What Are The Risks Of Engine Icing On Commercial Aircraft?
- Ice buildup on aircraft engines can severely compromise performance and affect the aircraft’s and its occupants’ safety.
- Pilots must follow de-icing procedures to remove ice from engine inlets and control surfaces before takeoff.
- Engine ice buildup can damage fan blades, cause compressor stall, and result in errors in flight instruments.
Commercial aircraft and engines are designed to fly in extreme weather conditions. From rain and hail to freezing fog and ice, aircraft can almost always ‘weather’ the storms with little or no danger. Aircraft have mechanisms that keep critical components, such as sensors, inlets, and control surfaces, warm and ice-free.
However, when an aircraft spends extended periods on the ground, particularly overnight, ice can build up, which, according to Boeing, may lead to severely compromised performance. Pilots must get the aircraft de-iced before beginning the journey. Pilots follow specific de-icing procedures depending on when the ice is detected on critical surfaces.
Engine inlet ice
Engines are an aircraft’s powerhouse, and they must provide sufficient performance during the entirety of the flight. Snow or ice can contaminate the engine inlet, fan blades, and compressor core. Pilots must follow de-icing procedures before the engine startup if the contaminant is detected during the pre-flight check. It must be addressed before takeoff if it is detected at any stage after pushback, such as during a taxi or while waiting on the apron.
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Following a snowstorm, airport snow removal procedures may contaminate engines if care is not taken. Ice-shedding procedures are part of the manual, and pilots ensure that all suspected parts of the engine and aircraft control surfaces are free from ice buildup before resuming the journey.
Effects of engine ice buildup
Aircraft engines are designed to intake a large flow of air through the inlet and guide it through various low-pressure (LP) and high-pressure (HP) compression stages. The uniformity of the flow ensures that the engines produce the required thrust for flight. Ice contamination on engine surfaces or the core severely affects the amount of thrust the engine can generate, putting the safety of aircraft and its occupants at risk.
Apart from the engine inlet, where loose contamination is mainly found, fan blades are most susceptible to ice formation due to precipitation. It occurs when the aircraft is closer to its idling speeds. Ice crystals can also form in the core, which may damage critical rotating components. Fan blade damage, compressor stall, and error data from flight instruments can be caused by engine ice buildup.
Engine ice is not removed using glycol-based fluids, as on other aircraft surfaces. The fluids can harm the engine bleed and other primary systems. The loose ice buildup on the engine inlets can be removed using a broomstick.
Photo: Denver International Airport
Warming the areas outside the broomstick range is another way to melt contaminants. This can be done by bringing the aircraft to a (warm) hangar or blowing warm air into the inlet. In such cases, the engine and exhaust covers retain the warm air, effectively melting the ice buildup. The air temperature must be controlled to ensure no damage is done to sensitive engine components and systems.
What are your thoughts on the causes, effects, and procedures of engine ice buildup? Share your opinion in the comments section.