Aircraft Auxiliary System: Ice Protection

Aircraft Auxiliary System - Ice Protection System

• Learning Objectives:
  • Students will learn about different types of ice.
  • Students will understand ice protection system principles.
  • Students will grasp how anti-icing systems work to prevent ice accumulation.
  • Students will describe sensor functions.

Ice Formation, Classification, and Effects

• Rain, snow, and ice are long-term transportation challenges.
• Flying adds a new complication, specifically concerning ice.
• Under specific atmospheric conditions, ice can rapidly build up on aircraft components.

Different Types of Ice Formation

• Clear Ice: Forms when large droplets are present in rain or cumuliform clouds. This results in hard, heavy, and tenacious ice, making removal difficult.
• Rime Ice: Lighter in weight than clear ice; its irregular shape and rough surface decrease the efficiency of aerodynamic airfoils.
• Mixed Ice: A combination of ice particles embedded in clear ice, creating a rough accumulation. Sometimes forms in a mushroom shape on leading edges.

Icing Effects

• Ice or frost accumulation on aircraft creates hazards, impacting safe flight.
• Icing effects are cumulative and can result in:
  • Increased drag
  • Reduced lift
  • Decreased thrust
  • Increased stalling speed
  • Increased weight

Icing Effects (Airplane Components)

• Ice protection systems prevent ice formation on or remove ice from:
  • Wing leading edges
  • Horizontal and vertical stabilizer leading edges
  • Engine cowl leading edges
  • Propellers
  • Propeller spinner
  • Air data probes
  • Flight deck windows
  • Water and waste system lines and drains
  • Antennae

Overview of Ice Protection System

• The system includes various components like wing anti-ice, engine anti-ice, ice detection, air data sensor heat, and windows with drain and water heating.
• Other components include pitot probe heat, total air temperature probe heat, engine temperature probe heat, and hydrophobic coating.
• Additional components are flight compartment window anti-ice, windshield wiper system, hydraulics, water supply, water tank heaters, and drain heaters.

Ice Detection

• Modern aircraft have ice detectors that alert the crew to icing conditions.
• Generally, an annunciator light signals detected ice.

Anti-Ice vs. De-Ice

• Anti-icing equipment is activated before encountering icing conditions to prevent ice formation.
• De-icing equipment removes ice that has already accumulated. Deicing equipment typically targets wings and stabilizer leading edges.

Ice Control Methods

• Different control methods for ice include:
  • Thermal Pneumatic
  • Thermal Electric
  • Chemical Anti Icing

Anti-Icing System

• Anti-icing is a preferred method on large, high-performance turbine-powered aircraft.