Ice And Rain Protection Flashcards
When does ice formation occur
When an aircraft is subject to moisture laden air and a temperature where moisture striking the aircraft is 0 degrees or colder.
What is the state called where water is below 0 degrees but is still in liquid state
Super cooled
What are the 4 classification of ice severity
Trace - not hazardous
Light - Causes problems for 1 hour or upwards
Moderate - potentially hazardous even in short contact
Severe - Aircraft should not fly in these conditions
What are the critical icing areas on an aircraft
Aerofoil surfaces
Engine intake
Rotor blades
Windscreen
Static vents and pitot probes
Control surfaces
Weapons and carriers
What are the effects of ice forming on aircraft
Decreases lift and increases drag
Added weight
Increase in fuel consumption
Reduce take off/climbing speed
Disrupt instrument readings
Ice chunks can cause physical damage
What is rotor blade icing
The buildup of ice formation on the tip of the blade, causing imbalances and blade shape changes
What is ice shedding
If blades take up a different rotational blade due to ice, violent vibrations can occur and CoG will be displaced
When should protective covers be fitted to the aircraft
When the aircraft is dry to avoid the cover freezing to a wet aircraft.
Should not be fitted over snow ice or frost
What 2 systems are used to detect ice
Pressure differential ice detector
Icing condition monitor
What are the 2 categories of ice protection system
Passive
Active
What is the difference between anti icing and de icing
Anti - prevents build up of ice
De - remove ice that has already formed
What are the 4 kinds of ice protection systems
Momentum separation device
Bleed air from engine
Electrical airframe
Mechanical airframe (rubber boots)
How does a mechanical ice protection (de icing boot) work
Inflation of rubber boots on leading edge that cracks and disperses ice on inflation and deflation
How does a hot air airframe work
Hot air is bled from the engine and directed through relevant areas to prevent and clear ice formation
How does electrical ice protection work
Electrical heating on the leading edges. Helicopters use intermittent heating of the blades to prevent ice buildup
What devices are used to protect a windscreen from ice and rain
Ice - thing gold leaf heating element
Rain - windscreen wipers
When should wiper blades be replaced
Worn to limits
Damaged
Contaminated
