2. Summer Monsoon regimes of the World

3. Monsoon winds from Southern Hemisphere

4. Global Pressure Pattern in July

5. Onset of Monsoon dates over India

6. Wind shears in Monsoon
Monsoon means strong reversal of winds implying wind shear conditions, creating a hazardous flight environ
Winds at lower levels at 3000 to 5000 ft peninsular India experiences low level Jet streams

7. Low Level Jet Stream in SW monsoon

8. 6000ft Westerly Winds 20 knots
Aircraft suffers a ballooning effect on account of low-level jet stream
Shear Zone
6000ft
Low level westerly jet stream of 40 knots and more
Temporary increase in airspeed giving a greater lift and significantly reduce the rate of decent and returning below the intended decent

9. Opposite situations will occur in winter with inversion of temperature over the helipad in association with foggy conditions
Shear Zone
Calm or light winds

10. Vertical/Slant visibility is deceptive

11. LATE CHIEF MINISTER, MR. Y
LATE CHIEF MINISTER, MR.Y.RAJASEKAR REDDY’S HELICOPTER CRASH

12. Flight Regulation for Helicopters
The helicopters are strictly expected to fly only under VMC.
Due to circumstances beyond the control, sometimes the craft has to enter the cloud.
Hence some elementary knowledge of conditions for the formation of clouds and their identification, to be refreshed by the participants is desirable

13. The Formation of Clouds
Cloud formation is associated with rising air
Rising air cools adiabatically
The air reaches its dew point
Cloud is formed
The form (shape) of the cloud depends upon the stability of the rising air
Layer (stratiform) cloud forms in stable air
Heaped (cumuliform) cloud forms in unstable air

14. Clouds can be categorized on the basis of the “lifting mechanism” that is the process which causes the air to move upwards

15. The formation of clouds
There are 4 categories:
Convection cloud
Orographic cloud
Turbulence cloud
Frontal cloud

16. Convection cloud Air is heated at the surface
Air rises, cools adiabatically and reaches its dewpoint
Cumulus or cumulonimbus cloud forms

17. Formation of convection cloud

18. Convection cloud Convection cloud can occur over land and sea
It often forms when cold air from high latitudes is moving southwards over the ocean
The rising air currents are called thermals

19. Formation of Convection cloud

20. Orographic cloud Air meets high ground
Air rises, cools adiabatically and reaches its dewpoint
Cloud can be stratiform (stable air) or cumuliform (unstable air)

21. Formation of Orographic cloud

22. Orographic cloud
The extent of the cloud depends upon the extent of the high ground
The height of the cloud is controlled by the height at which it reaches its dewpoint
Famous orographic clouds include the tablecloth and the levanter

23. Turbulence cloud The air is travelling across a colder surface
The air moves upwards as part of the turbulence
The air cools by conduction at the surface and adiabatically as it rises
The cloud formed is stratus cloud

24. Formation of Turbulence cloud

25. Stratus cloud

26. Cirrus cloud

27. Nimbostratus

28. Frontal cloud The warmer air rises upwards because it is less dense
The rising air cools adiabatically and reaches its dewpoint
The cloud will be Stform in stable air and Cuform in unstable air

29. Formation of frontal cloud: warm front

30. Formation of frontal cloud: cold front

31. Cloud Names

32. WMO System

33. Cloud Names Cirrus - Means a lock of hair or a tuft of horsehair
Cumulus - Means an accumulation or a pile
Stratus- Means to spread out, to cover a layer
Nimbus – Means Rain

34. Cloud Classifications
Height
W.M.O.
Form
Formation

35. Classification by Height
Cloud Base 3 – 18 km
Classification by Height
High
Cloud Base 3 – 18 km
Medium
Cloud Base 2 – 8 km
Low
Cloud Base 0 – 2 km
Cloud Base 0 – 2 km
Great Vertical Extent

36. Stratocumulus

37. Genera
High Clouds
Cirrus
Cirrocumulus
Cirrostratus

38. Cirrus
Detached clouds in the form of white, delicate filaments or white or mostly white patches or narrow bands. These clouds have a fibrous (hair-like) appearance, or a silky sheen, or both.

39. Cirrocumulus
Thin, white patch, sheet of layer of cloud without shading, composed of very small elements in the form of grains, ripples, etc. merged or separate, and more or less regularly arranged, most of the elements have an apparent width of less than one degree.

40. Cirrostratus
Transparent, whitish cloud veil of fibrous (hair-like) or smooth appearance, totally or partly covering the sky, and generally producing halo phenomena.

41. Genera
Medium Clouds
Altocumulus
Altostratus
Nimbostratus

42. Altocumulus
White or grey, or both white and grey, patch, sheet or layer of cloud, generally with shading, composed of laminae, rounded masses, rolls etc. which are sometimes partly fibrous or diffuse and which may or may not be merged; most of the regularly arranged small elements usually have an apparent width between one and five degrees.

43. Altostratus
Greyish or bluish cloud sheet or layer of striated, fibrous or uniform appearance, totally or partly covering the sky, and having parts thin enough to reveal the sun at least vaguely, as through ground glass. Altostratus does not show halo phenomena.

44. Nimbostratus
Grey cloud layer, often dark, the appearance of which is rendered diffuse by more or less continuously falling rain or snow, which in most cases reaches the ground.
It is thick enough throughout to blot out the sun. Low, ragged clouds frequently occur below the layer, with which they may or may not merge

45. Genera
Low Clouds
Stratocumulus
Stratus

46. Stratus
Generally grey cloud layer with a fairly uniform base, which may give drizzle, ice prisms or snow grains. When the sun is visible through the cloud, its outline is clearly discernible. Stratus does not produce halo phenomena except, possibly, at very low temperatures.
Sometimes stratus appears in the form of ragged patches.

47. Genera
Clouds of Great Vertical Extent
Cumulus
Cumulonimbus

48. Cumulus
Detached clouds, generally dense and with sharp outlines, developing vertically in the form of rising mounds, domes or towers, of which the bulging upper part often resembles a cauliflower the sunlit parts of these clouds are mostly brilliant white, their base is relatively dark and nearly horizontal.
Sometimes cumulus is ragged.

49. Cumulonimbus
Heavy and dense cloud, with a considerable vertical extent, in the form of a mountain or huge towers.
At least part of its upper portion is usually smooth, of fibrous or striated, and nearly always flattened; this part often spreads out in the shape of an anvil or vast plume.
Under the base of this cloud which is often very dark, there are frequently low ragged clouds either merged with it or not, and precipitation sometimes in the form of virga .

50. Classification by Form
Cirriform
Cumuliform
Stratiform

51. Cirriform
High Cloud
Tenuous
Ice crystals
Associated with depressions

52. Cumuliform
Unstable Air
Discrete clouds
Vigorous upward motion
Showers

53. Stratiform Stable Air Widespread Slow upward motion
Continuous precipitation

54. The Importance of Dew point Temperature
During pre flight planning, if you find temperature and dew point temperature are very close, you are bound to encounter clouds
The cloud base will be around
(T– Td ) x 400 ft
The Difference between ceiling and base of cloud The term ceiling is applicable when 5/8 or more is below
20,000 feet, otherwise the term base.

55. Reverting back to Monsoon Flying the following slides can amplify the hazards of aviation

56. Runway highly contaminated due to heavy rain
Sumai
Island
25 KTS SW
WINDS
Runway highly contaminated due to heavy rain 56

57. A passenger plane skidded off the runway and crashed into a building after landing on the Thai resort island of Samui on Tuesday, killing the chief pilot and injuring at least seven people including foreign tourists.
The Bangkok Airways flight landed in stormy weather and hit the airport's old air traffic control tower, which had been converted into a fire station, said Kanikka Kemawutanond, director-general of the Department of Civil Aviation. The co-pilot and six tourists were hurt. 57

58. The Controls of Monsoon
ITCZ
Elnino
Indian Ocean Dipolar Temperature effect
The Effect of Mascrean high pressure area
Madden Julian Oscillation 58

60. General Circulation

61. Animated circulation of global winds61

62. AIRFRANCE-447 CRASH ON 1ST JUNE 2009

63. ITCZ EQ PARIS ETA 9UTC 1ST JUNE ATLANTIC AFRICA CRASH 2UTC 1ST JUNE
LAT 4N
LONG30W
ITCZ EQ
CRASH 2UTC 1ST JUNE
BRAZIL
RIO
DEP 22UTC
31ST MAY

65. CRASH

72. Extreme Turbulence 72

73. Radar is only an aid not an end by itself
Contributing safety factors - The crew did not detect an area of convective turbulence (cloud), either visually or by radar. - The aircraft penetrated an area of severe convective turbulence. - The area of convective turbulence encountered by the aircraft comprised ice crystals. - The aircraft radar had limited capability to detect cloud that comprised ice crystals. [Minor safety issue]