Ice and rain protection

Question 1

Formation of ice

Answer 1

conditions, icing may occur in conditions of high humidity or air temp is at or below 0 degrees
due to local reduction in pressure, may occur in high humidity when the ambient air is above 0 degrees

Question 2

Types of icing and snow

Answer 2

rime ice - opaque, white, granular ice which forms on leading edges
clear ice - transparent, dense, tough and adhesive. slow freezing and can be severe
rain ice - aircraft frame at sub zero temp flies in an area where rain is falling from warmer air above.
packed snow - flying through wet snow or sleet either in or beneath clouds, occurs if airframe shapes are not well streamlined
hoar frost - light crystalline deposit which forms away from clouds and precipitation. temp must be below 0 degrees. example is an aircraft parked outside on clear winter nights.

Question 3

Effects from environment

Principles of operation

Answer 3

provision - aircraft will be prone to flying through tough weather conditions, the effects of which may endanger performance and safety.

Question 4

Areas which are sensitive to ice formation

Answer 4

aerofoil surfaces
engine intakes 
engine internal surfaces 
rotor blades and propellers 
windscreens 
instrumentation probes and vanes 
control hinges and linkages 
weapons and weapon carriers

Question 5

Effects of ice formation on aircraft

Answer 5

aerodynamic effects - pattern of the airflow becomes modified round the affected part.