Vayudoot Aviation

1. In which zone of a jet stream is the strongest CAT to be expected?

Exactly in the centre of the core.

The cold air side of the core

The warm air side of the core.

Exactly in the centre of the core.

2. At the top of orographic waves, in mountainous regions, the cloud most likely to be encountered is

cirrostratus.

cirrus.

altocumulus lenticularis.

cumulus mediocris.

3. A zone of strong convection currents is encountered during a flight. In spite of moderate gust you decide to continue the flight. What are your precautionary measures?

Decrease the speed / try to descend below the zone of convective currents

Increase the speed / try to descend below the zone of convective currents.

Increase the speed / try to climb above the zone of convective currents if aircraft performance parameters allow.

Decrease the speed / try to climb above the zone of convective currents if aircraft performance parameters allow

4. What is the effect of a strong low level inversion?

It promotes extensive vertical movement of air.

It results in good visual conditions

It prevents vertical windshear

It promotes vertical windshear.

5. You intend to carry out a VFR flight over the Alps, on a hot summer day, when the weather is unstable. What is the best time of day to conduct this flight?

Morning.

Early evening.

Afternoon

Mid-day.

6. Fallstreaks or virga are?

water or ice particles falling out of a cloud that evaporate before reaching the ground

strong downdraughts in the polar jet stream, associated with jet streaks

gusts associated with a well developed Bora

strong katabatic winds in mountainous areas and accompanied by heavy precipitation

7. Which degree of aircraft turbulence is determined by the following ICAO description? “There may be moderate changes in aircraft attitude and/or altitude but the aircraft remains in positive control at all times. Usually, small variations in air speed. Changes in accelerometer readings of 0.5 to 1.0 g at the aircraft’s enter of gravity. Occupants feel strain against seat belts. Loose objects move about. Food service and walking is difficult.”

Severe

Moderate.

Light.

Violent.

8. The presence of altocumulus lenticularis is an indication of the

presence of valley winds

development of thermal lows

presence of mountain waves

risk of orographic thunderstorms

9. What units are used to report vertical wind shear?

kt/100 FT.

kt

m/sec.

m/100 FT.

10. How does moderate turbulence affect an aircraft?

Large, abrupt changes in altitude or attitude occur but the aircraft may only be out of control momentarily

Changes in altitude or attitude occur but the aircraft remains in positive control at all times.

Continued flight in this environment will result in structural damage.

Rapid and somewhat rhythmic bumpiness is experienced without appreciable changes in altitude or attitude

11. Which cloud type may indicate the presence of severe turbulence?

Cirrocumulus

Altocumulus lenticularis

Stratocumulus

Nimbostratus

12. Which of the following conditions are most favourable to the formation of mountain waves?

Stable air at mountain top altitude and a wind at least 20 knots blowing across the mountain ridge.

Either stable or unstable air at mountain top and a wind of at least 30 knots blowing parallel to the mountain ridge.

Unstable air at mountain top altitude and a wind at least 20 knots blowing across the mountain ridge.

Moist unstable air at mountain top and wind of less than 5 knots blowing across the mountain ridge.

13. Which cloud type may indicate the presence of severe turbulence?

Altocumulus lenticularis

Nimbostratus

Stratocumulus

Cirrocumulus

14. A flight is to depart from an airport with runways 09 and 27. Surface wind is 270/05; an inversion is reported at 300 feet with turbulence and wind shear. The wind just above the inversion is 090/30. What is the safest departure procedure?

Depart runway 27 with maximum throttle during the passage through the inversion.

Depart on runway 09 with a tailwind.

Depart runway 27 with as steep an ascent as possible.

Take-off is not possible under these conditions.

15. Low level vertical wind shear can be expected during the night

in association with radiation inversions

and early morning only in summer

and early morning only in winter

in unstable atmospheres

16. The degree of clear air turbulence experienced by an aircraft is proportional to the

stability of the air

intensity of vertical and horizontal windshear

height of the aircraft

intensity of the solar radiation

17. The most dangerous low level wind shears are encountered

near valleys and at the windward side of mountains.

during any period when wind speed is greater than 35 kt and near valleys

when strong ground inversions are present and near thunderstorms

in areas with layered clouds and wind speeds higher than 35 kt

18. The vertical extent of the friction layer depends primarily on

wind speed, roughness of surface, temperature

roughness of surface, temperature, local time

temperature, local time, environmental lapse rate

stability, wind speed, roughness of surface

19. What is normally the most effective measure to reduce or avoid CAT effects?

Decrease of speed.

Increase of speed.

Change of course.

Change of flight level.

20. A wide body aircraft takes off on a clear night in Dhahran, Saudi Arabia. Shortly after take off the aircraft’s rate of climb drops to zero. This can be due to

sand/dust in the engines

low relative humidity

very pronounced downdrafts

a very strong temperature inversion

21. At the top of orographic waves, in mountainous regions, the cloud most likely to be encountered is

cumulus mediocris

cirrus.

cirrostratus.

altocumulus lenticularis.

22. On a clear summer day, turbulence caused by solar heating is most pronounced

about midmorning

during the early afternoon

immediately after sunset

during early morning hours before sunrise

23. Above and below a low level inversion the wind is likely to

change in direction but not in speed

change in speed but not in direction

change significantly in speed and direction

experience little or no change in speed and direction

24. Under which of the following conditions is the most severe CAT likely to be experienced?

A westerly jet stream at low latitudes in the summer

A straight jet stream near a low pressure area

A curved jet stream near a deep trough

A jet stream, with great spacing between the isotherms

25. Low level wind shear is likely to be greatest

at the condensation level when there is no night radiation.

at the condensation level when there is strong surface friction

at the top of the friction layer

at the top of a marked surface-based inversion

26. Vertical wind shear is

horizontal variation in the horizontal wind

vertical variation in the vertical wind

vertical variation in the horizontal wind

horizontal variation in the vertical wind

27. All pilots encountering Clear Air Turbulence are requested to report it. You experience CAT which causes passengers and crew to feel definite strain against their seat belt or shoulders straps. Unsecured objects are dislodged. Food service and walking are difficult. This intensity of CAT should be reported as

extreme

severe

light

moderate

28. The turbulence which occurs at high flight levels (above FL 250) is mainly of the type Clear Air Turbulence. In what way can moderate to severe Clear Air Turbulence affect an aircraft, the flight and the passengers?

The turbulence is a small scale one and can cause damage of worn out type. The manoeuvring of the aircraft will be made more difficult or even impossible. For the passengers the flight will be unpleasant.

The turbulence can be resembled with the roughness of a washing-board (small scale) and will not have influence on the aircraft and its solidity, but will make flight a little more difficult. The passengers will seldom notice anything of this turbulence

The turbulence is a large scale one (waving) so that the aircraft will be difficult to manoeuvre. The passengers will feel some discomfort.

The turbulence is wave like which makes the flight unpleasant for the passengers but the manoeuvring will not be affected essentially

Question Bank

Questions for TURBULENCE 1