Icing Flashcards
Problems with icing
Changes the shape of the wing
Increase the stall speed
Engine icing instrument error
Higher temperatures
The amount of freezing nuclei are reduced more at higher altitudes
Freezing process of SCWD
When the droplet hits the wing, part of the droplet freezes and releases latent heat which keeps part of it liquid. This liquid part flies along gone wing increasing the surface area
Rate of freezing for SCWD
For every degree below below 0 only 1/80 will freeze
Effect of icing on a thinner wings
Less air displacement
Sharper
More will adhere it it
Effect of high speed
Less opportunity for water droplets to move out the way which increases the risk
Different types of icing
Hoar frost Rime ice Clear ice Freezing rain Mixed ice Cloudy ice
Hoar frost
Sublimation due to rapid cooling now the earths surface causing ice to freeze in direct contact
Examples of hoar frost happening during flying
Flying through cold fronts to a warm front with high humidity, cold a/c causes sublimation
Fuel tanks of the wing remain colder for longer
Rime ice
Most common Higher altitudes flying in cloud Smaller SCWD white opaque in appearance Brittle Develops forward Mostly from stratus cloud due to min vertical extent
Clear ice
Rapid accumulation of ice covering a large surface area
Hard to remove
SCWD
Colder you are the less of the water droplets are pushed back
Common on Cu clouds due to currents
Freezing rain
Rain forms in a warm front and falls through into the cold front producing freezing rain
Can stretch hundreds of miles
Mixed ice
Mixture of rime and clear ice
Not very common
Mostly formed Nb
Gives a horn shape due to rime forming forwards and clear forming back wards
Cloudy ice/packed snow
Wing is wet and ice and snow crystals attach to the wing
Warm to cold
Builds forward
Ice crystals
Tiny crystals of frozen water vapour
Gets into engine and can cause a reduction in power
ITCZ is the areas at most risk of this
