Atmospheric icing

From Wikipedia, the free encyclopedia
Jump to: navigation, search
The effect of atmospheric icing on a tree.

Atmospheric icing occurs when water droplets in the atmosphere freeze on objects they contact. This can be extremely dangerous to aircraft, as the built-up ice changes the aerodynamics of the flight surfaces, which can increase the risk of a subsequent stalling of the airfoil. For this reason, ice protection systems are often considered critical components of flight, and aircraft are often deiced prior to take-off in icy environments.

Not all water freezes at 0 Â°C or 32 Â°F. Liquid water below this temperature is called supercooled, and such supercooled droplets cause the icing problems on aircraft. Below −20 Â°C (−4 Â°F), icing is rare because clouds at these temperatures usually consist of ice particles rather than supercooled water droplets. Below −42 Â°C (−43.6 Â°F), supercooled water cannot exist, therefore icing is impossible[citation needed].

Icing also occurs on towers, wind turbines, boats, oil rigs, trees and other objects exposed to low temperatures and water droplets.

Aircraft incidents[edit]

A number of aircraft crashes have been caused by ice. In other incidents icing was a contributory factor.

See also[edit]


  • FAA (U.S.) Advisory Circular 20-113: Pilot Precautions and Procedures to be taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems
  • FAA (U.S.) Advisory Circular 20-117: Hazards Following Ground Deicing and Ground Operations in Conditions Conducive to Aircraft Icing
  • FAA (U.S.) Advisory Circular 20-147: Turbojet, Turboprop, and Turbofan Engine Induction System Icing and Ice Ingestion
  • Wind Energy in Cold Climates: Icing on wind turbines

External links[edit]