How pilots battle icing conditions to keep flights safe

As winter continues, icing conditions present a serious challenge for pilots. In early January 2025, airports like Schiphol, Frankfurt, and Helsinki faced major disruptions due to heavy snow and icy conditions, while in the U.S., thousands of flights were canceled due to severe winter storms. While passengers often experience the inconvenience of waiting—especially since de-icing an aircraft can add up to 40 minutes or more to a flight—pilots must manage the serious risks of ice accumulation.

Managing these risks requires more than just initiating de-icing and anti-icing procedures. Pilots must remain aware of changing conditions while airborne, adjust altitude or course if necessary, and sometimes even divert to alternative routes.

“At BAA Training, we emphasize rigorous training to ensure pilots are well-prepared to navigate these winter hazards and maintain safe operations,” says Cristian Puig, Captain Cristian Puig, Deputy Head of Training at BAA Training.

The pilot’s role in de-icing and anti-icing before departure

On the ground, right before departure, heated glycol-based fluids are applied to remove ice and snow from aircraft surfaces. Anti-icing is usually applied after de-icing to prevent ice from accumulating during flight. Although de-icing is performed by specialized teams, pilots play a crucial oversight role. Before every winter flight, pilots inspect the aircraft for ice accumulation and confirm if de-icing has to be done or not. The pilot in command is ultimately responsible for deciding whether or not to carry out the de-icing procedure. They also monitor holdover time—the period during which anti-icing fluids remain effective—ensuring that the aircraft takes off before protection wears off.

“In winter operations, pilots must be proactive, not reactive, when it comes to icing,” explains Puig. “We train pilots to recognize the conditions that favor ice buildup and to request de-icing or anti-icing early, even before ice visibly forms.”

Detecting and responding to ice in flight: What pilots look for

Once airborne, ice can form rapidly, particularly in clouds with supercooled droplets. Pilots detect ice accumulation in two primary ways:

Visual Checks: Ice can be seen forming on cockpit window edges, windshield wipers, and wing leading edges. Some aircraft have visual indicators where ice begins to form first.

Instrument Warnings: Modern aircraft are equipped with ice detection sensors that alert pilots to early ice formation. Changes in airspeed, altitude, or engine performance can also signal the onset of icing. Another indicator of potential ice formation is experiencing vibrations, either in the structure or in the engines.
Icing is one of the events that pilots report to ATC so that controllers can warn other traffic about areas where ice formation is occurring.

“If you can see ice on your windshield wiper, you likely already have performance degradation on your wings,” notes Puig. “That’s why immediate action is key.”

Once the icing is detected, pilots have several countermeasures:

Activating Anti-Icing Systems: Many aircraft use bleed air heating (redirecting engine heat) to prevent ice formation on wings and engines. Sensors are electrically heated and some aircraft also have electrically heated elements on critical surfaces.

Using De-Icing Boots: Some aircraft, especially turboprops, use inflatable rubber boots on wings to break accumulated ice.

Changing Altitude or Course: Pilots may climb to a higher, warmer altitude or descend to an area with different atmospheric conditions to escape icing zones.
Failing to take corrective action can lead to increased stall speed, reduced control, and in extreme cases, loss of lift.

Simulator training to handle icing conditions

“In simulations, we train pilots to respond immediately to ice warnings,” Puig adds. “For example, during Type Rating training, pilots might enter a simulated cloud with freezing rain, triggering an ice buildup on the wings. The pilot immediately receives an ice warning, prompting them to activate the aircraft’s anti-icing systems, like the wing or engine anti-ice. They then monitor the instruments closely for signs of performance degradation, such as a decrease in airspeed or an increase in stall warning. In some scenarios, they might need to manually adjust the aircraft’s pitch to maintain control or change altitude to escape the icing conditions,” explains Puig.

The bottom line

While winter icing conditions present significant challenges, proper training makes all the difference. By prioritizing proactive training and realistic simulations, BAA Training ensures that pilots are equipped to detect, respond to, and manage icing threats effectively. This not only enhances their ability to make quick, informed decisions in critical situations but also ensures the safety of passengers and crew. Additionally, flying regularly and experiencing all kinds of weather helps refine skills, as everything in a pilot’s career truly comes through practice.The post How pilots battle icing conditions to keep flights safe appeared first on AeroTime.

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