraft and then freezing

water vapour turning directly into ice crystals on the aircraft surface

freezing rain striking the aircraft

small super-cooled droplets striking the aircraft

28. On the approach, the surface temperature is given as -5°C. The freezing level is at 3000 FT/AGL. At 4000 FT/AGL, there is a solid cloud layer from which rain is falling. According to the weather briefing, the clouds are due to an inversion caused by warm air sliding up and over an inclined front. Would you expect icing?

No, flights clear of cloud experience no icing

Yes, between ground level and 3000 FT/AGL

No, absolutely no icing will occur

Yes, but only between 3000 and 4000 FT/AGL.

29. Supercooled droplets can occur in

clouds but not in precipitation

clouds, fog and precipitation

precipitation but not in clouds

clouds but not in fog

30. What type of fronts are most likely to be present during the winter in Central Europe when temperatures close to the ground are below 0°C, and freezing rain starts to fall?

Cold fronts.

Warm fronts, warm occlusions.

Cold occlusions.

High level cold fronts.

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