17.5 Flashcards
Ice formation on a propeller when in operations produces what?
Distortion to aerofoil section
Which region is at the most risk of icing
Propeller blades, spinner and engine air intake
What fluid is used to prevent ice formation
Iso-Propyl-Alcohol (alcohol based fluid)
Where is the Iso-propyl-alcohol fluid stored
Reservoir housed within airframe
What does a propeller electric de-ice system consist of
- electrical energy source (resistance heating element)
Which third are the heating boots/mats containing electrical elements are bonded to
Inner third of each propeller blade
Electrical power is supplied from the aircraft system and is transferred from the engine by what
- spring loaded carbon brushes rubbing against copper slip rings
A single element boot/mat has how many electrical leads
- 2 electrical leads
Why is cyclic heating employed
-employed to lessen electrical load
- prevent run-back
A cyclic timer can be between
- 15-30 seconds
- complete cycle of 2 to 6 mins
What system is utilised to accommodate both propeller and spinner requirements
Two speed cycling system
What is fast cycle
- approx 2 mins. Used for atmospheric temp of +10c down to -6c
When is fast cycle used
- at high air temp when water concentrations are greater (10c to -6c)
When is a slow cycle used
Lower temp ranges (approx below -6*c)
What is a slow cycle
- approx 6 mins- Used for atmospheric temperatures below -6*c
